Characterization of ESKAPE pathogens at WWTPs in the North West province of South Africa

Abstract

The ESKAPE pathogens is an acronym and consists of: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterococcus spp. The ESKAPE group of bacteria have presented an alarming increase in MDR (Multi drug resistant) and virulence and have as a consequence been put on the watch list by the World Health Organization (WHO). This study aimed to determine the prevalence and characteristics of ESKAPE pathogens that were isolated from wastewater treatment plants before and after treatment. Samples were collected from the influent and effluent of the WWTPs (Wastewater treatment plants). In order to isolate the ESKAPE pathogens, selective chromogenic media was used. Pure isolates of the presumed ESKAPE pathogens were subjected to antibiotic susceptibility and virulence tests. The present project tested for the production of DNase, lipase, protease, and hemolysin. None of the presumptive ESKAPE organisms illustrated any DNase production, whereas some did exhibit lipase and protease production. Some also exhibited β-hemolysis activity. They presented a high resistance against various antibiotics that are readily used in clinical settings. Presumptive ESKAPE pathogens were also screened for the presence of antibiotic resistance genes including blaKPC, blaSHV, blaOXA-48, blaCTX, blaTEM, blaVIM, FOX and MOX. All genes screened were found within the presumptive ESKAPE organisms, except FOX and blaKPC. Since all genera associated with the ESKAPE group were identified by the present study, the results are a cause for concern, given further that most of the nosocomial infections that occur are caused by members of the ESKAPE pathogen group, notably S. aureus and P. aeruginosa. Some of the prominent health effects include bacterial pneumonia, urinary tract infections (UTIs), becteremia and infections in soft tissue. Not only are these pathogens a cause for concern in clinical settings, but they are becoming more prevalent in the environment. This may have health implications in communities that utilize these effluent-receiving waters, giving rise to a further cause for concern, as the fact that they are populating the environment may lead to an acceleration of infections, while proper treatment or health care facilities may not be available in the rural communities directly influenced by them due the use of effluent receiving waters.