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Prevalence and characterisation of Mycobacterium species in cattle and sheep at Gauteng abattoirs
Mareledwane, Vuyokazi Epipodia (University of Pretoria, 2022-04)
Bovine tuberculosis (bTB) is a zoonotic disease with a great economic impact estimated at billions of dollars annually worldwide. It is a highly infectious disease infecting mainly wildlife, domestic animals, and humans. The causative agent for the disease is a group of bacteria belonging to the Mycobacterium tuberculosis complex (MTBC). The current study aimed at investigating the prevalence and characterize Mycobacterium species in slaughter animals at Gauteng province abattoirs and to assess the risk of zoonotic tuberculosis posed to abattoir workers. In an attempt to fulfil the objective samples were collected from Gauteng province abattoirs. There is limited data available on abattoir-based studies on bovine tuberculosis (bTB) in South Africa. Abattoirs were chosen for this study as they provide important information of data and they play a key role in passive surveillance on the status of the prevalence of bTB in livestock. The study first reviewed the retrospective data for Mycobacterium spp. in the laboratory data in the Tuberculosis Laboratory at the Agricultural Research Council-Onderstepoort Veterinary Research (ARC-OVR) between 2007 and 2016. Samples that were submitted at the ARC-OVR from nine provinces of South Africa, were analysed for the prevalence of Mycobacterium spp. over these 10 years. The findings revealed that the total prevalence of Mycobacterium spp. was 18.47% [834/4516; 95% Confidence Interval: 17.37 – 19.63] with individual species prevalence at 11.47%, 5.20%, 1.53%, 0.24%, and 0.02%, for Mycobacterium bovis, Mycobacterium Other Than Tuberculosis (MOTT), Mycobacterium tuberculosis, Mycobacterium avium, and Mycobacterium orygis respectively. The findings revealed that M.bovis seems to be the most prevalent Mycobacterium species in both domestic animals at 62.26% and wildlife at 63.68%. The study found that factors for bTB such as the presence of wildlife reservoirs and contact with these reservoirs are a great influence on the transmission of the disease that could result in animals testing positive for Mycobacterium spp. Samples from Limpopo, Mpumalanga, and Gauteng provinces were most likely positive for Mycobacterium spp. The majority of samples from Gauteng province originated from captive wildlife. M. tuberculosis, which is mostly a human pathogen rather than M. bovis, was isolated. The study also highlights that wild carnivores and marine animals are more likely to test positive as these animals are likely to feed off infected prey. Study results showed that most of the organs were prone to infection by Mycobacterium spp. Improved data collection is required so that scientific research can target several aspects highlighted by the information obtained from the records. The laboratory data obtained in this study gave insight into the occurrence of Mycobacterium spp. in wildlife, livestock and their environment in South Africa and the factors that influence the transmission of mycobacteriosis such as bTB. Furthermore, we reviewed serological laboratory data in the Tuberculosis Laboratory at the Agricultural Research Council-Onderstepoort Veterinary Research (ARC-OVR) for the period 2011 - 2016. This was done to further highlight the importance that the combination of both bacteriological data and serology provide better insight into the epidermiology. Out of 10,369 fresh blood samples that were submitted from all of the provinces around South Africa and tested using the Bovigam® kit, the results showed that 1.54% (95% Confidence Interval: 1.30 – 1.78) were positive for bTB, 3.75% (95% Confidence Interval: 3.38 - 4.11) were avian reactors, and 2.29% (95% Confidence Interval: 3.38 - 4.11) were a combination of multiple reactors, equal reactors as well as animals that had a positive screening test. (A multiple reactor means an animal reacted positively to all tuberculin suggesting a possible infection with either Mycobacterium bovis or Mycobacterium forfuitum or both and in some instances even Mycobacterium avium. An equal reactor means an animal reacted positively to both avian or bovine tuberculin due to possible infection with either Mycobacterium bovis or Mycobacterium avium or both). Also, the results showed that the most number of samples tested were buffalo samples with 88.96% (95% Confidence Interval: 88.35-89.56), followed by domestic bovine (cattle) at 9.94% (95% Confidence Interval: 9.37 – 10.52). Our results showed that there is generally a low prevalence of bTB in South Africa. Furthermore, we collected fresh blood samples with corresponding tissue samples at the point of slaughter at abattoirs and samples were subjected to serological assays and bacterial cultureto detect the active interferon-gamma (IFN-γ) and isolate mycobacterial species respectively. The study was conducted at selected abattoirs in the Gauteng Province in South Africa where animals were also subjected to routine meat inspection. A total of 410 fresh blood samples were collected during the slaughter of animals (369 cattle and 41 sheep) from 15 abattoirs and analysed using a Bovigam® 1G-test kit (Prionics AG, Lelystad, The Netherlands) Bovigam test kit with bovine, avian, and fortuitum purified protein derivatives (PPD) as blood stimulating antigens. The estimated prevalence of bTB in cattle was 4.4% (95% Confidence Interval: 2.4%-7.3%) and the prevalence of avian reactors was 6.0% (95% Confidence Interval: 3.6%-9.2%). None of the sheep with valid test results (i.e. test samples that have passed quality control checks) were positive for bTB and none were avian reactors (95% Confidence Interval: 0% - 15%). Additionally, we collected a total of 2000 tissue samples comprising of lungs, liver, spleen, and lymph nodes were collected from 19 abattoirs. Additionally, 19 environmental samples were collected from feedlots, where animals usually drink as they await slaughter. These samples were cultured on Lowenstein-Jensen (LJ) media containing both pyruvate and glycerol. The cultures were monitored for growth over 10 weeks. Colonies that displayed morphology resembling that of Mycobacteria were first subjected to Ziehl-Neelsen (ZN) staining, then acid fast bacteria were subjected to a polymerase chain reaction (PCR) assay targeting Mycobacterium tuberculosis complex bacteria. No MTBC species were detected by PCR. The same isolates were subjected to the 16S rRNA PCR and gene sequence analysis to investigate and identify non-tuberculous mycobacteria (NTM) species. Isolations were made from eight animals originating from four abattoirs and were identified as Mycobacterium species by amplification of a product corresponding to 577 bp in size following gel electrophoresis. Sequence data analysis of the 8 isolates revealed only two of the isolates to be Mycobacterium colombiense (99.81% identity) and Mycobacterium simiae (99.42% identity). The remaining six isolates were identified as members of the Actinomadura species. From the environmental samples, isolation was made from three samples, and two were identified to genus level (Mycobacterium species). The remaining isolate was identified as Mycobacterium senuense (99.22% identity). For the slaughtered livestock, the results suggest that there was no risk of transmission of bTB to abattoir workers and the meat was probably safe to consume. Although NTM have been implicated to be potentially involved in causing tuberculosis-like diseases, their rate of occurrence in the current study was extremely low, hence insignificant. The study has,however, highlighted that the additional use of serological assays such as the interferon-gamma (IFN-γ) assay can help detect early signs of infection, thus establishing the status of infection. Additionally, interviews were conducted in the form of questionnaires to establish the knowledge, attitude, and practices (KAP) of abattoir workers regarding Tuberculosis (TB). The objective of the study was to obtain data from abattoir workers in Gauteng Province, South Africa and to assess the risk of zoonotic tuberculosis transmission among workers. This study revealed an overall knowledge score of the respondents to be 42% (95% Confidence Interval: 37.48 - 46.42) (P<0.001), with 88.35% of the respondents knowing of the disease. The overall knowledge of TB score was determined by calculating the overall average knowledge of the respondents. More than 45% of the participants were aware of zoonotic TB and how the disease is transmitted. Overall, the results of the study suggested that there are certain practices that abattoir workers are engaged in, such as the consumption of unpasteurized milk and undercooked or raw meat, slaughtering of animals at home as well as taking care of animals at home/work that may promote transmission of zoonotic tuberculosis among themselves and their communities at large. In conclusion, we report on the prevalence of Mycobacterium spp in slaughter animals in abattoirs in Gauteng Province, South Africa, the potential zoonotic risks posed to abattoir workers and on the 10-year retrospective data on samples submitted to the Tuberculosis laboratory (ARC-OVR) analysed for the prevalence of Mycobacterium spp. over this 10-year
The contribution of legal frameworks on access to information to socio-economic progress in Africa : case studies of Nigeria, South Africa and Uganda
Shyllon, Ololade Olakitan (University of Pretoria, 2016-09)
The wanting state of socio-economic development in Africa is well documented. The regrettable paradox is that, with the abundance of natural resources in the form of mineral deposits, arable land and human resources, most African States are well placed to ensure a the standard of living necessary for a dignified life for its people. However, corruption, bad governance, lack of transparency and accountability continue to deprive most on the continent of their basic socio-economic needs. Although not explicitly provided as a right in any of the international human rights instruments, access to information has come to be recognised internationally as a right, separate and distinct from the right of freedom of expression from which it originates. As a result, African States are increasingly adopting legal frameworks to give effect to this right within their domestic legal systems. This thesis adopts a descriptive, analytical and qualitative case study approach in demonstrating the utility of the constitutional, legislative and alternative generic frameworks on access to information in contributing to socio-economic progress. Using Nigeria, South Africa and Uganda as case studies, empirical evidence is provided of the enabling role of access to information in improving socio-economic progress in Africa. Despite the general historical deficiencies in their development and implementation in Africa, the combination of constitutional provisions and specific legislation on access to information, provide the best domestic legal framework for the effective domestic implementation of the right of access to information. Furthermore, beyond successful reliance on these legal frameworks, socio-economic progress can only be attained with the strategic use of information so acquired. However, given that majority of African States have neither of these frameworks, the use of alternative legal frameworks such as those on public procurement, environmental impact assessment and anti-corruption should continuously be explored and exploited as viable alternatives. To achieve more widespread and impactful contribution of access to information on socio-economic progress in Africa, this thesis recommends not only increased efforts towards the adoption and effective implementation of all three layers of legal frameworks but also calls for reinvigorated civil society efforts focusing on strategic advocacy, litigation, capacity building and collaboration.
Exposure of wild carnivores to rabies and Mokola viruses in provincial and private game reserves in Mpumalanga province
Letsholo, Samantha Laone (University of Pretoria, 2014-03)
Rabies, a disease caused by members of the genus Lyssavirus, family Rhabdoviridae is a significant veterinary and public health threat globally including South Africa. This fatal but preventable zoonotic disease causes encephalitis in all warm-blooded vertebrates including humans. At least 50 000 human fatalities and 5 million rabies exposures occur annually. However, in developing countries where both domestic (urban type) and wild (sylvatic type) rabies cycles are common and transmission occurs readily across species barriers, the disease has proven difficult to eradicate. In South Africa, the main maintenance host species include the domestic dog, Canis lupus familiaris, in Limpopo province, Mpumalanga, Eastern Cape and coastal KwaZulu/Natal provinces, and wildlife host species including the black-backed jackal, Canis mesomelas, the bat-eared fox, Otocyon megalotis, (both maintain the canid rabies biotype) and the yellow mongoose, Cynictis penicillata, that maintains the mongoose rabies biotype. There are currently 12 Lyssavirus species worldwide. In South Africa, Lagos bat virus and Duvenhage virus are rarely diagnosed in terrestrial animals and are generally associated with fruit-eating (Epomophorus wahlbergi) and insect-eating (Minopterus schreibersii) bats respectively. To date, Mokola virus (MOKV) and Ikoma virus (IKOV) are the only lyssaviruses that have not been recovered from bat species. Between 1928 and 2006, rabies was diagnosed in 4952 wildlife species in South Africa, the majority of which were mongoose species, especially Cynictis penicillata, followed by the bat eared fox, Otocyon megalotis, and the black-backed jackal, Canis mesomelas. Only one case of rabies was diagnosed in lions over the same period and no cases of Mokola virus infections have been documented in South African wildlife thus far. This project was undertaken to determine the prevalence of neutralising antibodies to RABV and MOKV, the latter a rabies-related virus, in serum samples originating from lions in private and provincial game reserves adjacent to the Mnisi communal area in Mpumalanga province and in the greater Kruger National Park. The expected benefits of the study include the evaluation of exposure of lions to RABV and MOKV in the above-mentioned region of South Africa, further improving the understanding of the epidemiology of the disease in a human/domestic animal/wildlife interface. Stored lion serum samples from the University of Pretoria, Department of Veterinary Tropical Diseases (n=140) and the Agricultural Research Council-Ondesterpoort Veterinary Institute (ARC-OVI), OIE Rabies Laboratory (n=20) and sera from other carnivores from the ARC-OVI (n=5) were tested for antibodies to classical rabies virus and Mokola virus using the fluorescent antibody virus neutralization test. All 165 sera were collected from private and provincial game reserves in Mpumalanga province between the years 1995 and 2012. The cut-off point for both RABV and MOKV serum samples was determined as 0.5 IU/ml and 0.95 IU/ml respectively. Any serum sample with a titre less than 0.5 IU/ml was regarded as negative, while any serum sample with a titre equal to or above 0.5 IU/ml was regarded as positive for RABV. Any serum sample with a titre less than an equivalent of log100.95 dilution was regarded as negative, while any serum sample with a titre equal to or above log100.95 dilution was regarded as positive for MOKV. Lion sera collected between 1995 and 2000 (n=140) had a 2.1% prevalence of RABV neutralizing antibodies and a 0.7% prevalence of MOKV antibodies. Sera collected from lions between 2010 and 2012 (n=20) had a 65.0% prevalence of RABV antibodies and a 26.3% prevalence of MOKV antibodies. Due to the uncertain vaccination status of samples collected between 2010 and 2012 and the significant differences in prevalence between the lion serum collected between 1995 and 2000 and between 2010 and 2012, the two groups of lions were treated as two separate populations. Other carnivores (n=5) had a prevalence of RABV neutralising antibodies of 40.0% and a prevalence of MOKV neutralising antibodies of 25.0%. When calculating the difference of proportions for the prevalences of the antibodies of the two lyssaviruses within each population, the prevalences were not significantly different. The results of the study suggest that lions in Kruger National Park have been exposed to RABV (2.1%) and or possibly another lyssavirus related to MOKV at low frequencies between 1995 and 2000. The sample sizes of the lions from other game reserves and other carnivores were too small to make a valid conclusion thus larger sample population sizes must be considered for future studies in these areas. Since the neutralising antibody prevalences in the Kruger National Park lions were not significantly different for both viruses, it can be concluded that if a lion presents with clinical signs of rabies, the disease is just as likely to be caused by RABV as MOKV.
The South African Philatelist : 2025
Bulpitt, A.; van der Molen, P.; Erasmus, L.; Wigston, D.; Messenger, R.; Rose, A. (The Philatelic Federation of Southern Africa, 2025)
The Philatelic Federation of South Africa (PFSA) is a voluntary association organised as a federation of clubs & societies for stamp collectors and philatelists of all ages and all types. To produce the up-to-date journal locally is no easy matter, but we shall continue to give our readers what we think they will appreciate most. The journal is managed by a collector for the benefit of collectors, and as no dealer has any choice in the management, philatelists will realise that they have a paper which will cater for their wants, and give them reliable, unbiassed advice.
Cardiac troponin I immunoassay validation, reference interval determination and serum cardiac troponin I changes in translocated southern-central black rhinoceros (Diceros bicornis minor) and southern white rhinoceros (Ceratotherium simum simum)
Rautenbach, Yolandi (University of Pretoria, 2024-10)
The abundance and range of occurrence of the two rhinoceros species in sub-Saharan Africa, the southern-central black (Diceros bicornis minor) and southern white (Ceratotherium simum simum) rhinoceros, have decreased dramatically. Common threats to rhinoceros conservation include poaching, habitat fragmentation and loss,international trade in illegal rhinoceros products, and reduced financial resources due to global financial recessions and pandemics. Translocation of wildlife species is a commonly used tool for the conservation of threatened and endangered animals, with a focus on restoring and enhancing populations. It plays an integral part in national and international conservation plans for African rhinoceros. Chemical immobilisation is often used during translocation, with etorphine forming the basis of most drug combinations used. Ensuring animal welfare during wildlife transport is critical and dehydration, electrolyte imbalances, a negative energy balance, muscle damage, protein catabolism, stress-induced immunomodulation, and oxidative stress are the main pathophysiological findings reported in rhinoceros translocated over long distances. Investigation into possible cardiomyopathy in transported rhinoceros has been hampered by the lack of validated immunoassays to measure serum biomarkers, specifically cardiac troponin I (cTnI), in rhinoceros. The broad objectives of this study were therefore to 1) sequence the cTnI gene in both rhinoceros species, to obtain the inferred amino acid sequences from the messenger ribonucleic acid (mRNA) transcript sequences, and assess the potential a^inity of several commercial cTnI immunoassays for detecting cTnI in African rhinoceros; 2) validate two point-of-care (POC) cTnI immunoassays for use in African rhinoceros; 3) to generate cTnI reference intervals (RIs) on the high-sensitivity (hs)-cTnI immunoassay in both rhinoceros species and apply subset partitioning in white rhinoceros that were chased by helicopter during capture versus those that were captured in a boma and therefore not chased; and 4) investigate the serum cTnI changes in long-distance translocated rhinoceros and in rhinoceros chemically immobilised with di^erent drug protocols during capture. Best practice guidelines for method validation, quality control (QC) and RI generation as published by the American Society for Veterinary Clinical Pathology were followed. Expert consensus recommendations on the clinical laboratory practice for hs-cTnI assays as advised by the International Federation of Clinical Chemistry Task Force on Clinical Applications of Biomarkers (IFCC TF-CB) were also complied with. The mRNA cTnI transcript sequences were obtained by RNA extraction from myocardium of deceased rhinoceros followed by primer design, complementary deoxyribonucleic acid (cDNA) synthesis using reverse transcription polymerase chain reaction, and Sanger sequencing. The percentage identity between black and white rhinoceros cDNA nucleotide sequences was 99%, while inferred amino acid sequences were identical. There were five amino acid di^erences between humans and rhinoceros in the epitope binding sites of immunoassay antibodies and five assays contained antibodies against epitopes that were not conserved. Nevertheless, only one assay was deemed unlikely to cross-react with rhinoceros cTnI and five assays were found to be suitable for further investigation into cTnI measurement in African rhinoceros. The Siemens Stratus CS Acute Care troponin I cTnI and Siemens Atellica VTLi hs-cTnI were the two POC cTnI immunoassays selected for analytical method validation. Validation experiments included precision studies, reportable range, haemoglobin interference studies, recovery studies, and detection limit studies with results assessed against two total allowable error (TEa) performance goals, namely 30% and 70%. Imprecision was acceptable and met low cTnI concentration performance goals. Thereportable ranges were similar to the manufacturer’s specifications. For the Stratus CS, high haemoglobin concentrations in white rhinoceros resulted in bias. The QC validation results showed that a simple 13s QC rule using two levels of QC material and a TEa of 70% could be used in both analysers, except at very low cTnI concentrations in the Atellica VTLi. This study showed that both cTnI POC analysers are suitable for use in African rhinoceros and analytical performance goals for low cTnI concentrations in hs-cTnI assays were met. To allow for the identification of cardiomyocyte injury in African rhinoceros, RIs were established for both species of rhinoceros using the validated hs-cTnI assay. Reference intervals were generated from 62 and 87 apparently healthy, free-living immobilised black and white rhinoceros, respectively. Additionally, the 99th percentile upper reference limits were also determined. Of interest is that subclass partitioning was valid for white rhinoceros based on whether they were immobilised in a boma or chased by a helicopter before being immobilised. Although chemical capture and translocation (involving capture and long-distance transport) in African rhinoceros are essential components of conservation strategies aimed at improving the conservation status of the species, several adverse pathophysiological e^ects, specifically hypoxaemia, acidosis and muscle damage, are associated with these processes which negatively impact rhinoceros’ welfare. Serum cTnI concentration was measured using the Atellica VTLI hs-cTnI assay on stored serum samples collected during four long-distance translocation studies in black and white rhinoceros and in one chemical immobilisation study in white rhinoceros. Measurement of serum cTnI concentration in rhinoceros translocated over long distances showed significantly increased cTnI concentrations during transportation and at release when compared to concentrations at capture. The degree of cTnI increase was more significant in cohorts chased and darted from helicopters. Concurrent skeletal and cardiac muscle damage was demonstrated in transported black and white rhinoceros, indicative of capture myopathy (CM) in these animals. Furthermore, hypoxaemia, acidosis and a negative energy balance were correlated with elevated cTnI concentrations, highlighting specific areas in procedures involving chemical immobilisation, capture, and transport that need to be addressed to mitigate these adverse effects. The results of this study will allow wildlife veterinarians involved in African rhinoceros conservation procedures, and in the treatment of injured animals, to assess if cardiomyocyte damage is present. This assessment will allow for cardioprotective adjustments to be implemented in these procedures, resulting in improved animal welfare. Demonstration of concurrent elevated skeletal and cardiac muscle biomarkers in translocated rhinoceros will assist wildlife veterinarians in identifying animals at risk of developing CM that should be kept in confinement (boma) at the receiving end of the journey for monitoring and reduction in stress before release.