Induction of experimental Candida arthritis in rats.

Experimental arthritis, caused by intravenously (IV) introduced Candida albicans, has been induced for the first time in rats. Four-week-old Sprague-Dawley rats were inoculated IV with three different strains of C. albicans and observed for 4 weeks. Each of the three strains tested was able to produce arthritis. The incidence of Candida arthritis increased in a dose-dependent manner and was more than 90% at sublethal doses. Joints of the limbs were affected predominantly, and at higher doses arthritis was produced in multiple (four or five) joints in individual animals, showing it to be polyarthritis. C. albicans was recovered from all cultures of affected limb joints, which were excised 12, 19 and 28 days after inoculation and showed different stages and degrees of joint swelling. Results of histopathology and radiography showed that the Candida arthritis involved not only periarticular inflammation but also changes in joint bones. In particular, metaphyseal enlargement, punched-out lesions at the diaphysis and the appearance of osteoclasts were the most prominent changes in affected bones. These pathological features are compared with those of Candida arthritis in humans.