Escherichia coli with virulence factors and multidrug resistance in the Plankenburg River

Abstract

Escherichia coli is a natural inhabitant of the gut and E. coli levels in water are considered internationally to be an indication of faecal contamination. Although not usually pathogenic, E. coli has been linked to numerous foodborne disease outbreaks, especially those associated with fresh produce. One of the most common ways through which E. coli can be transferred onto fresh produce is if contaminated water is used for irrigation. In this study, a total of 81 confirmed E. coli strains were isolated from the Plankenburg River as part of three separate studies over 3 years. During sampling, E. coli levels in the river were above the accepted levels set by the World Health Organization and the South African Department of Water Affairs and Forestry for safe irrigation of fresh produce, which indicates that transfer of E. coli during irrigation is highly probable. Multiplex polymerase chain reaction screening for pathogenic gene sequences revealed one enteroaggregative positive strain and four enteropathogenic positive strains. The four enteropathogenic strains were also found to be resistant to three or more critically and highly important antibiotics and were therefore classified as multidrug resistant strains. These results show that E. coli with enteropathogenic potential and multiple antimicrobial resistance properties has persisted over time in the Plankenburg River. Although the presence of several potential pathogens in the Plankenburg River has been reported, 8 the occurrence and types of pathogenic E. coli are not known. The aim of this study was therefore to determine the number, types and antibiotic susceptibility of potential pathogenic E. coli present in the Plankenburg River. Materials and methods Sampling Water samples from which E. coli was isolated were collected from the Plankenburg River (Stellenbosch, Western Cape Province) at three sites (P-0, P-1 and P-2). 8 The P-0 sampling site was about 5 km upstream of the P-1 site and was selected specifically to assess the impact of an informal settlement and industrial area on the water quality of the Plankenburg River. However, for large parts of each year, especially during the dry summer months, this site had no flowing water and therefore it was not sampled at the same frequency as the other sites. Two of the sites-P-1 and P-2-are situated downstream of an informal settlement and industrial area and have shown high levels of faecal contamination. 8 River water sampling was done in accordance with the SANS 5667-6 method 9 ; all samples were 1 L in volume.

Antibiotic Resistance and Extended-Spectrum Beta-Lactamase Production of Escherichia coli Isolated from Irrigation Waters in Selected Urban Farms in Metro Manila, Philippines

“…Among the E. coli isolates from irrigation water used in this study, the highest resistance was observed in tetracycline, followed by resistance to ampicillin. The resistance to these antibiotics was also observed among E. coli isolates from irrigation waters in several studies [25,26,28]. The presence of tetracycline-resistant E. coli in irrigation waters is particularly disturbing, as tetracycline is widely available and extensively used in developing countries as a first-line drug in the treatment of gastrointestinal infections [15,25,31].…”

“…The application of these waters for irrigation purposes raises public health concern as they may potentially contaminate and disseminate antibiotic-resistant and multidrug resistant E. coli in the primary production environment, such as agricultural soils and fresh produce [26,28]. The presence of antibiotic resistant and MDR E. coli in fresh produce exposes humans to serious health hazards as there are vegetables that do not undergo microbial inactivation or preservation treatment prior to consumption [6,29].…”

Occurrence, identification and antibiogram signatures of selected Enterobacteriaceae from Tsomo and Tyhume rivers in the Eastern Cape Province, Republic of South Africa

“…The ARB may initially be commensals living in the gastrointestinal tract, but after a while may acquire genetic materials such as plasmids, integrons, or transposons carrying various resistance genes and virulence factors, which can then transform these initially harmless bacteria into more virulent and resistant organisms (4,16). Also, a large portion of antibiotics used is not broken down into inactive constituents thereby retaining their properties even after discharge from the body into the environment (4,18,22,23). These sometimes travel to wastewater treatment plants (WWTPs) via domestic sewer lines or are excreted directly into the soil or surface waters, thereby further adding to the antibiotic resistance pressure impacted on the environment (24,25).…”

Identification and antimicrobial resistance prevalence of pathogenic Escherichia coli strains from treated wastewater effluents in Eastern Cape, South Africa

“…These are enterohemorrhagic (EHEC), enteropathogenic (EPEC), enteroaggregative (EAEC), enterotoxigenic (ETEC), enteroinvasive (EIEC), and diffusely adherent (DAEC) E. coli , while ExPEC (uropathogenic E. coli and neonatal meningitis E. coli ) are causative agents of infections in anatomical sites outside of the gastrointestinal tract, and are associated with urinary tract infections, neonatal meningitis, and septicemia (Lamprecht et al. ). Escherichia coli can be used as surrogate for antibiotic resistance surveillance because it is found more commonly in diverse hosts and environments, it acquires resistance easily (Erb et al.…”