Molecular characterization of the Mycobacterium tuberculosis complex (MTC) of raw milk from selected dairy farms in the Eastern Cape
- Authors: Komani, Nosiphiwo
- Date: 2013
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11276 , http://hdl.handle.net/10353/d1013157 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Description: Tuberculosis (TB) is an ancient infectious disease that has been infecting different populations around the globe and it has also been considered as one of the most successful human and animal disease. TB found in animals such as cattle and other known bovids is known as bovine tuberculosis. Bovine tuberculosis (BTB) is an infectious disease found in cattle mainly caused by Mycobacterium bovis. M. bovis is a member of the Mycobacterium tuberculosis complex (MTC) together with M. tuberculosis, M. africanum, and M. canetti where the natural host is humans; whereas M. caprae, M. microti and M. pinnipedii usually have animals as their natural host. In this study the molecular characterization of the MTC from cow milk in the Eastern Cape was investigated. One hundred and twenty samples (40 ml each) were collected from three dairy farms in the Eastern Cape, South Africa. These samples were processed using a modified Petroff decontamination method. Sample processing was followed by DNA isolation using a Zymo Bacterial/Fungal DNA Kit and the amplification and detection of the MTC was done using the Seeplex MTB Nested ACE assay. The drug susceptibility tests were done using GenoTypeMTBDRplus assay which detects mutations and resistance to INH (isoniazid) and RMP (rifampicin). The milk isolates were further analyzed using a spoligotyping method which is based on the PCR amplification of a highly polymorphic direct repeat locus in the M. tuberculosis genome which detects and types the MTC. A percentage of 20.8 % samples were found to be positive for MTC using the Seeplex MTB Nested ACE assay. There were 42.1 % samples that were resistant to both INH and RMP with the rest sensitive to either INH or RMP. The spoligotyping method showed that 78.3 % samples resembled Family 33 strains and the rest (21.7 %) resembled a spoligotyping signature known to be that of M.africanum. Both these strains belong to the Ancestral lineage with Indo-Oceanic and West Africa 2 lineage. The outcomes of our study showed that molecular methods for detection of MTC can be applied directly on milk samples without the need for culturing.
- Full Text:
- Date Issued: 2013
- Authors: Komani, Nosiphiwo
- Date: 2013
- Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11276 , http://hdl.handle.net/10353/d1013157 , Mycobacterium tuberculosis -- South Africa -- Eastern Cape , Milk -- South Africa -- Eastern Cape , Dairy farms -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape , Tuberculosis in cattle -- South Africa -- Eastern Cape
- Description: Tuberculosis (TB) is an ancient infectious disease that has been infecting different populations around the globe and it has also been considered as one of the most successful human and animal disease. TB found in animals such as cattle and other known bovids is known as bovine tuberculosis. Bovine tuberculosis (BTB) is an infectious disease found in cattle mainly caused by Mycobacterium bovis. M. bovis is a member of the Mycobacterium tuberculosis complex (MTC) together with M. tuberculosis, M. africanum, and M. canetti where the natural host is humans; whereas M. caprae, M. microti and M. pinnipedii usually have animals as their natural host. In this study the molecular characterization of the MTC from cow milk in the Eastern Cape was investigated. One hundred and twenty samples (40 ml each) were collected from three dairy farms in the Eastern Cape, South Africa. These samples were processed using a modified Petroff decontamination method. Sample processing was followed by DNA isolation using a Zymo Bacterial/Fungal DNA Kit and the amplification and detection of the MTC was done using the Seeplex MTB Nested ACE assay. The drug susceptibility tests were done using GenoTypeMTBDRplus assay which detects mutations and resistance to INH (isoniazid) and RMP (rifampicin). The milk isolates were further analyzed using a spoligotyping method which is based on the PCR amplification of a highly polymorphic direct repeat locus in the M. tuberculosis genome which detects and types the MTC. A percentage of 20.8 % samples were found to be positive for MTC using the Seeplex MTB Nested ACE assay. There were 42.1 % samples that were resistant to both INH and RMP with the rest sensitive to either INH or RMP. The spoligotyping method showed that 78.3 % samples resembled Family 33 strains and the rest (21.7 %) resembled a spoligotyping signature known to be that of M.africanum. Both these strains belong to the Ancestral lineage with Indo-Oceanic and West Africa 2 lineage. The outcomes of our study showed that molecular methods for detection of MTC can be applied directly on milk samples without the need for culturing.
- Full Text:
- Date Issued: 2013
Prevalence and antibiotic resistance determinants of Escherichia coli pathotypes obtained from raw milk in two farms from the Eastern Cape, South Africa: public health implications
- Authors: Caine, Lesley-Anne
- Date: 2013
- Subjects: Raw Milk -- Escherichia coli , Polymerase -- Chain Reaction (PCR)
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11277 , http://hdl.handle.net/10353/d1015525 , Raw Milk -- Escherichia coli , Polymerase -- Chain Reaction (PCR)
- Description: Milk quality continues to be a topic of intense debate in the dairy industry, medical and public health communities. Production of maximum quantities of high-quality milk is an important goal of every dairy operation. High-quality milk must contain a low number of somatic cells and low bacteria count, and must be free of human pathogens and antibiotic residues. The objective of this study was to determine the prevalence of E. coli in unpasteurized milk recovered from Middledrift and Fort Hare dairy. In this study 400 milk samples were collected from two commercial farms (Middledrift and Fort Hare) in the Eastern Cape, South Africa, 200 raw milk samples from each farm. Samples were cultured on violet red bile mug-agar (VRB-MUG Agar) and incubated at 37ºC for 24 hours and preliminary identified by Gram stain and catalase test. Isolates that were Gram negative and catalase positive were screened for a marker of E. coli uidA gene using PCR assays. Middledrift dairy farm had 50 (25%) E. coli isolated from raw milk and Fort Hare farm showed 37 (18.5%) E. coli present in the milk samples. The presence of E. coli found in the milk samples points to the fact that fecal contamination was unavoidable and traditional practices are likely to contribute to the contamination of the milk and proliferation of the microorganisms.
- Full Text:
- Date Issued: 2013
- Authors: Caine, Lesley-Anne
- Date: 2013
- Subjects: Raw Milk -- Escherichia coli , Polymerase -- Chain Reaction (PCR)
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11277 , http://hdl.handle.net/10353/d1015525 , Raw Milk -- Escherichia coli , Polymerase -- Chain Reaction (PCR)
- Description: Milk quality continues to be a topic of intense debate in the dairy industry, medical and public health communities. Production of maximum quantities of high-quality milk is an important goal of every dairy operation. High-quality milk must contain a low number of somatic cells and low bacteria count, and must be free of human pathogens and antibiotic residues. The objective of this study was to determine the prevalence of E. coli in unpasteurized milk recovered from Middledrift and Fort Hare dairy. In this study 400 milk samples were collected from two commercial farms (Middledrift and Fort Hare) in the Eastern Cape, South Africa, 200 raw milk samples from each farm. Samples were cultured on violet red bile mug-agar (VRB-MUG Agar) and incubated at 37ºC for 24 hours and preliminary identified by Gram stain and catalase test. Isolates that were Gram negative and catalase positive were screened for a marker of E. coli uidA gene using PCR assays. Middledrift dairy farm had 50 (25%) E. coli isolated from raw milk and Fort Hare farm showed 37 (18.5%) E. coli present in the milk samples. The presence of E. coli found in the milk samples points to the fact that fecal contamination was unavoidable and traditional practices are likely to contribute to the contamination of the milk and proliferation of the microorganisms.
- Full Text:
- Date Issued: 2013
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