Distribution of Escherichia coli O157:H7 in irrigation water, drinking water troughs, dairy wastewater and rectal swabs from three dairy farms in Amathole district municipality, Eastern Cape, South Africa
- Authors: Myataza, Asive https://orcid.org/0000-0001-5483-122X
- Date: 2016
- Subjects: Escherichia coli O157:H7 , Irrigation water
- Language: English
- Type: Master's theses
- Identifier: http://hdl.handle.net/10353/24150 , vital:62397
- Description: Escherichia coli belongs to the genus Escherichia which has five species, including E. hermanii, E. fergusonii, E. vulneris, E. blattae and E. coli (Willshaw et al., 2001). Some E. coli strains are pathogenic, and such strains are differentiated into different pathotypes based on the virulence factors they possess, mechanisms of pathogenesis, clinical manifestation and serotyping of their somatic, flagella and capsule (O, H and K) antigens; while some are nonpathogenic (Dikobe et al., 2011). These strains have been grouped into major pathotypes namely: enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), diffusely adherent E. coli (DAEC), enterohaemorrhagic E. coli (EHEC), uropathogenic E. coli (UPEC) and neonatal meningitis E.coli (NMEC) (Willshaw et al., 2001; Villegas-sepulveda et al., 2003; Kaper et al., 2004; Bugarel et al., 2011). Members of EPEC pathotype are Shiga-toxin producing (STEC) organisms, with E. coli O157:H7 serotype being recognized as the most frequent STEC serotype linked to diseases in human (Barkocy-Gallagher et al., 2001; Coombes et al., 2011; Dikobe et al., 2011; Jacob et al., 2013). E. coli O157:H7 is the major cause of haemorrhagic diarrhoea and haemolytic uremic syndrome (UHS) in humans, due to the production of Shiga-toxins that are similar to Shigella toxins (Villegas-sepulveda et al., 2003; Ngwa et al., 2013). These toxins are coded by genes which allow them to penetrate small intestines of human and animals (Chern et al., 2011). Dairy products and cattle are the major reservoirs of haemorrhagic E. coli O157: H7 (Elder et al., 2000; Elmali et al., 2005; Ayaz et al., 2014). Haemorrhagic E. coli O157:H7 is carried mostly in the gastrointestinal tracts of cows and other ruminants (Gun et al., 2003)and it is transmitted through ingestion of contaminated food and water, or through direct and indirect contact with infected cows and other ruminants and/or via a person to person transmission (Lahti et al., 2003). Almost 70percent of countries in the world use poorly treated water for irrigation; this is inclusive of developing countries, which lack well developed means of adequate water treatment due to unavailable financial resources (Gerba et al., 2011). Most communities in the Eastern Cape Province of South Africa are rural with poor water supply with majority of them relying on ground and surface waters that are impacted by insufficiently treated municipal water (which may harbour many pathogens) for domestic purposes (Ateba et al., 2008). Cows may contaminate drinking, recreational and irrigation waters with faecal matters or through direct contact with water (Solomon et al., 2002; Chern et al., 2011). A number of countries with water shortage tend to use insufficiently treated water for irrigation, leading to further contamination of irrigated crops (Fatoki et al., 2001). This has all resulted to elevated levels of E. coli O157:H7 related disease outbreaks and deaths of humans (Olsen et al., 2002). , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016
Assessment of the prevalence of faecal coliforms and Escherichia coli o157:h7 in the final effluents of two wastewater treatment plants in Amahlathi Local Municipality of Eastern Cape Province, South Africa
- Authors: Ajibade, Adefisoye Martins
- Date: 2014
- Subjects: Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Escherichia coli O157:H7 , Escherichia coli , Effluent quality -- Testing , Whole effluent toxicity testing , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11283 , http://hdl.handle.net/10353/d1016166 , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Escherichia coli O157:H7 , Escherichia coli , Effluent quality -- Testing , Whole effluent toxicity testing , Water -- Purification
- Description: The production of final effluents that meet discharged requirements and guidelines remain a major challenge particularly in the developing world with the resultant problem of surface water pollution. This study assessed the physicochemical and microbiological qualities of two wastewater treatment works in the Eastern Cape Province of South Africa in terms of the prevalence of faecal coliforms and Escherichia coli O157:H7 over a five month period. All physicochemical and microbiological analyses were carried out using standard methods. Data were collected in triplicates and analysed statistically using IBM SPSS version 20.0. The ranges of some of the physicochemical parameters that complied with set guidelines include pH (6.7 – 7.6), TDS (107 – 171 mg/L), EC (168 – 266 μS/cm), Temperature (15 – 24oC), NO3- (0 – 8.2 mg/L), NO2- (0.14 – 0.71 mg/L) and PO4 (1.05 – 4.50 mg/L). Others including Turbidity (2.64 – 58.00 NTU), Free Cl (0.13 – 0.65 mg/L), DO (2.20 – 8.48 mg/L), BOD (0.13 – 6.85 mg/L) and COD (40 – 482 mg/L) did not comply with set guidelines. The microbiological parameters ranged 0 – 2.7 × 104 CFU/100 ml for FC and 0 – 9.3 × 103 for EHEC CFU/100 ml, an indication of non-compliance with set guidelines. Preliminary identification of 40 randomly selected presumptive enterohemorrhagic E. coli isolates by Gram’s staining and oxidase test shows 100% (all 40 selected isolates) to be Gram positive while 90% (36 randomly selected isolates) were oxidase negative. Statistical correlation between the physicochemical and the microbiological parameters were generally weak except in the case of free chlorine and DO where they showed inverse correlation with the microbiological parameters. The recovery of EHEC showed the inefficiency of the treatment processes to effectively inactivate the bacteria, and possibly other pathogenic bacteria that may be present in the treated wastewater. The assessment suggested the need for proper monitoring and a review of the treatment procedures used at these treatment works.
- Full Text:
- Date Issued: 2014