Abstract:

Abstract:Objective To analyze the distribution and genotypes of 16S rRNA methylase genes in gram-negative bacilli isolated from hospitals in Changchun area and to provide a reasonable basis for the application of aminoglycosides. Methods  Amikacin-resistant and gentamicin-resistant strains were screened using agar dilution tests,and 16S rRNA methylase genes in gram-negative bacilli isolates were amplified by PCR and genotypes of 16S rRNA methylases (armA,rmtB,rmtA,rmtC,rmtD and npmA) were analyzed using gene sequencing.Results The resistant rates of 116 clinical isolates of gram-negative bacilli to amikacin and gentamicin were 42.2% and 75.0%,respectively. Fifty of 116 isolates were positive for 16S rRNA methylase genes（43.1%，50/116). The common genotypes of 16S rRNA methylase were armA and rmtB (12.1% and 31.0%);however,the rmtA,rmtC,rmtD and npmA genes were not found.Conclusion The genotypes of 16S rRNA methylase in gram-negative bacilli in Changchun area are armA and rmtB which  is one of the reasons to induce high resistance to aminoglycosides.

Key words: gram-negative bacilli, 16S rRNA methylase, antibiotic-resistance