FA - Micro - Clinical Bacteriology Flashcards
0
Q
Gram(+) + Branching filaments + Aerobe,acid fast.
A
Nocardia
1
Q
Gram(+) + Branching filaments + Anaerobe, not acid-fast.
A
Actinomyces
2
Q
Gram(+) + Cocci + Catalase(+) + Coagulase (+).
A
S.aureus
3
Q
Gram(+) + Cocci + Catalase(+) + Coagulase(-) + Novobiocin (S).
A
S.epidermidis
4
Q
Gram(+) + Cocci + Catalase(+) + Coagulase(-) + Novobiocin (R).
A
S.saprophyticus
5
Q
Gram(+) + Cocci + Catalase(-).
A
Streptococcus
6
Q
Gram(+) + Rods + Anaerobe.
A
Clostridium
7
Q
Gram(+) + Rods + Aerobe
A
Bacillus
8
Q
Gram(+) + Rods + Acid-fast
A
Mycobacterium
9
Q
Gram(+) + Rods.
A
Corynebacterium + Listeria.
10
Q
Gram(+) + Cocci + Catalase(-) + Hemolysis(partial hemolysis - green).
A
α-hemolytic:
- S.pneumoniae
- Viridans streptococci (mutans)
11
Q
S.pneumoniae features:
A
- Capsule
- Optochin sensitive
- Bile soluble (lysed by bile)
12
Q
Viridans streptococci features:
A
- NO capsule
- Optochin resistant
- Bile insoluble
13
Q
Gram(+) + Cocci + Catalase(-) + Hemolysis (complete hemolysis - clear).
A
β-hemolysis:
- Group A (S.pyogenes)
- Group B (S.agalactiae)
14
Q
Feature of S.pyogenes to distinguish from S.agalactiae?
A
Bacitracin sensitive.
15
Q
Gram(+) + Cocci + Catalase(-) + Hemolysis(no hemolysis)
A
γ-hemolytic:
- Group D (enterococcus)
- Non enterococcus
16
Q
E.faecalis:
A
Growth in bile and 6.5% NaCl.
17
Q
Nonenterococcus, growth in bile, not 6.5% NaCl.
A
S.bovis.
18
Q
Either α- or γ- hemolytic:
A
Enterococcus
19
Q
α-hemolytic bacteria:
A
Green ring around colonies on blood agar:
- S.pneumoniae
- Viridans streptococci
20
Q
β-hemolytic bacteria:
A
Clear area of hemolysis on blood agar:
- S.aureus
- S.pyogenes
- S.agalactiae
- L.monocytogenes
21
Q
What does S.aureus cause?
A
- Inflammatory disease
- Toxin-mediated disease
- MRSA infection
22
Q
What inflammatory disease does S.aureus cause?
A
- Skin infections
- Organ abscesses
- Pneumonia (often after influenza virus infection)
- Endocarditis
- Osteomyelitis
- Septic arthritis.
23
Q
What toxin-mediated disease does S.aureus cause?
A
- Toxic shock syndrome
- Scalded skin syndrome (exfoliative toxin)
- Rapid-onset food poisoning (enterotoxins)
24
What is the mechanism of MRSA staph resistance?
Altered penicillin-binding protein.
| --> Resistant to METHICILLIN + NAFCILLIN.
25
What is basically the TSST?
A superantigen that binds to MHC II and TCR --> POLYCLONAL T-cell activation.
26
What predisposes to toxic shock syndrome?
Use of vaginal packing or nasal tampons.
27
What happens with S.aureus food poisoning?
Ingestion of preformed toxin --> Short incubation period (2-6hr).
Enterotoxin is heat STABLE --> Not destroyed by cooking.
28
What must be kept in mind about S.epidermidis?
Contaminates blood cultures.
29
Of which conditions is S.pneumoniae the MCC?
MCC of:
1. Meningitis
2. Otitis media
3. Pneumonia
4. Sinusitis
30
With what is Pneumococcus often associated?
1. "Rusty" sputum
2. Sepsis in SCA and splenectomy.
3. NO virulence without capsule.
31
Which viridans strep causes subacute bacterial endocarditis at damaged valves?
S.sanguinis
| Sanguis = Blood
32
What does S.sanguinis make?
Dextrans
33
Where do the dextrans of S.sanguinis bind to?
To fibrin-platelet aggregates on damaged heart valves.
34
What does S.pyogenes cause?
1. Pyogenic --> Pharyngitis, cellulitis, impetigo erysipelas.
2. Toxigenic --> Scarlet fever, toxic shock-like syndrome, necrotizing fasciitis.
3. Immunologic --> RF, acute GN.
35
What is the role of ASO titer?
Detects recent S.pyogenes infection.
36
What are the main criteria for RF?
Jones criteria:
```
Joints - Polyarthritis
O - carditis
N - Nodules (subcutaneous)
E - Erythema marginatum
S - Sydenham chorea
```
37
Impetigo or pharyngitis more commonly precedes post-strep GN?
Impetigo.
38
What happens in Scarlet fever?
1. Blanching, sandpaper-like body rash.
2. Strawberry tongue.
3. Circumoral pallor.
in the setting of group A strep pharyngitis (ERYTHROGENIC TOXIN (++)).
39
What does S.agalactiae cause?
1. Pneumonia
2. Meningitis
3. Sepsis
mainly in Babies --> Group B for Babies.
40
What does S.agalactiae produce?
CAMP factor - which enlarges the area of hemolysis formed by S.aureus.
CAMP stands for the authors of the test, not cyclic AMP.
41
Which test is (+) for S.agalactiae?
Hippurate test
42
Whens should pregnant women be screened?
At 35-37wks.
43
What should be done if a positive culture is found?
Patients with (+) culture receive intrapartum penicillin prophylaxis.
44
To which drug are Enterococci resistant?
Penicillin G
45
What can the enterococci cause?
1. UTI
2. Biliary tract infections
3. Subacute endocarditis - Following GI/GU procedures.
46
Lancefield grouping is based on what?
On differences in the C carbohydrate on the bacterial wall.
47
What hemolysis do Enterococci produce?
VARIABLE hemolysis (either α- or γ-).
48
What does S.bovis in the blood mean?
Cancer in the colon.
49
What encodes the diphtheria exotoxin?
A β-prophage.
50
How does diphtheria toxin inhibits protein synthesis?
Via ADP-ribosylation of EF-2.
51
What are the symptoms of diphtheria?
1. Pseudomembranous pharyngitis (gray-white membrane).
2. Lymphadenopathy
3. Myocarditis
4. Arrhythmias
52
What is the lab diagnosis of C.diphtheriae?
Based on Gram(+) rods with metachromatic (blue and red) granules and POSITIVE Elek test for toxin.
53
What colonies does C.diphtheriae produce and in which agar?
Black colonies on cystine-tellurite agar.
54
What do spores have at their core?
Dipicolinic acid.
55
How do we kill spores?
Must autoclave by steaming at 121C for 15mins - as is done to surgical equipment.
56
Spore-forming gram(+) bacteria found in soil:
1. B.anthracis
2. C.perfringens
3. C.tetani
57
Is Coxiella burnetti spore former?
YES.
58
What does tetanospasmin block?
Glycine and GABA (both inhibitory) from Renshaw cells in spinal cord.
59
Is the botox heat labile or heat stable?
Heat labile.
60
What happens in floppy baby syndrome?
Ingestion of C.botulinum SPORES (not preformed toxin AS IN ADULTS) in honey causes disease.
61
What does the α-toxin of C.perfringens cause?
It is a lecithinase - a phospholipase - that cause myonecrosis (gas gangrene) and hemolysis.
62
How many toxins does C.difficile produce?
2 Toxins - A and B.
63
What is the role of toxin A?
Enterotoxin - Binds to the brush border of the gut.
64
What is the role of toxin B?
Cytotoxin, causes cytoskeletal disruption via actin depolymerization --> Pseudomembranous colitis --> Diarrhea.
65
Which 2 drugs are known to cause pseudomembranous colitis?
1. Ampicillin
2. Clindamycin
- -> Associated with PPI use.
66
How is C.difficile colitis diagnosed?
By detection of one or both toxins in stool BY PCR.
67
For recurrent cases of pseudomembranous colitis, what may prevent relapse?
Fecal transplant!!!
68
What happens in cutaneous anthrax?
PAINLESS PAPULE surrounded by vesicles --> Ulcer with black eschar (painless, necrotic) --> Uncommonly progresses to bacteremia and death.
69
What happens in pulmonary anthrax?
Inhalation of spores --> Flu-like symptoms that rapidly progress to:
1. Fever.
2. Pulmonary hemorrhage.
3. Mediastinitis.
4. Shock.
70
What is another name for pulmonary anthrax?
Woolsorter's disease - Inhalation of spores from contaminated wool.
71
What is the cause of "reheated rice syndrome"?
B.cereus
72
What are the features of B.cereus poisoning?
1. Emetic type --> usually seen with rice and pasta - Nausea and vomiting within 1-5hr.
2. Diarrheal type --> Causes watery, non bloody diarrhea, GI pain within 8-18hrs.
73
What substance is the cause of B.cereus EMETIC TYPE food poisoning?
Cereulide - a preformed toxin.
74
How is L.monocytogenes acquired?
1. Ingestion of unpasteurized dairy products and cold deli meats.
2. Via transplacental transmission
3. By vaginal transmission during birth.
75
What does L.monocytogenes form in order to avoid the immune system?
Form "rocket tails" (via actin polymerization) that allow intracellular movement and cell-to-cell spread across cell membranes --> Avoiding antibody.
76
What is characteristic about L.monocytogenes?
1. Tumbling motility in broth.
| 2. ONLY Gram(+) to produce LPS.
77
What can L.monocytogenes cause?
1. Amnionitis
2. Septicemia
3. Spontaneous abortion in pregnant women
4. Granulomatosis infantiseptica
5. Neonatal meningitis
6. Meningitis in immunocompromised patients
7. Mild gastroenteritis in healthy individuals
78
What is the treatment of L.monocytogenes?
1. Gastroenteritis usually self-limited.
| 2. Ampicillin in infants, immunocompromised patients, and the elderly in empirical treatment of meningitis.
79
Where do we find Actinomyces?
1. Normal oral flora.
2. Reproductive.
3. GI.
80
Where do we find Nocardia?
Found in soil.
81
What does actinomyces cause?
1. Oral/facial abscesses
2. Drain through sinus tracts
3. Forms yellow "sulfur granules"
- -> CAN ALSO CAUSE PID WITH IUDs.
82
What does Nocardia cause?
1. Pulmonary infections in immunocompromised (can mimic TB but with NEGATIVE PPD).
2. Cutaneous infections after trauma in immunocompetent.
83
How do we treat Actinomyces?
With penicillin.
84
How do we treat Nocardia?
With sulfonamides (TMP-SMX).
85
Who usually gets primary TB?
Nonimmune host (usually child).
86
What happens usually in primary TB?
1. Hilar nodes
2. Ghon focus (usually in mid zone of lung)
Ghon complex.
87
What are the 4 possible outcomes of primary TB?
1. Heals by fibrosis --> Immunity and hypersensitivity --> Tuberculin(+).
2. Progressive lung disease (HIV, malnutrition) --> Death (rare).
3. Severe bacteremia --> Miliary TB --> Death.
4. Preallergic lymphatic or hematogenous dissemination --> Dormant tubercle bacilli in several organs --> Reactivation in adult life.
88
Who usually gets secondary TB?
Partially immune hypersensitized host (usually adult) - Reinfection.
89
What happens in secondary TB?
Fibrocaseous cavitary lesion (usually upper lobes).
90
What happens when TB gets reactivated?
Extrapulmonary TB:
1. CNS --> Parenchymal tuberculoma or meningitis.
2. Vertebral body (Pott disease)
3. Lymphadenitis
4. Renal
5. GI + LIVER.
6. Adrenals
91
When is the PPD (+)?
1. Current infection
2. Past exposure
3. BCG vaccinated
92
When is PPD(-)?
1. No infection or anergic (steroids, malnutrition, immunocompromise)
2. Sarcoidosis
93
What is a more specific test for TB than BCG vaccination?
IFN-γ release assay (IGRA) - Has FEWER FALSE(+) from BCG vaccination.
94
Mention some Mycobacteria.
1. M.tuberculosis --> TB, often resistant to drugs.
2. M.kansasii --> Pulmonary TB-like symptoms.
3. M.avium-intracellulare --> Causes disseminated, non-TB disease in AIDS - often resistant to multiple drugs.
4. M. scrofulaceum (cervical lymphadenitis in children).
5. M. marinum (hand infection in aquarium handlers).
95
What is the prophylactic treatment for M.avium-intracellulare?
Azithromycin, when CD4
96
What are the 5 main TB symptoms?
1. Fever
2. Night sweats
3. Weight loss
4. Cough = Productive + Non productive
5. Hemoptysis
97
Cord factor creates ...?
A "serpentine cord" appearance in virulent M.tuberculosis strains.
1. Inhibits macrophage maturation.
2. Induces release of TNF-alpha.
98
What do sulfatides (SURFACE GLYCOLIPIDS) inhibit?
Phagolysosomal fusion.
99
What temperature does M.leprae like?
COOL temperatures --> skin and superficial nerves.
| --> "GLOVE AND STOCKING" loss of sensation.
100
Is it possible to grow M.leprae?
CANNOT be grown in vitro.
101
What is the reservoir of M.leprae in the US?
Armadillos.
102
What is another name for Leprosy?
Hansen disease.
103
What are the 2 forms of Hansen disease?
1. Tuberculoid
| 2. Lepromatous
104
What happens in lepromatous leprosy?
1. Presents diffusely over the skin, with leonine facies.
2. It is communicable.
3. Low cell-mediated immunity with a humoral Th2 response.
105
What happens in tuberculoid leprosy?
1. Limited to a few hypoesthetic, hairless skin plaques.
| 2. High cell-mediated immunity with a largely Th1-type immune response.
106
What is the treatment for leprosy?
1. Dapsone + rifampin for 6 months for tuberculoid form.
| 2. Dapsone + rifampin + clofazimine for 2-5yrs for lepromatous form.
107
Which type of leprosy can be lethal?
LEpromatous --> LEthal.
108
Gram(-) + Diplococcus + Maltose fermenter.
N.meningitis
109
Gram(-) + Diplococcus + Maltose NON fermenter.
N.gonorrhoeae
110
Gram(-) + "Coccoid" rods.
1. H.influenza
2. Pasteurella
3. Brucella
4. B.pertussis
5. Francisella tularensis
111
Gram(-) + Oxidase(+) + Comma-shaped + Grows in 42C.
C.jejuni
112
Gram(-) + Oxidase(+) + Comma-shaped + Grows in alkaline media.
V.cholerae
113
Gram(-) + Oxidase(+) + Comma-shaped + Produces urease.
H.pylori
114
Gram(-) + Rods + Lactose fermenter + Fast fermenter.
1. Klebsiella
2. E.coli
2. Enterobacter
115
Gram(-) + Rods + Lactose fermenter + SLOW fermenter.
1. Citrobacter
| 2. Serratia
116
Gram(-) + Rods + Lactose NON fermenter + Oxidase(-).
1. Shigella
2. Salmonella
3. Proteus
4. Yersinia
117
Gram(-) + Rods + Lactose NON fermenter + Oxidase(+).
Pseudomonas
118
Lactose-fermenting enteric bacteria grow what colonies on MacConkey agar?
PINK colonies.
119
Does E.coli produce β-galactosidase?
Yes - Breaks down lactose into glucose and galactose.
120
Lactose fermenters in EMB agar produce what colonies?
PURPLE/BLACK colonies. (E.coli --> purple with a green sheen).
121
What about penicillin and gram(-) bugs?
Penicillin G and Vancomycin CANNOT entry gram(-).
| Gram(-) may be susceptible to penicillin derivatives such as ampicillin and amoxicillin.
122
Which enzyme do BOTH Neisseria produce?
IgA protease.
123
Meningococci or gonococci have polysaccharide capsule?
Meningococci.
124
Is there a vaccine for gonorrhea?
NO - Due to rapid antigenic variation of pilus proteins.
125
Is there a vaccine for meningitis?
Yes, but type B NOT WIDELY AVAILABLE.
126
How is meningococci transmitted?
Respiratory and oral secretions.
127
What do gonococci cause?
1. Gonorrhea
2. Septic arthritis
3. Neonatal conjunctivitis
4. PID
5. F-H-C syndrome
128
What should be given to neonates to prevent from neonatal conjunctivitis?
Erythromycin
129
What do we give for meningitis PROPHYLAXIS?
1. Rifampin
2. Ciprofloxacin
3. Ceftriaxone - prophylaxis in close contacts.
130
How do we treat N.gonorrhoeae infection?
1. Ceftriaxone
| 2. Azithromycin/doxycycline for possible Chlamydia coinfection.
131
What is the treatment for meningitis?
Ceftriaxone or Penicillin G.
132
What do nontypeable strains of H.influenza cause?
MCC of mucosal infections:
1. Otitis media
2. Conjunctivitis
3. Bronchitis
- -> As well as invasive infections since the vaccine for capsular type B was introduced.
133
Does H.influenza produce IgA protease?
Yes
134
What does Haemophilus cause?
1. Epiglottitis
2. Meningitis
3. Otitis media
4. Pneumonia
135
Does H.influenza cause the flu?
NO - Influenza virus does.
136
What vaccine do we have for H.influenza?
Contains type B capsular polysaccharide (polyribosylribitol phosphate) conjugated to diphtheria toxoid or other protein.
Given between 2 and 18 months of age.
137
Does L.pneumophila gram stain good?
No, poor gram staining - Use silver stain.
138
Where does L.pneumophila grow?
Grow on charcoal yeast extract culture with iron and cysteine.
139
How is L.pneumophila detected clinically?
By the presence of antigen in urine.
140
How is L.pneumophila transmitted?
Aerosol transmission from environmental water source habitat (e.g., air conditioning systems, hot water tanks).
NO person-to-person contact.
141
What is the treatment for L.pneumophila?
Macrolide or quinolone.
142
What does L.pneumophila cause?
1. Legionnaire's disease
| 2. Pontiac fever
143
What happens in legionnaire's disease?
1. Severe pneumonia --> OFTEN UNILATERAL + LOBAR.
2. Fever
3. GI
4. CNS symptoms
- -> Common in SMOKERS + CHRONIC LUNG DISEASE.
144
What happens in Pontiac fever?
Mild flu-like syndrome.
145
What specific lab finding may L.pneumophila show?
HYPOnatremia.
146
Mention some general features of P.aeruginosa.
1. Aerobic + Motile
2. Non-lactose fermenting
3. Oxidase (+)
4. Produces pyocyanin (blue-green pigment)
5. Has grape-like odor.
147
What is the source for P.aeruginosa?
Water
148
What does P.aeruginosa produce?
1. Endotoxin --> Fever, shock
2. Exotoxin A (inactivates EF-2)
3. Phospholipase C --> Degrades cell membranes.
4. Pyocyanin --> Generate ROS.
149
With what is P.aeruginosa associated?
PSEUDOMONAS
1. Pneumonia, pyocyanin.
2. Sepsis.
3. Ecthyma gangrenosum.
4. UTIs.
5. Diabetes, drug use.
6. Osteomyelitis (eg puncture wounds).
7. Mucoid polysaccharide capsule.
8. Otitis externa (swimmer's ear).
9. Nosocomial infections (catheters, equipment).
10. A exotoxin.
11. Skin infections (hot tub folliculitis).
150
What is ecthyma gangrenosum?
1. Rapidly progressive, necrotic cutaneous lesions caused by Pseudomonas bacteremia.
2. Typically seen in immunocompomised patients.
151
What is the treatment for P.aeruginosa?
CAMPFIRE
1. Carbapenems.
2. Aminoglycosides.
3. Monobactams.
4. Polymyxins (eg polymyxin B, colistin).
5. Fluoroquinolones (eg ciprofloxacin, levofloxacin).
6. ThIRd- and 4th gen cephalosporins (eg ceftazidime, cefepime).
7. Extended-spectrum penicillins (eg piperacillin, ticarcillin).
152
What key facts should ring a bell for P.aeruginosa?
1. Water connection --> HOT TUB FOLLICULITIS.
2. Burn victims
3. Chronic pneumonia in CF patients associated with a biofilm.
153
Mention the major virulence factors of E.coli.
1. Fimbriae
2. K capsule
3. LPS endotoxin
154
What does fimbriae of E.coli do?
Cystitis - Pyelonephritis.
155
What does K capsule of E.coli do?
1. Pneumonia
| 2. Neonatal meningitis
156
What does LPS endotoxin of E.coli do?
Septic shock.
157
What is the toxin and mechanism of EIEC?
1. Microbe invades intestinal mucosa and causes necrosis and inflammation.
2. Clinical manifestations similar to Shigella.
158
What is the toxin and mechanism of ETEC?
1. Produces heat-labile and heat-stable enterotoxins.
2. NO inflammation or invasion.
- -> Traveler's diarrhea.
159
What is the toxin and mechanism of EPEC?
1. No toxin produced.
2. Adheres to apical surface.
3. Flattens villi.
4. Prevents absorption.
160
Who does EPEC usually hit?
Diarrhea, usually in children (Pediatrics).
161
What is the toxin and mechanism of EHEC?
1. O157:H7 is the most common serotype.
2. Produces Shiga-like toxin that causes HUS = Triad of anemia, thrombocytopenia, and acute renal failure DUE TO MICROTHROMBI forming on DAMAGED ENDOTHELIUM --> MECHANICAL HEMOLYSIS (schistocytes) + Platelet consumption + Decr. renal blood flow.
162
What is the mechanism of EHEC?
1. Microthrombi form on endothelium damaged by toxin --> Mechanical hemolysis (schistocytes formed) and DOWN renal blood flow.
2. Microthrombi consume platelets --> thrombocytopenia.
163
How do we distinguish EHEC from other E.coli?
Does NOT ferment sorbitol.
164
Mention some major features of K.pneumoniae?
1. Intestinal flora --> lobar pneumonia in alcoholics and diabetics when ASPIRATED.
2. Very mucoid colonies caused by abundant polysaccharide capsules.
3. Dark red "currant jelly" sputum (blood/mucus).
4. Also cause of nosocomial infection.
165
What are the 4A's of K.pneumoniae?
1. Aspiration pneumonia
2. Abscess in lungs and liver
3. Di-A-betics
4. Alcoholics.
166
Salmonella vs Shigella - Flagella?
Shigella has NO flagella.
167
Salmonella vs Shigella. Hematogenous spread?
Salmonella can spread hematogenously.
| Shigella only cell-to-cell transmission - NO hematogenous spread.
168
Salmonella vs Shigella. Reservoir?
Salmonella --> Many animals.
| Shigella --> Only humans and primates.
169
Salmonella vs Shigella. Hydrogen sulfide?
Salmonella --> Produces hydrogen sulfide (H2S).
| Shigella --> Does not produce hydrogen sulfide.
170
Salmonella vs Shigella. Antibiotics?
Salmonella --> May PROLONG fecal excretion.
| Shigella --> SHORTEN duration of fecal excretion.
171
Salmonella vs Shigella. PMNs or monocytes?
Salmonella --> Invades intestinal mucosa --> Monocytic response.
Shigella --> Invades intestinal mucosa --> PMN infiltration.
172
Salmonella vs Shigella. GI manifestations?
Salmonella --> Constipation, followed by diarrhea.
| Shigella --> Often causes bloody diarrhea (bacillary dysentery).
173
Salmonella vs Shigella. Lactose fermentation?
Both do NOT ferment lactose.
174
What does S.typhi cause?
Typhoid fever.
175
Where is S.typhi found?
Only in humans.
176
What characterizes S.typhi?
1. Rose spots on the abdomen.
2. Fever
3. Headache
4. Constipation --> Diarrhea
177
Where can S.typhi remain and cause a carrier state?
In the gallbladder.
178
What is a major cause of bloody diarrhea especially in children?
C.jejuni
179
How is C.jejuni transmitted?
1. Fecal-Oral through PERSON-TO-PERSON contact.
2. Via ingestion of undercooked, contaminated poultry or meat + unpasteurized milk.
3. Contact with INFECTED ANIMALS is also a risk factor.
180
What are the features of C.jejuni?
1. Comma or S-shaped WITH POLAR FLAGELLA.
2. 42C growth
3. Oxidase (+)
181
To what neurological condition is C.jejuni a common antecedent?
To Guillain-Barre syndrome and reactive arthritis.
182
What does V.cholera produce?
Rice-water diarrhea via enterotoxin that permanently activates Gs, incr. cAMP --> Sensitive to STOMACH ACID (acid labile).
==> Requires LARGE INOCULUM (high ID50) unless host has DECR. GASTRIC ACIDITY.
183
Mention some features of V.cholera?
1. Comma-shaped
2. Oxidase(+)
3. Grows in alkaline media
184
How is Y.enterocolitica transmitted?
Usually from:
1. Pet feces (e.g., puppies)
2. Contaminated milk
3. Pork
185
What can Y.enterocolitica cause?
Acute diarrhea or PSEUDOAPPENDICITIS --> RLQ pain due to MESENTERIC ADENITIS +/- TERMINAL ILEITIS.
186
What does Y.enterocolitica mimic?
Crohn disease or appendicitis.
187
Mention some features of H.pylori.
Curved, TERMINALLY FLAGELLATED, gram(-) rod that is:
1. Catalase (+).
2. Oxidase (+).
3. Urease (+).
188
Mention 2 ways to diagnose H.pylori.
1. Urea breath test
| 2. Fecal antigen test for diagnosis
189
Acidic or alkaline environment does H.pylori cause?
Alkaline --> Helps survive in acidic mucosa.
190
What is the MC initial therapy?
Triple therapy:
1. PPI
2. Clarithromycin
3. Either amoxicillin or metronidazole (Amoxi if ALCOHOLIC/ Metro if penicillin-allergy)
191
Mention the 3 spirochetes.
1. Borrelia
2. Leptospira
3. Treponema
==> Spiral-shaped bacteria with AXIAL FILAMENTS.
192
Of the 3 spirochetes, which one can be visualised?
Only Borrelia using aniline dyes (Wright or Giemsa stain) in light microscopy DUE TO SIZE.
193
How is Treponema visualized?
By
1. Dark-field microscopy.
2. Direct fluorescent antibody (DFA) microscopy.
194
Where is Leptospira interrogans found?
In water contaminated with animal urine.
195
Mention some features of leptospirosis.
1. Flu-like symptoms
2. Jaundice
3. Photophobia with CONJUNCTIVAL SUFFUSION (erythema without exudate).
4. MYALGIA, CLASSICALLY OF CALVES.
==> Prevalent among surfers and in tropics (Hawaii).
196
What is another name for Weil's disease?
Icterohemorrhagic leptospirosis.
197
What happens in Weil's disease?
Severe form with JAUNDICE + AZOTEMIA from liver and kidney dysfunction:
1. Fever.
2. Hemorrhage.
3. Anemia.
198
Ixodes tick carries which 3 microorganisms?
1. Borrelia burgdorferi
2. Babesia
3. Anaplasma spp.
199
What is the natural reservoir for B.burgdorferi?
The mouse.
200
Where is B.burgdurferi infection common?
In northeastern US.
201
Mention some initial symptoms of Lyme disease.
1. Erythema chronicum mirgans
2. Flu-like symptoms
3. +/- facial nerve palsy
202
Mention some later symptoms of Lyme disease.
1. Monoarthritis (large joints)
2. Migratory polyarthritis
3. Cardiac --> AV block
4. Neurologic --> Encephalopathy, facial nerve palsy, polyneuropathy.
203
What is the treatment for Lyme disease?
1. Doxycycline
| 2. Ceftriaxone
204
What is the treatment for Syphilis?
Penicillin G.
205
What is the presentation of 1o syphilis?
Localized disease presenting with painless chancre.
206
Can we visualize treponemes in fluid from chancre?
If available, use dark-field microscopy to visualize treponemes in fluid from chancre.
207
What is the serologic testing in 1o syphilis?
1. VDRL/RPR (non specific) (+) in 80%.
| 2. Confirm diagnosis with FTA-ABS (specific test).
208
What happens in 2o syphilis?
Disseminated disease with constitutional symptoms.
1. Maculopapular rash (palms and soles).
2. Condylomata lata = Smooth, moist, painless, wart-like white lesions on genitals.
3. Lymphadenopathy.
4. PATCHY HAIR LOSS.
==> Confirmable with dark-field microscopy.
209
What is the serologic testing during secondary syphilis?
VDRL/RPR (non specific)
| FTA-ABS is specific to confirm diagnosis.
210
Mention the main features of 3o syphilis.
1. Gummas (chronic granulomas)
2. Aortitis (vasa vasorum destruction)
3. Neurosyphilis (tabes dorsalis, "general paresis")
4. Argyll-Robertson pupil
211
Mention some signs of 3o syphilis.
1. Broad-based ataxia
2. (+) Romberg
3. Charcot joint
4. STROKE WITHOUT HTN
212
What should be tested for neurosyphilis?
Test CSF with VDRL + FTA-ABS + PCR.
213
Mention some features of congenital syphilis.
1. Saber shins
2. Saddle nose
3. CN VIII deafness
4. Hutchinson teeth
5. Mulberry molars
6. RHAGADES (linear scars at angle of mouth).
7. Snuffles (nasal discharge).
8. Short maxilla.
214
When does placental transmission of syphilis occur?
Typically after 1st trimester, so mother should be treated early in pregnancy.
215
What is the Argyll-Robertson pupil?
Constricts with accomodation but is not reactive to light.
| Associated with 3o syphilis.
216
How else do we call Argyll-Robertson pupil?
"Prostitute pupil" - accomodates but does not react.
217
Discuss the features of VDRL.
1. Detects nonspecific antibody that reacts with BEEF CARDIOLIPIN.
2. Inexpensive, widely available test for syphilis, quantitative, sensitive but not specific.
3. Many false positives.
218
False positives of VDRL include what?
1. Viral infection (mono, hep)
2. Some drugs
3. SLE
4. Leprosy.
5. Rheumatic fever.
219
What is the Jarisch-Herxheimer reaction?
Flu-like syndrome (fever, chills, headache, myalgia) after antibiotics are started - due to killed bacteria after releasing toxins.
220
Mention some main zoonotic bacteria.
1. Anaplasma spp
2. Bartonella spp
3. Borrelia burgdorferi
4. Borrelia recurrentis
5. Brucella spp
6. Campylobacter
7. Chlamydophila psittaci
8. Coxiella burnetti
9. Ehrlichia chaffeensis
10. Francisella tularensis
11. Leptospira spp
12. Mycobacterium leprae
13. Pasteurella multocida
14. Rickettsia prowazekii
15. Rickettsia rickettsii
16. Rickettsia typhi
17. Salmonella spp. (except S.typhi)
18. Yersinia pestis
221
What disease does Anaplasma spp cause?
Anaplasmosis
222
What is the transmission and source of Anaplasma?
Ixodes ticks (live on deer and mice).
223
What does Bartonella spp. cause?
1. Cat scratch disease
| 2. Bacillary angiomatosis
224
What disease does Borrelia recurrentis cause?
Relapsing fever.
225
How is relapsing fever transmitted?
Louse (recurrent due to variable surface antigens).
226
How is brucellosis transmitted?
Via unpasteurized dairy.
227
Mention what does Coxiella burnetti cause?
Q fever.
228
How is C.burnetti transmitted?
1. Aerosols of cattle
| 2. Sheep amniotic fluid
229
How is leprosy transmitted?
Humans with lepromatous leprosy - or armadillo (rare).
230
What does P.multocida cause?
1. Cellulitis
| 2. Osteomyelitis
231
What does R.prowazekii cause?
Epidemic typhus.
232
How is R.prowazekii transmitted?
HUMAN-TO-HUMAN via human body louse.
233
What does R.rickettsii cause?
Rocky mountain spotted fever.
234
How is R.rickettsii transmitted?
Dermacentor (DOG) ticks.
235
What does R.typhi cause?
Endemic typhus (NOT epidemic typhus).
236
How is R.typhi transmitted?
Via fleas.
237
Mention some features of G.vaginalis.
A pleomorphic, gram-VARIABLE rod involved in vaginosis.
238
What is the presentation of G.vaginalis infection?
Gray vaginal discharge with a FISHY smell - NON painful (vs. vaginitis).
239
Is G.vaginalis associated with sexual activity?
Yes - but NOT sexually transmitted.
240
What characterizes bacterial vaginosis?
Overgrowth of certain anaerobic bacteria in vagina.
241
What are the clue cells?
Seen in vaginosis:
| Vaginal epithelial cells covered with Gardnerella bacteria ==> Have STIPPLED appearance along OUTER MARGIN.
242
What is the treatment for G.vaginalis?
Metronidazole - or clindamycin.
243
Treatment for ALL Rickettsial diseases and vector-borne illness?
Doxycycline
244
Where is Rickettsia rickettsii endemic?
In the South Atlantic states, especially North Carolina ==> Despite its name, NOT IN THE ROCKY MOUNTAINS.
245
What characterizes the rash of R.rickettsii?
Typically starts at the wrists and ankles and then spreads to trunk, palms, and soles.
246
What does R.rickettsii cause?
Rocky Mountain spotted fever.
247
Classic triad of RM spotted fever?
1. Headache
2. Fever
3. Rash (vasculitis)
248
Palms and soles rash?
1. Coxsackievirus A infection (hand, foot, mouth disease)
2. RM spotted fever
3. 2o syphilis.
249
Cause and vector of endemic typhus?
R.typhi (fleas).
250
Cause and vector of epidemic typhus?
R.prowazekii (human body louse).
251
Feature of rash in typhus?
Starts centrally and spreads out, sparing palms and soles.
252
Cause and vector of Ehrlichiosis?
Ehrlichia (vector is tick).
253
Feature of Ehrlichiosis?
Monocytes with morulae (mulberry-like inclusions) in cytoplasm.
254
Cause and vector of anaplasmosis?
Anaplasma (tick).
255
Feature of anaplasma?
Granulocyte with morulae in cytoplasm.
256
Cause and vector of Q fever?
Coxiella burnetti (NO ARTHROPOD VECTOR).
257
Q fever transmission?
SPORES inhaled as aerosols from cattle/sheep amniotic fluid.
258
Q fever presentation?
As PNEUMONIA.
259
2 forms of Chlamydia?
1. Elementary body (small, dense) is "Enfectious" and Enters cell via Endocytosis --> Transforms into reticulate body.
2. Reticulate body Replicates in cell by fission --> Reorganizes into elementary bodies.
260
C.trachomatis causes what?
1. Reactive arthritis (Reiter syndrome)
2. Follicular conjunctivitis
3. Non gonococcal urethritis
4. PID
261
C.pneumoniae and C.psittaci cause what?
Atypical pneumonia - transmitted by aerosol.
262
What is the treatment for Chlamydiae?
1. Azithromycin (favored because one treatment).
| 2. Doxycycline
263
Special feature of C.psittaci?
Notable for an avian reservoir (PARROTS).
264
Lab diagnosis of Chlamydiae?
Cytoplasmic inclusions seen on Giemsa or fluorescent antibody - stained smear.
265
Unusual about the Chlamydial cell wall?
It lacks classic peptidoglycan (DUE TO REDUCED MURAMIC ACID) ==> Beta-lactam antibiotics LESS EFFECTIVE.
266
C.trachomatis types A, B, and C cause what?
Chronic infection - cause blindness due to follicular conjunctivitis in Africa.
ABC = Africa/Blindness/Chronic infection.
267
C.trachomatis types D-K cause what?
1. Urethritis
2. PID
3. Ectopic pregnancy
4. Neonatal pneumonia (staccato cough) WITH EOSINOPHILIA
5. Neonatal conjunctivitis
268
Chlamydia trachomatis types L1, L2, L3 cause what?
Lymphogranuloma venereum - small painless ulcers on genitals --> swollen, painful inguinal lymph nodes that ulcerate ("buboes").
269
Treatment for Lymphogranuloma venereum?
Doxycycline.
270
Classic cause of atypical pneumonia?
Mycoplasma pneumoniae.
271
Features of atypical pneumonia?
1. Insidious onset
2. Headache
3. Non productive cough
4. Patchy or diffuse interstitial infiltrate
5. X-ray looks WORSE than patient
6. High titer of cold agglutinins (IgM), which can agglutinate or lyse RBCs.
272
M.pneumoniae grows on?
Eaton agar - Contains sterols.
273
M.pneumoniae treatment?
1. Macrolide
2. Doxycycline
3. Fluoroquinolone
Penicillin INEFFECTIVE since Mycoplasma have no cell wall.
274
M.pneumoniae can be seen on Gram?
NO
275
Frequent outbreaks of M.pneumoniae?
Military recruits and prisons.
276
S.aureus - Protein A:
Virulence factor --> Binds Fc-IgG --> Inhibiting complement activation + Phagocytosis.
277
S.aureus - Commonly colonizes the?
NARES.
278
TSST presents as?
1. Fever.
2. Vomiting.
3. Rash.
4. Desquamation.
5. Shock.
6. End-organ failure.
==> Results in incr. AST + ALT + BILIRUBIN.
279
S.aureus has coagulase. Which means?
Forms fibrin clot around self --> Abscess.
280
Does S.pneumoniae have IgA protease?
YES.
281
Ehrlichiosis is transmitted via?
AMBLYOMMA - Lone Star ticks.
282
F.tularensis is transmitted via?
1. Ticks.
2. Rabbits.
3. Deer fly.
283
Yersinia pestis is transmitted via?
Fleas - Rats and prairie dogs are reservoirs.
284
Q fever is ...?
Queer - It has no rash or vector and its causative organism can survive outside its endospore form.
NOT in rickettsia genus, but closely related.
