Prevalence and antibiogram of some swine associated Shiga toxin producing Escherichia coli Serogroups and Salmonella species in Nkonkobe Municipality, Eastern Cape Province, South Africa
- Authors: Iwu, Chinwe Juliana
- Date: 2015
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11294 , http://hdl.handle.net/10353/d1021273 , Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Description: Gastrointestinal illnesses have continually become a global public health issue. Exposure to zoonotic food borne pathogens such as Salmonella and diarrhoegenic E. coli either by direct or indirect contact through the consumption of food producing animals is likely an important mode of infection to humans. More so, the use of antibiotics in farm animals similar to those used in humans can select for resistance in bacteria frequently harboured by them. These resistant strains can be passed on to humans through contaminated meat products and water leading to resistant infections with consequences such as prolonged illnesses, treatment failures, and increased morbidity and mortality. In animals, these can lead to reduced productivity. Monitoring the level of resistance among bacteria from animal isolates will help in generating data that could be used to create awareness of their presence in the environment and aid in preventing a potential epidemic in the community. In this study, we investigated the prevalence and antimicrobial resistance profile of Escherichia coli serogroups and Salmonella species in faecal samples collected from pigs in Nkonkobe Municipality in the Eastern Cape Province, South Africa between April – July, 2014. A total of 310 presumptive Shiga toxin producing Escherichia coli (STEC) were confirmed as E. coli spp using polymerase chain reaction (PCR) technique by amplification of the uidA gene, out of which 179 (58%) were confirmed positive. Approximately, serogrougs O157:H7, O145 and O26 made up 24% (n=43), 8% (n=14) and 20% (n=35) of the E. coli population respectively. Only E. coli O26 was positive for stx2 gene in 31% of the isolates harbouring the gene, while the other serogroups were non-pathogenic. Susceptibility of the isolates to 18 antibiotics was carried out in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem. Similarly, a relatively high susceptibility was observed in norfloxacin (83-100%), ciprofloxacin (63-100%), gentamycin (77-100%), and chloramphenicol (77-100%). However, all the isolates were resistant to tetracycline and its long acting counterpart oxytetracycline. Resistances observed against other antimicrobials are as follows: ampicillin (84-91%), streptomycin (14-100%), erythromycin (91-100%), ceftazidime (35%). Multiple antimicrobial resistance patterns and indices ranged from 3 to 12 and 0.2 to 0.7 to respectively. Genes encoding resistances to ampicillin (ampC), streptomycin (strA) and tetracycline (tetA) were frequently detected in 50-100%, 22-29% and 40-86% of the resistant isolates respectively. In the other arm of the dissertation, two hundred and fifty eight presumptive isolates of Salmonella were recovered from the faecal samples of pigs. Specific primers targeting serogroups A, B, C1, C2, and D were used to delineate the isolates into different serogroups using PCR. Only serogroup A (n=48) was detected. These isolates were examined for antimicrobial susceptibility by disc diffusion method using 18 antibiotics. The results showed that a large proportion of the isolates were resistant to tetracycline (100%), oxytetracycline (100%), ampicillin (75%), sulphamethoxazole/trimethoprim (75%) and streptomycin (75%). Majority of the isolates exhibited multidrug resistances with the predominant multiple antibiotic resistance (MAR) phenotype being against eleven antibiotics. A high multiple antibiotic resistance (MAR) index in a range of 0.3- 0.6 was observed. The incidence of genes encoding resistance against tetracycline (tetA), streptomycin (stra), and ampicillin (ampC) were 54%, 44% and 61% respectively. These findings reveal that pigs within the Nkonkobe Municipality in the Eastern Cape Province could harbour Shiga toxins and multidrug resistant serogroups of E. coli as well as resistant Salmonella which could be transmitted to humans through the food chain. To ensure public health safety, continuous monitoring and sufficient sanitation in swine industries must be ensured.
- Full Text:
- Date Issued: 2015
- Authors: Iwu, Chinwe Juliana
- Date: 2015
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11294 , http://hdl.handle.net/10353/d1021273 , Escherichia coli -- South Africa -- Eastern Cape , Salmonella infections -- South Africa -- Eastern Cape , Water -- Pollution -- Environmental aspects -- South Africa -- Eastern Cape , Escherichia coli infections -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape
- Description: Gastrointestinal illnesses have continually become a global public health issue. Exposure to zoonotic food borne pathogens such as Salmonella and diarrhoegenic E. coli either by direct or indirect contact through the consumption of food producing animals is likely an important mode of infection to humans. More so, the use of antibiotics in farm animals similar to those used in humans can select for resistance in bacteria frequently harboured by them. These resistant strains can be passed on to humans through contaminated meat products and water leading to resistant infections with consequences such as prolonged illnesses, treatment failures, and increased morbidity and mortality. In animals, these can lead to reduced productivity. Monitoring the level of resistance among bacteria from animal isolates will help in generating data that could be used to create awareness of their presence in the environment and aid in preventing a potential epidemic in the community. In this study, we investigated the prevalence and antimicrobial resistance profile of Escherichia coli serogroups and Salmonella species in faecal samples collected from pigs in Nkonkobe Municipality in the Eastern Cape Province, South Africa between April – July, 2014. A total of 310 presumptive Shiga toxin producing Escherichia coli (STEC) were confirmed as E. coli spp using polymerase chain reaction (PCR) technique by amplification of the uidA gene, out of which 179 (58%) were confirmed positive. Approximately, serogrougs O157:H7, O145 and O26 made up 24% (n=43), 8% (n=14) and 20% (n=35) of the E. coli population respectively. Only E. coli O26 was positive for stx2 gene in 31% of the isolates harbouring the gene, while the other serogroups were non-pathogenic. Susceptibility of the isolates to 18 antibiotics was carried out in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem. Similarly, a relatively high susceptibility was observed in norfloxacin (83-100%), ciprofloxacin (63-100%), gentamycin (77-100%), and chloramphenicol (77-100%). However, all the isolates were resistant to tetracycline and its long acting counterpart oxytetracycline. Resistances observed against other antimicrobials are as follows: ampicillin (84-91%), streptomycin (14-100%), erythromycin (91-100%), ceftazidime (35%). Multiple antimicrobial resistance patterns and indices ranged from 3 to 12 and 0.2 to 0.7 to respectively. Genes encoding resistances to ampicillin (ampC), streptomycin (strA) and tetracycline (tetA) were frequently detected in 50-100%, 22-29% and 40-86% of the resistant isolates respectively. In the other arm of the dissertation, two hundred and fifty eight presumptive isolates of Salmonella were recovered from the faecal samples of pigs. Specific primers targeting serogroups A, B, C1, C2, and D were used to delineate the isolates into different serogroups using PCR. Only serogroup A (n=48) was detected. These isolates were examined for antimicrobial susceptibility by disc diffusion method using 18 antibiotics. The results showed that a large proportion of the isolates were resistant to tetracycline (100%), oxytetracycline (100%), ampicillin (75%), sulphamethoxazole/trimethoprim (75%) and streptomycin (75%). Majority of the isolates exhibited multidrug resistances with the predominant multiple antibiotic resistance (MAR) phenotype being against eleven antibiotics. A high multiple antibiotic resistance (MAR) index in a range of 0.3- 0.6 was observed. The incidence of genes encoding resistance against tetracycline (tetA), streptomycin (stra), and ampicillin (ampC) were 54%, 44% and 61% respectively. These findings reveal that pigs within the Nkonkobe Municipality in the Eastern Cape Province could harbour Shiga toxins and multidrug resistant serogroups of E. coli as well as resistant Salmonella which could be transmitted to humans through the food chain. To ensure public health safety, continuous monitoring and sufficient sanitation in swine industries must be ensured.
- Full Text:
- Date Issued: 2015
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
- 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
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.
- Full Text:
- Date Issued: 2014
- 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.
- Full Text:
- Date Issued: 2014
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:
- Date Issued: 2014
- 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:
- Date Issued: 2014
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:
- Date Issued: 2014
- 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:
- Date Issued: 2014
Assessment of the prevalence of virulent Eschericia coli strains in the final effluents of wastewater treatment plants in the Eastern Cape Province of South Africa
- Authors: Osode, Augustina Nwabuje
- Date: 2010
- Subjects: Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11246 , http://hdl.handle.net/10353/d1001062 , Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Description: Escherichia coli (E. coli) is a common inhabitant of surface waters in the developed and developing worlds. The majority of E. coli cells present in water are not particularly pathogenic to humans; however, there are some present in small proportion that possess virulence genes that allow them to colonize the digestive tract. Pathogenic E. coli causes acute and chronic diarrheal diseases, especially among children in developing countries and in travelers in these locales. The present study, conducted between August 2007 and July 2008, investigated the prevalence and distribution of virulent E. coli strains as either free or attached cells in the final effluents of three wastewater treatment plants located in the Eastern Cape Province of South Africa and its impact on the physico-chemical quality of the receiving water body. The wastewater treatment plants are located in urban (East Bank Reclamation Works, East London), peri-urban (Dimbaza Sewage Treatment Works) and in rural area (Alice Sewage Treatment Works). The effluent quality of the treatment plants were acceptable with respect to pH (6.9-7.8), temperature (13.8-22.0 °C), dissolved oxygen (DO) (4.9-7.8 mg/L), salinity (0.12-0.17 psu), total dissolved solids (TDS) (119-162 mg/ L) and nitrite concentration (0.1-0.4 mg/l). The other xii physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1-4.0 mg/L); chemical oxygen demand (COD) (5-211 mg/L); electrical conductivity (EC) (237-325 μS/cm) and Turbidity (7.7-62.7 NTU). Results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. Presumptive E. coli was isolated from the effluent samples by culture-based methods and confirmed using Polymerase Chain Reaction (PCR) techniques. Antibiogram assay was also carried out using standard in vitro methods on Mueller Hinton agar. The viable counts of presumptive E. coli for the effluent samples associated with 180 μm plankton size ranged between 0 – 4.30 × 101 cfu/ml in Dimbaza, 0 – 3.88 × 101 cfu/ml in Alice and 0 – 8.00 × 101 cfu/ml in East London. In the 60 μm plankton size category E. coli densities ranged between 0 and 4.2 × 101 cfu/ml in Dimbaza, 0 and 2.13 × 101 cfu/ml in Alice and 0 and 8.75 × 101 cfu/ml in East London. Whereas in the 20 μm plankton size category presumptive E. coli density varied from 0 to 5.0 × 101 cfu/ml in Dimbaza, 0 to 3.75 × 101 cfu/ml in Alice and 0 to 9.0 × 101 cfu/ml in East London. The free-living presumptive E. coli density ranged between 0 and 3.13 × 101 cfu/ml in Dimbaza, between 0 and 8.0 × 101 cfu/ml in Alice and between 0 and 9.5 × 101 cfu/ml in East London. Molecular analysis successfully amplified target genes (fliCH7, rfbEO157, ial and aap) which are characteristic of pathogenic E. coli strains. The PCR assays using uidA-specific primer confirmed that a genetic region homologous in size to the E. coli uidA structural gene, including the regulatory region, was present in 3 of the E. coli isolates from Alice, 10 from Dimbaza and 8 from East London. Of the 3 E. coli isolates from Alice, 1 (33.3%) was positive for the fliCH7 genes and 3 was positive for rfbEO157 genes. Out of the 10 isolates from Dimbaza, 4 were xiii positive for fliCH7 genes, 6 were positive for the rfbEO157 genes and 1 was positive for the aap genes; and of the 8 isolates from East London, 1 was positive for fliCH7 genes, 2 were for the rfbEO157 genes, 6 were positive for the ial genes. Antimicrobial susceptibility profile revealed that all of the E. coli strains isolated from the effluent water samples were resistant (R) to linezolid, polymyxin B, penicillin G and sulfamethoxazole. The E. coli isolates from Dimbaza (9/10) and East London (8/8) respectively were resistant to erythromycin. All the isolates were found to be susceptible (S) to amikacin, ceftazidime, ciprofloxacin, colistin sulphate, ceftriaxone, cefotaxime, cefuroxime, ertapenem, gatifloxacin, gentamycin, imidazole, kanamycin, meropenem, moxifloxacin, neomycin, netilmicin, norfloxacin and tobramycin. The findings of this study revealed that the Alice wastewater treatment plant was the most efficient as it produced the final effluent with the least pathogenic E. coli followed by the Dimbaza wastewater treatment plant. In addition, the findings showed that the wastewater treatment plant effluents are a veritable source of pathogenic E. coli in the Eastern Cape Province watershed. We suggest that to maximize public health protection, treated wastewater effluent quality should be diligently monitored pursuant to ensuring high quality of final effluents.
- Full Text:
- Date Issued: 2010
- Authors: Osode, Augustina Nwabuje
- Date: 2010
- Subjects: Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11246 , http://hdl.handle.net/10353/d1001062 , Escherichia coli , Escherichia coli -- Genetics , Effluent quality -- Testing , Water -- Purification , Sewage disposal plants , Escherichia coli -- South Africa -- Eastern Cape , Whole effluent toxicity testing
- Description: Escherichia coli (E. coli) is a common inhabitant of surface waters in the developed and developing worlds. The majority of E. coli cells present in water are not particularly pathogenic to humans; however, there are some present in small proportion that possess virulence genes that allow them to colonize the digestive tract. Pathogenic E. coli causes acute and chronic diarrheal diseases, especially among children in developing countries and in travelers in these locales. The present study, conducted between August 2007 and July 2008, investigated the prevalence and distribution of virulent E. coli strains as either free or attached cells in the final effluents of three wastewater treatment plants located in the Eastern Cape Province of South Africa and its impact on the physico-chemical quality of the receiving water body. The wastewater treatment plants are located in urban (East Bank Reclamation Works, East London), peri-urban (Dimbaza Sewage Treatment Works) and in rural area (Alice Sewage Treatment Works). The effluent quality of the treatment plants were acceptable with respect to pH (6.9-7.8), temperature (13.8-22.0 °C), dissolved oxygen (DO) (4.9-7.8 mg/L), salinity (0.12-0.17 psu), total dissolved solids (TDS) (119-162 mg/ L) and nitrite concentration (0.1-0.4 mg/l). The other xii physicochemical parameters that did not comply with regulated standards include the following: phosphate (0.1-4.0 mg/L); chemical oxygen demand (COD) (5-211 mg/L); electrical conductivity (EC) (237-325 μS/cm) and Turbidity (7.7-62.7 NTU). Results suggest that eutrophication is intensified in the vicinity of the effluent discharge points, where phosphate and nitrate were found in high concentrations. Presumptive E. coli was isolated from the effluent samples by culture-based methods and confirmed using Polymerase Chain Reaction (PCR) techniques. Antibiogram assay was also carried out using standard in vitro methods on Mueller Hinton agar. The viable counts of presumptive E. coli for the effluent samples associated with 180 μm plankton size ranged between 0 – 4.30 × 101 cfu/ml in Dimbaza, 0 – 3.88 × 101 cfu/ml in Alice and 0 – 8.00 × 101 cfu/ml in East London. In the 60 μm plankton size category E. coli densities ranged between 0 and 4.2 × 101 cfu/ml in Dimbaza, 0 and 2.13 × 101 cfu/ml in Alice and 0 and 8.75 × 101 cfu/ml in East London. Whereas in the 20 μm plankton size category presumptive E. coli density varied from 0 to 5.0 × 101 cfu/ml in Dimbaza, 0 to 3.75 × 101 cfu/ml in Alice and 0 to 9.0 × 101 cfu/ml in East London. The free-living presumptive E. coli density ranged between 0 and 3.13 × 101 cfu/ml in Dimbaza, between 0 and 8.0 × 101 cfu/ml in Alice and between 0 and 9.5 × 101 cfu/ml in East London. Molecular analysis successfully amplified target genes (fliCH7, rfbEO157, ial and aap) which are characteristic of pathogenic E. coli strains. The PCR assays using uidA-specific primer confirmed that a genetic region homologous in size to the E. coli uidA structural gene, including the regulatory region, was present in 3 of the E. coli isolates from Alice, 10 from Dimbaza and 8 from East London. Of the 3 E. coli isolates from Alice, 1 (33.3%) was positive for the fliCH7 genes and 3 was positive for rfbEO157 genes. Out of the 10 isolates from Dimbaza, 4 were xiii positive for fliCH7 genes, 6 were positive for the rfbEO157 genes and 1 was positive for the aap genes; and of the 8 isolates from East London, 1 was positive for fliCH7 genes, 2 were for the rfbEO157 genes, 6 were positive for the ial genes. Antimicrobial susceptibility profile revealed that all of the E. coli strains isolated from the effluent water samples were resistant (R) to linezolid, polymyxin B, penicillin G and sulfamethoxazole. The E. coli isolates from Dimbaza (9/10) and East London (8/8) respectively were resistant to erythromycin. All the isolates were found to be susceptible (S) to amikacin, ceftazidime, ciprofloxacin, colistin sulphate, ceftriaxone, cefotaxime, cefuroxime, ertapenem, gatifloxacin, gentamycin, imidazole, kanamycin, meropenem, moxifloxacin, neomycin, netilmicin, norfloxacin and tobramycin. The findings of this study revealed that the Alice wastewater treatment plant was the most efficient as it produced the final effluent with the least pathogenic E. coli followed by the Dimbaza wastewater treatment plant. In addition, the findings showed that the wastewater treatment plant effluents are a veritable source of pathogenic E. coli in the Eastern Cape Province watershed. We suggest that to maximize public health protection, treated wastewater effluent quality should be diligently monitored pursuant to ensuring high quality of final effluents.
- Full Text:
- Date Issued: 2010
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