Detection of Class 1 and 2 Integrons, β-Lactamase Genes and Molecular Characterization of Sulfonamide Resistance in Escherichia coli Isolates Recovered from Poultry in China

This study aimed to detect integrons, β-lactamase genes and to characterize sulfonamide resistant e. coli isolates recovered from poultry. all the isolates (n=38) were investigated for the presence of integrons, sul1, sul2, sul3 genes by pcr. class 1 and class 2 integron were present in 79 and 16%, respectively. additional resistance gene cassette embedded in class 1 and 2 integrons was aada1, aada5, dfra17 and aada22, dfra, respectively. sul1 and sul2 genes were detected in 42.1 and 60.5% isolates, respectively. both the sul1 and sul2 were present in 23% isolates. however, sul3 gene was not present. co-existence of sul1 and sul2 with class 1 integrons was found in 28.9 and 60.5% of class 1 integron positive isolates, respectively. whereas, a less percentage of isolates showed a low level of resistance to β-lactams and no blactx-m, blashv and blatem was found. the mic results showed resistance to sulfadiazine and sulfamethoxazole-trimethoprim in 88 and 84% isolates, resistance to penicillin, ampicillin, amoxicillin was 52, 52 and 44%, respectively. chloramphenicol, florfenicol, tetracycline and gentamycin resistance was found in 51, 5, 42 and 67% isolates, respectively. this study revealed high frequency of class 1 integrons, sul genes among poultry e. coli isolates, therefore further spread of sul genes and integrons is predictable.