title: Enhancement of growth of aerobic, anaerobic, and facultative bacteria in mixed infections with anaerobic and facultative gram-positive cocci.
abstract: The potential for mutual enhancement of growth of seven strains of anaerobic and facultative gram-positive cocci (AFGPC), seven aerobic and facultative organisms, and two Bacteroides spp. commonly isolated with AFGPC in mixed infection was evaluated. Enhancement was studied by measuring the relative increase in the colony-forming units of the two bacterial components inducing subcutaneous abscesses in mice. Of the 56 combinations, AFGPC were enhanced in 6 and inhibited in 1. The aerobic and facultative bacteria were enhanced in 32 of the 42 combinations and depressed in none. The Bacteroides spp. were enhanced in 12 of the 14 combinations and suppressed in none. The organisms uniformly enhanced by AFGPC were Group A streptococci, Pseudomonas aeruginosa, and Bacteroides fragilis (all seven instances), followed by Escherichia coli (six of seven instances), Bacteroides asaccharolyticus and Klebsiella pneumoniae (five instances each), Staphylococcus aureus (four instances), and Group D streptococci (three instances). It is apparent that in mixed infection with AFGPC the rate of growth of Bacteroides spp. and facultative and aerobic bacteria is enhanced much more than the rate of growth of AFGPC.
mesh_terms: D000038:Abscess / Q000382:microbiology; D000818:Animals; D001419:Bacteria / Q000254:growth & development*; D001420:Bacteria, Aerobic / Q000254:growth & development; D001421:Bacteria, Anaerobic / Q000254:growth & development; D001424:Bacterial Infections / Q000382:microbiology*; D001431:Bacteriological Techniques; D006094:Gram-Positive Bacteria / Q000254:growth & development; D006801:Humans; D008297:Male; D051379:Mice; D012107:Research Design; D013559:Symbiosis