[Evaluation of aminoglycoside resistance phenotypes and genotyping of acetyltransferase in Escherichia coli].

OBJECTIVE: To investigate the prevalence of aminoglycoside resistance and genotyping of acetyltransferase in Escherichia coli. METHODS: Resistance phenotypes to 12 antibiotics of 44 Escherichia coli isolates were analyzed using agar dilution method and 3 aminoglycoside resistance genes aac(3)-I, II and aac(6')-I were determined by PCR method. RESULTS: In 44 clinical isolates, the occurrence of ESBLs was 45.45%, resistance rates were discrepant for amikacin (18.18%), gentamicin (56.82%) and tobramycin (61.36%), the prevalence of phenotype TG (tobramycin and gentamicin) indicative of aac(3)-II production and TGA (tobramycin, gentamicin and amikacin) indicative of aac(6')-I production were 36.36% and 18.18%, respectively. The most common aminoglycoside resistance genotype of acetyltransferase was aac(3)-II (52.27%) and aac(6')-I was lower (29.55%), but no aac(3)-I was detected. CONCLUSION: At least 2 acetyltransferase genes exist in this area i.e. aac(3)-II and aac(6')-I.