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Genetic characterization of ticks and tick borne prokaryotic pathogens of urban stray dogs in Potchefstroom, South Africa
Get PDFThe North-West University, Doctor of Philosophy in Science with Environmental
Sciences, Potchefstroom CampusTicks are well documented for their ability to transmit pathogenic organisms of medical, veterinary and economical importance mostly to a variety of animal hosts and humans. Ticks harbour various members of bacteria, archaea, and eubacteria and several eukaryotic organisms, including fungi, nematodes, and protozoa, collectively referred to as the microbiome. Associations between the ticks and the microbiota affect several aspects of the ticks such as their vectorial competence, survival, and reproductive fitness. The bacterial composition of ticks varies due to a lot of factors, including but not limited to the tick’s life cycle, host ecology, and the absence or presence of bacterial pathogens. Therefore, this study aimed at conducting a systematic review focusing on the global prevalence of R. sanguineus and H. elliptica, as well as the tick-borne pathogens they harbour. This study also sought to identify the tick species and tick-borne pathogens infesting dogs collected from the Potchefstroom Animal Welfare Society (PAWS). Lastly this study aimed to identify the bacterial communities of dog blood and ticks from the PAWS in comparison to colony ticks from gnotobiotic hosts. For the systematic review, the Scopus, ScienceDirect, PubMed, and Web of Science databases were searched for English journal articles which were assessed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This systematic review was registered on PROSPERO under the following ID: CRD42022327372. Of the studies included in the systematic review, 247 and 19 articles collected and identified R. sanguineus and H. elliptica respectively, whereas 15 articles managed to collect and identify both tick species. In total 121 articles were included in the systematic review that reported the presence of haemoparasite infections within R. sanguineus or H. elliptica ticks. Respectively, 119 and 2 of the aforementioned articles reported the presence of tick-borne pathogens within R. sanguineus and H. elliptica ticks respectively. In addition, only 1 article reported the presence of tick-borne pathogens within both R. sanguineus and H. elliptica ticks. The prevalence of the haemopathogens was similar to the prevalence of their tick hosts, thus indicating the potential of tick-borne pathogens to spread and inhabit new niches. Articles included in the systematic review reported the presence of R. sanguineus and H. elliptica ticks collected from companion animals, vegetation, livestock, humans, as well as several wildlife species. The tick species identification method in the included articles of the systematic review was done employing morphological identification (n=222), as well as a combination of morphological identification and conventional PCR (n=29). Articles that detected tick-borne pathogens within R. sanguineus used molecular techniques (n=139) as well as morphological techniques (n=5). Articles that detected tick-borne pathogens within H. elliptica used molecular techniques (n=2). There were 64 countries that reported the presence of R. sanguineus, whereas H. elliptica was only reported in 6 countries. It is considered that R. sanguineus has a global prevalence, mainly in regions that are tropical or subtropical. H. elliptica was reported in South Africa and countries with close proximity to South Africa. The close proximity between ticks and travelling hosts or migratory hosts (such as birds), is one of the main contributors to the global prevalence of R. sanguineus and the prevalence of H. elliptica in the neighbouring countries of South Africa. In this study tick specimens (n=300) and blood (n=50) were collected from naturally infected dog hosts (n=50) residing at the PAWS located in Potchefstroom of the North West Province, South Africa. In addition, eggs were also collected (n=6 egg batches) from ticks that laid eggs after collection. Tick specimens were morphologically identified and genetically using PCR CO1 and 18S rRNA assays, whilst genus or species specific PCR assays were performed for detection of various bacterial pathogens of veterinary importance from tick pools (n=81), egg batches (n=6), and dog blood (n=50). The PCR amplicons were Sanger sequenced and aligned using the nucleotide Basic Local Alignment Search Tool (BLASTn) for confirmation of detected pathogen identity. In this study, two tick species were identified namely R. sanguineus with an overall abundance of 70.7% (212/300) and H. elliptica with an overall abundance of 29.3% (88/300) based on morphological key features and DNA analysis. For the CO1 gene all of the tick specimens morphologically identified as H. elliptica were 96.89 to 97.74% similar to H. elliptica gene sequences on the NCBI database. On the other hand, the tick species morphologically identified as R. sanguineus were 97.20 to 99.84% similar to R. sanguineus gene sequences on the NCBI database. For the 18S rRNA gene all of the tick specimens morphologically identified as H. elliptica were 99.26 to 99.63% similar to H. elliptica gene sequences on the NCBI database. On the other hand, the tick species morphologically identified as R. sanguineus were 98.53 to 99.90% similar to R. sanguineus gene sequences on the NCBI database. None of E. canis or A. phagocytophylum were detected by PCR from DNA of ticks, egg batches, or dog blood samples from this study. The overall occurrence of C. burnetii within pooled tick DNAs was 9.88% (8/81). The C. burnetii were harboured by 8.82% (3/34) of H. elliptica ticks and 10.64% (5/47) of R. sanguineus ticks. The overall occurrence of C. burnetii within egg batches was 16.67% (1/6). The C. burnetii was present in 25% (1/4) H. elliptica egg batches. One of the PCR products was successfully sequenced and BLASTn search results revealed that the aforementioned gene sequence was 96.89 to 100% similar to C. burnetii sequences on the NCBI database. The overall occurrence of Rickettsia spp. within tick pools was 6.17% (5/81). Rickettsia spp. were harboured by 11.76% (4/34) of H. elliptica ticks and 2.13% (1/47) of R. sanguineus ticks. The overall occurrence of Rickettsia spp. within egg batches was 16.67% (1/6). Rickettsia spp. were present in 25% (1/4) H. elliptica egg batches. The BLASTn results revealed that two of the Rickettsia spp. were 98.75 to 100% similar to R. conorii gene sequences on the NCBI database. Another two Rickettsia spp. sequences. BLASTn search results revealed that they were 97.18 to 99.70% similar to R. massiliae gene sequences on the NCBI database. In addition, one R. sanguineus tick pool was co-infected with both C. burnetii and Rickettsia spp. Lastly, this study used Illumina next-generation sequencing targeting the V3 and V4 regions of the 16S rRNA gene to determine bacterial microbiota from R. sanguineus (n=1) and H. elliptica (n=1), dog blood samples from which ticks were collected. The microbiota of these ticks and dog blood was compared with that of colony reared ticks. Dominant bacterial phyla were identified as Proteobacteria (54.02%), Bacteroidetes (18.03%), and Actinobacteria (11.76%). The dominant bacterial classes were identified as Gammaproteobacteria (41.61%), Bacteroidia (17.93%), Alphaproteobacteria (11.20%), and Actinobacteria (11.11%). Dominant orders were identified as Betaproteobacteriales (14.78%) and Coxiellales (14.40%). Dominant bacterial families were identified as Coxiellaceae (14.40%) and Burkholderiaceae (12.12%). The dominating bacterial genera were identified as Coxiella (14.40%). Additionally, at class and genus levels the relative abundance between the R. sanguineus and H. elliptica of the colony ticks from gnotobiotic hosts were similar, whereas the relative abundances of the R. sanguineus and H. elliptica ticks and their natural dog hosts were similar indicating similarities between the species richness, whereas the relative abundance between the colony ticks from gnotobiotic hosts and the ticks collected from naturally infected dog hosts was different indicating differentiation between the species richness. The results of the study indicate the presence of several bacterial communities harboured by and shared between R. sanguineus and H. elliptica ticks from naturally infected dog hosts, dog blood, and R. sanguineus and H. elliptica ticks from gnotobiotic hosts. The aforementioned bacterial communities are taxonomically similar among all the sample types but the relative abundances of the bacterial communities of both the dog blood and ticks from natural dog hosts differ compared to the ticks from gnotobiotic hosts, specifically among the Rickettsia spp. and Coxiella spp. that were very high in the tick specimens collected from gnotobiotic hosts. Additionally, several bacterial genera detected in the sample types were of medical, veterinary, and ecological importance. The systematic review has provided consolidated insight on the prevalence of R. sanguineus, H. elliptica, and their tick-borne pathogens, as well as other associated subjects, such as the expansion of ticks and their tick-borne pathogens to non-endemic areas, the effects of coinfections, and tick identification and parasite detection methods. The results of this study indicate that dogs admitted to PAWS are infected by R. sanguineus and H. elliptica ticks which are harbouring tick-borne pathogens responsible for causing zoonotic diseases.-Chemical Industries Education & Training Authority
- CHIETA bursar
The benefits and challenges of clinical accompaniment of nursing students: A systematic review
Get PDF, North-West University, Mahikeng CampusThe clinical accompaniment of nursing students is crucial in providing quality healthcare. The benefits thereof include the building of confidence, professionalism, and self-esteem in both nursing students and educators equally, which therefore contribute to providing high levels of holistic healthcare to patients.
Prior to this study, limited research was available on the benefits of clinical accompaniment for nursing students. As such, identification of the advantages thereof will be helpful in identifying gaps found in the clinical accompaniment of nursing students.
The purpose of this study was to determine the best available evidence regarding the benefits and challenges of clinical accompaniment of nursing students. A qualitative systematic literature review was conducted as a design.
The seven steps of systematic reviews adopted from the manual of the Academy of Nutrition and Dietetics (Deepa et al., 2016:311) were followed. These steps comprise of: (1) the identification of a clear clinical problem, (2) the comprehensive identification of studies and generation of search strategy, (3) the review of study relevance, (4) evaluation of the methodological quality of individual studies included in the review, (5) extraction of data from each study and document, (6) data analysis, and (7) drawing of conclusions. After the first three steps, a sample of 37 studies were obtained and it was eligible for critical appraisal, after which only 21 qualitative studies were finally included, as they met the inclusion criteria, and were retained for data extraction and analysis.
Two categories and 10 themes with four sub-themes emerged from the synthesis. The main categories include the benefits of clinical accompaniment and challenges experienced during clinical accompaniment of nursing students, effective clinical supervision, and support to students, positive or negative contribution of the Clinical Learning Environment (CLE) for nursing students, and challenges experienced by nursing students during their stay in the clinical environment.
The results show that the review of 21 qualitative articles and sources support the findings of the review. Strategies to identify the benefits and challenges of clinical accompaniment to nursing students emerged in the two themes and sub-themes, from the appraised literature.
The review shows that collaboration within departments and clinical learning areas will have positive developmental effects and strengthen the clinical accompaniment of nursing students. Challenges and solutions in nursing education are common within different countries and it is therefore important to create Nursing Education Institutions that is conducive to learning. Therefore, NEIs need more reforms to increase the capacity of nurse educators who will be responsible for further education of future nurses in our country.Master
Genomic insight on Klebsiella variicola isolated from wastewater treatment plant has uncovered a novel bacteriophage
No full textArticle, Faculty of Natural and Agricultural Sciences (Unit for Environmental Sciences and Management)--Northwest Universtity, PotchestroomKlebsiella variicola is considered an emerging pathogen, which may colonize a variety of hosts, including environmental sources. Klebsiella variicola investigated in this study was obtained from an influent wastewater treatment plant in the North‑West Province, South Africa. Whole genome sequencing was conducted to unravel the genetic diversity and antibiotic resistance patterns of K. variicola. Whole genome core SNP phylogeny was employed on publicly available 170 genomes. Furthermore, capsule types and antibiotic resistance genes, particularly beta‑lactamase and car‑bapenems genes were investigated from the compared genomes. A 38 099 bp bacteriophage was uncovered along‑ side with K. variicola genome. Whole genome sequencing revealed that the extended beta‑lactamase blaLEN (75.3%) of the beta‑lactamase is dominant among compared K. variicola strains. The identified IncF plasmid AA035 confers resistance genes of metal and heat element subtypes, i.e., silver, copper, and tellurium. The capsule type KL107‑D1 is a predominant capsule type present in 88.2% of the compared K. variicola genomes. The phage was determined to be integrase‑deficient consisting of a fosB gene associated with fosfomycin resistance and clusters with the Wbeta genus Bacillus phage group. In silico analysis showed that the phage genome interacts with B. cereus as opposed to K. variicola strain T2. The phage has anti‑repressor proteins involved in the lysis‑lysogeny decision. This phage will enhance our understanding of its impact on bacterial dissemination and how it may affect disease development and antibiotic resistance mechanisms in wastewater treatment plants. This study highlights the need for ongoing genomic epidemiological surveillance of environmental K. variicola isolates
Towards modelling the linguistic execution of communicative goals of political persuasion in selected presidential Covid-19 related speeches
Get PDFDoctor of Philosophy in Linguistics and Literary Theory, North-West University, Potchefstroom CampusThe Covid-19 pandemic triggered a significant surge in speeches from political leaders, aimed at persuading the public to adhere to strict social distancing measures to mitigate the spread of the virus. This study was designed to comprehensively model the linguistic execution of communicative goals of political persuasion in selected presidential Covid-19 related speeches. In this study, persuasion was analysed from communicative, linguistic, and pragmatic perspectives. The study aimed to shed light on how language was strategically employed during the pandemic to influence public behaviours and perspectives concerning Covid-19 as well as compliance with the recommended protocols. The primary focus of this study centred on the speeches delivered by three presidents: Xi Jinping of the People’s Republic of China, Donald Trump of the United States of America, and Cyril Ramaphosa of the Republic of South Africa. To achieve a comprehensive understanding of persuasion, the study employed theory triangulation, incorporating Systemic Functional Linguistics (Halliday, 1965) as the central framework operationalised through the Goals-Plans-Actions theory (Dillard, 1989), Speech Act theory (Austin, 1962; Searle, 1969), and Linguistic Propaganda Identification model (Maritz, 2009). Theory triangulation enabled a thorough comprehension of the communicative goals, elements of persuasion, and strategies of persuasion used by the three presidents in their Covid-19 related speeches. In addition, it highlighted that persuasion is multi-faceted. Therefore, exploring it accordingly from an interdisciplinary theoretical framework brings to the fore a tapestry of interlinked components; one weave reinforcing the other. Modelling this intricate interplay of goals, elements and strategies set this thesis apart from other studies conducted on persuasion, Covid-19 related communication and presidential speech styles. The study’s methodology embraced an interpretivist qualitative paradigm, amalgamating theory triangulation and discourse-textual analysis. Data for the study was drawn from purposively sampled fifteen (15) speeches, to map the linguistic traits of persuasion while striving for data saturation through an inductive logical approach. The data analysis process involved a thorough two-staged examination of the sampled speeches, employing a manual close-reading and ATLAS.ti software analysis techniques. During the analysis, a provisional model specifically designed for this study served as a comprehensive checklist for identifying communicative goals, elements of persuasion, and strategies of persuasion. This model was developed based on an extensive review of the literature pertaining to persuasion in the context of political discourse. Stringent ethical considerations were accurately addressed, including requisite approvals from pertinent committees. The central finding of the study spotlights the prevalence of primary and secondary communicative goals within presidential Covid-19 speeches, accentuating calculated endeavours to achieve persuasive outcomes. These goals were strategically deployed to sway public attitudes and conduct towards Covid-19, thereby manifesting a nuanced interplay between primary and secondary goals, and their consequential impact on the elements and strategies of persuasion. This implies that primary goals guide cognitive processes in encoding and retrieval, while secondary goals set boundaries for linguistic and communicative choices to initiate and maintain social action. Subsequent in-depth analyses revealed a comprehensive spectrum of communicative, linguistic, and pragmatic elements of persuasion that were adroitly harnessed by the three presidents to mold public perceptions and attitudes during the Covid-19 pandemic. Also, communicative strategies of persuasion emerged as particularly conspicuous, succeeded by pragmatic and linguistic strategies of persuasion. Ultimately, the study culminated in the reconstruction of the provisional model, resulting in the development of a comprehensive model that guides the linguistic execution of communicative goals in the context of political persuasion.
The resultant comprehensive model integrates six intricate categories: message, elements of persuasion, strategies of persuasion, communicative goals, goal influence factors, and the theoretical properties of persuasion. This model augments the comprehension of how linguistic constituents were wielded in the domain of political persuasion against the backdrop of Covid-19-related presidential speeches. The study underscores the perpetual significance of the message as the central conduit for persuasion, encompassing linguistic tools to mold attitudes, convictions, and behaviours of the targeted audience. While acknowledging its groundbreaking contributions, the resultant comprehensive model is acknowledged to be context-bound, bearing limitations concerning its extensibility to disparate political contexts and communicators. The study advocates adopting longitudinal approaches, comparative analyses, and quantitative methodologies to broaden the model’s scope and applicability. In its entirety, this thesis has advanced the boundaries of knowledge in linguistics, political communication, and crisis management, with practical implications for public health communication and governance during pandemics
Legal mechanisms for holding traditional authorities accountable for administering mining royalties in South Africa
Get PDFMaster of Science in International Child Law, North-West University, Potchefstroom CampusThe aim of the study was to analyse the additional legal mechanisms that traditional communities can use to hold traditional authorities accountable for the administration of mining royalties. Mining activities poses severe social, environmental and health impacts on the lives of surrounding communities. In order to mitigate these severe impacts, mining royalties were introduced to improve the lives of those affected by mining activities and uplift their social life. The Traditional and Khoi-San Leadership Act empowers traditional councils to enter into agreement or partnership with anyone, including mining companies subject to a prior and informed consultation with the relevant community that they represent. The majority of the community members who attend the meeting must approve the agreement or partnership. The agreement or partnership must furthermore be based on good governance principles. Traditional authorities are often regarded by outsiders as the ‘custodians of communities’ and they are thus consulted. This is based on a misconception that they are the owner of the land that falls within their jurisdiction and therefore consent from the affected communities is not needed. Based on this misconception, mining lease agreements are negotiated and concluded. Proceeds flowing from these lease agreements in the form of royalties sometimes falls in the hands of these traditional authorities without the knowledge of the traditional communities. Accountability pertaining to the administration of mining royalties has been compounded by the conduct of some traditional authorities, underlying tensions and flaws in the legislation as well as lack of uniformity in the provinces pertaining to the regulation of traditional authorities. There have been several cases where mining royalties have been mismanaged and relevant traditional communities have not had any legal mechanism that they could use as a vehicle to hold their traditional authorities accountable. It is against this backdrop that this study sought to analyse mechanisms such as the Public Protector, Auditor General and The Special Investigating Unit as additional mechanisms that traditional communities can use to bring traditional authorities to account for the administration of mining royalties.-North West University ( Faculty of Law
Exploring opportunities for implementing waste-to-energy projects in the City of Johannesburg Metropolitan Municipality
Get PDFNorth-West University, Master of Environmental Management with Waste
Management, Potchefstroom CampusThis study explores opportunities for implementing waste-to-energy technologies to alleviate the City of Johannesburg’s (CoJ) current waste management challenges as well as the current energy crisis in the country. Globally, untreated, unsafe disposal, and inefficient waste collection have contributed to a waste crisis, while a rapidly increasing world population has increased waste generation, and a higher demand for energy. Waste-to-energy is therefore increasingly viewed as a viable solution to waste management and energy supply challenges. However, South Africa underutilises waste for energy generation. CoJ has initiated the adoption of waste-to-energy projects for electricity, but little progress has been made on the actual implementation. This study therefore investigates the potential for implementing waste-to-energy projects in the CoJ to recommend strategies for successfully enhancing both waste management and energy generation in the city. A qualitative approach was used to conduct the study and semistructured interviews were utilised for collecting primary data. Using purposive sampling, 20 managers and employees in CoJ’s waste management and energy departments were selected. The study found that implementing waste-to-energy projects offers numerous benefits to CoJ, including freeing up landfill space, improving energy supply, and contributing to environmental sustainability. Additionally, the study found that the successful implementation of waste-to-energy projects is complex and hinges on a number of factors, including the availability of human, financial, and technological resources, a supportive regulatory and policy environment, and the participation of all stakeholders. Recommendations include the development of employee skills and competencies and the mobilisation of financial resources through increased focus on public-private partnerships. Management is also encouraged to collaborate with policymakers to revise legislation, regulations, and policies that govern waste management and renewable energy and replace it with supportive legislation and policies. Lastly, management should promote a culture of separation at the source and increase the level of public participation
Exploring the impact of texting on the formal writing of English second language high school learners
Get PDFMaster of Arts in English
Studies, North-West University, Potchefstroom CampusThis study explored the impact of textspeak on the formal writing of a selected group of English second language high school learners. The general aims of the study were to establish how widespread the use of textspeak (the kind of language and spelling often containing short forms of words that people use when they are writing text messages) is among high school learners in the chosen community, sourcing the relevant English language educators’ perspectives on the phenomenon of textspeak, assessing whether there is any evidence of the use of texspeak features in the written work of learners as well as identifying the types of textspeak features if any, used by grade 8 and 11 learners in their written work. Seventy learners from a Setswana dominated school in a lower income community in Potchefstroom, North West province participated in the study. The study included 32 grade 8 learners and 38 grade 11s. Questionnaires were completed by the learner participants to determine the frequency and volume of their textspeak use and features of textspeak they reportedly use while texting. Learners also wrote an essay attached to the questionnaire for
the purpose of discovering whether textspeak features were present in the written work. Textspeak resembles standard English in many ways however, it has defining linguistic properties that distinguish it. These features included lack of punctuation, punctuation used inappropriately, use of abbreviations and acronyms, use of letters and numbers, use of more punctuation than is necessary, use of shortenings/contractions, use of slang, use of smileys, grammar as well as spelling errors which are not textspeak related. The results of this study indicate that high school students are ardent textspeak users and that socio-economic variables do not factor significantly into cell phone accessibility. Many
reported using textspeak in their written work. However, the written work shows that textspeak represents a tiny fraction of language. Despite containing a few textspeak features, the essays contained a lot of non-standard features which were not textspeak related. These errors pertained to concord, word classes and punctuation, and were a result of not applying formally taught rules. Consequently, with the small number of textspeak features made by a relatively small number of students (mostly in grade 11), there could be other factors that influence students’ writing. Put differently, from the results of this study, there is little need for concern about the impact of textspeak on the future of standard written English. This is not to suggest however, that possible dangers of textspeak are ruled out; 80% of the teachers’ responses hint to the negative impacts of textspeak. Five English language teachers from the same school also
completed a questionnaire regarding the visible textspeak features in the learners’ written work. They commented on the use of textspeak in relation to academic writing. Four of the five teachers indicated that textspeak hampers written literacy. One educator noted that textspeak has a positive impact on written literacy
Empirical evidence of fake news awareness levels among students
No full textJournal Article, Faculty of Natural and Agricultural Sciences, Unit for Data Science and Computing (UDSC) -- Potchefstroom CampusThe modern information landscape is flooded with fake and fabricated stories that are designed to mislead. It is especially the proliferation of social media platforms such as Facebook, Twitter, TikTok, etc., that have become breeding grounds for these deceptive narratives. The effect is severe and wide-ranging and may impact individuals, organisations, and communities. It is particularly younger people and students who are susceptible to misinformation as they are known for their heavy social media use. One way to combat the spreading of misinformation and its associated negative consequences is to increase fake news awareness levels. In this study, a fake news awareness measuring instrument was developed to assess the awareness and literacy levels of a selected group of university students. The main objective was to determine whether students could recognise fake news stories. The results of the survey also highlighted information on various other aspects associated with fake news, e.g. the spreading of fake news, guidelines on how to educate people about fake news, general behaviour, and news preferences of students. The study revealed that students are indeed in many cases not able to identify whether a news article is fake or real. A set of recommendations is offered to increase the fake news literacy levels of younger social media users
Isothermal amplification assays for point of-care diagnostics of bovine brucellosis and tuberculosis in South Africa
Get PDFDoctor of Philosophy in Science with Zoology , North-West University, Potchefstroom CampusBovine brucellosis, caused by Brucella abortus, is a disease of global socio-economic importance. Bovine tuberculosis (bovine TB) is a chronic wasting disease of cattle caused primarily by Mycobacterium bovis. Complete eradication of these diseases is reliant on the removal of diseased animals from herds; however, this is often challenging due to the absence of reliable, quick, and cost-effective diagnostic tools. This study aimed to conduct systematic reviews on molecular diagnostic techniques for bovine brucellosis and tuberculosis. Furthermore, this study sought to develop South African-specific molecular diagnostic assays based on PCR and LAMP technology for improved laboratory and fieldfriendly diagnostics of bovine brucellosis and bovine TB. A systematic review and meta analysis of peer-reviewed journal articles published between 1990 and 2020 revealed enhanced diagnostic performance with LAMP (sensitivity of 92.0% [95% CI 78.0–98.0%] and specificity of 100.0% [95% CI 97.0–100.0%]). The analysis further suggested that sample type and target gene choice influence assay performance, thus recommending the use of tissue (sensitivity 92.7% [95% CI 82.0–98.0%]) and serum (sensitivity 91.3% [95% CI 86.0–95.0%]) for brucellosis detection. The BruAb2_0168 gene PCR assay had
a sensitivity of 92.3% [95% CI 87.0–96.0%], and specificity of 99.3% [95% CI 98.0100.0%]. Overall, depending on specific needs and available resources published LAMP, conventional PCR and qPCR assays reported by some literature may preferentially be used where applicable.
Conventional PCR, nPCR and LAMP assays were designed based a unique region of the B. abortus genome. Primer specificity was ensured by testing against closely related species. The respective sensitivities were determined by serial 10-fold dilutions of synthetic plasmid DNA. The nPCR can detect down to 1 x 10-7 of the diluted cPCR’s limit of detection and was therefore more sensitive than both cPCR (pathogen DNA detectable at 1 x 103 copies) and LAMP (detectable at 1 x 100 copies), which, in turn, outperformed cPCR. When evaluated on 100 field samples, the nPCR displayed a high positivity rate of 68% surpassing cPCR (13%) and LAMP (59%). Limitation encountered with the cPCR led to its exclusion from further consideration. Therefore, only the nPCR and LAMP achieved technology readiness level 6. Based on the findings of this study, the adoption
of the nPCR by reference laboratories is recommended due to its robustness and superior performance. Concurrently, LAMP testing conducted on serum samples, presents promising prospects for optimization and integration into a portable testing device, positioning it ideally for efficient point-of-care diagnostics for brucellosis. Controlling bovine TB requires highly sensitive, specific, quick, and reliable diagnostic methods. A systematic review and meta-analysis were conducted to evaluate molecular diagnostic tests for M. bovis detection to inform test selection by authorities. Despite showing promising potential in diagnostic accuracy, the existing tests for detecting M. bovis lack the capability to accurately differentiate it from other species within the Mycobacterium tuberculosis complex (MTC). Their design, based on non-specific gene targets, poses limitations in achieving accurate and reliable diagnosis. However, the findings attribute improvement in diagnostic test performance to the choice of sample type
and target gene. Test sensitivity was higher with milk (90.9% [95% CI: 56.0%-98.7%]), while assays developed on the RD4 gene among others demonstrated improved specificity (90.7% [95% CI: 52.2%-98.9%]). Since the RD4 region is the only target identified by genome sequence data as being distinctive for recognizing M. bovis it is recommended for future assay development. The availability of a sufficiently accurate diagnostic test combined with the routine screening of milk samples holds the potential to mitigate the risk of zoonotic transmissions of M. bovis, presenting a significant advancement in controlling its spread. To develop molecular diagnostic assays for detection of M. bovis a region of the M. bovis genome that allows distinction between M. bovis and other species within the MTC was targeted. Conventional PCR, and LAMP assays were designed and optimized for reaction sensitivity and specificity, followed by a nPCR assay. All assays were specific. The cPCR exhibited a sensitivity of 1 x 103 copies in the lab and classified 24% of field samples as positive for M. bovis. LAMP with a laboratory sensitivity of 1 x 101 copies was consistently more sensitive in the field with a positivity rate of 56% and the nPCR exhibited greater sensitivity than both method both in the lab and with field samples with a positivity rate of 85%. While the cPCR assay was excluded from further consideration due to limitations encountered in this study, the designed LAMP assay shows great potential for use as a field-friendly screening test for M. bovis particularly with milk samples. Though the test had moderate sensitivity, it can help inform decision making in the field and the adoption of rapid containment measures while confirmatory tests are conducted. These results further suggest that the nPCR is a robust and specific test that can be used for the routine laboratory confirmation of M. bovis and is therefore recommended for adoption by reference laboratories in South Africa. Overall, both these technologies are at technology
readiness level 6 and have the potential to be licensed and commercialized.-National Research Foundation (NRF)
- Council for Scientific and Industrial Research (CSIR –
SA)Doctora
Molecular prevalence and distribution of tick-borne bacterial and protozoan pathogens of sheep and goats in Africa: A systematic review and meta-analysis
Get PDFArticle, Faculty of Natural and Agricultural Sciences (Unit for Environmental Sciences and Management)-- Northwest University, Potchefstroom CampusTick-borne pathogens (TBPs) are a major impediment to the health, welfare, and production of small ruminants across the world, including Africa. Comprehensive information about the epidemiology of TBPs infecting sheep and goats across Africa is lacking. Therefore, this study was undertaken to determine the prevalence through a meta-analysis of selected TBPs in blood DNA from domestic sheep and goats in Africa obtained using molecular-based methods. The literature review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines using five English electronic databases (PubMed, Science Direct, Springer Link, Web of Science, and African Journals Online (AJOL). The search was performed with no restriction in time through to 18th January 2023. Of the 63 full-text articles subjected to eligibility, only 30 articles met the eligibility criteria and were included in the review. The overall pooled prevalence of selected TBPs varied considerably between host species (sheep vs. goats), with Anaplasma ovis (44.50 vs. 48.40%), Ehrlichia ruminantium (5.50 vs. 2.00%), Coxiella burnetii (4.40 vs. 1.70%), Borrelia theileri in sheep (5.20%), Babesia ovis (1.70% vs. 1.90%), Theileria ovis (40.50% vs 10.00%), T. separata (1.00% vs 1.00%) and T. lestoquardi in sheep (8.40%). However, the prevalence of the selected TBPs was generally higher in sheep compared to goats. Several genetic loci were targeted in the characterization of tick-borne pathogens, such as 16S rDNA, groEL, and msp4 for Anaplasma ovis, pCS20 for Ehrlichia ruminantium, Insertion Sequence (IS1111) for Coxiella burnetii, flaB (flagellin) and 16S rRNA for Borrelia theileri, 5.8S rRNA and 18S rRNA for Babesia/Theileria, as well as the utilization of numerous PCR variants including conventional polymerase chain reaction (PCR), nested-PCR, qPCR, Loop-mediated isothermal amplification (LAMP), and reverse line blotting (RLB). In conclusion, A. ovis was the most widely distributed and prevalent TBP affecting small ruminants within the continent. Hence, this warrants adequate attention towards early diagnosis and treatment of infected animals as well as the control of the tick vectors involved in their transmission