Orchitis and Epididymitis in Koalas (Phascolarctos cinereus) Infected With Chlamydia pecorum.

Although Chlamydia causes disease of the urethra and prostate of male koalas, its impact on the testis and epididymis has not been examined. This study describes chronic-active and granulomatous orchitis and epididymitis with interstitial fibrosis associated with infection by Chlamydia pecorum in 2 of 18 adult male koalas being euthanized at a koala hospital, 8 of which also had chlamydial prostatitis. By immunohistochemistry and transmission electron microscopy, chlamydial inclusions were demonstrated within Sertoli cells directly associated with mild inflammation surrounding intact seminiferous and epididymal tubules, marked pyogranulomatous inflammation around disrupted tubules, replacement of tubules by interstitial fibrosis, and aspermia. The presence of C. pecorum but not Chlamydia pneumoniae was detected by quantitative polymerase chain reaction of formalin-fixed tissues of the left and right testes and right epididymis in 1 animal. This is the first report of orchitis and epididymitis in a koala infected with C. pecorum.