The role of encapsulation in the pathogenesis of anaerobic gram-positive cocci.
The pathogenicity of 22 anaerobic and facultative Gram-positive cocci (AFGPC) was investigated by inoculating them into mice and determining their ability to cause subcutaneous abscesses. Only 11 heavily encapsulated isolates (greater than 50% of the cells were encapsulated) induced abscesses. However, when the other 11 isolates were injected with Bacteroides sp. or facultative and aerobic bacteria, abscesses were formed in 8 of the 11 combinations. The AFGPC recovered from the mixed infections contained many encapsulated cells. Encapsulation also occurred in cocci injected with capsular material or with Formalin-killed cells of Klebsiella pneumoniae or capsule-positive Bacteroides sp. After acquisition of capsules, these strains could induce abscesses on reinoculation in mice.
D000038:Abscess / Q000382:microbiology; D000818:Animals; D001421:Bacteria, Anaerobic / Q000472:pathogenicity* / Q000648:ultrastructure; D006094:Gram-Positive Bacteria / Q000472:pathogenicity* / Q000648:ultrastructure; D008297:Male; D051379:Mice