The rapid growth of multidrug-resistant is a global public health concern. The aim of this study was to detect integrons, colistin and resistance genes in and . A total of 63 isolates of ( = 18) and ( = 45) from fecal samples of layers and rats at chicken farms were screened for antibiotic resistant genes. Conventional PCR was performed for the detection of integrons (classes 1, 2, and 3), colistin (-1-5) and β-lactamase (, , , , , , , and ) resistant genes. Of these isolates, 77% and 27% of and harboured the 4 encoded gene for colistin, respectively. The prevalence of class 1 integrons for and was 100% for each serovar, while for class 2 integrons of and it was 49% and 33% respectively, while class 3 integron genes was not detected. Our study also detected high levels of encoding genes ( gene), namely , , and from both and . This, to our knowledge, is the first report of resistance gene detection in serovars in South Africa. This study also highlights the importance of controlling rats at poultry farms in order to reduce the risk of transmission of antibiotic resistance to chickens and eventually to humans.