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.