NBME Microbiology Exam Verified Questions/Answer

NBME Microbiology Exam Verified Questions/Answer
Catalase positives - Pseudomonas
Listeria
Aspergillus
Candida
E. coli
S. aureus
Serratia

Urease positives - Cryptococcus
H. pylori
Proteus
Ureaplasma
Nocardia
Klebsiella
S. epidermidis
S. saprophyticus

Yellow sulfur granules - Actinomyces israelii

Yellow pigment colonies - S. aureus

Blue-green pigment colonies - Pseudomonas aeruginosa

Red pigment colonies - Serratia marcescens

Binds Fc region of immunoglobulin - Protein A (S. aureus)

IgA protease expressed by - S. pneumoniae
H. influenzae
Neisseria

M protein expressed by - Group A Strep (pyogenes)

Diphtheria toxin causes - pharyngitis with pseudomembranes, and bull
neck

Shiga toxin causes - dysentery and hemolytic uremic syndrome

Shiga like toxin causes - hemolytic uremic syndrome

, Shiga like toxin expressed by - EHEC

Heat labile toxin expressed by - ETEC

Heat stable toxin expressed by - ETEC

Heat labile toxin moa - inc cAMP

Heat stable toxin moa - inc cGMP

Edema factor expressed by - Bacillus anthracis

Cholera toxin moa - permanently activates Gs

Rice water diarrhea - Vibrio cholerae

Pertussis toxin moa - disables Gi, impairs phagocytosis

Whooping cough caused by - Bordatella pertussis

Tetanus toxin moa - prevents release of GABA and glycine

Botulinum toxin moa - prevents ACh release

Alpha toxin expressed by - Clostridium perfringens

Gas gangrene caused by - Clostridium perfringens

Streptolysin O expressed by - S. pyogenes

Streptolysin O effect - lyses RBC

Positive ASO titer diagnostic for - rheumatic fever

Toxic Shock syndrome caused by - S. aureus,
S. pyogenes

Toxic Shock Syndrome Toxin (TSST-1) expressed by - S. aureus