Anaerobic bacteria in jaw cysts.

The bacterial flora of the fluid content of 54 cysts of the jaws with a history suggestive of infection were studied. Forty-seven of these cysts were subsequently considered to be infected and from 78.6% of these, positive bacterial cultures were developed. Of the bacterial strains 89.2% were anaerobes and only 10.8% were pure aerobes or facultative anaerobes. Microorganisms isolated from each specimen ranged from 1 to 4 bacterial species. Gram positive anaerobic cocci revealed to be the most frequent bacterial group (36.9%), followed by Gram negative anaerobic rods (29.8%), Gram positive aerobic cocci being the third most common group of the isolates (19.0%). Antibiotic sensitivity tests of the isolated anaerobic cocci to a group of nine antibiotics revealed chloramphenicol and minocycline as the most effective. All anaerobic rods tested, were sensitive to metronidazole.