Investigation of Virulence Factors and Effect of Chlorine and Sunlight on Carbapenems-Resistant Enterobacteriaceae from Water Samples

Carbapenems are the last line resort antibiotics in the fight against the diseases caused by Carbapenemase-Producing Enterobacteriaceace(CPE). The study aimed to investigate the presence of virulent factors in CPE (Escherichia coli and Klebsiella pneumoniae) and effect of sunlight and chlorine on them. Thirty water samples from streams and wells were collected and their microbial quality assessment was carried out following standard procedures. Antibiotic sensitivity testing of isolates, detection of virulence factors, OXA genes and plasmid and effect of chlorine and sunlight were carried out using standard techniques. Thirty-five isolates (E. coli (fifteen, 42.9%) and K. pneumonia (twenty, 57.1%) were recovered from the water samples and 28 (80%) demonstrated multiple antibiotics resistance (MAR). The MAR organisms were further subjected to carbapenems (meropenem and doripenem) and only 2 (33.3%) of E. coli and 4 (66.7%) of K. pneumoniae were resistant to these antibiotics. The detection of virulent factors showed that out of five carbapenem-resistant organisms (CRO) investigated, 2 (40%) possessed OXA gene of 320 bp and 4 (80%) contained plasmid of >1300bp. Also, number of colony forming unit of CRO reduced with exposure rate to sunlight and chlorine. The study showed that OXA gene and plasmid were detected in isolates and revealed health risk posed to clinical therapy. However, the study revealed that sunlight and chlorine at adequate exposure and concentration are very effective in treating water contaminated with CRO, thereby reducing the incidence of health risk in the community.