Investigation of Ureaplasma urealyticum biovars and their relationship with antimicrobial resistance

Purpose: To develop Taqman fluorescence quantitative polymerase chain reaction (PCR) method for investigating the characteristics of the distributions of Ureaplasma urealyticum (UU) biovars and to explore the relationship between UU biovars and antimicrobial resistance. Materials and Methods: By the method of culture, Ureaplasma species were detected. Taqman fluorescence quantitative PCR for detecting UU biovars were developed and UU clinical isolates were detected to distinguish biovars. The broth micro-dilution susceptibility testing methods were used to determine UU susceptibility. Results: By Taqman PCR method, UU biovars was successfully detected. Of 126 samples, biovar 1 was found in 73 (57.94%). There was a statistical difference between genital-urinary tract infection group and asymptomatic group (P<0.05). In the region, UU biovar 1 to 9 kinds of agents kept higher susceptibility rates, but biovar 2 maintained higher susceptibility rates only to tetracyclines. Compared with biovar 1, UU biovar 2 resistance rates to 7 kinds of agents were higher (P<0.05). Conclusions: (1) Our new established Taqman PCR method is a useful tool for screening UU biovars. (2) UU biovar 1 predominated in asymptomatic population; whereas in genital-urinary tract infection population UU biovar 2 had a higher proportion. (3) The characteristics of drug resistance were different between UU biovars. Overall, both two biovars remained higher susceptibility rates to tetracyclines. A majority of biovor 1 strains were sensitive to macrolides and quinolones; while only a small number of biovar 2 strains kept sensitive to roxithromycin and quinolones, a large proportion of biovar 2 strains were found in intermediate ranges.