Wax D of Mycobacterium tuberculosis induced osteomyelitis accompanied by reactive bone formation in Buffalo rats

A suspension of heat-killed Mycobacterium tuberculosis in liquid paraffin h as been reported to induce foot swelling accompanied by new bone formation in Buffalo (BUF) rats, which are low responders to the induction of adjuvan t arthritis. In the present study, we found that wax D, a mycobacterial cel l wall peptidoglycan fragment-arabinogalactan-mycolic acid complex, was an effective component of this bacterium for the induction of osteomyelitis ac companied by reactive bone formation in BUF rats. Chronic inflammation was produced in BUF rats by a single subcutaneous injection of wax D suspended in liquid paraffin. Other Mycobacterium species and Gordona bronchialis wer e also capable of inducing this reaction. Other bacterial cells including t he acid-fast bacteria Nocardia and Rhodococcus, purified cell walls and pep tidoglycans from Lactobacillus plantarum, wax C, cord factor, arabinogalact an and mycolic acid prepared from M. tuberculosis were inactive in this res pect. In addition, when wax D was administered as a water in-oil emulsion ( Freund's type adjuvant), bone formation scarcely occurred in BUF rats. In F isher (F344) and Wistar rats, both of which are responder strains to adjuva nt arthritis, wax D in liquid paraffin did not induce bone formation. (C) 1 998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.