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:
- 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.
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Evaluation of some wastewater treatment facilities in Chris Hani and Amathole district municipalities as potential sources of Escherichia coli in the environment
- Authors: Mazwi, Sinazo Nomathamsanqa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11285 , http://hdl.handle.net/10353/d1019804 , Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Description: Access to clean and safe water is essential for the survival of human beings. Pollution of freshwater sources constitutes a major problem hindering access to safe water for drinking and other domestic uses. Wastewater effluent discharges often impact the microbiological qualities of surface waters with its attendant health and environmental problems. This study evaluated the microbiological qualities of the discharged effluents of four selected wastewater treatment plants in Amathole and Chris Hani District Municipalities of the Eastern Cape Province over a twelve-month sampling period. Microbiological analysis (faecal coliform, Escherichia coli and Escherichia coli O157:H7) was done using standard methods and polymerase chain reaction method was used to confirm identities ofbacterial isolates. Presumptive bacteria counts ranged as follows: faecal coliforms 0 to 1.6 × 103 CFU/100 ml, E. coli 0 to 1.4 × 103 CFU/100 ml and E. coli O157:H7 0 to 9.6 × 102 CFU/100 ml. Forty eight percent (305/626) of the presumptive E. coli isolates were confirmed using species-specific uidA gene which code for β-glucuronidase enzyme in E. coli. Antibiotic susceptibility profile of the isolate using a panel of 10 antibiotics shows 100% (150/150) resistance to antibiotics rifampicin and penicillin G while 49.3% (74/150) of the isolates and 46.7% (70/150) were susceptible to streptomycin and cefotaxime respectively. Multiple antibiotic resistance phenotypes (MARP) of the isolates showed resistance to two or more test antibiotics while the calculated multiple antibiotic resistance index (MARI) for the tested isolated is 0.49. The detection of potentially pathogenic E. coli in the final effluents suggestspotential danger to the receiving water bodies where the effluents are discharge. The high MARI valued obtained in this study indicates that the isolates are form environment where the tested antibiotics are being used and may further lead to the spread of multiple antibiotics resistance among other pathogens that may be present in the same environment.
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- Authors: Mazwi, Sinazo Nomathamsanqa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11285 , http://hdl.handle.net/10353/d1019804 , Escherichia coli -- South Africa -- Eastern Cape , Water -- Purification
- Description: Access to clean and safe water is essential for the survival of human beings. Pollution of freshwater sources constitutes a major problem hindering access to safe water for drinking and other domestic uses. Wastewater effluent discharges often impact the microbiological qualities of surface waters with its attendant health and environmental problems. This study evaluated the microbiological qualities of the discharged effluents of four selected wastewater treatment plants in Amathole and Chris Hani District Municipalities of the Eastern Cape Province over a twelve-month sampling period. Microbiological analysis (faecal coliform, Escherichia coli and Escherichia coli O157:H7) was done using standard methods and polymerase chain reaction method was used to confirm identities ofbacterial isolates. Presumptive bacteria counts ranged as follows: faecal coliforms 0 to 1.6 × 103 CFU/100 ml, E. coli 0 to 1.4 × 103 CFU/100 ml and E. coli O157:H7 0 to 9.6 × 102 CFU/100 ml. Forty eight percent (305/626) of the presumptive E. coli isolates were confirmed using species-specific uidA gene which code for β-glucuronidase enzyme in E. coli. Antibiotic susceptibility profile of the isolate using a panel of 10 antibiotics shows 100% (150/150) resistance to antibiotics rifampicin and penicillin G while 49.3% (74/150) of the isolates and 46.7% (70/150) were susceptible to streptomycin and cefotaxime respectively. Multiple antibiotic resistance phenotypes (MARP) of the isolates showed resistance to two or more test antibiotics while the calculated multiple antibiotic resistance index (MARI) for the tested isolated is 0.49. The detection of potentially pathogenic E. coli in the final effluents suggestspotential danger to the receiving water bodies where the effluents are discharge. The high MARI valued obtained in this study indicates that the isolates are form environment where the tested antibiotics are being used and may further lead to the spread of multiple antibiotics resistance among other pathogens that may be present in the same environment.
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Prevalence and pathogenicity of vibrios in treated final effluents of selected wastewater treatment plants in the Amathole District Municipality of Eastern Cape Province of South Africa
- Authors: Badela, Andiswa Unathi
- Date: 2014
- Subjects: Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11284 , http://hdl.handle.net/10353/d1019774 , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Description: Waterborne diarrhoeal infections continue to be a major health setback in developing countries, especially in rural areas which lack adequate supply of portable water and sanitation facilities. Globally, waterborne diarrhoeal infections occur with an estimated mortality rate of 10–25 million deaths per year, 95% of which are children under the age of 5 years. The Vibrio species is one of the major groups of enteric pathogens that are responsible for diarrhoeal infections. Many strains of these bacterial species continue to cause epidemics of diarrhoea throughout the world. In this study, the prevalence of Vibrio pathogens in wastewater final effluents was assessed. Wastewater final effluent and discharge point samples were collected monthly between September 2012 and August 2013. All samples were collected aseptically using sterile 1 L Nalgene bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6 h of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Presumptive Vibrio densities varied from 0 to 2.11 × 102 cfu/100 ml. Out of 300 confirmed Vibrio isolates; 13.3% (40/300) were Vibrio fluvialis, 22% (66/300) were confirmed to be Vibrio parahaemolyticus, and 24.7% (74/300) proved to be Vibrio vulnificus, and 40% (120/300) were other Vibrio species which were not assessed for in this study. The strains of Vibrio fluvialis were found to exhibit 100% resistance to Polymixin and Tetracycline. However, Gentamicin was active against all the three Vibrio species selected for the purpose of this research. The recovery of Vibrio species in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering the fact that Vibrio is a pathogenic bacterium. The findings of this study underline the need for constant monitoring of the microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works.
- Full Text:
- Authors: Badela, Andiswa Unathi
- Date: 2014
- Subjects: Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11284 , http://hdl.handle.net/10353/d1019774 , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Description: Waterborne diarrhoeal infections continue to be a major health setback in developing countries, especially in rural areas which lack adequate supply of portable water and sanitation facilities. Globally, waterborne diarrhoeal infections occur with an estimated mortality rate of 10–25 million deaths per year, 95% of which are children under the age of 5 years. The Vibrio species is one of the major groups of enteric pathogens that are responsible for diarrhoeal infections. Many strains of these bacterial species continue to cause epidemics of diarrhoea throughout the world. In this study, the prevalence of Vibrio pathogens in wastewater final effluents was assessed. Wastewater final effluent and discharge point samples were collected monthly between September 2012 and August 2013. All samples were collected aseptically using sterile 1 L Nalgene bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6 h of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Presumptive Vibrio densities varied from 0 to 2.11 × 102 cfu/100 ml. Out of 300 confirmed Vibrio isolates; 13.3% (40/300) were Vibrio fluvialis, 22% (66/300) were confirmed to be Vibrio parahaemolyticus, and 24.7% (74/300) proved to be Vibrio vulnificus, and 40% (120/300) were other Vibrio species which were not assessed for in this study. The strains of Vibrio fluvialis were found to exhibit 100% resistance to Polymixin and Tetracycline. However, Gentamicin was active against all the three Vibrio species selected for the purpose of this research. The recovery of Vibrio species in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering the fact that Vibrio is a pathogenic bacterium. The findings of this study underline the need for constant monitoring of the microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works.
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Prevalence of pathogenic Escherichia coli strains in the final effluents of four wastewater treatment plants in the Eastern Cape Province of South Africa
- Authors: Seti, Nozuko Zukiswa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11286 , http://hdl.handle.net/10353/d1019808 , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Description: Water is an essential need that stimulates health and well being. Increase in population size and urbanization negatively affect water resources due to high demands of effluent outputs. Wastewater is an important reservoir for Escherichia coli and can present significant acute toxicity if released into receiving water sources without being adequately treated. E. coli is used as indicator organism for the detection of faecal contamination. These strains have been considered to be one of the primary causes of diarrhoeal infections worldwide. The present study was conducted between September 2012 and June 2013 to assess the prevalence of pathogenic E. coli strains in the final effluents of four wastewater treatment plants in Chris Hani and Buffalo City Municipalities in the Eastern Cape Province of South Africa. Standard membrane filtration technique was used for bacteriological analysis and molecular based technique was used for identification of E. coli pathotypes. The results were recorded in colony forming units/100 ml. Faecal coliforms ranged between 0-9.6×10³ CFU/100 ml for the wwtp-Q and E. coli densities ranged between 0-8.4×10³ CFU/100ml. Faecal coliforms ranged between 4×10²-9.7×10³ CFU/100 ml for wwtp-M and E. coli densities ranged between 1.2×10¹-8.4×10³ CFU/100 ml. The wwtp-E showed to have bacterial counts of faecal coliforms ranging between 4.0×10³-8.2×10³ CFU/100 ml and E. coli densities ranging between 3.5×10¹-7.1×10³ CFU/100 ml. The WWTP-K in this study was only assessed for the presence of E. coli. Faecal coliforms were assessed by the other members of the group. This plant showed to have E. coli densities ranging between 0-7.5×10²CFU/100 ml. A total of 200 presumptive E. coli isolates were subjected to screening by conventional PCR in which (29%) of the wwtp-M isolates were positively identified as E. coli, (16%) of the wwtp-K, (22%) of the wwtp-Q and (34%) of the wwtp-E isolates were positively confirmed as E. coli. A total of 100 randomly selected E. coli isolates were characterised into different pathotypes. (16%) of positive isolates were detected as EPEC and 11% were detected as UPEC strains. There was no detection for the ETEC strains. Antibiotic susceptibility patterns of E. coli strains showed high levels of resistance to Penicillin G, Erythromycin, Tetracycline and Sulfamethoxazole. High levels of Susceptibility were observed in antibiotics such as Chloramphenicol, Amoxicillin and Tetracycline. The results of this study reveal that the plants were above the recommended Standard limit of zero CFU/100 ml for effluents meant to be discharge into receiving water sources. This study reveals inadequacy of the plants studied to produce effluents of acceptable quality.
- Full Text:
- Authors: Seti, Nozuko Zukiswa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11286 , http://hdl.handle.net/10353/d1019808 , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Description: Water is an essential need that stimulates health and well being. Increase in population size and urbanization negatively affect water resources due to high demands of effluent outputs. Wastewater is an important reservoir for Escherichia coli and can present significant acute toxicity if released into receiving water sources without being adequately treated. E. coli is used as indicator organism for the detection of faecal contamination. These strains have been considered to be one of the primary causes of diarrhoeal infections worldwide. The present study was conducted between September 2012 and June 2013 to assess the prevalence of pathogenic E. coli strains in the final effluents of four wastewater treatment plants in Chris Hani and Buffalo City Municipalities in the Eastern Cape Province of South Africa. Standard membrane filtration technique was used for bacteriological analysis and molecular based technique was used for identification of E. coli pathotypes. The results were recorded in colony forming units/100 ml. Faecal coliforms ranged between 0-9.6×10³ CFU/100 ml for the wwtp-Q and E. coli densities ranged between 0-8.4×10³ CFU/100ml. Faecal coliforms ranged between 4×10²-9.7×10³ CFU/100 ml for wwtp-M and E. coli densities ranged between 1.2×10¹-8.4×10³ CFU/100 ml. The wwtp-E showed to have bacterial counts of faecal coliforms ranging between 4.0×10³-8.2×10³ CFU/100 ml and E. coli densities ranging between 3.5×10¹-7.1×10³ CFU/100 ml. The WWTP-K in this study was only assessed for the presence of E. coli. Faecal coliforms were assessed by the other members of the group. This plant showed to have E. coli densities ranging between 0-7.5×10²CFU/100 ml. A total of 200 presumptive E. coli isolates were subjected to screening by conventional PCR in which (29%) of the wwtp-M isolates were positively identified as E. coli, (16%) of the wwtp-K, (22%) of the wwtp-Q and (34%) of the wwtp-E isolates were positively confirmed as E. coli. A total of 100 randomly selected E. coli isolates were characterised into different pathotypes. (16%) of positive isolates were detected as EPEC and 11% were detected as UPEC strains. There was no detection for the ETEC strains. Antibiotic susceptibility patterns of E. coli strains showed high levels of resistance to Penicillin G, Erythromycin, Tetracycline and Sulfamethoxazole. High levels of Susceptibility were observed in antibiotics such as Chloramphenicol, Amoxicillin and Tetracycline. The results of this study reveal that the plants were above the recommended Standard limit of zero CFU/100 ml for effluents meant to be discharge into receiving water sources. This study reveals inadequacy of the plants studied to produce effluents of acceptable quality.
- Full Text:
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