Molecular mechanism analysis of multidrug resistance (MDR)in Escherichia coli isolates

Background and Aim : Excessive use of antibiotics has made Escherichia coli resistant to a largenumber of antibiotics. The aim of this study was to identify the molecular mechanism of multidrugresistance (MDR) in E. coli isolated from Iranian eggs.Methods : The studied E. coli were collected from ۸۰۰ egg samples of different Iranian brands inwhich the resistance to tetracycline, nitrofurantoin and sulfonamide antibiotics had beenpreviously studied. From the collected samples, ۱۲ samples of multidrug-resistant E. coli (MDR)were selected, and the presence of resistance genes in the above strains was confirmed by usingspecific primers and PCR.Results : The results showed that not all strains had the resistance genes studied and the presenceof Tet b gene in ۵۰% of strains, Tet D in ۲۵% of strains, Tet e in ۳۵% of strains and Tet a,respectively. It was identified in ۴۵% of strains. Sul۱ gene was also observed in ۲۵% of strains,Sul۲ gene in ۵۰% of strains and Nfsa in ۳۰% of strains.Conclusion : The results showed that not all identified genes were expressed under the influenceof antibiotics, and only ۶۰% of them were expressed, so only the identification of the gene in PCRand its expression in Real Time PCR indicate the sources and mechanism of resistance. Is not. Thelack of expression of some genes and the lack of identification of some of the studied genesindicate the use of multidrug-resistant bacteria from other mechanisms in the development ofmultidrug resistance

کلیدواژه ها:

Escherichia coli ، Multidrug resistance ، Resistance genes ، Real Time PCR