microbiology exam 3

Nonfermenters

Generally oxidase positive. Long thin gram negative bacilli or coccobacilli

Pseudomonas aeruginosa

GNR! Infections in CF patients, skin rashes (hot tub). Metallic sheen. Pyoverdin and pyocyanin. Mostly beta hemolytic

P. fluorescens + putida

Contaminated equipment. Pyoverdin only.

P. stutzeri

Wrinkled, leathery colonies.

Acinetobacter

Sticks to ventilators, humidifiers, catheters.

S. maltophilia

Contaminates blood drawing equipment. Oxidase negative.

Burkholderia cepacia

Pneumonia in CF and CGD patients. Oxidase negative, oxidizes lots of stuff. Mallei causes glanders

B. pseudomallei

Possible bioterrorism. Overwhelming septicemia.

Vibrio species

Cholera. 10 species in human infections, found in all water types. Facultative anaerobic. Small GNR, curved in gram stains. Positive string test. Grows on TCBS

V. parahaemolyticus

1-8% NaCl, raw oysters/seafood. Self limiting. Summer diarrhea. Green on TCBS

Vibrio Culture

BAP, MAC (nonfermenting), TCBS. Cholerae is yellow.

Aeromonas

Straight GNR. In fresh water. Glucose fermenting, oxidase + indole positive. Gastroenteritis.

Plesiomonas

GNR. Fresh and mixed water. Glucose fermenting. Susceptible to vibriostat disks. Gastroenteritis from undercooked seafood or tainted water. On IBB it appears white or pink.

Campylobacter

Seagull wing GNR. Oxidase + catalase positive. Darting motility. From animals, water, dairy or poultry.

Campylobacter Culture

Brucella agar w 10% sheep blood. Capnophilic! 5-10% O2, 10% CO2

Neisseria

Aerobic, Capnophilic GN diplococci. Usual flora of upper respiratory + genitourinary tracts.

N. gonorrhoeae

GN Diplococci. Acute pyogenic infection. 95% of males show symptoms, 50% of females. Arthritis if disseminated. CHOC or MTM

N. meningitidis

Carried in nasopharynx. Highly fatal, transmitted by respiratory secretions. Stiff neck. Penicillin to treat! BAP + CHOC 35C 3-5% CO2. GN diplococci

M. catarrhalis

Normal Flora of respiratory tract. DNAse positive, scoots on plate.

Haemophilus Species

GN coccobacilli or rods. 10 involved in human infections. Needs X (hemin) and V (NAD) factors to grow. Para only needs V. Satellitism, dies quickly

H. influenzae

Epiglottitis, tracheitis, cellulitis. Grows on CHOC

Haemophilus morphology

Translucent, moist, smooth convex colonies. Mousy or bleach odor.

Quad Plate

I, II, III are for growth (G or NG). IV is for beta hemolysis

HACEK Group

GN bacilli. Increased CO2 (5-10%). Endocarditis. Usual Flora in the mouth.

Eikenella corrodens

Bite wounds. Needs X factor and CO2. Bleach like odor, colonies pitting agar

Kingella

Beta hemolytic. In kids less than 5, bone and joints

Pasturella multocida

Grows on BAP + CHOC. Dog and cat bites + scratches.

Legionella

BCYE agar. Urine for antigen testing. L-cysteine is needed to grow. In water