Abstract: Objective To determine the susceptibility of Ureaplasma urealyticum(Uu) to 7 kinds of antimicrobial agents,to compare the result with tetracycline resistant determinant(tetM) detected by PCR technique.Methods Forty two Uu isolates were subcultured for 3 generations and then cultured with drugs with a series of concentrations from 64μg/ml～0.06μg/ml.MIC was determined when the color of culture medium did not change from yellow to red in 72h culture.The tetM determinant in the isolates was detected by PCR with specific primers,and PCR products were digested by Taq 1 restrictive endonuclease.Results The antimicrobial activity of tetracyclines to Uu was low.No Uu strains resistant simultaneously to 3 groups of antibiotics were found in the study.Detection rate of tetM was 71.4% with correspondent digested fragments.Conclusion The susceptibility of Uu isolates to tetracycline group was low,but higher to macrolides and fluoroquinolones.Uu strains carrying tetM determinant might become drug resistant ones which should be monitored and followed up with MIC determination.

Key words: Ureaplasma urealyticum, Microbial sensitivity tests