Antibiotic resistance genes in farm animal slaughterhouse wastes in Al-Dewanyiah province, Iraq

Abstract

Environment represents as a reservoir for emerging and disseminating of antibiotic resistance genes. Slaughterhouse waste is one of the important sources of antibiotic resistance genes (ARGs) even after treatment processes. This study was conducted to evaluate role of farm animal slaughterhouse in dissemination of antibiotics resistance in Al-Dewanyiah, Iraq. A total of eighty samples were collected from the central farm animal slaughterhouse. The detection was based on three mobile genetic elements and nine antibiotic resistance genes. The results showed that tetO & tetK are common resistance genes in the tested samples with great relative abundance 60%. While, MGE transposon (Tn3) was detected in 80% of the tested samples. Gene encoding resistance to quinolone, methicillin, aminoglycoside and β-lactamases were also detected in the tested samples. Presence of three class of integrons as a mobile genetic were tested and the results of type 1 recorded high abundance (P>0.05) as a compare with type 2 and type 3 integrons. Furthermore, concentrations of ARGs and MGEs per gram of sample were tested using qPCR. The genes encoding for tetracycline resistance and transposon (Tn3) were found in higher concentration (P>0.05) (copy number) per gram of slaughterhouse sediments comparing with the selected genes. Quantification of ARGs and MGEs in the slaughterhouse wastes indicates that those wastes represent as a hotspot for dissemination of antibiotic resistance to the environment. Low darning and no treatment for slaughterhouse wastes might increase abundance of ARGs and resistant bacteria in the natural environment.