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Flashcards in Micro Deck (127)
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91

Slow lactose fermenter

Citrobacter
Serratia

92

H2S production on TSI agar

Salmonella
Proteus

93

Neisseria

VPN agar (Thayer Martin)
Metabolize glucose
Produce IgA protease
Gonococci: IC (within neutrophils), no vaccine (Ag variation of pilus), Fitz-Hugh-Curtis Syndrome
Meningococci: polysaccharide capsule, maltose fermenter, vaccine, Waterhouse-Friderichsen syndrome

94

Haemophilus influenze

IgA protease
Chocolate agar - V (NAD+), X (hematin)

95

Most common cause of mucosal infections (otitis media, conjunctivitis, bronchitis)

Nontypeable (unencapsulated) H. flu

96

Cause of epiglottitis
- drooling, inspiratory stridor

H. flu

97

Hib vaccine

Type b capsular polysaccharide + PRP conjugated to diptheria toxoid
- Given between 2 and 18 mo

98

Bordatella pertussis

Pertussis toxin (disables Gi)
Tracheal cytotoxin (cleaves cilia epi of resp tract)
Whooping cough
Vaccine (Tdap, DTap)
Lymphocytic infiltrate from immune resopnse

99

Legionella pneumophila

Gram stains poorly - use silver stain
Charcoal yeast extract medium with iron and cysteine
Dx: Ag in urine
HYPONATREMIA
Water sources (AC)
Pneumonia + diarrhea + hyponatremia

100

Legionnaires' Disease
- Legionella pneumophila

Sever pneumonia, fever, GI, and CNS sx
Smokers, chronic lung DZ

101

Pontiac Fever
- Legionella pneumophila

Mild flu-like syndrome

102

Pseudomonas aeruginosa

Non-lactose fermenting
Pyocyanin (blue-green)
Grape-like odor
Endotoxin (fever, shock)
Exotoxin A (inactivates EF-2)
Phospholipase C (degrades cell membranes)
Pyocanin (generates ROS)
Mucoid polysaccharide capsule --> biofilm formation

103

Malignant otitis externa

Pseudomonas
Can spread to mastoid, temporal bones
Increased risk in elderly, IC, DM

104

Ostemyelitis in diabetics and IV drug users

Pseudomonas

105

Most common cause of respiratory failure in CF patients

Pseudomonas
Mucoid polysaccharide capsule --> biofilm formation

106

Burn patients

Pseudomonas

107

Hot tub folliculitis

Pseudomonas

108

Ecythema gangrenosum

Pseudomonas
Rapidly progressive necrotic cutaneous lesion
Seen in IC

109

Proteus mirabilis

Swarming motility
Urease + --> staghorn struvite stones
Fish odor

110

Helicobacter pylori

Flagellated
Catalase +, oxidase +, urease +
Dx: urea breath test, fecal antigen test
Produces ammonia --> alkaline environment
Colonizes stomach antrum
Risk of gastric adenocarcinoma and MALT lymphoma

111

Leptospira interrogans

Spirochete
Water contaminated with animal urine

112

Leptospirosis
- Leptospira interrogans

Flue-like sx, myalgias (CALVES), jaundice, photphobia with conjunctival suffusion (erythema w/o exudate)
Surfers and in tropics (Hawaii)

113

Weil Disease (Icterohemorrhagic Leptospirosis)
- Leptospira interrogans

severe form with jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, anemia

114

Borrelia burdorferi

Lyme DZ
Vector: Ixodes deer tick
Reservoir: mouse
NE US
Erythema migrans
AV block
Bells palsy
Encephalopathy
Chronic arthritis

115

Treponema pallidum

Painless chancre
Dark field microscopy
VDRL +
Maculpapular rash on palms and soles
Condyloma lata
VDRL/RPR+, confirm with FTA-ABS
Gummas
Aortitis (vasa vasorum destruction)
Neurosyphilis (tabes dorsalis)
Argyll Robertson pupil
Broad-based ataxia, + Romberg, Charcot joints

116

Congenital Syphilis

rhagades, snuffles, saddle nose, notched teeth, mulberry molars, short maxilla, saber shins, CNIII deafness

117

VDRL false positives

Viral infection
Drugs
Rheumatic fever
Lupus and leprosy

118

Anaplasma spp.

Anaplasmosis
Ixodes tick (live on deer and mice)

119

Bartonella spp.

Immunocompetent --> Cat scratch DZ --> fever, LAD (stellate granulomas w/ central necrosis)
IC --> bacillary angiomatosis --> raised red vascular lesions

120

Borrelia recurrentis

Relapsing fever
Louse (variable surface Ag)