Variability of the Chlamydia trachomatis omp1 gene detected in samples from men tested in male-only saunas in Melbourne, Australia

A recent screening program in Melbourne, Victoria, Australia, has shown that Chlamydia trachomatis is an important infection among men who frequent male-only saunas. To evaluate the C. trachomatis isolates circulating in local saunas, the C. trachomatis-positive samples collected during the program underwent amplification and sequencing of the omp1 gene, and the corresponding serovars were deduced. Forty-seven C. trachomatis-positive samples collected (from October 2001 to September 2002) from 39 men were evaluated. The deduced serovars found, in descending order of prevalence, were D, G, and J; and serovars B, E, F, and H were each found in single samples. The seven different serovars identified in the study sample indicate that local saunas are a reservoir of multiple C. trachomatis strains, possibly maintained by the introduction of new patrons or regular patrons who have been exposed to C. trachomatis elsewhere. No significant genetic variants were found, as most variable positions were silent and were detected only in single samples.