Introduction: Mycoplasma genitalium (Mg) is a sexually transmitted pathogen associated with non-gonococcal urethritis, cervicitis, pelvic inflammatory disease and infertility. Since Mg is very difficult to culture from clinical samples, typing strains relies on the variability of a 281pb fragment of the mgpB gene, encoding the adhesin MgPa. Here we present the analysis of the sequences of 14 Mg strains detected from clinical samples between 2013 and 2016.

Methods This was a retrospective study in which we analysed all the Mg positive samples diagnosed in our laboratory in the period 2013–2016. Detection of Mg was performed by in-house PCR assay using primers previously described; the resulting 281pb fragments from Mg positive specimens were sequenced by Sanger method. Sequences were analysed and compared with all currently available clinical sequences.

Results A total of 452 genital samples were tested, from which 17 resulted positive for Mg. Of these, only 14 could be successfully sequenced. The analysis of sequenced samples revealed eight different types of sequences. When compared with published data, four sequence types (representing a total of 10 different strains) resulted identical to previously reported genotypes. The relative frequencies of these genotypes were: 29% genotype 1 (4/14), 29% genotype 2 (4/14), 7% genotype 4 (1/14), and 7% genotype 21 (1/14, 7%). The remaining sequences showed between one and four nucleotide differences compared to already existing variants; in three of them this resulted in amino acid changes.

Conclusion This is the first study to characterise the molecular types of Mg among clinical strains in our country. Through comparative sequence analysis, eight different mgpB region variants were identified, four of which have not been report in the past. This reveals the presence of new sequence variants in Argentina. Further studies are needed to evaluate the association between these sequence variants and clinical/epidemiological data that could help us to understand the dynamics of Mg infection in the region.