Isolation and Molecular Characterisation of Vancomycin Resistant Bacteria Isolated from Selected Well Water in Ula-Ubie Community, Ahoada, Rivers State

Abstract

The resistance of bacteria to vancomycin has made the treatment of some infections more difficult to handle. The aim of this study was to isolate and molecularly characterize vancomycin resistant bacteria in selected well water with a view of determining the level of resistance in the environment. fifty (50) well water samples were collected from ten different stations in Ula-Ubie community, Ahoada, Rivers State for a period of six months (January 2019 to June, 2019). Bacteria diversity was analysed using standard microbiological techniques. In this technique, aliquots of 10-1, 10-2 and 10-3 dilutions were seeded into prepared Nutrient agar and Brain Heart infusion agar (BHI). Microbial loads were enumerated and distinct bacterial colonies were picked and inoculated on freshly prepared nutrient agar. Purification of isolates was done by streaking on freshly prepared nutrient agar plates until isolates were void of mixed culture. The isolates were further characterized using biochemical and molecular methods and preserved in bijou bottles containing 5 ml of 10% (v/v) glycerol. Isolates from the glycerol were subcultured on fresh nutrient agar plates before each use. The vancomycin resistant bacteria were screened using the culture-based screening method. In this method, sterile nutrient medium was supplemented with different concentrations of the vancomycin antibiotics. Inoculation of bacterial isolates on the vancomycin supplemented agar followed before plates were incubated. The ensuing bacterial isolates were characterized using biochemical and molecular methods. Ninetine (19) bacteria isolates were screened for vancomycin and of this numbers, six (6) were positive for vancomycin resistance. The agar rose gel electrophoresis showed the presence of vanA and vanB gene which could be responsible for the resistance to the vancomycin observed in most isolates. The presence of vancomycin resistant genes in these isolates is of public health concern due to the transfer of resistance to other isolates. Standard hygienic practice is therefore recommended in the use of well water.