Molecular Mechanisms of Macrolide Resistance of Mycoplasma pneumoniae

OBJECTIVE To investigate macrolide resistance and main molecular mechanisms in Mycoplasma pneumoniae. METHODS Thirty two throat swabs from children infected with M. pneumoniae were cultured by modified Hayflick medium. Antibiotic susceptibility test was used to screen the macrolide-resistant M. pneumoniae. The 23S rRNA gene sequences of the strains were determined with polymerase chain reaction and sequencing. RESULTS Nineteen strains were isolated from 32 throat swabs successfully.Fifteen strains were resistant to macrolide antibiotics according to the results of antibiotic susceptibility test. Once the strain was resistant to one of macrolide antibiotics,it would be resistant to the others. Sequencing results of the sensitive strains and the standard strain FH were completely same. Fifteen resistant strains presented A2063G point mutation in 23 SrRNA region Ⅴ, in which 2 examples showed the coexistence of the sensitive strain and the resistant strain. CONCLUSIONS Macrolide-resistant M. pneumoniae is common and serious at present. The antibiotic resistant isolate carries point mutations of the 23S rRNA region Ⅴ.