Gram negative bacteria Flashcards
1
Q
Bacteria associated with HUS
A
EHEC-O157:H7 and Shigella
2
Q
Bacteria associated with Aspiration pneumonia and lung Abscesses with currant-jelly sputum
A
Klebsiella
3
Q
Bacteria associated that grow pink colonies on McConkey agar, lactose fermenters, multi-drug resistant and cause nosocomial pneumonia & UTIs
A
Klebsiella, Serratia, Enterobacter
4
Q
Acid-labile gram negative rod, non-lactose fermenter, oxidase negative causing pea-soup diarrhea
A
Salmonella typhi
5
Q
Treatment for Salmonella typhi
A
Ceftriaxone or fluoroquinolones
6
Q
Virulence factor for S. typhi
A
Endotoxin and Vi capsule
7
Q
Virulence factor for non-typhoidal Salmonella
A
Type III secretion system
8
Q
Shigella mechanism of spread
A
M-cell to M-cell in Peyer patches using rocket propulsion via actin filaments
9
Q
Gram negative rod, non-lactose fermenter, oxidase negative with green colonies on Hektoen agar
A
Shigella
10
Q
Salmonella grows what color colonies
A
Black colonies on Hektoen agar
11
Q
Salmonella requirement for infectivity
A
Large inoculum since acid labile
12
Q
Key feature of Shigella to cause infectivity
A
Invasion of M cells in Peyer patches
13
Q
Sexually active male with asymmetric joint pain
A
N. gonorrhoeae infection
14
Q
Gram-negative diplococci that is maltose positive
A
N. meningitidis
15
Q
Futz-Hugh-Curtis syndrome is associated with what organism
A
N. gonorrhoeae
16
Q
N. meningitidis close contacts require…
A
Prophylaxis treatment with either Rifampin, Ciprofloxacin, or ceftriaxone
17
Q
N. gonorrhoeae infections require treatment with…
A
Ceftriaxone + azithromycin or doxycycline for possible chlamydial infection
18
Q
Complications of N. gonorrhoeae infection in women
A
PID causing infertility and/or Fitz-Hugh-Curtis syndrome
19
Q
Adrenal insufficiency, fever, DIC, shock are what type of syndrome
A
Waterhouse-Friderichsen syndrome
20
Q
What type of immune deficiency predisposes to Neisseria infections
A
Complement deficiency C5-C9
21
Q
What type of patients are predisposed to increased risk of meningococcal infections
A
Sickle-cell and asplenic patients are at increased risk of infections from encapsulated organisms
22
Q
Source of resistance in N. gonorrhoeae
A
Pili have antigenic variation
23
Q
Which vaccine type is not available for meningococcal infections
A
Type B
24
Q
Special media needed to grow Neisseria bacteria
A
Thayer-Martin (VPN) chocolate agar
25
What allows Neisseria ability to invade
IgA protease permits attachment to mucosal surfaces by cleaving IgA
26
What gives Neisseria its strong endotoxin activity
Lipooligosaccharide (LOS)
27
E. coli virulence factor causing neonatal meningitis
K-capsule
28
E. coli virulence factor causing pneumonia
K-capsule
29
K-capsule virulence factor in E coli causes...
Pneumonia and neonatal meningitis
30
Main cause of UTIs in sexually active women
E. coli
31
E. coli virulence factor that causes cystitis and pyelonephritis
Fimbriae
32
E. coli endotoxin that causes septic shock
LPS
33
E. coli species that does not ferment sorbitol
EHEC
34
E. coli species that causes traveler's diarrhea
ETEC
35
What causes HUS in EHEC infection
Shiga-like toxin inhibits 60s subunit of ribosome
36
E. coli that typically causes diarrhea in children
EPEC
37
E. coli that causes diarrhea similar to Shigella
EIEC
38
Mechanism of ETEC for causing traveler's diarrhea
Heat Labile toxin increase cAMP
| Heat Stable toxin increases cGMP
39
Gram negative encapsulated rod that looks like safety pin on bipolar staining
Yersinia enterocolitica
40
Mode of transmission for Yersinia pestis
Fleas from rats or prairie dogs
41
Mode of transmission for Yersinia enterocolitica
Pet feces (puppies) contaminated milk or pork
42
Bacteria with safety pin appearance that causes bloody diarrhea
Yersinia enterocolitica
43
Toddler with right lower quadrant pain and bloody diarrhea with pet puppy has what infection
Yersinia enterocolitica
44
Recent camper to desert has buboes was infected how
Flea bites (Y. pestis)
45
Treatment for Y. pestis
Streptomycin with tetracycline
46
Treatment for Y. enterocolitica
Streptomycin with tetracycline
47
Complications of gram negative, oxidase positive, S-shaped rod that grows at 42 degrees C
Reactive arthritis, bloody diarrhea, and ascending paralysis
48
Source of infection for gram negative, oxidase positive, S-shaped rod that grows at 42 degrees C
Fecal-oral via person-person or eating contaminated poultry or contact with infected animals
49
Complication of coma-shaped, gram negative, oxidase positive bacteria that grows in alkaline media
Profuse rice-water diarrhea
50
Mechanism of cholera toxin
Permanent activation of Gs increases cAMP
51
Patient on antacids is at risk of infection from this gram-negative, comma-shaped, oxidase positive organism
Vibrio cholerae
52
Oral fluid therapy in cholera infection stimulates what
Na/Glucose transporter
53
Triple positive motile gram negative curved rod is found in what section of the stomach
Antrum
54
Risk factors for triple positive motile gram negative curved rod
PUD, gastric adenocarcinoma, MALT lymphoma
55
Typical area of gastritis and peptic ulcers in a triple positive motile gram negative curved rod
Duodenum
56
Treatment for H. pylori
Amoxicillin, Clarithromycin, and PPI
57
Alternative antibiotic in H. pylori if allergic to amoxicillin
Metronidazole
58
Diagnostic test for H. pylori
Urea breath test or fecal antigen test
59
Gram-negative rod associated with hot tub folliculitis
Pseudomonas
60
Most common cause of respiratory failure in CF patients
Pseudomonas infection
61
Blue-green pigment that produces a grape-like odor
Pyocyanin
62
Function of pyocyanin in Pseudomonas
Generates ROS
63
At risk groups for Pseudomonas induced osteomyelitis
Diabetes and IV drug users
64
Nosocomial infections associated with Pseudomonas
UTIs and pneumonia
65
Skin complication of oxidase and catalase positive organism that produces a blue-green pigment
Ecthyma gangrenosum and hot tub folliculitis
66
Pseudomonas virulence factor that inactivates EF-2
Exotoxin A
67
Effect of inactivating EF-2
Decreased protein synthesis by inhibiting 60s ribosomal subunit
68
Treatment of choice for Pseudomonas
Piperacillin with beta-lactamase inhibitor
69
Treatment choice for UTI caused by Pseudomonas
Fluoroquinolones
70
Treatment for severe gram negative infections like Pseudomonas
Aminoglycosides with beta-lactamase inhibitor
71
Urease positive bacteria with swarming motility when plated that forms staghorn calculi
Proteus
72
Urease positive organism with fishy odor that causes UTI
Proteus
73
Treatment of choice for UTI caused by Proteus
Sulfonamides
74
Mechanism of infection for Bordetella pertussis
Filamentous hemaglutinin attach to respiratory epithelium and releases pertussis toxin and tracheal cytotoxin
75
Pertussis toxin mechanism of action
Ribosylates Gi activating AC which increases cAMP leading to impaired phagocytosis
76
Tracheal cytotoxin mechanism of action
Damages ciliated cells of tracheal epithelium
77
Stages of pertussis infection
Catarrhal phase, Paroxysmal phase, and Convalescent phase
78
Phase of pertussis infection characterized by low grade fevers and coryza (stuffy nose)
Catarrhal phase
79
Phase of pertussis infection characterized by paroxysms of intense cough followed by inspiratory "whooping cough" and possible vomiting
Paroxysmal phase
80
Phase of pertussis infection characterized by gradual recovery of chronic cough
Convalescent phase
81
Pertussis characteristics
Gram-negative aerobic, coccobacillus that causes distinctive whooping cough
82
Bacteria characterized as having "100 days cough"
Bordetella pertussis
83
Best way to prevent Bordetella pertussis
Acellular vaccine
84
Treatment for pertussis infection
Early treatment with macrolides
85
Small gram negative coccobacillary rod grown on chocolate agar that contains NAD+ and hematin for growth
Haemophilus influenzae
86
What is required to grow H. influenzae when plated
Chocolate agar with factors V (NAD+) and X (hematin)
87
Presents with cherry-red epiglottis, inspiratory stridor and drooling in children
Haemophilus influenzae
88
The most common type of H. influenzae strain that causes otitis media, conjunctivitis, and bronchitis
Nontypeable (Unencapsulated) strains
89
Reason H. influenzae can grow with S. aureus
Provides NAD+ (factor V) through hemolysis of RBCs
90
H. influenzae vaccine contains what strain
Type b capsular polysaccharide conjugated to diphtheria toxoid or other protein given between 2 - 18 months
91
Common complications of H. influenzae
Epiglottitis, Meningitis, Otitis media, Pneumonia
92
What group of patients are at increased risk of Haemophilus infections
Sickle cell patients or asplenic patients
93
Treatment for H. influenzae systemic disease or meningitis
Ceftriaxone
94
What is given to close contacts in Haemophilus infections
Rifampin
95
Haemophilus mucosal infection treatment
Amoxicillin +/- clavulanate
96
Gram negative, oxidase positive rod, not visualized well with gram stain presents with disorientation and hyponatremia in smoker
Legionella
97
Grown on charcoal yeast extract medium with iron and cysteine
Legionella
98
Mild flu like syndrome characterized by fever and malaise in gram-negative rod not visualized well with gram stain
Pontiac fever
99
Atypical pneumonia more common in smokers with patchy unilobar infiltrate on chest x-ray associated with hyponatremia and presents with confusion and high fever
Legionnaire's disease
100
Pneumonia, hyponatremia, and diarrhea
Legionnaire's disease
101
Used for rapid diagnosis of Legionnaire's disease
Urine antigen test
102
Complication of Bartonella infection in immunocompromised
Bacillary angiomatosis
103
Complication of Bartonella infection in immunocompetent
Axillary lymphadenopathy
104
Cause of Bartonella infection
Cat scratch
105
Treatment for Bartonella infection
Doxycycline +/- macrolides
106
Organism causing undulant fevers and anorexia after consuming unpasteurized dairy
Brucella
107
Treatment for Brucella infection
Doxycycline or tetracycline and rifampin to block oxidative burst
108
Chronic complication of Brucella infection
Hepatosplenomegaly and osteomyelitis
109
Vector that causes tularemia
Dermacenter tick commonly from rabbit
110
Facultative intracellular, gram negative coccobacilli spread via dermacenter tick that causes painful ulcer
Francisella tularensis
111
Reservoir for dermacenter tick that causes tularemia
Rabbit
112
Recovery from tularemia infection depends on what?
Cell-mediated immunity
113
Complication of tularemia
Granulomas with caseating necrosis in reticuloendothelial cells
114
Treatment for tularemia
Aminoglycosides (streptomycin)
115
Cause of cellulitis and osteomyelitis commonly from dog or cat bites
Pasteurella multocida
116
Characteristics of Pasteurella multocida
Catalase and oxidase positive, gram negative, bipolar, encapsulated bacteria that grows on 5% sheep's blood
117
Treatment for Pasteurella
Penicillin + beta-lactamase inhibitor (clavulanate)
118
Recent traveler to New England presents with bull's eye rash contracted what disease?
Lyme disease
119
Vector for Borrelia burgdorferi
Ixodes tick
120
Main reservoir for Ixodes tick
White footed mouse
121
Obligatory host for Ixodes tick
Deer
122
Incidental host for Ixodes tick
Humans
123
In addition to Lyme disease, what else does Ixodes tick transmit
Erlichiosis and babesiosis
124
Cardiac complication of Lyme disease
Heart block
125
Patient initially presented with bull's eye rash now has bilateral facial paralysis recently travelled to...
The Northeastern United States
126
Late stage complications of Lyme disease
Heart block, bilateral Bell's palsy, encephalopathy and migratory arthritis
127
Stains used to visualize spirochetes
Giemsa and Wright stain
128
Borrelia burgdorferi has what shape
Spirochete
129
Treatment for Lyme disease
Doxycycline; Ceftriaxone if severe
130
Patient who recently travelled to Hawaii and presents with fever and conjunctivitis without pus most likely came in contact with...
water contaminated with animal urine
131
Complications of question mark-shaped spirochete commonly found in urine contaminated water
Renal dysfunction and jaundice from liver damage
132
Most likely organism in a water-skier who presents with azotemia, high creatinine levels and fever
Leptospira
133
Spirochete causing painless chancre is best visualized how?
Dark-field microscopy
134
Screening test for syphilis
VDRL
135
Patients with positive screening test for syphilis need what test to confirm diagnosis?
FTA-ABS
136
Characteristics of secondary syphilis
Maculopapular rash on palms and soles of feet weeks to months after infection, Condyloma latum
137
Patient who presents with gummas after initial presentation of painless chancre is at risk for developing what cardiac complications
Aortitis
138
Mechanism of aortitis in secondary syphilis
Destruction of vasa vasorum
139
Complication of treating syphilis with antibiotics
Jarisch-Herxheimer reaction (fever, chills, headache, myalgias) from killed spirochetes releasing toxins
140
Organism associated with leading cause of blindness worldwide
Chlamydiae trachomatis A-C
141
Complication in neonates born to mother's with Chlamydiae
Neonatal pneumonia with eosinophilia and neonatal conjunctivitis
142
Complications of Chlamydiae trachomatis in women
PID and ectopic pregnancy
143
Those infected with Chlamydiae are often co-infected with...
N. gonorrhoeae
144
Treatment for Chlamydiae includes...
Azithromycin or doxycycline and ceftriaxone (gonorrhea)
145
Most common bacterial STI in the U.S.
Chlamydiae
146
Obligate intracellular organism that cannot make its own ATP
Chlamydiae
147
Infectious form of Chlamydiae
Elementary body
148
Replicative form of Chlamydiae
Reticulate body
149
The lack of cell wall in Chlamydiae renders what class of antibiotics ineffective
Beta-lactam antibiotics
150
What strain of Chlamydiae causes atypical pneumonia
C. pneumonia and C. psittaci
151
C. psittaci is transmitted how?
Parrots
152
Reticulate bodies are visualized how?
Giemsa or fluorescent antibody stain
153
Chlamydiae is diagnosed how?
PCR or Nucleic Acid Amplification Test (NAAT)
154
Q fever is caused by...
Coxiella burnetti
155
Coxiella burnetti is transmitted how?
Inhalation of spores in animal droppings or animal amniotic fluid
156
Farm worker with fever, cough and headache is at risk for developing what complication
Hepatitis (Q-fever)
157
Q fever presents as...
Cough, fever, headache, pneumonia and hepatitis
158
Sexually active girl who presents with gray vaginal discharge with fishy smell will have what type of cells under microscopy
Vaginal epithelial cells covered with gram-variable rods (Clue cells)
159
Used to diagnose Gardnerella vaginalis
KOH prep (enhances fishy odor)
160
Treatment for Gardnerella vaginalis
Metronidazole
161
Mycoplasma pneumoniae typically affects what population group
Young adults < 30 years (18-40) or military recruits
162
What provides stability to membrane in Mycoplasma pneumoniae
Sterols
163
Presentation of Mycoplasma pneumoniae
Insidious onset, headache, nonproductive cough, and patchy or diffuse interstitial infiltrate on x-ray
164
Walking pneumonia is typically caused by what organism
Mycoplasma pneumoniae
165
Test to confirm Mycoplasma pneumoniae infection
IgM cold agglutinin test; causes RBCs to agglutinate or lyse
166
What is used to culture Mycoplasma pneumoniae
Eaton agar
167
What class of antibiotics are ineffective in treating Mycoplasma pneumoniae
Penicillins since no cell wall
168
Treatment for Mycoplasma pneumoniae
Macrolides, doxycycline or fluoroquinolones
169
Weakly gram negative, coccobacilli, obligate intracellular organism unable to produce NAD+ and CoA
Rickettsia
170
Used to diagnose Rickettsial infections
Weil-Felix agglutination test
171
Treatment for Rickettsial infections
Doxycycline
172
Presentation for Rickettsia prowazekii
Myalgias, arthralgias, pneumonia and encephalitis
173
R. prowazekii causes what disease
Epidemic typhus
174
Epidemic typhus is spread by what vector
Human body louse
175
Epidemic typhus causes what type of rash
Rash starts centrally and spreads out sparing hands, feet and head
176
What two organism cause typhus
R. typhi - endemic typhus
| R. prowazekii - epidemic typhus
177
Patient recently returned from a trip now presents with rash on wrist that spreads to trunk, palms and soles. What region of the U.S. did he visit?
South Atlantic states
178
Patient visited his daughter in North Carolina and 2 weeks later develops a rash that starts at wrist and ankles and spreads centrally. What organism caused this?
Dermacenter tick
179
Symptoms of Rocky Mountain spotted fever
Headache, fever, myalgia and centrally spreading rash
