Isolation of Mycoplasma genitalium from patients with urogenital infections: first report from the Latin-American region

Isolation of Mycoplasma genitalium from clinical specimens remains difficult. We describe a modified culture system based on Vero cells grown in medium 199 with 2% foetal bovine serum (FBS). The culture system was evaluated using early passage M. genitalium strains M6271 and M6311 with growth monitoring by quantitative TaqMan PCR. Eleven endocervical swabs and one male urethral swab positive by 16S rRNA and MgPa1-3 PCRs were quantified and inoculated into Vero cell suspensions in medium 199 supplemented with 2% FBS and antibiotics. Cultures were incubated for 14 days. Cell passages and growth monitoring by TaqMan PCR were performed until the growth of M. genitalium reached ≥10(6) geq/mL. Confirmation of the new M. genitalium strains was performed by sequencing a 281 bp fragment of mgpB. The growth of Mycoplasma genitalium strains was recorded for all urogenital swab specimens in the modified cell-culture system. Growth of M. genitalium was obtained within 2 months and yielded 12 M. genitalium strains with all 11 isolates from females of an identical, but unique genotype. To our knowledge, this is the first successful isolation of M. genitalium in the Latin-American region. The use of Vero cell culture in 199 medium with 2% FBS is a method comparable to the Ultroser G culture system for isolation of M. genitalium. Genotyping of clinical samples and isolates should be performed to document the absence of cross-contamination.