Molecular detection of class 1, 2 and 3 integrons and some antimicrobial resistance genes in Infantis isolates.

BACKGROUND AND OBJECTIVES

Multidrug resistant strains have been observed around the world in recent years. Many mechanisms contribute to the spread of antimicrobial resistance genes. This study aimed at determining the distribution and transmission of class 1, 2 and 3 integrons among MDR isolates collected from a selection of chicken broilers in the north of Iran.

MATERIALS AND METHODS

PCR assays were used to detect genes for tetracyclines ( and ), chloramphenicol ( and ), and streptomycin (). Also, the presence of class 1, 2 and 3 integrons in all MDR isolates was evaluated using specific primers for the integrase genes of integrons and .

RESULTS

Class 1, 2 and 3 integrons were present in 36%, 42% and 4% of the MDR isolates, respectively. Out of the tetracyclines resistant isolates, 47 (100%) and 5 (10.6%) carried genes, respectively, while no isolate was positive for the gene. All 36 chloramphenicol-resistant strains carried and genes. Nine (18%) Infantis isolates harbored the gene, conferring resistance to sterptomycin.

CONCLUSION

This study found a high frequency of antimicrobial resistance genes among isolates; therefore, management strategies are needed to prevent food-borne diseases caused by MDR from food supplies.