Quick Review Cards for Medical Laboratory Science

Anaerobic Gram-Positive Rodscontinued Clinical Microbiology Review 205

PATHOGENICITY GRAM STAIN OTHER

Clostridium tetani

Propionibacterium

Lactobacillus

Rare in U.S. because of DTaP

vaccine. Lab confirmation

rarely required.

Most common anaerobic GPR.

Catalase & indole pos.

Aerotolerant anaerobes. Grow

better under anaerobic condi-

tions. Colonies vary greatly.

May resemble S. viridans.

Catalase neg.

Causes tetanus. Deep wounds infected

with soil

Normal skin flora. Common contaminant

of blood cultures. Causes acne; infec-

tions associated with artificial joints,

catheters, shunts, artificial heart valves;

keratitis; bacteremia; endocarditis

Normal in mouth, GI tract. Predominant

flora of vagina during reproductive

years. Produces lactic acid, maintains

vaginal pH. Absence in vagina predis-

poses to bacterial vaginosis & yeast in-

fections. Rare cause of endocarditis,

septicemia in immunocompromised

GPR with swollen terminal

spores. “Drumstick.” “Tennis

racquet.” Becomes gram neg

after 24 hr.

Club-shaped, pleomorphic

GPR. Diphtheroid-like.

Pleomorphic, long, thin, non–

spore-forming GPR, often in

chains. Chains of rods in THIO.