[Comparison of 3 culture methods for genital mycoplasmas].

BACKGROUND: To compare and evaluate two commercial methods for Mycoplasma hominis and Ureaplasma urealyticum with the isolation in agar A7 medium. METHOD: One hundred and twenty three vaginal and cervical swabs in women prostitutes, and urethral swabs in men, were studied for Mycoplasma hominis and Ureaplasma urealyticum isolation in agar A7 medium (BioMérieux; France), Mycoplasma IST (BioMérieux, France) and MycoFast ALL-IN (Unipath, U.K.). RESULTS: Of all 123 samples studied, it was isolated 24 Mycoplasma hominis (19.5%) and 56 Ureaplasma urealyticum (45.5%) in agar A7. The sensitivity was 100% for Mycoplasma hominis and Ureaplasma urealyticum in Mycoplasma IST versus 29.2% and 50% in MycoFast ALL-IN, both respectively. Specificity was lower for Ureaplasma urealyticum (59.7%) in Mycoplasma IST than in MycoFast ALL-IN (100%). It was found a tetracycline resistance of 15% and 12.5% for Ureaplasma urealyticum and Mycoplasma hominis, both respectively. CONCLUSIONS: The use of commercial methods permits to count the genital mycoplasmas, being Mycoplasma IST better than MycoFast ALL-IN for Mycoplasma hominis isolation. Both methods have limitations for Ureaplasma urealyticum and they require the use of agar A7. Mycoplasma IST could be a good method to survey tetracycline resistance.