Ultrastructural aspects of infection with Treponema pallidum subspecies pertenue (Pariaman strain).

OBJECTIVE To study ultrastructural aspects of infection with Treponema pertenue (Pariaman strain), originating from West Sumatra, Indonesia. MATERIALS AND METHODS Biopsy material originating from skin lesions in ten young children suffering from early infectious yaws in Indonesia, and rabbit testicular tissue inoculated with T pertenue. Human skin as well as rabbit testicular tissue was examined by means of conventional electron microscopy. RESULTS In human skin, treponemes were found in interepidermal spaces in 5 out of 10 specimens. In two of five positive specimens, treponemes were also seen in the dermis. In one out of five specimens from rabbit testicular tissue a profusion of treponemes was found lying in the interstitial myxomatous tissue. Microorganisms showed no adhesion to fibroblasts. CONCLUSION This ultrastructural study of T pertenue demonstrated the scarcity and focal distribution of treponemes in tissue and did not reveal any morphological differences from the Gauthier strain of T pertenue. No differences from the ultrastructure of T pallidum were observed either.