Microbiology Flashcards
1
Q
Asymptomatic bacteriuria: Diagnosis in catheterized urine.
A
Requires isolation of 10² colony-forming units per mL of the same species.
Only one sample is required.
2
Q
Asymptomatic bacteriuria: Who needs treatment?
A
Those who are pregnant or who will undergo urological instrumentation.
3
Q
UTI pathogen: Most common.
A
E. coli.
4
Q
UTI pathogen: Older male with obstructive uropathy.
A
Enterococcus.
5
Q
UTI pathogens: Culture-negative (3).
A
Mycoplasma hominis.
Ureaplasma urealyticum.
Chlamydia trachomatis.
6
Q
UTI pathogen: Fungal.
A
Candida spp.
7
Q
Hemorrhagic cystitis:
A. Pathogen.
B. Clinical background.
A
A. Adenovirus, esp. types 11 and 21.
B. Bone-marrow transplant.
8
Q
Sensitivity and specificity of urine-dipstick tests:
A. Leukocyte esterase.
B. Nitrite.
A
A. SN: 70-95%; SP: 70%.
B. SN: 50%; SP: 95%.
9
Q
Viral agents of diarrhea:
A. In winter.
B. Foodborne and infective with small inoculum.
A
A. Rotavirus.
B. Norwalk-like viruses.
10
Q
Bacterial agents of diarrhea:
A. Traveler’s diarrhea.
B. Hemolytic-uremic syndrome.
A
A. Enterotoxigenic E. coli.
B. Enterohemorrhagic E. coli (O157:H7).
11
Q
Enterohemorrhagic E. coli: Toxin.
A
Shiga toxin.
12
Q
Salmonella bacteremia: Who is at risk (2)?
A
Those with sickle-cell disease or indwelling prostheses.
13
Q
Bacterial enteritis: Leading agent in the U.S.
A
Campylobacter jejuni.
14
Q
Campylobacter jejuni: Diseases other than enteritis.
A
Guillain-Barré syndrome.
Reactive arthritis.
15
Q
Most virulent strain of Clostridium difficile:
A. Name.
B. Basis of virulence.
A
A. B1/NAP1/027.
B. Mutation in tcdC leads to increased production of toxins A and B.
16
Q
Clostridium difficile: Reference method of testing for infection.
A
Cytotoxicity assay.
17
Q
Clostridium difficile: Genes implicated in pathogenesis.
A
tcdA: Toxin A.
tcdB: Toxin B.
tcdC: Regulator of the toxins.
18
Q
Another bacterial agent of antibiotic-associated colitis.
A
Klebsiella oxytoca.
19
Q
Entamoeba histolytica: Preferred test.
A
Enzymatic immunoassay of stool.
20
Q
Non-microscopic test for neutrophils in stool.
A
Stool lactoferrin.
21
Q
Bacterial agents of pneumonia: Community-acquired, single most common.
A
Streptococcus pneumoniae.
22
Q
Bacterial agents of pneumonia: In patients with COPD (3).
A
Haemophilus influenzae.
Moraxella catarrhalis.
Legionella pneumophila.
23
Q
Bacterial agents of pneumonia: Alcoholics (3).
A
S. pneumoniae.
K. pneumoniae.
Gram-negative aerobic bacilli.
24
Q
Bacterial agents of pneumonia: Bird handlers.
A
Chlamydophila psittaci.
25
Bacterial agents of pneumonia: Bronchiectasis (3).
Pseudomonas aeruginosa.
Burkholderia cepacia.
Staphylococcus aureus.
26
Bacterial agents of pneumonia: Atypical pneumonia.
Mycoplasma pneumoniae.
Chlamydophila pneumoniae.
27
Bacterial agents of pneumonia: Necrotizing (2).
S. aureus.
Ps. aeruginosa.
28
Bacterial agents of pneumonia: Hospital-acquired, single most common.
S. aureus.
29
Legionella pneumophila: Environmental associations (3).
Hot tubs.
Cooling towers.
Construction sites (dust).
30
Legionella pneumophila: Clinical manifestations (5).
High fever.
Hyponatremia.
Renal dysfunction.
Diarrhea.
Neurological abnormalities.
31
Coronaviruses that cause pneumonia (3).
SARS coronavirus.
NL63.
HKU1.
32
Human papillomaviruses that cause pneumonia.
K1, WU.
33
Hantavirus: Animal vector.
The deer mouse.
34
Hantavirus: Findings on peripheral smear (4).
Thrombocytopenia.
Neutrophilia without toxic granules.
Erythrocytosis.
Immunoblastic lymphocytosis.
35
Agents of endocarditis: Native valves (most common).
S. aureus.
36
Agents of endocarditis: Diseased valves, most common.
Streptococci, esp. viridans streptococci.
37
Agents of endocarditis: Prosthetic valves, very early, most common (3).
S. aureus.
S. epidermidis.
Gram-negative bacilli.
38
Agents of endocarditis: Prosthetic valves, early, most common (2).
S. epidermidis.
S. aureus.
39
Agents of endocarditis: Prosthetic valves, late, most common.
Streptococci.
40
Culture-negative endocarditis: Bacterial causes (5).
Coxiella burnetii.
Bartonella.
Legionella.
Chlamydia.
Tropheryma whippeli.
41
Culture-negative endocarditis: Noninfectious causes (3).
Libman-Sacks endocarditis.
Marantic endocarditis.
Carcinoid heart syndrome.
42
Culture-negative endocarditis: A third cause.
Previous antibiotic therapy.
43
Viral agents of encephalitis: Most common (2).
California encephalitis.
St. Louis encephalitis.
44
Viral agents of encephalitis: Herpesviridae (2).
HSV1, HHV6.
45
Amoebic agents of encephalitis (3).
Acanthamoeba spp.
Naegleria fowleri.
Balamuthia mandrillaris.
46
Agents of aseptic meningitis:
A. Most common.
B. Others (4).
A. Enteroviruses.
B. HSV-2, LCM virus, mumps virus, HIV.
47
Agents of aseptic meningitis: Seasonal variation.
Summer and fall: Enteroviruses.
Winter and spring: LCM virus.
48
Bacterial agents of meningitis: Neonates (3).
Group-B streptococci.
Gram-negative bacilli.
Listeria monocytogenes.
49
Bacterial agents of meningitis: Populations most affected by Listeria monocytogenes.
Neonates.
Elderly.
Immunocompromised.
Iron-overloaded.
50
Bacterial agents of meningitis: Infants, young children, young adults.
N. meningitidis.
S. pneumoniae.
H. influenzae.
51
Who is at highest risk of serious infections by N. meningitidis?
Those with a deficiency of C5-C9.
52
Bacterial agents of meningitis: Adults.
S. pneumoniae.
N. meningitidis.
53
Bacterial agents of meningitis: Southeast Asia.
Streptococcus suis.
54
HSV encephalitis: Unique findings in CSF (3).
Very high protein.
Blood.
Low glucose.
55
Most common agents of infections of prosthetic joints at:
A. Less than 3 months (2).
B. 3-24 months (2).
C. Beyond 24 months.
A. S. aureus, Gram-negative bacilli.
B. S. epidermidis, P. acnes.
C. S. epidermidis.
56
Infections of prosthetic valves: Cutoffs for leukocyte count and percentage of neutrophils in synovial fluid (2).
A. Knee: 1700/mL, >65% neutrophils.
B. Hip: 4200/mL, >80% neutrophils.
57
Severe sepsis: Definition.
Sepsis with organ dysfunction.
58
Septic shock: Definition.
Sepsis with refractory hypotension.
59
Sepsis vs. the systemic inflammatory-response syndrome: Theoretical difference.
SIRS is sepsis with no infectious source.
60
Sepsis vs. SIRS: Distinguishing test.
Procalcitonin: Elevated in sepsis.
61
Indicators of catheter-related sepsis (3).
Culture of catheter tip yields 5 times as many colonies as the blood culture.
Culture of catheter tip becomes positive at least 2 hours before the blood culture.
Cultures of catheter tip and blood yield the same organism.
62
Neonatal sepsis: Most common agents (2).
E. coli.
Group-B streptococci.
63
Agents of bacteremia in patients with colon cancer (2).
Streptococcus bovis.
Clostridium septicum.
64
Agent of fungal meningitis: Most common.
Cryptococcus.
65
Agent: Erythrasma.
Corynebacterium diphtheriae.
66
Agent: Juvenile periodontitis.
Aggregatibacter actinomycetemcomitans.
67
Agent: Glanders.
Burkholderia mallei.
68
Agent: Meliodosis.
Burkholderia pseudomallei.
69
Agent: Rocky Mountain spotted fever.
Rickettsia rickettsii.
70
Agents: Visceral larva migrans.
Toxocara canis, Toxocara cati.
71
Agent: Erysipelas.
Streptococcus pyogenes.
72
Agent: Erysipeloid.
Erysipelothrix rhusiopathiae.
73
Agent: Freshwater cellulitis.
Aeromonas hydrophilia.
74
Agent: Saltwater cellulitis.
Vibrio vulnificus.
75
Agent: Lymphogranuloma venereum.
Chlamydia trachomatis.
76
Agent: Acute epiglottitis.
Haemophylus influenzae.
77
Agents: Monoarticular arthritis (2).
Staphylococcus aureus.
Streptococci.
78
Agent: Arthritis in abusers of intravenous drugs.
Pseudomonas aeruginosa.
79
Agent: Polyarthritis in the sexually active.
Neisseria gonorrhoeae.
80
Agent: Croup.
Parainfluenza viruses 1-3.
81
Agents: Otitis media (3).
Streptococcus pneumoniae.
Haemophilus influenzae.
Moraxella catarrhalis.
82
Agent: Carrión's disease.
Bartonella bacilliformis.
83
Agent: Verruga peruana.
Bartonella bacilliformis.
84
Agent: Uterine infection following septic abortion.
Clostridium perfringens.
85
Agent: Rat-bite fever.
Streptobacillus moniliformis.
86
Agent: Black piedra.
Piedraia hortae.
87
Agent: White piedra.
Trichosporon beigelii.
88
Agent: Tinea versicolor.
Malessezia furfur.
89
Agent: Tinea nigra.
Hortaea werneckii.
90
Agents: Chromoblastomycosis (3).
Phialophora verrucosa.
Cladophialophora spp.
Fonsecaea pedrosoi.
91
Agent: Lobomycosis.
Lacazia loboi.
92
Agents: Phaeohyphomycosis (3).
Phialophora verrucosa.
Exophiala jeanselmi.
Alterneria spp.
93
Agents: Eumyotic mycetoma (3).
Exophiala jeanselmi.
Madurella spp.
Pseudallescheria boydii.
94
Agents: Actinomycotic mycetoma (3).
Actinomyces spp.
Nocardia spp.
Streptomyces.
95
Agent: Rhinosporidiosis.
Rhinosporidium seeberi.
96
Agent: Rhinoscleroma.
Klebsiella rhinoscleromatis.
97
Agent: Roseola infantum (exanthem subitum).
HHV6.
98
Agent: Fifth disease.
Parvovirus B19.
99
Agent: African sleeping sickness.
Trypanosoma brucei.
100
Agent: Adiaspiromycosis.
Emmonsia parva.
101
Agent: Fungal otitis media.
Aspergillus niger.
102
Agent: Hand-foot-mouth disease.
Coxsackie A virus.
103
Agent: Viral myocarditis.
Coxsackie B virus.
104
Agent: Dog heartworm.
Dirofilaria immitis.
105
Agent: Tickborne encephalitis.
Tickborne-encephalitis virus.
106
Agent: Murine typhus.
Rickettsia typhi.
107
Agent: Epidemic typhus.
Rickettsia prowazekii.
108
Agent: Rickettsialpox.
Rickettsia akari.
109
Agent: Relapsing fever.
Borrelia recurrentis.
110
Agent: Trench fever.
Bartonella quintana.
111
Vector: Dog heartworm.
Anopheles spp.
112
Vectors: Lymphatic filariasis (2).
Anopheles spp.
Culex spp.
113
Vector: Yellow fever.
Aedes spp.
114
Vectors: Lyme disease (3).
Eastern U.S.: Ixodes scapularis.
Western U.S.: I. pacificus.
Europe: I. ricinus.
115
Vector: Babesia.
Ixodes spp.
116
Vector: Anaplasmosis.
Ixodes spp.
117
Diseases of which Amblyomma americanum is the vector (3).
Ehrichliosis.
Tularemia.
Southern tick-associated illness.
118
Dermacentor spp.: Diseases of which it is a vector (3).
Rocky Mountain spotted fever.
Tularemia.
Colorado tick fever.
119
Vector: Trachoma.
Musca sorbens.
120
Vector: Onchocercosis.
Simulium spp.
121
Vector: Rickettsialpox.
Mite.
122
Viral cytopathic effect: Tear-shaped cells.
Enteroviruses.
123
Viral cytopathic effect: Focal plaques in human diploid fibroblasts.
CMV.
124
Viral cytopathic effect: Grapelike clusters.
Adenoviruses.
125
Viral cytopathic effect: Syncytia.
Respiratory syncytial virus.
126
Viral cytopathic effect: Sweeping, with globular cells.
HSV-1, HSV-2.
127
Viral cytopathic effect: Minimal or none.
Influenza viruses.
Parainfluenza viruses.
128
Adenovirus infection: Histology.
Smudgy intranuclear inclusion.
129
CMV infection: Location of inclusions.
Nuclear and cytoplasmic.
130
Measles infection: Location of inclusions.
Cytoplasmic and nuclear.
131
RSV infection: Location of inclusions.
Cytoplasmic only.
132
DNA viruses: Those with envelopes.
Herpesviridae.
Hepadnaviridae.
Poxviridae.
133
DNA viruses: Those with single-stranded DNA.
Parvoviridae.
Bocavirus.
134
DNA viruses: Those with circular DNA.
Papillomaviridae.
Polyomaviridae.
135
DNA viruses: Families.
```
Adenoviridae.
Bocavirus.
Herpesviridae.
Hepadnaviridae.
Poxviridae.
Parvoviridae.
Papillomaviridae.
Polyomaviridae.
```
136
RNA viruses: Helical.
```
Paramyxoviridae.
Orthomyxoviridae.
Rhabdoviridae.
Bunyaviridae.
Filoviridae.
Deltavirus.
Coronaviridae.
Arenaviridae.
```
137
RNA viruses: Those with negative-sense RNA.
```
Paramyxoviridae.
Orthomyxoviridae.
Rhabdoviridae.
Bunyaviridae.
Filoviridae.
Deltavirus.
Arenaviridae.
```
138
RNA viruses: Which have double-stranded RNA?
Reoviridae.
139
RNA viruses: Which have circular RNA?
Bunyaviridae.
Arenaviridae.
Deltaviridae.
140
RNA viruses: Which have no envelope?
Astroviridae.
Picornaviridae.
Reoviridae.
Caliciviridae.
141
Herpes encephalitis: Classic gross finding.
Hemorrhagic necrosis of the anterior pole of both temporal lobes.
142
Neonatal herpes: Feared complications (3).
Encephalitis.
Chorioretinitis.
Sepsis.
143
HSV infection: Definitive method of diagnosis.
Cell culture.
144
Varicella: Risk factors for serious disseminated infection in adults (2).
Pregnancy.
Immunocompromise.
145
Varicella, congenital: Diagnosis (3).
Maternal history of infection, or
Characteristic skin lesions on neonate, or
Serological evidence of infection in neonate.
146
Varicella, congenital: Period of highest risk of transplacental infection.
During the third trimester.
147
Varicella: Reactivation syndromes.
Herpes zoster.
Ramsey Hunt syndrome.
148
Varicella: Time to cytopathic effect in culture.
About 2 weeks.
149
Varicella: Other diagnostic methods (3).
Serology (present of IgM or a 4-fold rise in IgG).
PCR.
DFA of skin scrapings.
150
Congenital CMV infection: Clinical manifestations (10).
Low birthweight.
Microcephaly.
Intracerebral calcifications.
Chorioretinitis.
```
Hepatosplenomegaly.
Jaundice.
Thrombocytopenia.
Petechiae.
Purpura.
```
Sensorineural hearing loss.
151
CMV colitis: Clinical presentation.
Can mimic exacerbation of idiopathic inflammatory bowel disease.
152
CMV infection: Antigen used in DFA.
pp65.
153
EBV: Associated neoplasms (7).
```
Burkitt's lymphoma.
Hodgkin's lymphoma.
Primary effusion lymphoma.
Post-transplant lymphoproliferative disorder.
Lymphomatoid granulomatosis.
Oral hairy leukoplakia.
Nasopharyngeal carcinoma.
```
154
EBV:
A. Cell that it infects.
B. Cell that proliferates in response to infection.
A. The B cell.
B. The CD8-positive T cell.
155
Duncan's disease: Definition.
X-linked immunoproliferative disorder with predisposition to fulminant infection by EBV.
156
Duncan's disease: Typical mechanism of death.
Hepatic necrosis.
157
Duncan's disease: Abnormal gene.
SH2D1A, which encodes a subunit of the SLAP-associated protein.
158
Duncan's disease: Immunological defect resulting from the abnormal gene.
Uncontrolled activation of T/NK cells during infection by EBV.
159
EBV serology: The basic tests (5).
Monospot.
IgM anti-VCA.
IgG anti-VCA.
IgG anti-EA.
Anti-EBNA.
160
EBV serology: Pattern in one who has never been infected.
All results are negative.
161
EBV serology: Early acute infection.
Positive: IgM and IgG anti-VCA.
Negative: IgG-anti-EA.
Monospot may be positive.
162
EBV serology: Acute infection.
Positive: IgM and IgG anti-VCA, anti-EA, Monospot.
Anti-EBNA may also be positive.
163
EBV serology: Convalescence.
Positive: IgG anti-VCA, anti-EA, anti-EBNA.
Negative: IgM anti-VCA, Monospot.
164
EBV serology: Remote infection.
Positive: Anti-EA, anti-EBNA.
Negative: IgM anti-VCA, Monospot.
IgG anti-VCA may be undetectable.
165
Monospot: How it works.
EBV induces heterophile antibodies that react with horse erythrocytes in the presence of guinea-pig kidney but not in the presence of bovine-erythrocyte stroma.
166
Monospot: Relevance of sensitivity to patient's age.
Less sensitive in patients under age 4.
167
EBV: Antigen used in immunochemistry.
LMP1.
168
HHV6:
A. Disease.
B. Cell of latency.
A. Roseola infantum (exanthem subitum).
B. T cells.
169
HHV7:
A. Disease.
B. Cell of latency.
A. Roseola infantum.
B. Lymphocyte.
170
HHV8: Associated neoplasms (3).
Multicentric Castleman's disease.
Primary effusion lymphoma.
Kaposi's sarcoma.
171
HHV8: Antigen used in immunochemistry.
LANA1.
172
Types of adenovirus that cause
A. Respiratory infections.
B. Hemorrhagic cystitis.
C. Gastroenteritis in children.
A. 1-14 and 21.
B. 11 and 21.
C. 40 and 41.
173
Parvovirus B19: Histology.
Smudgy nuclear inclusions.
174
Bocavirus:
A. Definition.
B. How detected.
A. A respiratory virus.
B. By PCR only.
175
JC and BK viruses:
A. When acquired.
B. Clinical presentation of acute infection.
A. In childhood.
B. Asymptomatic.
176
Reactivation of JC virus:
A. Disease.
B. Affected cell.
C. Histology.
A. Progressive multifocal leukoencephalopathy.
B. Oligodendroglia.
C. Smudgy nuclear inclusions.
177
Reactivation of BK virus: Diseases (2).
Hemorrhagic cystitis.
Polyomaviral nephropathy.
178
Merkel-cell polyomavirus: Associated diseases (2).
Merkel-cell carcinoma.
CLL.
179
HPV types: Plantar wart.
1, 2.
180
HPV types: Common wart.
2, 1, 4.
181
HPV types: Plane wart.
3, 10.
182
HPV types: Oral focal epithelial hyperplasia.
13, 32.
183
HPV types: Epidermodysplasia verruciformis.
2, 3, 10, 5, 8.
184
Epidermodysplasia verruciformis:
A. Inheritance.
B. Time of expression.
C. Significance.
A. Autosomal recessive.
B. In the first decade.
C. May progress to SCC.
185
HPV types: Condyloma acuminatum.
6, 11.
186
HPV types: LSIL.
6, 11.
187
HPV types: HSIL (7).
16, 18, 31, 33, 35, 39, 45, others.
188
HPV types: Cervical adenocarcinoma.
16, 18.
189
HPV types: Bowenoid papulosis.
16, 18.
190
Recurrent respiratory papillomatosis: Types (2) and how they are acquired.
Adult: Sexual contact.
Juvenile: Passage through the birth canal.
191
Agents of bioterrorism: CDC category A (6).
Smallpox.
Hemorrhagic-fever viruses.
Bacillus anthracis.
Yersinia pestis.
Clostridium botulinum.
Francisella tularensis.
192
Hepatitis A: Incubation.
15-30 days.
193
The presence of HBsAg can mean what?
Acute hepatitis B.
Chronic carrier state.
194
Presence of HBeAg indicates what?
Active viral replication.
195
Presence of anti-HBc indicates what?
Exposure to HBV at some point in life.
196
Presence of anti-HBe means what?
Chronic carrier state without active viral replication.
197
Early serologic markers of HBV infection:
A. Order of appearance.
B. Relevance to clinical manifestations.
A. HBsAg, HBeAg, anti-HBc.
B. Emergence of antibodies coincides with appearance of symptoms.
198
Chronic hepatitis B: Definition.
Persistence of HBsAg for >6 months.
199
Population at greatest risk for chronic hepatitis B.
Neonatals infected transplacentally.
200
Rheumatological disease associated with chronic hepatitis B.
Polyarteritis nodosa.
201
When does HBV DNA become detectable in the serum?
Before HBsAg.
202
Chronic hepatitis B without detectable HBeAg:
A. Clinical significance.
B. Cause.
A. Can progress to fulminant hepatic failure.
B. Stop codon in C region or pre-C region of genome of HBV.
203
Replicative hepatitis B: Definition.
Presence of >10⁵ copies of HBV DNA per mL.
204
Expected serology: Resolved hepatitis B.
Anti-HBs.
Anti-HBc.
205
Expected serology: Immunization against HBV.
Anti-HBs only.
206
Expected serology: Acute hepatitis B.
HBsAg, IgM anti-HBc.
207
Expected serology: Chronic hepatitis B.
HBsAg, anti-HBc.
208
Hepatitis C: How many patients develop a chronic infection?
About 60%.
209
Hepatitis C: How many patients with chronic infection develop cirrhosis?
About 15%.
210
Hepatitis C: Extrahepatic manifestations.
Cryoglobulinemia with its attendant complications, e.g. anemia, glomerulonephritis.
211
Hepatitis C: Expected test results in a very early infection.
HCV RNA only.
212
Hepatitis C: Expected test results in acute infection.
HCV RNA.
Enzymatic immunoassay for anti-HCV.
RIBA.
213
Hepatitis C: Expected test results in chronic infection.
HCV RNA.
Enzymatic immunoassay for anti-HCV.
RIBA.
214
Hepatitis C: Expected test results in resolved infection.
Enzymatic immunoassay for anti-HCV.
RIBA.
215
Hepatitis C: What do these results mean?
EIA for anti-HCV: Positive.
RIBA: Negative.
HCV RNA: Negative.
False-positive result for anti-HCV.
216
Hepatitis C: Endpoint of antiviral therapy.
When HCV RNA has remained undetectable for >24 months after completion of therapy.
217
Hepatitis C genotypes:
A. Most common in the United States.
B. Most likely to develop resistance to antiviral therapy.
A. Genotype 1.
B. Genotype 1a.
218
Hepatitis E: Approximate mortality in pregnant women.
30%.
219
"Non-hepatitis" viruses that can cause hepatitis (6).
HSV1, HSV2.
VZV.
EBV.
CMV.
Yellow-fever virus.
220
Influenza A: Mechanism of antigenic drift bzw. antigenic shift.
Drift: Point mutations in genes for hemagglutinin or neuraminidase.
Shift: Genetic reassortment between strains.
221
Hemagglutinin: Role in pathogenesis of influenza.
Binds to sialic-acid-containing receptors on respiratory epithelial cells.
222
Hemagglutinin: Role in diagnosis.
The expression of hemagglutinin on infected cells is the basis of the hemadsorption test.
223
Rapid test for influenza:
A. Method.
B. Sensitivity.
C. Specificity.
A. Direct immunofluorescence.
B. 50-80%.
C. Highly specific.
224
Hemagglutinin inhibition: Uses.
Serologic diagnoses of infection.
Determination of viral subtype and strain.
225
Parainfluenza virus: How to diagnose infection (3).
PCR.
Immunofluorescence.
Hemadsorption.
226
Measles virus: Diseases (3).
Measles.
Atypical measles.
Subacute sclerosing panencephalitis.
227
Measles: Prodrome.
Cough, coryza, conjunctivitis.
228
Atypical measles: Typical patient.
Teenager who has received only one vaccination.
229
Subacute sclerosing panencephalitis:
A. Risk.
B. Period of incubation.
A. About 0.001%.
B. About 7 years.
230
Virus that can cause pancreatitis.
Mumps virus.
231
Respiratory syncytial virus:
A. Infectivity.
B. Host immunity.
A. Infects nearly all exposed children.
B. Short-lived; recurrent infection is the rule.
232
Respiratory syncytial virus: Detection (3).
PCR.
Immunofluorescence.
Cell culture.
233
Human metapneumovirus: Disease.
Lower respiratory infection.
234
Coxsackie A virus: Diseases.
Hand-foot-mouth disease.
Herpangina.
235
Coxsackie B virus: Diseases (3).
Myocarditis.
Pericarditis.
Epidemic pleurodynia.
236
Rhinovirus: Special condition of culture.
Incubation at 32 degrees.
237
Bunyaviridae: Examples (4).
Bunyavirus.
Hantavirus.
Nairovirus.
Rift Valley fever virus.
238
Rubella virus: Family.
Togaviridae.
239
Rubella during pregnancy:
A. When the fetus is most vulnerable.
B. How to prevent it.
A. During the first trimester.
B. Measure titers in women who intend to become pregnant.
240
Congenital rubella: Affected organs (3).
Ears: Sensorineural deafness.
Eyes: Cataracts, glaucoma, microphthalmia.
Heart: Patent ductus arteriosus.
241
Yellow fever: Histology (4).
Mid-zonal necrosis.
Microvesicular steatosis.
Apoptotic bodies.
No inflammation.
242
Flaviviridae: Examples (5).
Yellow-fever virus.
Dengue-fever virus.
St. Louis encephalitis virus.
West Nile virus.
Hepatitis C virus.
243
West Nile virus: Usual host.
Birds.
244
Rabies virus:
A. How does it get to the CNS?
B. How does it become transmissible to other animals?
A. Through retrograde fast axonal transport from the site of the bite.
B. It travels along the peripheral nerves to the salivary glands.
245
Rabies: Diagnostic histologic findings (2) and the location of each.
Negri bodies: Purkinje cells.
Babeș nodules: Microglia.
246
Rabies: How to diagnose histologically without doing a brain biopsy.
Biopsy of skin, including hair follicles.
247
Arenaviridae: Origin of name.
Incorporation of the host's ribosomes imparts a sandy (granular) appearance.
248
Lymphocytic choriomeningitis virus:
A. Family.
B. Natural hosts.
A. Arenaviridae.
B. Rodents, esp. house mice and hamsters.
249
HTLV-1:
A. Transmission.
B. Affected cell.
A. Parenteral.
B. CD4-positive T lymphocyte.
250
HTLV-1:
A. Family.
B. Diagnosis of infection.
A. Retroviridae.
B. Screening ELISA, confirmatory western blot or PCR.
251
HTLV-1: Late sequelae of infection (2).
Tropical spastic paraparesis.
Adult T-cell leukemia/lymphoma.
252
Tropical spastic paraparesis: Histology.
Demyelination of the upper thoracic and lower cervical spinal cord.
253
Adult T-cell leukemia/lymphoma:
A. Lifetime risk.
B. Incubation.
A. About 5% for those infected before age 20.
B. 20-30 years.
254
Adult T-cell leukemia/lymphoma: Clinical presentation (3).
Jaundice.
Hepatosplenomegaly.
Weight loss.
255
Adult T-cell leukemia/lymphoma: Other possible clinical features (4).
Rash.
Increased thirst.
Hypercalcemia.
Increased circulating IL-2 receptors.
256
How long after infection does ___ become detectable?
A. anti-HIV antibody
B. p24 protein
A. 6-8 weeks.
B. 2-3 weeks.
257
Definition of a positive western blot for HIV.
Presence of band for any 2 of the following:
p24.
gp41.
gp120/160.
258
A western blot show bands but not in a combination that is considered positive.
A. Interpretation.
B. How to proceed.
A. Indeterminate.
B. If a repeat test at 6 months is indeterminate and there are no risk factors for HIV, then the result is called negative. If there are risk factors, then nucleic-acid testing must be done.
259
CD4 counts: Guidelines (2).
Measure the CD4 counts at consistent times of day.
Use age-specific reference intervals.
260
Preferred test for monitoring response to antiretroviral therapy.
HIV RNA.
261
Proviral DNA:
A. Definition.
B. Application.
A. DNA derived from viral RNA by reverse transcriptase.
B. May be used to confirm infection by HIV.
262
CD4 count: How often should it be performed?
Every 6 months while the disease is stable.
263
Viral load vs. CD4 count as predictors of outcomes.
Long term (10 years): Viral load is better.
Short term (6 months): CD4 count is better.
264
Viral load:
A. How reported.
B. Significant change.
A. As log units (for example, 1000 = 3 log units).
B. 0.5 log units.
265
Viral load: Relevance to HAART (2).
Viral load determines
- When to start HAART.
- The efficacy of HAART.
266
Use of HIV RNA to diagnose infection by HIV.
A positive result should be confirmed as soon as possible by ELISA and western blot.
267
Neonatal infection by HIV: Preferred test.
PCR for proviral DNA, although HIV RNA may be just as good.
268
Examination of stool for parasites: Number and timing of specimens.
Three specimens, at least 24 hours apart.
269
Fresh stool: When to examine for parasites.
Within an hour if possible; otherwise, preserve the stool in formalin or alcohol.
270
Parasites that may be missed by routine stains for ova and parasites (3).
Cryptosporidium.
Cyclospora cayetanensis.
Cystoisospora belli.
271
How to identify those parasites that may be missed by routine stains (2).
Modified stain for acid-fast bacilli.
Modified saffranin stain.
272
Culture medium: Free-living amoebae.
Tap-water agar on a bed of E. coli.
273
Culture medium: Leishmania and Trypanosoma.
Novy-MacNeal-Nicolle medium.
274
Culture medium: Trichomonas vaginalis.
Diamond's medium.
275
Morphologically indistinguishable amoebae.
Entamoeba histolytica.
Entamoeba dispar (albeit without ingested RBCs).
276
Trophozoite of E. histolytica / E. dispar:
A. Size.
B. Motility.
A. 15-20 μm.
B. Unidirectional.
277
Trophozoite of E. histolytica / E. dispar:
A. Size and location of karyosome.
B. Distribution of chromatin.
A. Small and central.
B. Fine and even along the nuclear membrane.
278
Cyst of E. histolytica / E. dispar:
A. Number of nuclei.
B. Chromatoidal bars.
A. Never more than 4.
B. Rounded ends.
279
Trophozoite of Entamoeba coli.
A. Size.
B. Motility.
A. 20-25 μm.
B. Nondirectional.
280
Trophozoite of Entamoeba coli:
A. Size and location of karyosome.
B. Distribution of nuclear chromatin.
A. Large and eccentric.
B. Clumped along the nuclear membrane.
281
Cyst of Entamoeba coli.
A. Number of nuclei.
B. Chromatoidal bars.
A. Up to 8.
B. Frayed ends.
282
Trophozoite of Entamoeba hartmanni.
A. Size.
B. Motility.
A. 5-10 μm.
B. Nondirectional.
283
Trophozoite of Entamoeba hartmanni:
A. Size and location of karyosome.
B. Distribution of nuclear chromatin.
A. Small and central.
B. Fine and even along the nuclear membrane.
284
Cyst of Entamoeba hartmanni:
A. Number of nuclei.
B. Chromatoidal bars.
A. Never more than 4.
B. Rounded ends.
285
Entamoeba histolytica: A better method than morphology for detection in stool.
Enzymatic immunoassay.
286
Entamoeba histolytica: Most common location of ulcer.
Cecum.
287
Non-pathogenic amoebae (2).
Iodamoeba bütschlii.
Endolimax nana.
288
Endolimax nana: Distinguishing morphologic features (2).
Small size of trophozoite: 5-10 μm.
"Ball-in-socket" karyosome.
289
Iodamoeba bütschlii: Distinguishing morphologic features (2).
Large vacuole that takes up the iodine stain.
"Ball-in-socket" karyosome.
290
Pathogenic free-living amoebae: Major genera.
Acanthamoeba.
Naegleria.
Balamuthia.
291
Naegleria fowleri: Disease.
Primary amoebic meningoencephalitis.
292
Trophozoite of Naegleria fowleri:
A. Size.
B. Morphology of nucleus and karyosome.
A. 10-35 μm.
B. Small nucleus; large, dense, central karyosome.
293
Naegleria fowleri: Treatment of CSF specimens that may contain it.
Do not refrigerate.
294
Acanthamoeba spp. and Balamuthia mandrillaris:
A. Disease.
B. How they enter the body.
A. Granulomatous amoebic encephalitis.
B. Through skin or lungs.
295
Acanthamoeba spp. and Balamuthia mandrillaris: Histology.
Found around vessels.
296
Acanthamoeba spp.: Another disease.
Amoebic keratitis.
297
Trophozoite of Acanthamoeba spp.:
A. Nucleus.
B. Karyosome.
A. Small.
B. Large, central.
298
Cyst of Acanthamoeba:
A. Number of nuclei.
B. Size of karyosome.
C. Another distinguishing feature.
A. One.
B. Large.
C. Double wall.
299
Leading cause of protozoal diarrhea.
Giardia intestinalis.
300
Giardia intestinalis: Motility in wet preparation.
"Falling-leaf" motility.
301
Cyst of Giardia intestinalis:
A. Shape.
B. Nuclei.
A. Oval.
B. Four, arranged along a central axoneme.
302
Giardia intestinalis: Preferred method of identification.
Enzymatic immunoassay.
303
Chilomastix mensili: Disease.
None.
304
Chilomastix mensili: Differences from G. intestinalis (4).
Rotary motility.
No axoneme.
Lemon-shaped cyst.
Cyst has one nucleus.
305
Trophozoite of Dientamoeba fragilis: Distinguishing features (4).
Round.
Binucleate.
Each nucleus contains a central, "fractured" karyosome.
Internalized flagellum.
306
Cyst of Dientamoeba fragilis: Distinguishing feature.
No cyst form has been described.
307
Dientamoeba fragilis: Diseases (2).
Diarrhea.
Pruritus ani.
308
Dientamoeba fragilis: Concomitant pathogen.
Enterobius vermicularis.
309
Trichomonas vaginalis:
A. Number of nuclei.
B. Motility.
A. One.
B. Jerky and nondirectional.
310
Leishmania spp.:
A. Characteristic organelle.
B. Another genus of protozoans that possess this organelle.
A. Kinetoplast.
B. Trypanosoma.
311
Leishmania spp.: Genera of vectors (2).
The sandflies
− Phlebotomus.
− Lutzomyia.
312
Leishmania: Important species (4) and disease caused by each.
L. brasiliensis, L. mexicana: Cutaneous, mucocutaneous.
L. major, L. tropica: Cutaneous, visceral (also affects marrow).
313
Trypanosomes: Important species (2) and how to distinguish them.
T. cruzi: Large kinetoplast.
T. brucei: Small kinetoplast.
314
Trypanosomes: How best to find them in the peripheral blood.
Look in the buffy coat.
315
Chagas' disease: Most common site of inoculation.
The face.
316
Romaña's sign.
Periorbital and palpebral swelling as a sign of inoculation by the reduviid bug.
317
Trypanosoma brucei: Vector.
Glossina spp.
318
The one ciliated protozoon known to infect humans.
Balantidium coli.
319
Balantidium coli: Morphology of trophozoite (4).
Large: 100 μm.
Circumferential cilia.
Rod- or horseshoe-shaped macronucleus.
Micronucleus.
320
Microsporidia: Important genera (2).
Enterocytozoon.
Encephalitozoon.
321
Microsporidia: Where to find them on biopsies.
In the apical aspect of enterocytes.
322
Microsporidia: How to find them in stool samples.
Use a modified trichrome stain.
323
Cryptosporidium: Important species (2).
Cryptosporidium parvum.
Cryptosporidium hominis.
324
Cryptosporidium spp.: Where to look for them in a biopsy.
Attached to the brush border of enterocytes.
325
Cryptosporidium spp.: How to find them on a stool sample.
Use a modified acid-fast stain.
326
Cyclospora cayetanensis: Where to look for them on a biopsy.
Within the cytoplasm of enterocytes, where different developmental forms of the organism can be seen.
327
Cystoisospora belli: Distinction from C. cayetanensis (2).
Larger size: 25-30 μm rather than 8-10 μm.
Elliptical rather than circular.
328
Oocyst of Sarcocystis spp.:
A. Size.
B. Number of nuclei.
A. 15-20 μm.
B. Two.
329
Sarcocystis spp.: Affected tissues.
Muscle, intestine.
330
Sarcocystis spp.: Unique property that aids in identification.
Auto-fluorescence in ultraviolet light.
331
Toxoplasma gondii: Two forms.
Tachyzoite.
Bradyzoite.
332
Tachyzoite of Toxoplasma gondii: Size and shape.
3-5 μm; bow-shaped (τοξον); large, eccentric nucleus.
333
Toxoplasma gondii: How acquired (4).
Ingestion of cat feces.
Ingestion of infected meat.
Transfusion of blood; transplantation of tissues.
Transplacental transmission.
334
Toxoplasma gondii: Interpretation of IgG titers.
Very high or rising: Acute infection.
Low: Resolved infection.
335
Toxoplasma gondii: Effects on the fetus (2).
Early in gestation: Death.
Late: CNS disease.
336
Plasmodium spp.: Injected form.
The sporozoite.
337
Plasmodium spp.: Development in the hepatocyte.
Sporozoites develop into merozoites, which go on to infect erythrocytes.
338
Plasmodium spp.: Development in the erythrocyte.
Merozoites develop into trophozoites and then into schizonts and then into more merozoites. The merozoites burst out of the red cell and infect others.
Some merozoites develop into gametocytes.
339
Plasmodium spp.: What happens to the gametocytes?
They burst out of the erythrocyte and get ingested by the mosquito, along with red cells that contain trophozoites.
In the stomach of the mosquito, the gametocytes get fertilized and give rise to sporozoites.
340
Plasmodium spp.:
A. How long after inoculation do symptoms appear?
B. How long after inoculation do fever cycles begin?
A. About a week.
B. A few weeks.
341
Plasmodium spp.: Paroxysmal symptoms are associated with ___.
Intravascular hemolysis.
342
Tertian fever:
A. Definition.
B. Cause.
A. Fever spike every 48 hours.
B. Plasmodium vivax, ovale, falciparum.
343
Quartan fever:
A. Definition.
B. Cause.
A. Fever spike every 72 hours.
B. Plasmodium malariae.
344
Plasmodium: Species typically associated with the nephrotic syndrome.
Plasmodium malariae.
345
Plasmodium: Species most likely to affect the CNS.
Plasmodium falciparum.
346
Plasmodium: Species that causes "blackwater fever".
Plasmodium falciparum.
347
Relapse of malaria:
A. Associated species.
B. Mechanism.
A. P. vivax, P. ovale.
B. Reinfection of erythrocytes by merozoites from the liver.
348
Plasmodium:
A. Species that infects young red cells.
B. Species that infects old red cells.
C. Species with no preference.
A. P. vivax, P. ovale.
B. P. malariae.
C. P. falciparum.
349
Plasmodium spp.: Fluorescent stains used in detection.
Acridine orange.
Rhodamine.
350
Plasmodium spp.: Best time to collect blood for examination.
Before the next fever spike.
351
Plasmodium falciparum: Morphology of the ring form (4).
Less than one third the diameter of the RBC.
Some may have 2 chromatin dots.
Appliqué forms may be seen.
Multiply infected red cells are common.
352
Plasmodium malariae: Morphology of the mature trophozoite (2).
Band and basket forms that do not fill the red cell.
Conspicuous hematin pigment.
353
Plasmodium spp.: Number of merozoites in the schizont.
P. vivax: 12-24.
P. ovale: 6-14.
P. malariae: 6-12.
P. falciparum: Schizont rarely seen in the blood.
354
Plasmodium malariae: Unique morphologic feature of the schizont.
Merozoites surround a large clump of hematin pigment.
355
Plasmodium: Species exhibiting Schüffner's dots.
P. vivax.
P. ovale.
356
Plasmodium spp.: Appearance of hematin pigment.
P. malariae: Coarse.
All others: Fine.
357
How to distinguish Schüffner's dots from hematin pigment.
Schüffner's dots: Pale purple-pink.
Hematin pigment: Brown-black.
358
Plasmodium spp.: How many oil-immersion fields should be examined on a ___ smear?
A. Thick.
B. Thin.
A. At least 100.
B. At least 300.
359
Plasmodium falciparum: Name and appearance of unique inclusion in erythrocytes.
Maurer's clefts: Round or comma-shaped red dots.
360
Plasmodial parasitosis:
A. Response to therapy.
B. Definition of severe parasitosis.
A. Initial increase precedes decrease.
B. Parasites in >2% of red cells.
361
Babesia spp.: Pigment found in erythrocytes.
None.
362
Babesia spp.: Interpretation of titers.
At least 1 to 1024: Active infection.
No more than 1 to 64: Remote infection.
363
Babesia spp.:
A. In North America.
B. In Europe.
A. Babesia microti.
B. Babesia divergens.
364
Babesiosis in the northeastern U.S.:
A. Vector.
B. Reservoirs.
A. Ixodes scapularis.
B. White-footed mouse, whitetail deer.
365
Babesiosis in Europe: Vector.
Ixodes ricinus.
366
Babesiosis: Clinical features.
Non-periodic fever.
Hemolysis.
367
Babesiosis: Risk factors for fatal disease (2).
Asplenia.
Immunocompromise.
368
Enterobius vermicularis: How to recognize it in tissue sections.
By its lateral alae.
369
Enterobius vermicularis: Shape of egg.
Oval, with one flat side.
370
Enterobius vermicularis: Residence of adult female.
Cecum and appendix.
371
Trichuris trichiura: Shape of egg.
Like a thick-walled barrel with a plug in each end.
372
Trichuris trichiura: Complication of infection in children.
Rectal prolapse.
373
Ascaris lumbricoides: Shape of egg.
Round to oval, bile-stained, with a thick, rough wall.
374
Ascaris lumbricoides: Life in human host.
Eggs get ingested.
Larvae cross mucosa to get carried in the blood to the lungs, whence they get expectorated and swallowed.
Adult worms infest the duodenum.
375
Ascaris lumbricoides: Complications of infestation (4).
Löffler's syndrome.
Appendicitis.
Bowel obstruction.
Cholangitis.
376
Mouthparts of ___.
A. Necator americanus.
B. Ankylostoma duodenale.
A. Cutting plates.
B. "Teeth".
377
Necator americanus and Ankylostoma duodenale: Egg.
Morula in a thin shell.
378
Hookworms: Life in human host.
Larvae enter through the skin, travel through the blood to the lungs, and get expectorated and swallowed.
Adults infest the duodenum.
379
Strongyloides stercoralis: Residence of adult females.
Intestinal crypts.
380
Strongyloides stercoralis: Egg.
Similar to that of the hookworms but not usually found in the stool.
381
Strongyloides stercoralis: Form found in the stool and how to recognize it.
Rhabditiform larva.
Similar to larvae of hookworms, but with shorter buccal cavity and a large genital primordium.
382
Strongyloides stercoralis: Simple diagnostics tests other than examination of stool (2).
String test.
Duodenal aspirate.
383
Strongyloides stercoralis: Life in human host.
Similar to that of hookworms.
384
Strongyloides stercoralis: Complications (2).
Auto-infection: Worms re-enter lungs from duodenum and get expectorated and swallowed.
Hyperinfection in the immunocompromised.
385
Bloodborne microfilariae: Main species (4).
Wuchereria bancrofti.
Brugia malayi.
Loa loa.
Mansonella perstans.
386
Bloodborne microfilariae: Which has no sheath?
Mansonella perstans.
387
Bloodborne microfilariae: Which species are
A. Diurnal.
B. Nocturnal.
C. Without preference.
A. Loa loa.
B. Wuchereria bancrofti, Brugia malayi.
C. Mansonella perstans.
388
Bloodborne microfilariae: Nuclei of tail.
No nuclei: W. bancrofti.
Two, discontinuous: B. malayi.
Continuous row: Loa loa, M. perstans.
389
Bloodborne microfilariae: Residence of adults.
Lymphatics: W. bancrofti, B. malayi.
Subcutis: Loa loa.
Subcutis and body cavities: M. perstans.
390
Bloodborne microfilariae: Vectors.
W. bancrofti, B. malayi: Mosquito.
Loa loa: Mango fly (Chrysops).
M. perstans: Biting midge (Culicoides).
391
Loa loa: Disease.
Transient migratory edema.
392
Onchocerca volvulus:
A. Vector.
B. Diagnosis of infestation.
A. Simulium blackfly.
B. Detection of worm in snips of skin.
393
Dirofilaria immitis:
A. Vector.
B. Histology.
A. Mosquito.
B. Degenerating worm in granuloma in lung or subcutis.
394
Toxocara spp.: Diseases (2).
Visceral larva migrans.
Ocular larva migrans.
395
Toxocara spp.: Clinical manifestations (3).
Hypereosinophilia.
Pneumonitis.
Hepatosplenomegaly.
396
Fasciolopsis buski:
A. How acquired.
B. Affected organ.
A. From the ingestion of freshwater plants.
B. Duodenum.
397
Fasciolopsis buski: Egg.
150 μm, thin shell, unshouldered operculum.
398
Fasciola hepatica:
A. How acquired.
B. Affected organ.
A. From the ingested of freshwater plants.
B. Liver, biliary tract.
399
Fasciola hepatica:
A. Egg.
B. Adult.
A. Indistinguishable from that of Fasciolopsis buski.
B. Cephalic cone.
400
Clonorchis sinensis:
A. How acquired.
B. Affected organ.
A. From the ingestion of undercooked freshwater fish.
B. Biliary tract.
401
Clonorchis sinensis:
A. Egg.
B. Adult.
A. 30 μm, shouldered operculum, abopercular knob.
B. Snoutlike cephalic region.
402
Paragonimus westermani:
A. How acquired.
B. Affected organs.
A. From the ingestion of undercooked crustaceans.
B. Lungs.
403
Paragonimus westermani: Egg.
90 μm, shouldered operculum, no abopercular knob.
404
Diphyllobothrium latum: Egg.
60 μm; flat, unshouldered operculum; abopercular knob.
405
Schistosomes:
A. How they enter the body.
B. Residence in the body.
A. The fork-tailed cercariae penetrate the skin.
B. Pelvic and mesenteric vessels.
406
Schistosomiasis: Stages of infection.
Acute: Immune complexes.
Chronic: Reaction to eggs in tissue.
407
Schistosoma mansonii: Affected organs.
Liver.
Colon (from infiltration of inferior mesenteric vessels).
408
Schistosoma japonicum: Affected organs.
Liver.
CNS (rarely).
409
Schistosoma haematobium: Affected organ.
Urinary bladder.
410
Schistosoma intercalatum: Affected organ.
Intestine.
411
Schistosomes: Distinguishing the species by their eggs.
S. haematobium: Terminal spine.
S. mansonii: Lateral spine.
S. japonicum: Small lateral knob; smaller and more spherical egg.
412
Taenia saginata: Trivial name.
Beef tapeworm.
413
Taenia saginata: Egg.
30-40 μm, thick wall with radial striations, 3 pairs of hooklets.
414
Taenia saginata:
A. Scolex.
B. Proglottid.
A. Four suckers, unarmed (i.e. without hooklets) rostellum.
B. Longer than wide; >13 lateral uterine branches.
415
Taenia saginata: Ingested form.
Encysted organisms (cysticerci).
The eggs of T. saginata are not infectious.
416
Taenia solium:
A. Trivial name.
B. Egg.
A. Pork tapeworm.
B. Indistinguishable from that of T. saginata.
417
Taenia solium:
A. Scolex.
B. Proglottid.
A. Four suckers, armed rostellum.
B. Longer than wide; <13 lateral uterine branches.
418
Cyst of Taenia solium:
A. Size.
B. Morphology.
A. 1 cm.
B. Double row of hooklets.
419
Taenia solium: How acquired (2).
By the ingestion of infected pork.
By the ingestion of eggs shed in feces.
420
Diphyllobothrium latum: Scolex.
Almond-shaped, with two longitudinal sucking grooves.
421
Diphyllobothrium latum: Proglottid.
Wider than long; uterus resembles rosette.
422
Hymenolepis nana: Egg.
Oval, 40-60 μm, with a polar thickenings and a double shell enclosing three pairs of hooklets.
423
Hymenolepis nana: How acquired (2).
By the accidental ingestion of infected beetles.
By person-to-person transmission.
424
Hymenolepis diminuta:
A. Trivial name.
B. How acquired.
A. Rat tapeworm.
B. By the ingestion of insect-contaminated food.
425
Hymenolepis diminuta: Egg.
Spherical, 60-80 μm, no polar thickenings.
426
Dipylidium caninum:
A. Egg.
B. Proglottid.
A. Similar to that of Hymenolepis diminuta, but occurring in packets of 5-15.
B. Two genital pores, one on each side.
427
Dipylidium caninum: Acquisition.
Ingestion of fleas that have fed on infected dogs and cats.
428
Echinococcus spp.: Cyst.
Contains protoscolices and hooklets.
429
Echinococcus spp.: Definitive host.
The dog.
430
Organisms that often infect someone already infected with ___.
A. Ascaris lumbricoides.
B. Enterobius vermicularis.
C. Babesia spp. (2).
D. HTLV.
A. Trichuris trichiura.
B. Dientamoeba fragilis.
C. Anaplasma phagocytophilum, Borrelia spp.
D. Strongyloides stercoralis.
431
Parasitosis that is worse with ___.
A. B-cell deficiency.
B. Splenectomy.
A. Giardiasis.
B. Babesiosis.
432
Usual fungal media:
A. Examples (3).
B. Conditions of incubation.
A. Sabouraud's dextrose agar, inhibitory mold agar, brain-heart-infusion agar.
B. Four to six weeks at 25-30 degrees.
433
How does ___ inhibit the growth of bacteria?
A. Sabouraud's dextrose agar.
B. Inhibitory mold agar.
C. Brain-heart-infusion agar.
A. Low pH, much dextrose.
B. Chloramphenicol.
C. Chloramphenicol and gentamicin.
434
Cycloheximide: Use in fungal media.
Excludes saprophytes but permits growth of most pathogenic fungi.
435
Cycloheximide: Pathogenic fungi that cannot grow in it.
Cryptococcus spp.
Many species of Candida.
Aspergillus spp.
Zygomycetes.
436
Cornmeal and potato-dextrose agars: Purpose.
Identification of fungal isolates by pigment and reproductive structures.
437
Agar with Tween 80: Purpose.
Identification of yeast isolates by their reproductive structures.
438
Agar with olive oil: Purpose.
Isolation and cultivation of Malassezia spp.
439
Birdseed (niger-seed) agar: Purpose.
To demonstrate phenol oxidase activity in Cryptococcus neoformans.
440
Yeasts vs. molds:
A. Macroscopic appearance of colony.
B. Temperature of growth.
A. Yeasts: creamy or mucoid; molds: fuzzy.
B. Yeasts: 37 degrees; molds: 25-30 degrees.
441
Macroscopic features of colonies of ___.
A. Hyaline septate molds.
B. Dematiaceous molds.
C. Zygomycetes.
A. White or colored surface; usually light reverse.
B. Dark surface and/or reverse (due to melanin).
C. Rapid growth.
442
Thermally dimorphic fungi: Medically important species (6).
Histoplasma capsulatum.
Blastomyces dermatitidis.
Coccidioides immitis.
Paracoccidioides brasiliensis.
Sporothrix schenckii.
Pencillium marneffi.
443
Histoplasma capsulatum:
A. Microscopy of yeast form.
B. Colony morphology.
A. 2-4 μm, narrow-based budding.
B. Cottony and white.
444
Histoplasma capsulatum:
A. Microconidia.
B. Macroconidia.
A. Small, smooth, tear-shaped.
B. Large, spiny, thick-walled.
445
Histoplasma capsulatum: Non-morphologic test for identification.
Assay for Histoplasma antigen in serum or urine.
446
Histoplasma capsulatum: Favorable condition of soil.
Rich in nitrogen from the feces of chickens and bats.
447
Histoplasma capsulatum: Affected organs (2).
Lungs.
Reticuloendothelial system in disseminated infections.
448
Histoplasma capsulatum var. duboisii:
A. Geographic distribution.
B. Affected organs.
A. Western and Central Africa.
B. Skin, bones, subcutis.
449
Histoplasma capsulatum var. duboisii:
A. Morphology in vitro.
B. Morphology in vivo.
A. Same as that of Histoplasma capsulatum var. capsulatum.
B. Yeast: 7-15 μm, narrow-based budding.
450
Blastomyces dermatitidis:
A. Microscopy of yeast form.
B. Colony morphology.
A. 8-15 μm, thick-walled, broad-based budding.
B. Cottony and white, turning tan with age.
451
Blastomyces dermatitidis: Conidia.
Single and smooth and borne on straight, delicate conidiophores that emerge directly from the hyphae ("lollipop conidia").
452
Blastomyces dermatitidis:
A. Primary affected organs.
B. Organs affected in disseminated disease.
A. Lungs.
B. Skin, bones, mucous membranes.
453
Coccidioides immitis:
A. Size of spherule and of endospores.
B. Colony morphology.
A. 10-100 μm; 2-5 μm.
B. Moist, gray, and glabrous, turning cottony and white with maturity.
454
Coccidioides immitis: Microscopy of mold.
Hyphae and barrel-shaped arthroconidia alternating with empty cells.
455
Coccidioides immitis:
A. Primary affected organs.
B. Organs affected in disseminated disease.
A. Lungs.
B. Skin, bones.
456
Coccidioides: Another medically important species and its geographic distribution.
Coccidiodes posadosii: Southwestern United States, Mexico, Central America.
457
Paracoccidioides brasiliensis:
A. Microscopy of yeast.
B. Colony morphology.
A. 10-50 μm, circumferential budding.
B. White or tan; variable texture.
458
Paracoccidioides brasiliensis: Microscopy of mold form.
Smooth conidia borne on short, thick conidiophores that emerge directly from the hyphae.
459
Paracoccidiodes brasiliensis:
A. Primary affected organ.
B. Organs affected in disseminated disease (3).
A. Lungs.
B. Skin, mucous membranes, reticuloendothelial system.
460
Sporothrix schenckii:
A. Microscopy of yeast.
B. Colony morphology (mold).
A. 4-6 μm, cigar-shaped, narrow-based budding.
B. Moist, white to pale orange, turning brown with age.
461
Sporothrix schenckii: Microscopy of mold.
Clusters of microconidia borne on conidiophores.
462
Sporothrix schenckii:
A. Route of infection.
B. Affected organ.
A. Trauma.
B. Local lymphatics.
463
Penicillium marneffi:
A. Microscopy of yeast.
B. Colony morphology (mold).
A. 3-5 μm, ovoid, binary fission (no budding).
B. Powdery or velvety; white and becoming tan with age; red pigment surrounds colonies.
464
Penicillium marneffi: Microscopy of mold.
Brushlike clusters of phialides.
465
Penicillium marneffi: Endemicity.
Southeast Asia.
466
Aspergillus fumigatus: Color of colony (2).
Surface: Blue-green with a white apron.
Reverse: Light.
467
Aspergillus fumigatus: Microscopy.
Uniseriate phialides cover top ⅔ of the vesicle.
Phialides bear round conidia, 2-4 μm.
468
Aspergillus flavus: Color of colony (2).
Surface: Yellow-green to olive green.
Reverse: Light.
469
Aspergillus flavus: Microscopy.
Uniseriate or biseriate phialides cover whole vesicle.
470
Aspergillus niger: Color of colony (2).
Surface: Dark brown or black.
Reverse: Light.
471
Aspergillus niger: Microscopy.
Biseriate phialides cover whole vesicle; conidia are dark, round, and rough.
472
Aspergillus terreus: Color of colony (2).
A. Surface: Cinnamon brown.
B. Reverse: Yellow or orange.
473
Aspergillus terreus: Microscopy.
Biseriate phialides cover top ⅔ of vesicle; long chains of conidia.
474
Aspergillus spp.: Immunological test.
ELISA for galactomannan or for 1,3-β-glucan.
475
Infections caused by Aspergillus spp.:
A. In an immunocompetent host with cavitary lung disease.
B. In a host with atopy (2).
C. In an immunocompromised host (2).
A. Fungus ball.
B. Allergic sinonasal or bronchopulmonary aspergillosis.
C. Invasive sinonasal or bronchopulmonary aspergillosis.
476
Special clinical significance of
A. Aspergillus niger.
B. Aspergillus terreus.
A. Pulmonary infection leads to deposition of calcium oxalate in the tissues.
B. Resists amphotericin B.
477
Fusarium spp.: Infections.
Fungal keratitis.
Infections of burns.
Infections similar to those caused by Aspergillus spp.
478
Pseudallescheria boydii / Scedosporium boydii: Infections (3).
Fungal keratitis.
Eumycotic mycetoma.
Pneumonia after near-drowning.
479
Pseudallescheria boydii / Scedosporium boydii: Special clinical significance.
Resists amphotericin B.
480
Hyaline hyphomycetes with conidia in clusters: Genera (3).
Fusarium.
Acremonium.
Gliocladium.
481
Fusarium: Microscopy.
Canoe-shaped macroconidium contains 3-6 cells.
482
Acremonium: Microscopy.
"Diphtheroid" clusters of microconidia borne on threadlike conidiophores.
483
Gliocladium: Microscopy.
Resembles a mulberry (microconidia) held in the tips of four fingers (phialides).
484
Hyaline hyphomycetes with conidia in chains: Genera (3).
Penicillium.
Paecilomyces.
Scopulariopsis.
485
Penicillium: Microscopy.
Brushlike clusters of flask-shaped phialides bearing round conidia.
486
Paecilomyces: Microscopy.
Brushlike clusters of vase-shaped phialides bearing oval or spindle-shaped conidia.
487
Scopulariopsis: Microscopy.
Lemon-shaped microconidia that emerge one from another, forming chains.
Microconidia begin smooth but become spiny with maturity.
488
Hyaline hyphomycetes with single conidia: Genera (3).
Chrysosporium.
Sepedonium.
Beauveria.
489
Chrysosporium: Microscopy.
Resembles Blastomyces dermatitidis.
490
Sepedonium: Microscopy.
Resembles Histoplasma capsulatum.
491
Beauveria: Microscopy.
Geniculate conidiophores bear round or oval conidia.
492
Dermatophytes: Special biochemical property.
Resist cycloheximide.
493
Trichophyton rubrum: Colony.
Red reverse due to pigment.
494
Trichophyton rubrum: Microscopy.
Small, tear-shaped microconidia arranged on the hyphae like "birds on a wire".
495
Trichophyton mentagrophytes: Microscopy.
Clusters of microconidia; spiral hyphae.
496
Trichophyton tonsurans: Microscopy.
Variable sizes and shapes of microconidia.
497
Microsporum canis: Morphology.
Fusiform macroconidium terminates in a knob and contains >6 cells.
Transverse septa.
498
Microsporum gypseum: Microscopy.
Elongated ovoid macroconidium has rounded end and contains no more than 6 cells.
Transverse septa.
499
Epidermophyton floccosum: Microscopy.
Smooth, club-shaped microconidia contain 2-6 cells and transverse septa.
500
Dematiaceous molds: Colony morphologies (3).
Dark surface and dark reverse.
Dark surface and light reverse.
Light surface and dark reverse.
501
Bipolaris: Microscopy.
Smooth, oval microconidia with transverse septa, arising from geniculate conidiophores.
Germ tubes may arise from each end of a macroconidium.
502
Drechslera: Microscopy.
Resembles Bipolaris, but the germ tubes arise from the sides of the macroconidia.
503
Exserohilum: Microscopy.
Macroconidia are long and narrow, resembling pea pods, and terminate in a nipplelike knob.
504
Helminthosporium: Microscopy.
Resembles a bottle brush, with side-by-side macroconidia arranged in whorls along the conidiophores.
505
Curvularia: Microscopy.
Transversely septate macroconidia are bent due to overgrowth of the central cell.
506
Alternaria: Microscopy.
Muriform conidium of which the pointed end is apposed to the blunt end of the next, forming a chain.
507
Ulocladium: Microscopy.
Oval muriform macroconidium borne on a geniculate conidiophore.
508
Stemphylium: Microscopy.
Oval muriform macroconidium borne on a straight conidiophore, resembling cotton candy on a stick.
509
Dematiaceous molds with yeastlike early growth: Genera (2).
Hortaea.
Exophiala.
510
Slow-growing dematiaceous fungi that are moldlike throughout their growth: Genera (2).
Pseudallescheria boydii.
Scedosporium prolificans.
511
Pseudallescheria boydii / Scedosporium boydii: Colony.
"House mouse gray" surface: Conidia are pigmented.
Light reverse: Hyphae are not pigmented.
512
Pseudallescheria boydii / Scedosporium boydii: Sexual structure.
Cleistothecium.
513
Pseudallescheria boydii / Scedosporium boydii: Alternative sexual form and its microscopy.
Graphium.
Conidiophores form a bundle (synnemata) resembling a sheaf of wheat.
514
Pseudallescheria boydii / Scedosporium boydii: Antiobiotic therapy.
Resists amphotericin B.
Usually responds to triazoles.
515
Scedosporium prolificans: Colony.
Dark surface and dark reverse.
516
Scedosporium prolificans: Sexual form.
None described.
517
Scedosporium prolificans: Microscopy.
Truncated round conidia in clusters borne on conidiophores that have a swollen base.
518
Scedosporium prolificans: Antibiotic therapy.
Resists amphotericin B, triazoles, and echinocandins.
519
Dematiaceous molds: Infections (3).
Chromoblastomycosis.
Eumycotic mycetoma.
Phaeohyphomycosis.
520
Chromoblastomycosis: Histology (3).
Pseudoepitheliomatous hyperplasia.
Pigmented hyphae.
Sclerotic (muriform) bodies.
521
Chromoblastomycosis: Route of infection.
Puncture wound.
522
Chromoblastomycosis: Genera (3).
Phialophora.
Fonsecaea.
Cladophialophora.
523
Eumycotic mycetoma: Histology.
Mold form granules within subcutaneous nodules.
524
Eumycotic mycetoma: Genera (3).
Exophiala.
Madurella.
Pseudallescheria.
525
Eumycotic mycetoma: Route of infection.
Puncture wound.
526
Rhizopus spp.:
A. Sporangia.
B. Sporangiophores.
A. Tend to collapse, forming umbrella shapes.
B. Nodal, unbranched; no apophysis.
527
Mucor spp.:
A. Sporangia.
B. Sporangiophores.
A. Globose.
B. No rhizoids; branched or unbranched; no apophysis.
528
Lichtheimia (Absidia) spp.:
A. Sporangia.
B. Sporangiophores.
A. Globose or mushroom-shaped.
B. Internodal, branched; conical apophysis.
529
Cunninghamella spp.
A. Sporangia.
B. Sporangiophores.
A. Sporangioles, each containing a single spore, are connected by the hairlike denticles to the columella.
B. Branched; terminate in a globose columella.
530
Chromagar: Uses.
Selection for yeasts.
Differentiation among yeasts based on colony color.
531
Germ-tube test: Purpose.
Presumptive identification of Candida albicans.
532
Germ-tube test: Procedure.
The yeast isolate is incubated in serum at 37 degrees for no more than 3 hours.
Production of true hyphae is a positive result.
533
Germ-tube test: True hypha vs. pseudohypha.
True hypha: No constriction between the hypha and the yeast cell.
534
Germ-tube test: Positive organisms (2).
Candida albicans.
Candida dublinensis.
535
Which yeast rapidly ferments trehalose?
Candida glabrata.
536
Candida albicans: Colony.
Produces filamentous radial extensions ("feet").
537
Candida albicans: Microscopy.
Yeasts give rise to pseudohyphae that have blastoconidia at their septa and terminate in a chlamydospore.
538
Candida albicans: Appearance on Chromagar.
Green colonies.
539
Candida glabrata:
A. Growth.
B. Microscopy.
A. Slower than that of other candidae.
B. Yeasts only.
540
Candida glabrata: Antiobiotic therapy.
Sensitive to amphotericin B and to echinocandins.
Less sensitive to azoles.
541
Cryptococcus spp.:
A. Content of cell wall.
B. Microscopy.
C. Immunological test.
A. Melanin.
B. Yeasts only: 3-15 μm, narrow-based budding.
C. Capsular-polysaccharide antigen in CSF.
542
Phenol oxidase test:
A. Substrate.
B. Positive result.
C. Positive organism.
A. Caffeic acid (birdseed agar).
B. Brown colonies.
C. Cryptococcus neoformans.
543
Urease-positive yeasts: Genera (3).
Cryptococcus.
Rhodotorula.
Trichosporon.
544
Cryptococcus gattii:
A. Geography (2).
B. Botanical association.
A. Tropics, Pacific Northwest.
B. Eucalyptus tree.
545
Pneumocystis jiroveci: Colony.
Cannot be cultured in vitro.
546
Pneumocystis jiroveci: Chemical abnormality accompanying pneumonia.
High serum LDH.
547
Gram-positive vs. Gram-negative bacteria: Structure of cell.
Gram-positive: Thick peptidoglycan wall, no outer membrane.
Gram-negative: Thin peptidoglycan wall, outer membrane.
548
Active pigments in bacterial stains:
A. Gram stain (2).
B. Acid-fast stain.
A. Crystal violet, saffranin.
B. Carbolfuchsin.
549
Stains for acid-fast bacilli: Kinyoun method vs. Ziehl-Neelsen method.
Kinyoun method: No heat, more phenol.
550
Fite's stain for acid-fast bacilli:
A. Method.
B. Purpose.
A. Use of a weaker decolorizer.
B. Identification of Nocardia spp. and certain protozoa.
551
Stains for acid-fast bacilli: Fluorescent stain.
Auramine-rhodamine.
552
Buffered charcoal−yeast extract agar:
A. Other contents (2).
B. Purpose of charcoal.
C. Purpose of agar.
A. Iron, cysteine.
B. To bind inhibitors of growth.
C. Recovery of Legionella spp.
553
Mueller-Hinton agar: Purpose.
Testing for sensitivity to antimicrobials.
554
Thioglycolate broth: Purpose.
Cultivation of bacteria with little or no tolerance for oxygen.
555
MacConkey agar: Inhibitors (2).
Crystal violet.
Bile salts.
556
Eosin−methylene blue agar: Inhibitors.
Aniline dyes.
557
Campy-BAP: Inhibitors.
Antimicrobials to which campylobacters are naturally resistant.
558
Hektoen enteric agar: Inhibitors (3).
Bile salts.
Acid fuchsin.
Bromthymol blue.
559
Hektoen enteric agar: Purpose.
Recovery of Salmonella and Shigella spp.
560
Salmonella-Shigella agar: Inhibitors (3).
Bile salts.
Sodium citrate.
Brilliant green.
561
Selenite broth:
A. Inhibitor.
B. Purpose.
A. Sodium selenite.
B. Recovery and cultivation of Salmonella spp.
562
TCBS agar:
A. Contents.
B. Purpose.
A. Thiosulfate, citrate, bile salt, sucrose.
B. Recovery of vibriones.
563
Cefsulodin-irgasan-novobiocin agar: Purpose.
Recovery of yersiniae.
564
CNA agar:
A. Inhibitors.
B. Purpose.
A. Colistin, nalidixic acid.
B. Recovery of steptococci and cultivation of them according to hemolysis.
565
Lim broth: Purpose.
Recovery of group-B streptococci.
566
Regan-Lowe medium: Purpose.
Recovery of Bordetella spp.
567
Thayer-Martin agar:
A. Inhibitors.
B. Purpose.
A. Vancomycin, colistin, nystatin, SMX.
B. Recovery of neisseriae from nonsterile sites.
568
MacConkey agar: Use as a differential medium.
Fermenters of lactose: Pink or red colonies.
Others: Translucent colonies.
569
EMB agar: Use as a differential medium.
Fermenters of lactose: Green or purple-black colonies.
Others: Translucent colonies.
570
Hektoen enteric agar: Use as a differential medium.
Fermenters of lactose and/or sucrose: Yellow or orange colonies.
Producers of H₂S: Black colonies.
Others: Translucent colonies.
571
Salmonella-Shigella agar: Use as a differential medium.
Fermenters of lactose: Pink or red colonies.
Producers of H₂S: Black colonies.
Others: Translucent colonies.
572
TCBS agar: Use as a differential medium.
Fermenters of sucrose: Yellow colonies.
Others: Translucent colonies.
573
CIN agar: Use as a differential medium.
Fermenters of mannitol: Colorless colonies with a red center ("bullseyes").
Others: Translucent colonies.
574
Bacteria that grow best at 25-30 degrees (3).
Yersinia enterocolitica.
Pseudomonas fluorescens.
Pseudomonas putida.
575
Campylobacters that cause diarrhea: Optimal temperature for growth.
42 degrees.
576
Listeria: Effect of temperature (3).
37 degrees: Optimal for growth.
25 degrees: Motility.
4 degrees: Can still multiply.
577
Catalase test: Possible confounder.
Blood agar: Red blood cells have inherent catalase activity.
578
Catalase: Genera of positive bacteria (4).
Staphylococcus.
Listeria.
Bacillus.
Campylobacter.
579
Tube-based coagulase test: Timing.
Must be read at 4 hours and at 24 hours.
580
Slide-based coagulase test:
A. Advantage.
B. Disadvantage.
C. Reason for the disadvantage.
A. Faster than the tube-based test.
B. Many false positives and false negatives.
C. Detects clumping factor but not free coagulase.
581
Novobiocin: Purpose.
To distinguish Staphylococcus saprophyticus (resistant) from other coagulase-negative staphylococci.
582
Optochin:
A. How to recognize it.
B. Purpose.
A. It is the P disk.
B. To distinguish Streptococcus pneumoniae (sensitive) from viridans streptococci.
583
CAMP test: Biochemical basis.
CAMP factor potentiates staphylococcal β-hemolysin.
584
CAMP test: Procedure.
The isolate is streaked at right angles to the streak of Staphylococcus aureus.
585
CAMP test: Positive results (2).
Group-B streptococci: Arrowhead at the junction of the streaks.
Listeria: Rectangle.
586
PYR test: Positive result.
Red color due to hydrolysis of PYR.
587
PYR test: Positive organisms (3).
Streptococcus pyogenes.
Enterococci.
Staphylococcus lugdunensis.
588
Bile-esculin test:
A. Procedure.
B. Positive result.
A. Incubation of an inoculated bile-esculin slant for 24 hours.
B. Black color due to hydrolysis of esculin.
589
Bile-esculin test: Positive organisms (2).
Enterococci.
Streptococcus bovis.
590
Oxidase test:
A. Reagent.
B. Positive result.
A. p-Phenylenediamine.
B. Blue color.
591
Oxidase test: Positive bacteria (6).
Capnocytophaga.
Legionella.
Moraxella.
Neisseria.
Pasteurella, Pseudomonas.
Curved Gram-negative rods.
592
Indole test: Mechanism of a positive result.
Pink color due to deamination of tryptophan to produce indole.
593
Indole test: Positive organisms (2).
Escherichia coli.
Pasteurella spp.
Others.
594
Rapid-urease test:
A. Positive result.
B. Positive organisms (2).
A. Change from yellow to pink.
B. Helicobacter pylori, Proteus spp.
595
β-Glucuronidase test:
A. Positive result.
B. Positive bacteria.
A. Fluorescence in ultraviolet light.
B. E. coli; streptococci of the anginosus group.
596
Hippurate test:
A. Reagent.
B. Positive result.
A. Ninhydrin.
B. Purple-blue color.
597
Hippurate test: Positive bacteria (5).
Group-B streptococci.
Listeria monocytogenes.
Legionella pneumophila.
Garderella vaginalis.
Campylobacter jejuni.
598
Lysozyme test:
A. Positive result.
B. Positive bacteria.
A. Growth in lysozyme broth.
B. Nocardia spp.
599
Methicillin-resistant Staphylococcus aureus:
A. Gene.
B. Protein.
A. mecA.
B. PBP2A.
600
MRSA: Identification (3).
Disk-diffusion method using cefoxitin disk.
DNA hybridization for mecA.
Latex agglutination for PBP2A.
601
MRSA: Detection in a nasal swab (2).
Culture.
PCR.
602
Carriage of Streptococcus pneumoniae:
A. Population.
B. Site.
A. Children.
B. Oropharynx.
603
Carriage of Clostridium difficile:
A. Population.
B. Site.
A. Infants.
B. Colon.
604
Carriage of Neisseria meningitidis: Site.
Oropharynx.
605
Staphylococcus lugdunensis:
A. Normal habitat.
B. Diseases.
A. Skin.
B. Similar to those causes by Staphylococcus aureus.
606
Staphylococcus lugdunensis:
A. Coagulase.
B. Other biochemical tests (2).
A. Negative but may be falsely positive with the slide-based method.
B. Positive: PYR, ornithine decarboxylase.
607
Streptococcus pyogenes:
A. Biochemical tests (2).
B. Lancefield group.
C. Hemolysis on blood agar.
A. Hydrolyzes PYR, sensitive to bacitracin.
B. A.
C. β.
608
Streptococcus pyogenes: Immunological complications of infection (3).
Acute rheumatic fever.
Post-streptococcal glomerulonephritis.
Pediatric autoimmune neuropsychiatric disorders.
609
Jones' criteria for acute rheumatic fever: Major.
Subcutaneous nodules.
Pharyngitis.
Erythema marginatum.
Carditis.
Chorea.
610
Jones' criteria for acute rheumatic fever: Minor.
Fever.
Arthralgia.
Prolonged PR interval.
Elevated ESR and/or CRP.
611
Jones' criteria for acute rheumatic fever: How many must be met?
Two major criteria or one major criterion and two minor criteria.
612
Use of antibiotics to prevent complications of infection by Streptococcus pyogenes (2).
May prevent rheumatic heart disease.
Does not prevent glomerulonephritis.
613
Group-B streptococci:
A. Species.
B. Hemolysis on blood agar.
A. Streptococcus agalactiae.
B. β.
614
Group-B streptococci: Biochemical tests (2).
CAMP positive.
Hydrolyzes hippurate.
615
Screening of pregnant females for Group-B streptococci:
A. When?
B. Sample for collection.
A. At 35-37 weeks of gestation.
B. The same swab is used to collect from the vagina and the rectum.
616
Laboratory testing of pregnant females for Group-B streptococci:
A. Required initial step.
B. Methods (2).
A. Incubation in enrichment broth.
B. Culture, PCR.
617
Streptococcus pneumoniae:
A. Hemolysis of blood agar.
B. Biochemical test.
A. α.
B. Sensitive to optochin.
618
Viridans streptococci:
A. Hemolysis on blood agar.
B. Biochemical test.
C. Microscopy.
A. α.
B. Resists optochin.
C. Long chains.
619
Viridans streptococcus: Groups (4).
Streptococcus mitis.
Streptococcus mutans.
Streptococcus salivarius.
Streptococcus anginosus.
620
Streptococcus mitis group: Diseases (2).
Endocarditis
− Native valves.
− Prosthetic valves (late).
621
Streptococcus mutans group: Diseases (2).
Dental caries.
Endocarditis.
622
Streptococcus salivarius group: Diseases (2).
Bacteremia.
Endocarditis.
623
Streptococcus anginosus:
A. Disease.
B. Representative species.
A. Abscesses.
B. Streptococcus intermedius.
624
Enterococci:
A. Type of hemolysis.
B. Lancefield group.
A. None.
B. D.
625
Enterococci: Biochemical properties (3).
Hydrolysis of PYR.
Hydrolysis of esculin in bile.
Growth in 6.5% NaCl.
626
Enterococci that are naturally resistance to vancomycin:
A. Species (2).
B. Mechanism.
A. E. casseliflavus, E. gallinarum.
B. vanC.
627
Enterococcus faecium: Mechanisms of resistance to vancomycin (3).
vanA.
vanB.
vanD.
628
Enterococcus faecium: Mechanism of resistance to penicillin.
Altered penicillin-binding proteins.
629
Enterococcus faecium also resists which other classes of antibiotics (5)?
Cephalosporins.
Carbapenems.
Aminopenicillins.
Methicillin et al.
Ticarcillin et al.
630
Streptococcus bovis group:
A. Type of hemolysis.
B. Lancefield group.
A. None.
B. D.
631
Streptococcus bovis group: Biochemical properties (3).
Does not hydrolyze PYR.
Does not grow in 6.5% NaCl.
Hydrolyzes esculin in bile.
632
Association of Streptococcus bovis group with malignancy:
A. What malignancy?
B. What species?
A. Colon cancer.
B. S. gallolyticus subsp. gallolyticus.
633
Veillonella spp.: Significance (2).
Normal mucosal flora.
Participates in polymicrobial infections.
634
Neisseria spp.:
A. Requirement for incubation.
B. Biochemical property.
A. CO₂-rich environment.
B. Oxidase positive.
635
Neisseria spp.: Culture media (3).
Thayer-Martin agar.
Martin-Lewis agar.
New York City agar.
636
Neisseria gonorrhoeae: Percentage of infected individuals who are asymptomatic (2).
Males: 10%.
Females: 50%.
637
Neisseria gonorrhoeae infection in males: Complication of ascending infection.
Acute epididymis.
638
Neisseria gonorrhoeae infection in females:
A. Clinical manifestations.
B. Complication of ascending infection.
A. Pruritus, discharge, urethritis.
B. Pelvic inflammatory disease.
639
Neisseria gonorrhoeae: Complications of disseminated infection (2).
Purulent arthritis.
Fitz-Hugh-Curtis syndrome.
640
Serotypes of Neisseria meningitidis:
A. Basis.
B. Most important in the U.S.
C. Relevance to vaccination.
A. Capsular polysaccharide.
B. B, C, Y.
C. Serogroup B is not represented in the tetravalent vaccine.
641
Moraxella catarrhalis:
A. Growth on blood agar.
B. Biochemical test.
A. Grows well and produces "hockey puck" colonies.
B. Oxidase positive.
642
Moraxella catarrhalis: Diseases.
Pneumonia in smokers (COPD exacerbation).
Otitis media in children.
643
Kingella kingae:
A. Hemolysis.
B. Microscopy.
C. Diseases (4).
A. β.
B. Coccobacilli in pairs or short chains.
C. Endocarditis in adults; septic arthritis, osteomyelitis, and occult bacteremia in children.
644
Clostridium spp.: Basic characteristics (2).
Anaerobic spore-formers.
645
Clostridium perfringens:
A. Microscopy.
B. Growth on blood agar.
C. Preliminary identification.
A. Gram-positive "boxcar-shaped" rods in short chains.
B. Double zone of β hemolysis.
C. Demonstration of lecithinase activity.
646
Clostridium septicum:
A. Colony morphology.
B. Disease.
A. Forms swarms rather than colonies.
B. Bacteremia secondary to GI disease, esp. colon cancer.
647
Clostridium botulinum: Diagnosis of disease.
Identification of toxin in serum, stool, vomitus, or food.
648
Clostridium tetani: Diagnosis of disease.
Based on clinical findings.
649
Clostridium difficile:
A. Preferred culture medium.
B. Condition of culture.
A. Cycloserine-cefoxitin-fructose-egg yolk agar.
B. Strictly anaerobic.
650
Clostridium difficile: Colony morphology.
Yellow, ground-glass appearance; fluorescence in ultraviolet light.
651
Clostridium difficile:
A. Odor of culture.
B. Microscopy.
A. "Horse manure".
B. Thin, uniform bacilli with subterminal or free spores.
652
Clostridium difficile: Traditional method of detection of production of toxin.
Cytotoxicity culture.
653
Clostridium difficile: Current method of detection of production of toxin.
Molecular tests for the genes for toxins A and B.
654
Clostridium difficile: ELISA tests.
ELISA for glutamate dehydrogenase in stool (more sensitive).
ELISA for toxins A and B in stool.
655
Clostridium difficile: Virulent type.
B1/NAP1/027.
656
Clostridium difficile: Roles of PCR.
Detection of tcdA and tcdB.
Detection of tcdC in B1/NAP1/027.
657
Actinomyces spp.:
A. Important difference from Clostridium spp.
B. Important differences from Nocardia spp.
A. Actinomyces spp. form no spores.
B. Actinomyces spp. are anaerobic and are not acid fast.
658
Actinomyces israelii: Colony morphology.
"Molar tooth".
659
Actinomyces israelii: Diseases (4).
Actinomycoses.
Cervicofacial: Trauma, surgery.
Thoracic: Aspiration.
Intraabdominal: Appendicitis, diverticulitis, surgery.
Female genital tract: IUD.
660
Propionibacterium acnes: Disease.
Infection of foreign bodies such as prosthetic joints.
661
Bacillus spp. vs. Clostridium spp.
Bacteria of both genera form spores.
Bacillus spp. are aerobic.
662
Bacillus spp.: Additional properties (2).
Motile (except B. anthracis).
Catalase positive.
663
Bacillus spp.: Medium for testing for motility.
Semisolid medium (liquid media are unsafe).
664
Bacillus anthracis: Properties of colonies (3).
"Medusa head".
Tenacious.
Non-hemolytic.
665
Inhalational anthrax: Radiological finding.
Widened mediastinum due to hemorrhagic mediastinitis.
666
Bacillus cereus:
A. Location of spores.
B. Colony morphology (2).
C. Motility.
A. Subterminal.
B. β-Hemolytic, not tenacious.
C. Motile.
667
Bacillus cereus:
A. Distinctive biochemical property.
B. Oxygen tolerance.
A. Produces lecithinase.
B. Facultatively anaerobic.
668
Bacillus cereus: Diseases (2).
Food poisoning.
Serious infections in those with a weak immune system or a shunt.
669
Listeria monocytogenes: Similarities to group-B streptococci (5).
Morphology on Gram stain.
CAMP positive.
Hydrolyzes hippurate.
Vague β hemolysis.
Infects neonates.
670
Listeria monocytogenes: Important biochemical difference from group-B streptococci.
Listeria monocytogenes is catalase positive.
671
Listeria monocytogenes: Motility in wet mounts.
Tumbling.
Best demonstrated at 20-25 degrees.
672
Listeria monocytogenes: Motility in a motility tube.
Makes umbrella shape.
673
Diseases caused by Listeria monocytogenes:
A. Pregnant women (2).
B. Fetuses.
A. Flulike illness, bacteremia.
B. Chorioamnionitis.
674
Diseases caused by Listeria monocytogenes:
A. Neonates (3).
B. Immunocompromised (2).
A. Sepsis, meningitis, abscesses.
B. Sepsis, meningitis.
675
Erysipelothrix rhusiopathiae: Microscopy.
Coccobacilli occurring individually or in short chains.
Non-branching filaments.
676
Erysipelothrix rhusiopathiae: Motility.
Nonmotile.
677
Erysipelothrix rhusiopathiae: Biochemical properties.
Catalase negative.
Produces H₂S.
678
Erysipelothrix rhusiopathiae: Antibiosis.
Inherently resists vancomycin.
679
Erysipelothrix rhusiopathiae: How the infection is acquired.
Erysipeloid is acquired through exposure of a wound to animals that carry the bacterium.
680
Nocardia spp.:
A. Microscopy.
B. Staining.
A. Branching, beaded filaments.
B. Weakly acid fast (with Fite's stain).
681
Nocardia: Properties of colonies (3).
Chalky white, turning orange-pink with maturity.
"Musty basement" odor.
682
Nocardia spp.: Diseases (3).
Actinomycotic mycetoma.
Invasive pulmonary infection.
Disseminated infection that can involve the CNS.
683
Rhodococcus equi: Microscopy.
Gram-positive cocci, coccobacilli, or coryneform rods.
684
Rhodococcus equi: Staining (2).
Positive: AFB stain (modified).
Often found within histiocytes.
685
Rhodococcus equi:
A. Colony morphology.
B. Diseases.
A. Salmon-colored, slimy.
B. Opportunistic infections, esp. pulmonary.
686
Corynebacterium diphtheriae: Growth on agar.
Grows well on blood agar, but Tinsale agar is better for isolation.
687
Cornyebacterium diphtheriae: Appearance on selective agar.
Brown-black colonies on modified Tinsdale agar due to reduction of tellurite to Te.
688
Tropheryma whippeli:
A. Habitat.
B. Risk factor for infection.
A. Ubiquitous.
B. Selective immune deficiency.
689
Tropheryma whippeli:
A. Epidemiology of infection.
B. Staining.
A. Affects mainly older men.
B. Positive for PAS, negative for AFB.
690
Bacteroides fragilis:
A. Antibiosis.
B. Colony morphology.
A. Produces β-lactamases.
B. Small and shiny on blood agar.
691
Bacteroides fragilis: Gram-stain morphology.
Variable.
"Safety pin" staining of organisms grown in liquid media.
692
Porphyomonas: Color of colonies.
Brown-black in natural light.
Brick-red fluorescence in ultraviolet light.
693
Porphyromonas: Oxygen tolerance.
Anaerobic.
694
Fusobacterium: Infections (2).
Tonsillitis with thrombophlebitis of the internal jugular vein.
Placental infections.
695
Enterobacteriaceae: Risk factors for nasopharyngeal carriage (3).
Hospitalization.
Uncontrolled diabetes mellitus.
Chronic alcoholism.
696
Lipopolysaccharide: Major components (2).
Lipid A.
O antigen.
697
Escherichieae: Genera.
Escherichia.
Shigella.
698
Klebsielleae: Genera.
Klebsiella.
Enterobacter.
Serratia.
Hafnia.
Pantoea.
699
Proteeae: Genera.
Proteus.
Morganella.
Providencia.
700
Enterobacteriaceae: Tribes that contain only one genus (4).
Salmonelleae.
Citrobactereae.
Edwardsielleae.
Yersinieae.
701
Enterobacteriaceae: Strong fermenters of lactose.
Escherichia coli.
Enterobacter spp.
Klebsiella spp.
702
Enterobacteriaceae: Producers of H₂S.
Salmonella.
Edwardsiella.
Citrobacter.
Proteus.
703
Enterobacteriaceae: Strong producers of urease.
Proteus.
Morganella.
Providencia rettgeri.
704
Enterobacteriaceae: Nonmotile members at 37 degrees.
Shigella.
Klebsiella.
Yersinia (motile at 22 degrees).
705
Enterobacteriaceae: Producers of a positive Voges-Proskauer reaction.
The Klebsielleae.
706
Enterobacteriaceae: Producers of phenylalanine deaminase.
The Proteeae.
707
KIA/TSI slants: Contents (4).
Sugars.
Peptides.
Iron.
Phenol red.
708
KIA/TSI slants: Sugars.
KIA: Lactose and glucose at 10 : 1.
TSI: Lactose and sucrose at 10 : 1.
709
KIA/TSI slants: pH at which phenol red changes color.
6.8 (to yellow).
710
KIA/TSI slants: When interpreted.
At 24 hours.
711
KIA/TSI slants: Alkaline/alkaline.
Nonfermenters of glucose (i.e. non-Enterobacteriaceae).
Pseudomonas, others.
712
KIA/TSI slants: Alkaline/acid with black precipitate.
Fermenters of glucose but not of lactose that produce H₂S.
Salmonella, Proteus, Edwardsiella, Citrobacter.
713
KIA/TSI slants: Alkaline/acid with no precipitate.
Fermenters of glucose but not of lactose that produce no H₂S.
Shigella, Serratia, Morganella, Providencia, Yersinia.
714
KIA/TSI slants: Acid/acid.
Strong fermenters of lactose.
Escherichia coli, Enterobacter, Klebsiella.
715
KIA/TSI slants: Purpose of the peptides.
To detect nonfermenters of lactose. At first, fermentation of glucose turns all of the agar yellow. However, when the glucose is used up, oxidative metabolism of the peptides (which are in the slant, where the oxygen is) begins, which turns the slant back to red.
716
Enterobacteriaceae: Indole positive (5).
Escherichia coli.
Edwardsiella tarda.
Klebsiella oxytoca.
Citrobacter koseri.
The Proteeae.
717
Escherichia coli O157:H7: Identification on a culture plate.
Does not ferment sorbitol on sorbitol-MacConkey agar.
718
Traveler's diarrhea: Mechanism.
Enterotoxigenic E. coli produces "choleralike" toxins.
719
Enteroinvasive Escherichia coli: Properties (4).
Similar to Shigella, EIEC
− Causes dysentery.
− Produces T3SS, similar to shigatoxin.
− Does not ferment lactose.
− Is nonmotile.
720
Enteropathogenic E. coli: Properties.
Causes a disease that resembles shigellosis but does not produce a shigatoxin-like substance.
721
Enteroaggregative E. coli: Diseases (2).
Infantile diarrhea in poor countries.
Chronic refractory diarrhea in HIV patients.
722
Salmonella: Causes of bacteremia.
S. typhi.
S. paratyphi.
S. choleraesuis.
723
Salmonella: Causes of typhoid fever.
S. typhi.
S. paratyphi.
724
Typhoid fever:
A. Affected parenteral organs.
B. Role of gallbladder.
A. Reticuloendothelial cells of liver, spleen, gallbladder.
B. Serves as source of continual reinfection of bowel.
725
Shigella: Most important pathogens.
United States: Shigella sonnei.
Poor countries: Shigella flexneri.
726
Shigella: Species that can cause the hemolytic-uremic syndrome.
Shigella dysenteriae.
727
Shigella: Species that can cause reactive arthritis.
Shigella flexneri.
728
Klebsiella: Important pathogens (3).
Klebsiella pneumoniae: Pneumonia.
Klebsiella oxytoca: Neonatal sepsis.
Klebsiella rhinoscleromatis: Rhinoscleroma.
729
Yersinia: Medium and temperature of isolation.
CIN agar at room temperature.
730
Yersinia: Natural history.
Zoonotic organism that only accidentally infects humans.
731
Yersinia: Important pathogens (3).
Yersinia enterocolitica: Transfusion-related sepsis.
Yersinia pestis: Plague.
Yersinia pseudotuberculosis: Necrotizing granulomas.
732
Enterobacteriaceae vs. other enteric Gram-negative bacteria.
The latter may be oxidase positive.
733
Vibrio cholerae: Identification (2).
Culture: Yellow colonies on TCBS agar.
String test.
734
Vibrio cholerae: Classification.
O1: Cause of most cases of cholera.
Non-O1.
735
Vibrio parahaemolyticus:
A. Identification.
B. Diseases (2).
A. Culture: Green colonies on TCBS agar.
B. Foodborne illness, esp. in Japan; wound infections associated with seawater.
736
Vibrio vulnificus:
A. Habitat.
B. Diseases.
A. Seawater containing little salt, as in the Gulf of Mexico.
B. Foodborne illness with vomiting and diarrhea; wound infections associated with seawater.
737
Aeromonas and Plesiomonas:
A. Habitats.
B. Clinical significance.
A. Fresh water (including hospital sources); brackish water (such as aquaria).
B. Isolation in the stool may not indicate infection.
738
"Non-enteric" Gram-negative bacilli: Definition.
Those that grow on MacConkey agar but do not ferment glucose.
739
Pseudomonas aeruginosa:
A. Motility.
B. Hemolysis.
C. Temperature of growth.
A. Uses a polar flagellum.
B. β (often).
C. Grows well at 42 degrees.
740
"Fastidious" Gram-negative bacteria: Definition.
Those that form pinpoint colonies on enriched media but none at all on MacConkey agar.
741
Francisella tularensis:
A. Culture.
B. Biochemistry.
A. Requires cysteine and cystine.
B. Oxidase negative, urease negative; produces β-lactamases.
742
Brucella: Culture (2).
Chocolate agar in a CO₂-rich environment.
Routine media with a long incubation.
743
Brucella: Important pathogens.
Brucella abortus: Cattle.
Brucella melitensis: Sheep, goats.
Brucella suis: Swine.
744
Brucella: Acquisition of infection.
Ingestion of unpasteurized dairy products.
Working with or slaughtering farm animals.
745
Brucellosis: Clinical triad.
Lymphadenopathy.
Hepatosplenomegaly.
Malodorous perspiration.
746
Brucella: Affected organs (3).
Heart: Endocarditis, a main cause of death.
Liver: Granulomatous hepatitis.
Fetus: Spontaneous abortion.
747
Bordetella: Required nutrients (3).
Nicotinic acid, cysteine, methionine.
Does not require X factor or V factor.
748
Bordetella: Other conditions for culture (4).
Bordet-Gengou or Regan-Lowe agar.
Supplemental CO₂.
35 degrees.
Incubation for 2-4 days.
749
Pasteurella: Biochemical properties (3).
Catalase positive.
Indole positive.
Oxidase positive.
750
Legionella: Gram stain.
Invisible.
751
Legionella: Detection other than culture (2).
Direct immunofluorescence.
Latex agglutination.
752
Legionella: Prevalent serogroup.
Serogroup 1.
753
Campylobacter jejuni:
A. Conditions of culture.
B. Biochemical properties (3).
A. Campy-BAP at 42 degrees.
B. Oxidase positive, catalase positive, hippurate hydrolysis.
754
Capnocytophaga canimorsus: Conditions of culture (2).
Supplemental CO₂.
May not be isolable from blood using routine media.
755
Capnocytophaga canimorsus: Biochemical properties (2).
Catalase positive.
Oxidase positive.
756
Streptobacillus moniliformis:
A. Appearance in culture.
B. Appearance on Gram stain.
A. "Puffball" colonies in thioglycolate broth.
B. Gram-variable tangled filaments with swellings.
757
Haemophilus species: Requirements for X factor and V factor.
All species require V factor except H. ducreyi, which requires X factor only.
H. influenzae, H. haemolyticus, and H. aegypti require both factors.
758
Haemophilus species: Hemolytic ones.
H. haemolyticus, H. parahaemolyticus, and H. aegypti.
759
"HACEK" bacteria:
Aggregatibacter aphrophilus.
Aggregatibacter actinomycetemcomitans.
Cardiobacterium hominis.
Eikenella corrodens.
Kingella kingae.
760
Helicobacter pylori: Properties of serologic test (2).
IgG anti-Helicobacter pylori
− Becomes detectable 4 weeks after infection.
− Remains elevated for weeks after successful treatment.
761
Helicobacter pylori: Uses of the urea breath test (2).
To diagnose infection.
To confirm eradication.
762
Helicobacter pylori: Uses of the test for stool antigen (2).
Same as for the urea breath test.
763
Helicobacter pylori: When to test for eradication.
4-12 weeks after completion of treatment.
764
Coxiella burnetii:
A. Classification.
B. Growth in vivo.
C. Microscopy.
A. γ-Proteobacteria.
B. Obligate intracellular parasite.
C. Pleomorphic Gram-negative coccobacilli.
765
Coxiella burnetii: Acquisition of infection.
Through exposure to the urine, feces, or birthing fluids of farm animals.
766
Acute Q fever:
A. Presentation.
B. Mortality.
C. Frequent cause of death.
A. Nonspecific.
B. 1-2%.
C. Myocarditis.
767
Acute Q fever: Sites of characteristic granulomas.
Liver, bone marrow.
768
Chronic Q fever:
A. Sites of infection.
B. Mortality.
A. Heart (endocarditis), blood vessels (endovasculitis), bones, joints.
B. High.
769
Q fever: Clinical setting of recrudescence.
Pregnancy.
770
Q fever: Diagnosis (2).
Serology.
PCR on infected tissue.
771
Treponema pallidum subsp. pallidum:
A. Oxygen tolerance.
B. Motility.
A. Microaerophilic.
B. Flexing.
772
Syphilis: Average period of incubation.
3 weeks.
773
Primary stage of venereal syphilis:
A. Symptom.
B. Duration.
C. Possible immunological complication.
A. Chancre.
B. 1-8 weeks.
C. Jarisch-Herxheimer reaction.
774
Secondary stage of venereal syphilis: Organ-specific manifestations (5).
Condylomata lata.
Hepatitis.
Arthritis.
Rash.
Meningitis, aseptic.
775
Secondary stage of venereal syphilis: Possible immunological complications.
Jarisch-Herxheimer reaction.
Immune-complex-mediated glomerulonephritis.
776
Tertiary stage of venereal syphilis: Affected sites.
Nervous system.
Cardiovascular system.
Bones and skin: Gummata.
777
Venereal syphilis: Common histologic findings.
In all stages:
− Obliterative endarteritis.
− Plasmacytic infiltrate.
778
Treponema pallidum subsp. pallidum: Direct visualization (4).
Darkfield microscopy.
Direct immunofluorescence.
Immunohistochemistry.
Silver stains.
779
Syphilis: Types of test (5).
Treponemal: Syphilis IgG, FTA-ABS, TP-PA.
Nontreponemal: VDRL, RPR.
780
Syphilis: Reliability of tests over time.
Nontreponemal antibodies tend to wane.
Treponemal antibodies persist indefinitely.
781
Syphilis: Use of tests.
Diagnosis of infection: Syphilis IgG.
Confirmation of active disease: Nontreponemal test.
782
Diseases caused by
A. Treponema pallidum subsp. pertenue.
B. Treponema pallidum subsp. endemicum.
C. Treponema carateum.
A. Yaws.
B. Endemic (nonvenereal) syphilis.
C. Pinta.
783
Borreliae: Morphology and motility.
Loosely coiled; corkscrew-like.
784
Lyme disease: Bacterial agents by region (3).
North America: Borrelia burgdorferi.
Europe: B. afzelii, B. garinii.
785
Lyme disease: Distribution in the United States.
Northeast.
Upper Midwest.
Northern California and Oregon.
786
Lyme disease in North America:
A. Reservoir.
B. Vectors.
A. White-footed mouse.
B. Ixodes scapularis, Ixodes pacificus.
787
Lyme disease: Stages.
Early: Erythema migrans.
Second: Palsy of the facial nerve; atrioventricular block.
Third: Arthropathy.
788
Lyme disease: Diagnosis.
Serology.
789
Borrelia burgdorferi: Common co-infecting organisms.
Babesia spp.
Anaplasma phagocytophilum.
790
Leptospira interrogans: Morphology.
Tightly coiled, with hooked ends.
791
Leptospirosis:
A. Clinical triad.
B. Routes of infection.
C. Usual host.
A. Meningitis, nephritis, hepatitis.
B. Conjunctivae, skin.
C. The rat.
792
Leptospirosis:
A. Area of highest incidence in the United States.
B. Diagnosis.
A. Hawaii.
B. Serology.
793
Intestinal spirochetosis: Organism.
Brachyspira aalborgi.
794
Chlamydia trachomatis: Neonatal infections (3).
Inclusion-body conjunctivitis.
Pneumonia.
Otitis.
795
Chlamydia trachomatis: Diagnosis (2).
Gold standard: Demonstration of McCoy cells in culture.
Current method: Nucleic-acid amplification.
796
Cause of
A. Psittacosis.
B. Atypical pneumonia.
A. Chlamydophila psittaci.
B. Chlamydophila pneumoniae.
797
Cause of
A. Lymphogranuloma venereum.
B. Granuloma inguinale.
A. Chlamydia trachomatis.
B. Calymmatobacterium granulomatis.
798
Rocky Mountain spotted fever:
A. Cause.
B. Area of highest incidence in the United States.
C. Vector.
A. Rickettsia rickettsiae.
B. The Southeast.
C. Dermacentor variabilis, the American dog tick.
799
Rocky Mountain spotted fever: Triad of early infection.
Fever.
Severe headache.
Centripetal rash beginning at wrists and ankles.
800
Rocky Mountain spotted fever: Later manifestations (3).
Renal failure.
Disseminated intravascular coagulation.
CNS disease.
801
Rocky Mountain spotted fever: Risk factor for fulminant disease.
Glucose-6-phosphate dehydrogenase deficiency.
802
Cause of
A. Human monocytoid ehrlichiosis.
B. Human granulocytic anaplasmosis.
A. Ehrlichia chafeensis.
B. Anaplasma phagocytophilum.
803
Ehrlichia/Anaplasma: Microscopy.
Modulae within intracellular vacuoles.
804
Cause and vector
A. Trench fever.
B. Oroya fever / verruga peruana.
A. Bartonella quintana; human body louse.
B. Bartonella bacilliformis; Lutzomyia spp.
805
Bartonella henselae: Diseases.
Cat-scratch disease.
Bacillary angiomatosis.
806
Bacillary angiomatosis: Affected organs (3).
Lymph nodes.
Skin.
Viscera.
807
Mycoplasma pneumoniae: Significance in transfusion medicine.
Can induce cold agglutinins against the I antigen.
808
Mycoplasma hominis:
A. Disease.
B. Colony morphology.
A. Non-gonococcal urethritis.
B. "Fried eggs".
809
Mycobacteria: Stains (2).
Stains for acid-fast bacilli.
Auramine-rhodamine fluorochromes.
810
Value of mycobacterial culture (3).
Gold standard.
More sensitive than nucleic-acid amplification.
Required for testing for sensitivity to antibiotics.
811
Mycobacteria: Preferred growth medium.
Broth, typically Middlebrook broth.
812
Mycobacteria: Molecular methods of identification (2).
Nucleic-acid amplification.
Multiplex PCR.
813
Mycobacteria: Traditional methods of identification.
Rate of growth: Rapid or slow.
Pigmentation: Photochromogen, scotochromogen, non-chromogenic.
Biochemical reactions.
814
Mycobacteria that infect the lung (5).
M. tuberculosis.
M. avium complex.
M. kansasii.
M. xenopi.
M. abscessus.
815
Mycobacteria that infect lymph nodes (4).
M. tuberculosis.
M. avium complex.
M. scrofulaceum.
M. haemophilum.
816
Mycobacteria that infect skin and soft tissues (6).
M. abscessus.
M. fortuitum.
M. chelonae.
M. marinum.
M. ulcerans.
M. haemophilum.
817
Mycobacteria that infect the gastrointestinal tract (2).
M. tuberculosis.
M. avium complex.
818
Mycobacterium tuberculosis:
A. Rate of growth.
B. Colony morphology.
C. Preferred temperature.
A. Slow.
B. Flat, dry, white, wrinkled.
C. 37 degrees.
819
Mycobacterium tuberculosis:
A. Presence of cord factor.
B. Pigmentation.
A. Forms cords in broth.
B. Non-chromogenic.
820
Mycobacterium tuberculosis complex: Members.
M. tuberculosis.
M. canettii.
M. africanum.
M. microti.
M. bovis.
821
Mycobacterium tuberculosis: Possible outcomes of primary infection (3).
Spontaneous eradication.
Resolution (latency), with tubercles.
Active infection.
822
Tuberculosis: Tests of pleural fluid (4).
Smear.
Culture.
Nucleic-acid amplification.
Adenosine deaminase.
823
Tuberculosis: How to collect a sample in one who cannot produce adequate sputum.
Obtain a gastric aspirate.
824
Tuberculin skin test: Causes of a positive result (4).
Active tuberculosis.
Latent tuberculosis.
Infection with non-TB mycobacteria.
BCG vaccination.
825
Tuberculin skin test: Frequent cause of false negative.
Anergy in the immunocompromised.
826
Newer immunological test for tuberculosis: How it works.
T lymphocytes release much IFN-γ when exposed to ESAT-6 and CFP-10 in vitro.
827
Mycobacterium avium complex: Affected populations.
Immunocompromised.
Immunocompetent.
828
Mycobacterium avium complex: Classical cases of infection in the immunocompetent (3).
Cavitary lung disease of the upper lobe, mimicking tuberculosis, in a heavy smoker.
Weak cough in an elderly woman (Lady Windermere syndrome).
Hypersensitivity reaction from a hot tub.
829
Mycobacterium avium complex: Characteristics of culture (2).
Slow growth.
May or may be pigmented.
830
Scrofula: Leading cause in the United States.
Mycobacterium avium complex.
831
Mycobacterium kansasii:
A. Type of infection.
B. Factors that predispose to infection (2).
C. Culture (2).
A. Resembles tuberculosis.
B. Immunosuppression; preexisting lung disease.
C. Slow-growing; photochromogenic.
832
Mycobacterium marinum: Habitat.
Fresh water or seawater.
833
Mycobacterium ulcerans: Disease.
Buruli ulcer.
834
Mycobacteria: Rapid growers.
M. chelonae.
M. fortuitum.
M. abscessus.
835
Mycobacteria: Non-photochromogens.
M. paratuberculosis.
M. avium complex.
M. terrae.
M. triviale.
M. shimoidae.
836
Mycobacteria: Photochromogens.
M. kansasii.
M. marinum.
M. asiaticum.
M. simiae.
837
Mycobacteria: Scotochromogens.
M. scrofulaceum.
M. szulgai.
M. xenopi.
M. celatum.
M. gordonae.
M. flavescens.
838
Mycobacterium leprae:
A. Culture.
B. Best stain.
A. Cannot be cultured in vitro.
B. Fite's stain.
839
Asymptomatic bacteriuria: Diagnosis in voided urine (2).
Requires isolation of at least 10⁵ colony-forming units per mL of the same species.
In females, two consecutive samples are needed.
