Resistance of ESBLs producing Escherichia coli to aminoglycoside antibiotics and detection of inactive enzyme genes

Objective: To investigate the resistance of extended spectrum β-lactamase(ESBLs) producing Escherichia coli to aminoglycoside antibiotics and genotyping of aminoglycoside inactive enzymes.Methods: Kirby-Bauer(K-B) method was employed to detect the resistance of 38 strains of ESBLs producing Escherichia coli to 4 aminoglycoside antibiotics(amikacin netihmicin,gentamicin and tobramycin).And 6 kinds of aminoglycoside inactive enzymessaac(3) -Ⅰ,aac(3) -Ⅱ,aac(6') -Ⅱ,aac(6') -Ⅰb-cr,ant(2'') -Ⅰ and ant(3'') -Ⅰ were determined by polymerase chain reaction(PCR).Results: The resistance rates of the 38 ESBLs producing Escherichia coil to the 4 kinds of aminoglycoside antibiotics were 28.9%,39.5%,76.3% and 76.3% respectively;the positive rates of aminoglycoside inactive enzyme genes of aac(3) -Ⅱ,aac(6') -Ib-cr,ant(3'') -Ⅰ and ant(2'') -Ⅰ were 63.2%,36.8%,10.5% and 2.6%,respectively;aac(3) -Ⅰ,aac(6') -Ⅱ were not found in these strains.Conclusions: The aminoglycoside inactive enzyme genes producing Escherichia coil are predominantly aac(3) -Ⅱ and aac(6') -Ib-cr AMEs genes.The aminoglycoside resistance profiles are related to AMEs gene patterns.More attention should be paid to drug resistance mechanism in management of clinical infections.