Characterization of Escherichia coli strains isolated from geese by detection of integron-mediated antimicrobial resistance. (December 2022) - Sun, Wanying
Highlights: Drug resistance of pathogenic Escherichia coli of goose origin and its correlation with the resistance of the integron-gene cassette it carries, as detected by drug sensitivity tests. Multi-drug resistance was evident in the strains tested, with high resistance levels to ampicillin, amoxicillin, imipenem, tetracycline, and doxycycline. Empty integrons and class I integrons that allow the widespread spread of drug resistance were detected in the trial. Gene cassettes are closely associated with the development of a considerable number of drug resistance with integrons. ABSTRACT: Objectives: Current research shows that the resistance of Escherichia coli (E. coli) is mainly related to integron gene cassettes. To assess the resistance of E. coli of goose origin and the carriage of its integron genes in four farms in Heilongjiang Province, antibiotic resistance phenotypes and the presence of various types of integrons were investigated. Methods: In this study, test strains were sampled and isolated from the farms, and 109 test strains were tested for drug sensitivity of 15 different antimicrobial drugs by the Kb disc diffusion method. Polymerase chain reaction was used to detect E. coli in three types of integrase genes ( intI1, intI2, and intI3 ) and for sequencing analysis of the class I integron gene cassette. Results: Susceptibility test results show that more than 70% of tested strains exhibit resistant phenotypes to ampicillin, amoxicillin, imipenem, tetracycline, and doxycycline. The detection rate of class I integrons was 68.91%, while class II integrons and class III integrons were not detected. The detection rate of class I integrin gene cassette was 7.42%. Sequence analysis showed that strains carried different integron gene cassettes: dfrA17-aadA5, dfrA1-aadA1, dfrA27-arr-3, and aminoglycoside 3′'-nucleotidyltransferase. Conclusions: Results suggest that the detection rate of class I integrons is highly correlated with their drug resistance. Class I integrons provide a valuable guide to studying the spread and the expression of resistance genes and thus finding effective measures to prevent bacterial resistance.