Distribution of culturable vibrio species in freshwater resources of Cacadu, or Tambo and Chris Hani district municipalities
- Authors: Gaqavu, Sisipho
- Date: 2017
- Subjects: Vibrio--South Africa--Eastern Cape Vibrio infections--South Africa--Eastern Cape Foodborne diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11571 , vital:39085
- Description: Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29percent) followed by V. vulnificus (4percent), V. fluvialis (4percent) and the least was V. parahaemolyticus (3percent). The remaining unidentified 60percent were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83percent of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use.
- Full Text:
- Date Issued: 2017
- Authors: Gaqavu, Sisipho
- Date: 2017
- Subjects: Vibrio--South Africa--Eastern Cape Vibrio infections--South Africa--Eastern Cape Foodborne diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/11571 , vital:39085
- Description: Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29percent) followed by V. vulnificus (4percent), V. fluvialis (4percent) and the least was V. parahaemolyticus (3percent). The remaining unidentified 60percent were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83percent of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use.
- Full Text:
- Date Issued: 2017
Screening of shark liver extracts for potential antimicrobial properties against selected pathogenic bacterial strains
- Authors: Mrwetyana, Thandolwethu
- Date: 2017
- Subjects: Fishes -- Diseases Pathogenic bacteria
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/13004 , vital:39431
- Description: The growing problem of antimicrobial resistance prevents the effective treatment of bacterial infections. Traditional antibiotics such as penicillin have been rendered ineffective against most microbial pathogens. This has led to an increased need for the development of new and improved drugs. The marine environment contains a great array of organisms with unique biological properties, but still remains one of our most underutilized biological resources. The aim of this study was to screen different shark liver extracts for antimicrobial properties. After optimizing the extraction methods, the liver extracts (oil and aminosterol) of three different shark species, namely the Dogfish (Squalus acanthias), the Catshark (Scyliorhinus capensis) and the Hammerhead (Sphyrna zygaena) shark, were screened for antimicrobial properties using the Kirby-Bauer disc diffusion method against selected bacterial pathogens (Helicobacter pylori, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus), after which the MIC was determined using the modified broth micro-dilution described by Vollekova et al. (2001). The most active extract was fractionated using thin layer chromatography, and TLC-direct bioautography was used to determine the antimicrobial properties of the fractionated compounds. The Folch et al and the Shinnar et al methods yielded the highest extract volumes for oil and aminosterol consecutively, and the catshark and dogfish aminosterol extract showed greater levels of bioactivity against all selected bacterial pathogens, with S. aureus showing highest susceptibility levels to both extracts. A total of 22 compounds were observed in the developed plates with two compounds (Rf 0.53 and 0.79) showing antimicrobial activity. Certain shark liver extracts possess antimicrobial properties that have the potential to be used in the development of new antimicrobial drugs.
- Full Text:
- Date Issued: 2017
- Authors: Mrwetyana, Thandolwethu
- Date: 2017
- Subjects: Fishes -- Diseases Pathogenic bacteria
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/13004 , vital:39431
- Description: The growing problem of antimicrobial resistance prevents the effective treatment of bacterial infections. Traditional antibiotics such as penicillin have been rendered ineffective against most microbial pathogens. This has led to an increased need for the development of new and improved drugs. The marine environment contains a great array of organisms with unique biological properties, but still remains one of our most underutilized biological resources. The aim of this study was to screen different shark liver extracts for antimicrobial properties. After optimizing the extraction methods, the liver extracts (oil and aminosterol) of three different shark species, namely the Dogfish (Squalus acanthias), the Catshark (Scyliorhinus capensis) and the Hammerhead (Sphyrna zygaena) shark, were screened for antimicrobial properties using the Kirby-Bauer disc diffusion method against selected bacterial pathogens (Helicobacter pylori, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus), after which the MIC was determined using the modified broth micro-dilution described by Vollekova et al. (2001). The most active extract was fractionated using thin layer chromatography, and TLC-direct bioautography was used to determine the antimicrobial properties of the fractionated compounds. The Folch et al and the Shinnar et al methods yielded the highest extract volumes for oil and aminosterol consecutively, and the catshark and dogfish aminosterol extract showed greater levels of bioactivity against all selected bacterial pathogens, with S. aureus showing highest susceptibility levels to both extracts. A total of 22 compounds were observed in the developed plates with two compounds (Rf 0.53 and 0.79) showing antimicrobial activity. Certain shark liver extracts possess antimicrobial properties that have the potential to be used in the development of new antimicrobial drugs.
- Full Text:
- Date Issued: 2017
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