Role of heavy metals pollution on emergence of antibiotic co-resistance in E. coli isolates

Abstract

Background: Heavy metal pollution in water is one of the most serious environmental problems. These findings have prompted the idea that metal-exposed bacteria may have altered resistance to antibiotics. This study was performed to investigate the presence of heavy metal resistance genes (HMRGs) in Escherichia coli.Methods: HMRGs and antibiotic resistance of 100 E. coli from sewage and fresh water were detected by PCR. Minimum inhibitory concentrations (MICs) of heavy metals were determined by the broth micro dilution method. Antibiotic discs used to detect multidrug resistance, was recovered and assembled using third-generation sequencing.Results: The frequency of different HMRGs in E. coli ranged from 1–67%., while prevalence of ESBL genes ranged 5-17% in freshwater isolates, and 54- 96% in swage isolates. MICs of heavy metals for E. coli ranged widely from ≤8.0-800 mg/L. Moreover, HMRGs (PbRT, cadD arsB, PcoA, czrc, and chrA) were found to be significantly associated with one or more ARGs ( tetA, blaTEM, blaSHV and blaCTX) (P < 0.05).Conclusion: In conclusion, HMRGs were widely present in E. coli isolated Dujla river and sewage water were significantly associated with DRGs . It is remarkable that the coexistence of HMRGs, DRGs and ARGs confer co-resistance to heavy metals, and antibiotics.Keywords: Heavy metals; Antibiotic resistance