Molecular characterisation of antibiotic-resistant bacteria from water

Antibiotic resistance is a global menace because it can be shuttled between different environments. In this book, isolation, antibiogram and molecular characterisation of bacteria from six water distribution systems of dams in southwestern Nigeria were described. Some bacteria isolated include E.coli, Proteus, Aeromonas, Klebsiella and Morganella. High resistance to antibiotics such as tetracycline, ampicillin, gentamicin and sulphamethoxazole was observed in these bacteria. Molecular characterization using PCR detected presence of tetA, tetB encoding resistance to tetracycline, sul 1 and sul 2 encoding resistance to sulfa drugs, blaCTX and blaTEM encoding resistance to beta-lactams and aph(3')c encoding resistance to aminoglycosides among these bacteria. High percentage of class 1 and class 2 integrons which are mobile genetic elements that bacteria used in shuttling resistance, was also observed. Microarray analysis of these bacteria revealed the presence of other tetracycline resistance genes such as tetJ and tetH. Occurrence of these genes and integrons in these water samples showed they can be sources of dissemination of antibiotic resistance, hence a threat to public health.