Detection of aminoglycosidemodifying enzyme genes in extendedspectrum βlactamasesproducing strains of Escherichia coli FREE

Abstract:

ObjectiveTo detect aminoglycosidemodifying enzyme (AMEs) genes and drugresistance among extendedspectrum βlactamases (ESBLs)producing Escherichia coli (E.coli) in an area.MethodsESBLsproducing strains were detected by confirmatory test in 75 strains of E.coli; the susceptibility of 75 strains to 6 kinds of aminoglycosides (AGs) were detected by disk agar diffusion method; and the genotypes of AMEs genes were detected by PCR.ResultsIn 75 strains of E.coli, 37 (49.33% ) ESBLsproducing strains were confirmed. The resistant rates to AGs in ESBLsproducing strains were as follows: gentamycin 78.38%, streptomycin 75.68%, kanamycin 67.57%, tobramycin 64.86%, netilmicin 24.32%, and  amikacin 13.51%; Five kinds of AMEs genes were detected in ESBLsproducing strains and the main genes were aac(3)Ⅱ(64.86%) and aac(6′)Ⅰ(45.95%); the next were ant(3＂)Ⅰ（29.73%）, ant(2＂)Ⅰ（10.81%） and aac(3) Ⅰ（5.41%）, aac(6′)Ⅱ wasn’t  found. Except ant(2＂)Ⅰand aac(3)Ⅰ, the detection rates of the other 3 genes in ESBLs strains were higher than that of nonESBLs strains, and the carrying rates of 2 kinds of gene were also higher than nonESBLs strains (P<0.05). ConclusionThe carrying rates of  AMEs in ESBLsproducing E.coli are high in this area, and resistant rates to AGs are also high, the monitor should be intensified.

Key words:

Escherichia coli; extendedspectrum &beta;lactamases; aminoglycosidemodifying enzymes; genes; drug resistance, microbial