A preliminary study on the resistance mechanism of Ureaplasma urealyticum to erythromycin / 中华皮肤科杂志

ABSTRACT

Objective To study the resistance mechanism of Ureaplasma urealyticum (Uu) to erythromycin.Methods The susceptibility of 73 clinical isolates of Uu to erythromycin was evaluated by using broth dilution techniques. PCR and DNA sequencing were carried out to screen hot spot mutations at the variable region of 23S ribosomal RNA in erythromycin-resistant strains of Uu. Moreover, erythromycin resistance methylase genes (ermA, ermB, ermC) and efflux pump genes (mefA/E, msrA/B, mreA) were screened by using PCR with specific primers. Results There were 35 (47.95%) resistant Uu strains out of the 73 isolates, and the minimal inhibitory concentration varied from 8 to 32 mg/L among these resistant strains. The ermB gene was detected in 19 (54.29%) resistant strains, and msrA/B gene in 9 (25.71%) resistant strains. Two resistant strains harbored both ermB gene and msrA/B gene. No mutation at 23S ribosomal RNA or amplification of resistance-associated genes was noted in sensitive or reference strains of Uu. Conclusion The ermB and msrA/B genes may be responsible for the erythromycin resistance of Uu.