Prevalence of Aminoglycoside Resistance Genes in Enterococcus Strains in Kermanshah, Iran

Background: this study aimed to investigate the occurrence of aminoglycoside resistance and the prevalence of the resistance- modifying enzyme genes, ant(3”)-iii, ant(6’)-ia, aac(6')-ie- aph(2”)-ia, and aph(2’)-id, in enterococcus strains isolated in kermanshah province, west of iran.methods: in this cross-sectional study, 108 enterococcal isolates from urine, wound, blood, and cerebrospinal fluid samples were collected. the enterococcus species were recognized by standard phenotypic/biochemical tests. the antimicrobial resistance forms were detected using a disc diffusion method. polymerase chain reaction was designed to identify aminoglycoside resistance genes, including ant(3”)-iii, ant(6’)-ia, aac(6')-ie-aph(2”)-ia, and aph(2’)-id.results: totally, 108 strains with a final diagnosis of enterococcus were extracted from 84 (77.8%) urine, 14 (13%) wound, 6 (5.6%) blood, and 4 (3.7%) cerebrospinal fluid samples. among the 108 enterococcus specimens, 94 (87%) cases were enterococcus faecalis and 14 (13%) were enterococcus faecium. the highest frequency of resistance was observed for erythromycin (88.9%), while the lowest was found for streptomycin (44.4%). the frequency of high-level gentamicin resistance was 42.2%. among the identified specimens, 42.6% contained the aac(6')- ie-aph(2”)-i gene, 20.4% contained the ant(6’)-ia gene, and 15.7% contained the ant(3”)-iii gene. a significant correlation was found between phenotypic gentamicin resistance and the presence of the aminoglycoside resistance genes (p<0.05). conclusion: this study showed the high resistance of enterococcus strains isolated from hospital samples. compared with the previous studies, the strains isolated in our study showed a higher percentage of resistance to aminoglycosides.