[Studies on bone infections induced by non-spore-forming anaerobic bacteria--clinical investigation and an experimental osteomyelitis (author's transl)].

Little information is available in Japan regarding the clinical and experimental bone infections induced by non-spore-forming anaerobic bacteria. 1) The detection of anaerobic bacteria using the pre-reduced anaerobically sterilized GAM medium was carried out on 15 patients admitted to the Department of Orthopedic Surgery, Gifu University Hospital due to bone infections in the past 2 years (1977-1978). Anaerobic bacteria were isolated and identified in 7 patients out of the 15 (46.7%). Complications of various kinds of neurological disease, such as caudal nerve injury, spinal cord tumor and other neuropathies, were also detected in these patients. In addition, the complication of diabetes mellitus was found in 2 patients. All patients had open wounds, decubitus on sacral region or intractable ulcer of foot infected with both anaerobes and aerobes. II) The attempt to make an experimental osteomyelitis was undertaken using non-spore-forming anaerobic bacteria B. fragilis. A) B. fragilis (10(5) CFU) adsorbed on a 10 mm No. 8 silk thread was inserted into the medullary cavity of the left tibia of Sprague Dawley rat through trocar equipped with a mandrine. Experimental osteomyelitis was shown to be quite similar to that of human by X-ray and pathohistological examinations. By using this procedure, it is possible not only to produce an osteomyelitis in 100 per cent, but also to observe it for 16 weeks without any loss of test rats. B) Injection of B. fragilis (10(6) CFU) with 5% sodium morrhuate into the medullary cavity of the rat tibia through a microsyringe did not induce osteomyelitis produced by S. aureus or P. aeruginosa. On the other hand, sodium morrhuate was observed to have an inhibitory effect on the growth of B. fragilis in vitro.