Integron-Mediated Multidrug and Quinolone Resistance in Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae

Background: despite intensive care and treatment strategies, the development of antibiotic resistance to empirical drugs is concerning. objectives: theaimof this studywasto characterize extended-spectrum-β-lactamase (esbl)-producing escherichia coliandklebsiella pneumoniae for integron-mediated quinolone resistance and multidrug resistance (mdr). methods: in this cross-sectional study, 71 e. coli and 63 k. pneumoniae clinical isolates underwent antibiotic susceptibility testing with the kirby-bauer method, followed by esbl phenotypic screening with the combination disc method. the isolates were then genotypically characterized with pcr for the presence of integrons and the gyra, parc, bla_ctx-m-3, bla_tem, and bla_shv genes. resistance to antibiotics was confirmed by sequencing. results: k. pneumoniae was a potent esbl producer (71.4%) in comparison to e. coli (57.7%). the predominant esbl genotypes in e. coli and k. pneumoniae confirmed by sequencing were bla_ctx-m-15 (67.60%) and bla_shv-1 (80.95%), respectively. imipenem was the only antibiotic active against the esbl-producing isolates. approximately 54% of the isolates exhibited mdr patterns. mdr was more frequently related to the presence of bla_ctx-m-3 in comparison to other genotypes. the prevalence of class 1 integrons was 15 (45.4%) and 22 (66.6%) of the e. coli and k. pneumonia isolates, respectively. within the esbl group, a class 1 genetic element was associated with the bla_ctx-m-3 genotype in e. coli (36.58%) and k. pneumoniae (51.11%). overall, almost half of the esbl producers, irrespective of genus, were simultaneously resistant to quinolones. the simultaneous presence of class 1 and 2 integrons in quinolone-resistant isolates was the most frequent observation. conclusions: the high prevalence of multidrug and esbl-mediated resistance is a therapeutic concern. the co-emergence of esbls and quinolone resistance in e. coli and k. pneumoniae suggests the preservation of the power of antibiotics in the face of the antibiotic-resistance crisis.