The Study of Resistance to Aminoglycosides among Escherichia coli Strains Isolated from Different Water Sources

Antibiotic resistance rates especially against aminoglycosides in E. coli are rapidly rising. Antibiotic-resistant bacteria such as E. coli released from humans and animals into water sources may act as a donor of antimicrobial resistance genes for other pathogenic E. coli strains. The aim of this study was to investigate the prevalence of antibiotic resistance to aminoglycosides among E. coli strains isolated from different water sources in Alborz province.
The study included all E. coli strains isolated from different surface water sources in Alborz province in 2013. Bacterial strains were isolated, detected and identified by standard microbiological and biochemical tests. To screen the aminoglycosid-resistant isolates, the antimicrobial susceptibility testing was determined according to Kirby Baur assay. Susceptibility patterns of isolates were determined to lincomycin, rifampin, streptomycin, gentamicin, tobramycin, kanamycin, clindamycin, amikacin and azithromycin.
One hundred E. coli strains were isolated from water sources and examined in this study. Antibiotic susceptibility testing showed that 95.7, 94.7, 93.7, 28.1, 27.08, 10.4, 7.4, 6.6 and 4.1 percentages of the isolates were resistant to clindamycin, lincomycin, rifampin, streptomycin, gentamicin, tobramycin, kanamycin, amikacin and azithromycin respectively.
This study reflects an increasing prevalence of aminoglycosides resistant E. coli strains circulating in water sources. Dissemination of these resistant strains is of particular concern in water sources.