High distribution of 16S rRNA methylase genes rmtB and armA among Enterobacter cloacae strains isolated from an Ahvaz teaching hospital, Iran.
The emergence of 16S rRNA methylase genes encoded on plasmids confers high-level aminoglycoside resistance (HLAR). This study aimed to investigate the prevalence of 16S rRNA methylases among Enterobacter cloacae strains isolated from an Ahvaz teaching hospital, Iran. A total of 68 E. cloacae clinical strains were collected between November 2017 and September 2018. The MICs of aminoglycosides were assessed using the agar dilution method. The presence of 16S rRNA methylase genes, including armA, rmtA to rmtH, and nmpA was evaluated by PCR. The transferability of 16S rRNA methylase-harboring plasmids was evaluated by conjugation assay. The genetic diversity of all isolates was evaluated by ERIC-PCR. The armA and rmtB genes were the only 16S rRNA methylase genes detected in this study (29 out of 68 isolates; 42.64%). The transferability by conjugation was observed in 23 rmtB or/and armA positive donors. HLAR phenotype was in 33 of 68 strains. Ten clonal types were obtained by ERIC-PCR and significant associations (p < 0.05) were between the clone types and aminoglycoside susceptibility, as well as with profile of the 16S rRNA methylase genes. In conclusion, both horizontal transfer and clonal spread are responsible for dissemination of the rmtB and armA genes among E. cloacae strains.
['Amin|Mansour|M|', 'Mehdipour|Golshan|G|', 'Navidifar|Tahereh|T|']
D000617:Aminoglycosides D000900:Anti-Bacterial Agents D003227:Conjugation, Genetic D024881:Drug Resistance, Bacterial D016972:Enterobacter cloacae D004756:Enterobacteriaceae Infections D014644:Genetic Variation D005838:Genotype D060005:Genotyping Techniques D006784:Hospitals, Teaching D006801:Humans D007492:Iran D008826:Microbial Sensitivity Tests D017720:Molecular Epidemiology D010957:Plasmids D016133:Polymerase Chain Reaction D015995:Prevalence D012359:tRNA Methyltransferases
16S rRNA methylase ERIC-PCR