Genotypic characterisation of ESKAPE pathogens from groundwater

Abstract

This study aimed to investigate the presence, antibiotic susceptibility profiles, and virulence genes determinants of ESKAPE pathogens isolated from water obtained from different groundwater sources of some villages of Zeerust and Mahikeng in the North-West Province, South Africa. To achieve this, 60 samples of water were obtained randomly from taps and boreholes in Zeerust and Mahikeng between December 2020 and October 2021. ESKAPE pathogens were isolated and positively identified using morphological (Gram-staining), biochemical (oxidase and catalase) tests and molecular (species-specific PCR) methods. The antimicrobial resistance profiles of the isolates were determined using the Kirby-Bauer disc diffusion method. Virulence genes were also screened using PCR. Among all the samples examined, a total number of 5, 16, 18 and 32 isolates were amplified for the species-specific genes of S. aureus, K. pneumoniae, P. aeruginosa and E. cloacae respectively. None of the isolates amplified for the E. faecium and A. baumannii species-specific genes. A large proportion (60%–100%) of the isolates were resistant to piperacillin, ampicillin, amoxicillin, cefuroxime and eaztreonam. On the other hand, low-level resistance (0%–33%) was observed for gentamicin and kanamycin. In addition, out of five S. aureus isolates, 2 (40%) amplified for the sec gene while 3 (60%) amplified for the sea gene. The fimH-1 gene was detected in 38% of the K. pneumoniae isolates while the ycfm gene was detected in 63% of the isolates. One of the major virulence factors of Pseudomonas aeruginosa, the enzyme elastase (LasB) was detected in 61% of the isolates while algD was detected in 50% of the isolates. For the E. cloacae isolates, 94% and 22% amplified for the fliI and rpos genes respectively. The findings of this study indicate that groundwater from some areas of Zeerust and Mahikeng is contaminated and this can cause serious

health problems in the communities, especially for immunocompromised individuals. Therefore, there is a need for routine testing and surveillance of groundwater and implementation of basic water treatment methods in the communities such as boiling and usage of sodium hypochlorite solutions.