In vitroIsolation ofTreponema pallidumsubsp.pallidumfrom Fresh and Frozen Needle Aspirates of Primary Experimental Syphilis Lesions

ABSTRACT Isolation of Treponema pallidum subsp. pallidum strains still relies on rabbit intratesticular inoculation of clinical samples. Here, we report an alternative isolation approach based on the inoculation of fresh and frozen needle aspirates of primary experimental lesions into culture plates suitable for in vitro propagation of the syphilis agent. SUMMARY We report on a rabbit-free in vitro isolation approach for syphilis strains that can be easily adapted to clinical specimens.