Antibiotic resistance profiles of Escherichia coli isolates from river sources in Durban, South Africa

Abstract

Lack of access to potable water has forced many inhabitants of informal settlements in South Africa to rely on surface water sources for their daily water needs, thus exposing these communities to microbial contamination that can result in water-borne diseases. These water sources also serve as natural habitats of pathogenic E. coli strains which harbour virulence factors, which could play a role in the disease process, as well as various multi-drug resistant water-borne pathogens. This study investigated the microbiological quality of two river waters in Durban, South Africa, using total coliform and faecal coliform population as indices. The virulence markers and antibiogram profiles of the E. coli isolates from these rivers were also determined. The results indicated that water from these river sources were of poor microbiological quality and unfit for human consumption. Antibiotic Resistance Profiles of the isolates revealed that 97.1% of the Palmiet River isolates and 71.15% of the Umgeni River isolates were multiresistant to the antibiotics tested, with all the isolates found to be resistant to novobiocin. Characterization of the virulence markers revealed the presence of stx1, cnf1 and eaeA genes, indicating the possible health risk associated with the ingestion of water from these rivers. The inherent health risks associated with the use of these river water emphasises the need for safe water supply and provision of proper sanitation facilities for the inhabitants of the informal settlements along these river banks.

Characterization of bacterial pathogens in rural and urban irrigation water

“…High resistance to ampicillin and cephalothin was also noted in E. coli isolated from the Umgeni and Palmiet rivers located in South Africa (Olaniran et al 2009). …”

“…factor that has resulted in over use of these drugs within the medical community (Olaniran et al 2009). High resistance to ampicillin and cephalothin was also noted in E. coli isolated from the Umgeni and Palmiet rivers located in South Africa (Olaniran et al 2009).…”

“…Rivers flowing through urban areas may be exposed to higher levels of pollution compared to rural areas through domestic and industrial waste disposal (Walters et al 2011) increasing the risk of contamination with antibiotic-resistant bacterial pathogens. Olaniran et al (2009) suggested contamination of surface water sources with pollutants as a factor influencing increased prevalence of antibiotic-resistant pathogens. Therefore, irrigation water sources may serve as reservoirs of antibiotic-resistant pathogens thereby posing a food safety and public health threat in the case that new pathogens emerge.…”

“…Therefore, irrigation water sources may serve as reservoirs of antibiotic-resistant pathogens thereby posing a food safety and public health threat in the case that new pathogens emerge. Multiple resistances to antibiotics were noted in E. coli isolated from rivers close to urban/densely populated areas (Olaniran et al 2009;Da Silva et al 2011). Antibiotic resistance can be used to determine relatedness of environmental E. coli as well as the source of contamination (Wiggins et al 1999).…”

Fluctuations of indicator and index microbes as indication of pollution over three years in the Plankenburg and Eerste Rivers, Western Cape, South Africa

“…In all the reports published to date (Barnes and Taylor, 2004;Germs et al, 2004;Griesel and Jagals, 2002;Olaniran et al, 2009;Paulse et al, 2009), it was found that faecal indicator organisms exceeded the South African Department of Water Affairs (DWA) and World Health Organisation (WHO) guideline limits of 1 000 E. coli per 100 mℓ water for irrigation of fresh produce (DWAF, 1996;WHO, 1989).…”