Abstract

Salmonella enterica is considered a zoonotic pathogen that acquires antibiotic resistance in livestock. In the current study, a total of 18 Salmonella enterica isolates recovered from cloacal swabs of diseased and freshly dead broilers were serotyped and assessed for susceptibility to clinically important antibiotics. The multi-resistant isolates were examined for the presence of the antiseptic resistance genes including quaternary ammonium (qacEΔ1) and class 1 integron-integrase (intI1) by PCR. The results of serotyping of 18 Salmonella isolates indicated that five isolates belonged to Salmonella Typhimurium, four isolates belonged to each of Salmonella Kentucky and Salmonella Enteritidis, three isolates belonged to Salmonella Molade and one isolate belonged to each of Salmonella Inganda and Salmonella Larochelle. Fifteen Salmonella isolates (83.3%) were multi-resistant to at least three antibiotics with a multidrug resistance index value of 0.473. All of the intI1-positive strains carried qacEΔ1, confirming that the qacEΔ1 gene is linked to the integrons. The study concluded that the presence of the qacEΔ1 resistance gene and class 1 integrase in multi-drug resistant Salmonella strains might be contributed to co-resistance or cross-resistance mechanisms.