In-Vitro Activities of Tetracyclines, Macrolides, Fluoroquinolones and Clindamycin against Mycoplasma hominis and Ureaplasma ssp. isolated in Germany over 20 years

ABSTRACT

Based on the increase of resistance of genital mycoplasmas to effective antibacterials with worldwide significant differences, we compared the susceptibilities of a wide range of clinical isolates over several years. The susceptibilities of 469 M. hominis (n=290) and ureaplasma (n=179) isolates, collected during 1983 and 1989-2004, to eleven antibacterials were determined by agar dilution method. Additionally, the results from the routine testing (2005-2008) were considered. Doxycycline was the most active tetracycline against ureaplasmas and M. hominis (MIC₉₀s, 1 and 8 mg/L, respectively). Significantly more M. hominis isolates (∼10-13%) were resistant to tetracyclines compared to ureaplasmas (∼1-3%). Ofloxacin was effective against both species (>95% susceptibility). Ciprofloxacin was moderately active against M. hominis and less active against ureaplasmas (70.3 and 35.2% susceptibility). Clarithromycin and josamycin were the most potent macrolides (MIC₉₀, 0.5 mg/L) against ureaplasmas. Erythromycin exhibited the lowest activity (MIC₉₀, 8 mg/L) like clindamycin, non-active against ureaplasmas, but the most potent drug against M. hominis. Cross-resistance was found between the antibacterials with the higher level between tetracyclines (53-93%), macrolides and erythromycin (70-100%) and between erythromycin and ciprofloxacin (43-55%). M. hominis has become more resistant to tetracyclines and fluoroquinolones over the years 1989-2004, with no changes in 2005-2008. Ureaplasmas have become more resistant to CIP in 1997-2004, showing high resistance to ERY over the time period (1989-2008). Doxycycline is still the drug of first-choice for ureaplasmal infections and may be used by co-infection with M. hominis. Finally, this study gives recommendation for alternatives in cases of resistance towards the commonly used antimicrobials.