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16 pages, 1728 KB  
Article
Phylogeographic and Host Interface Analyses Reveal the Evolutionary Dynamics of SAT3 Foot-And-Mouth Disease Virus
by Shuang Zhang, Jianing Lv, Yao Lin, Rong Chai, Jiaxi Liang, Yan Su, Zhuo Tian, Hanyu Guo, Fuyun Chen, Guanying Ni, Gang Wang, Chunmei Song, Baoping Li, Qiqi Wang, Sen Zhao, Qixin Huang, Xuejun Ji, Jieji Duo, Fengjun Bai, Jin Li, Shuo Chen, Xueying Pan, Qin La, Zhong Hong and Xiaolong Wangadd Show full author list remove Hide full author list
Viruses 2025, 17(12), 1641; https://doi.org/10.3390/v17121641 - 18 Dec 2025
Viewed by 171
Abstract
Foot-and-mouth disease virus (FMDV) serotype SAT3 is a rarely studied serotype primarily circulating in southern Africa, with African buffalo (Syncerus caffer) serving as its key reservoir. In this study, we performed a comprehensive phylogenetic and phylodynamic analysis of SAT3 based on [...] Read more.
Foot-and-mouth disease virus (FMDV) serotype SAT3 is a rarely studied serotype primarily circulating in southern Africa, with African buffalo (Syncerus caffer) serving as its key reservoir. In this study, we performed a comprehensive phylogenetic and phylodynamic analysis of SAT3 based on 81 full-length VP1 gene sequences collected between 1934 and 2018. Maximum likelihood and Bayesian analyses revealed five distinct topotypes, each with clear geographic and host associations. Notably, topotypes I, II and III were observed in both African buffalo and cattle (Bos taurus), while topotype IV appeared restricted to African buffalo. Likelihood mapping indicated moderate to strong phylogenetic signal, and the mean substitution rate was estimated at 3.709 × 10−3 substitutions/site/year under a relaxed molecular clock. The time to the most recent common ancestor (TMRCA) was traced back to 1875. Discrete phylogeographic reconstruction identified Zimbabwe as a major center, with multiple supported cross-border transmission routes. Host transition analysis further confirmed strong directional flow from buffalo to cattle (BF = 1631.09, pp = 1.0), highlighting the wildlife–livestock interface as a key driver of SAT3 persistence. Together, these results underscore the evolutionary complexity of SAT3 and the importance of integrating molecular epidemiology, spatial modeling, and host ecology to inform FMD control strategies in endemic regions. Full article
(This article belongs to the Special Issue Foot-and-Mouth Disease Virus)
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25 pages, 837 KB  
Article
Hunters’ Perceptions and Protected-Area Governance: Wildlife Decline and Resource-Use Management in the Lomami Landscape, DR Congo
by Gloire Mukaku Kazadi, Médard Mpanda Mukenza, John Kikuni Tchowa, François Malaisse, Dieu-Donné N’Tambwe Nghonda, Jan Bogaert and Yannick Useni Sikuzani
Conservation 2025, 5(3), 49; https://doi.org/10.3390/conservation5030049 - 5 Sep 2025
Viewed by 2400
Abstract
The periphery of Lomami National Park in the Democratic Republic of the Congo (DR Congo) is experiencing intense and increasing hunting pressure, driven by both local subsistence needs and growing urban demand for bushmeat. This situation poses a serious challenge to sustainable natural [...] Read more.
The periphery of Lomami National Park in the Democratic Republic of the Congo (DR Congo) is experiencing intense and increasing hunting pressure, driven by both local subsistence needs and growing urban demand for bushmeat. This situation poses a serious challenge to sustainable natural resource management and underscores the need to realign protected-area policies with the realities faced by surrounding communities. In the absence of comprehensive ecological monitoring, this study used hunters’ perceptions to assess the current availability of mammalian wildlife around the park. From October to December 2023, surveys were conducted using a snowball sampling method with 60 hunters from nine villages bordering the park. Results show that hunting is a male-dominated activity, mainly practiced by individuals aged 30–40 years, with firearms as the primary tools. It occurs both in the park’s buffer zones and, alarmingly, within its core protected area. This practice has contributed to the local disappearance of key species such as African forest elephant (Loxodonta cyclotis), African buffalo (Syncerus caffer), and African leopard (Panthera pardus pardus), and to the marked decline of several Cephalophus species. These patterns of overexploitation reveal critical weaknesses in current conservation strategies and point to the urgent need for integrated, community-based resource management approaches. Strengthening law enforcement, improving ranger support, and enhancing participatory governance mechanisms are essential. Equally important is the promotion of sustainable alternative livelihoods—including livestock farming, aquaculture, and agroforestry—to reduce hunting dependence and build long-term resilience for both biodiversity and local communities. Full article
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32 pages, 3767 KB  
Systematic Review
Distribution and Prevalence of Ticks and Tick-Borne Pathogens at the Wildlife-Livestock Interface in Africa: A Systematic Review
by Tsireledzo Goodwill Makwarela, Nimmi Seoraj-Pillai and Tshifhiwa Constance Nangammbi
Vet. Sci. 2025, 12(4), 364; https://doi.org/10.3390/vetsci12040364 - 13 Apr 2025
Cited by 1 | Viewed by 3384
Abstract
Ticks and tick-borne diseases (TBDs) significantly impact African animal health and agricultural productivity, especially at the wildlife–livestock interface. This systematic review analyzed 20 eligible studies from East, Southern, and limited parts of Central Africa to determine the distribution and prevalence of key tick [...] Read more.
Ticks and tick-borne diseases (TBDs) significantly impact African animal health and agricultural productivity, especially at the wildlife–livestock interface. This systematic review analyzed 20 eligible studies from East, Southern, and limited parts of Central Africa to determine the distribution and prevalence of key tick species and associated pathogens. Rhipicephalus appendiculatus and Amblyomma variegatum were the most commonly reported tick species, with R. appendiculatus exhibiting up to 50.5% prevalence in cattle and buffalo in Uganda. The most frequently detected pathogens included Theileria parva, Anaplasma marginale, and Coxiella burnetii, with T. parva showing high prevalence in cattle populations coexisting with wildlife. Notably, geographic disparities were observed, with Central and West Africa being underrepresented. Most pathogen detections occurred in Kenya, Uganda, Tanzania, Botswana, and South Africa, indicating regional hotspots for tick-borne disease transmission. This review highlights the urgent need for enhanced surveillance, region-specific vector control programs, and integrated One Health approaches to address the ecological, agricultural, and zoonotic challenges of tick-borne pathogens across Africa. Full article
(This article belongs to the Special Issue Control Strategies of Ticks and Tick-Borne Pathogens)
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10 pages, 1853 KB  
Article
Genetic Diversity in the Diminazene Resistance-Associated P2 Adenosine Transporter-1 (AT-1) Gene of Trypanosoma evansi
by Shoaib Ashraf, Ghulam Yasein, Qasim Ali, Kiran Afshan, Martha Betson, Neil Sargison and Umer Chaudhry
Animals 2025, 15(5), 756; https://doi.org/10.3390/ani15050756 - 6 Mar 2025
Cited by 1 | Viewed by 1117
Abstract
Trypanosomes are parasitic protozoa that cause severe diseases in humans and animals. The most important species of Trypanosmes include Trypanosoma evansi and Trypanosoma brucei gambiense. The most well-known human diseases are sleeping sickness in Africa and Chagas disease in South America. The [...] Read more.
Trypanosomes are parasitic protozoa that cause severe diseases in humans and animals. The most important species of Trypanosmes include Trypanosoma evansi and Trypanosoma brucei gambiense. The most well-known human diseases are sleeping sickness in Africa and Chagas disease in South America. The most identified animal diseases include Nagana in the African tsetse fly belt and Surra in South Asia, North Africa, and the Middle East. Surra is caused by Trypanosoma evansi. Diminazene resistance is an emerging threat caused by T. evansi infecting animals. The underlying mechanism of diminazene resistance is poorly understood. Trypanosoma brucei gambiense causes African sleeping sickness. The development of diminazene resistance in Trypanosoma brucei gambiense is associated with the alterations in the corresponding P2 adenosine transporter-1 (AT-1) gene. In the present study, by extrapolating the findings from Trypanosoma brucei gambiense, we analyzed genetic diversity in the P2 adenosine transporter-1 gene (AT-1) from T. evansi to explore a potential link between the presence of mutations in this locus and diminazene treatment in ruminants. We examined T. evansi-infected blood samples collected from goats, sheep, camels, buffalo, and cattle in seven known endemic regions of the Punjab province of Pakistan. Heterozygosity (He) indices indicated a high level of genetic diversity between seven T. evansi field isolates that had resistance-type mutations at codons 178E/S, 239Y/A/E, and 286S/H/I/D/T of the P2 adenosine transporter-1 (AT-1) locus. A low level of genetic diversity was observed in 19 T. evansi field isolates with susceptible-type mutations at codons A178, G181, D239, and N286 of the P2 adenosine transporter-1 (AT-1) locus. Our results on T. evansi warrant further functional studies to explore the relationship between diminazene resistance and the mutations in AT-1. Full article
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19 pages, 6373 KB  
Review
The Current Epizootiological Situation of Three Major Viral Infections Affecting Cattle in Egypt
by Sherin R. Rouby, Ahmed H. Ghonaim, Xingxiang Chen and Wentao Li
Viruses 2024, 16(10), 1536; https://doi.org/10.3390/v16101536 - 28 Sep 2024
Cited by 3 | Viewed by 5286
Abstract
One of the major factors hindering efficient livestock production is the presence of high-impact infectious animal diseases, such as foot and mouth disease (FMD), lumpy skin disease (LSD), and bovine ephemeral fever (BEF), which are notable viral infections affecting cattle in Egypt, leading [...] Read more.
One of the major factors hindering efficient livestock production is the presence of high-impact infectious animal diseases, such as foot and mouth disease (FMD), lumpy skin disease (LSD), and bovine ephemeral fever (BEF), which are notable viral infections affecting cattle in Egypt, leading to significant economic losses. FMD is caused by the foot and mouth disease virus (FMDV) of the genus Aphthovirus in the Picornaviridae family. LSD is caused by lumpy skin disease virus (LSDV) of Capripox genus within the Poxviridae family, subfamily Chordopoxvirinae. BEF is caused by bovine ephemeral fever virus (BEFV) of genus Ephemerovirus in the Rhabdoviridae family. FMD is a highly contagious viral infection of domestic and wild cloven-hooved animals and can spread through the wind. On the other hand, LSD and BEF are arthropod-borne viral diseases that mainly affect domestic cattle and water buffalo. Despite government vaccination efforts, these three viral diseases have become widespread in Egypt, with several reported epidemics. Egypt’s importation of large numbers of animals from different countries, combined with unregulated animal movements through trading and borders between African countries and Egypt, facilitates the introduction of new FMDV serotypes and lineages not covered by the current vaccination plans. To establish an effective control program, countries need to assess the real epizootic situation of various infectious animal diseases to develop an efficient early warning system. This review provides information about FMD, LSD, and BEF, including their economic impacts, causative viruses, global burden, the situation in Egypt, and the challenges in controlling these diseases. Full article
(This article belongs to the Special Issue Advances in Endemic and Emerging Viral Diseases in Livestock)
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10 pages, 867 KB  
Article
A Systematic Assessment of Leishmania donovani Infection in Domestic and Wild Animal Reservoir Hosts of Zoonotic Visceral Leishmaniasis in India
by Gajala Deethamvali Ghouse Peer, Anjali Priyadarshini, Archana Gupta, Arpana Vibhuti, Elcio Leal, Antonio Charlys da Costa, Carlos Prudencio, Kirtanjot Kaur, Saheem Ahmad, V. Samuel Raj and Ramendra Pati Pandey
Microbiol. Res. 2024, 15(3), 1645-1654; https://doi.org/10.3390/microbiolres15030109 - 23 Aug 2024
Cited by 4 | Viewed by 5352
Abstract
Leishmaniasis is a neglected disease with a global spread that affects both domestic and wild animals in addition to people. Leishmania donovani is the suspected anthroponotic cause of visceral leishmaniasis (VL) in India, where it is an endemic disease. The reservoir hosts play [...] Read more.
Leishmaniasis is a neglected disease with a global spread that affects both domestic and wild animals in addition to people. Leishmania donovani is the suspected anthroponotic cause of visceral leishmaniasis (VL) in India, where it is an endemic disease. The reservoir hosts play a crucial role in the life cycle of the Leishmania parasite. The complicated connection between the pathogen, vector, and reservoir exhibits geographical and temporal diversity. Human-to-human and, to a lesser extent, human-to-animal transmission are the principal mechanisms for the maintenance of anthroponotic diseases. A number of animals were examined for the presence of Leishmania parasites and the findings were reviewed in order to examine the role of animal reservoirs in domestic transmission of cutaneous leishmaniasis in endemic regions of India. The analysis objective was to assess the research conducted on domestic animals’ propensity to spread L. donovani in endemic areas, with a particular emphasis on how proximity and animal density may impact the prevalence of human leishmaniasis. Species of the L. donovani complex have distinct enzootic, zoonotic, and anthroponotic life cycles that depend on the environment. The majority of Leishmania spp. are zoonotic, spreading from non-human mammals to humans. Many nations have leishmaniasis as an endemic disease, and the Indian subcontinent (ISC) has an estimated two to three lakh people who are at risk. This systematic review evaluates the gaps in our understanding of disease transmission that contradict conventional wisdom about the reservoir(s) of visceral leishmaniasis and efforts to manage it on the Indian subcontinent. Fundamental concerns in VL epidemiology and ecology will be clarified by a better understanding of L. donovani infection in domestic animals and its transfer to sandflies. A deliberate, systematic search was conducted on PubMed, Science Direct, and Google Scholar using keywords such as “Leishmania donovani”, “zoonotic visceral leishmaniasis”, and “wild animal reservoir for Leishmania donovani”. A total of 530 potentially relevant references were obtained from these databases, and 507 were not considered due to copy avoidance, irrelevant titles, research publications from nations other than India, or modified compositions. Among the remaining 23 investigations, 20 were rejected, and only 3 were included in the present study. Finally, three research papers with 867 goats, 161 cattle, 106 chickens, 26 sheep, three buffaloes, 406 dogs, and 309 rats were reported. Along with these data, studies across Asian and African countries that are considered VL-endemic areas have been discussed. According to the review, goats are the epidemic’s primary host and possible reservoir in several regions of India. In the endemic regions of the disease, some species of rodents, along with the canines, appear to be maintaining the L. donovani transmission cycle. Full article
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12 pages, 2323 KB  
Article
Detection and Genome Sequencing of Lumpy Skin Disease Viruses in Wildlife Game Species in South Africa
by Antoinette van Schalkwyk, Pravesh Kara, Robert D. Last, Marco Romito and David B. Wallace
Viruses 2024, 16(2), 172; https://doi.org/10.3390/v16020172 - 24 Jan 2024
Cited by 8 | Viewed by 3285
Abstract
Lumpy skin disease virus (LSDV) has recently undergone rapid spread, now being reported from more than 80 countries, affecting predominantly cattle and to a lesser extent, water buffalo. This poxvirus was previously considered to be highly host-range restricted. However, there is an increasing [...] Read more.
Lumpy skin disease virus (LSDV) has recently undergone rapid spread, now being reported from more than 80 countries, affecting predominantly cattle and to a lesser extent, water buffalo. This poxvirus was previously considered to be highly host-range restricted. However, there is an increasing number of published reports on the detection of the virus from different game animal species. The virus has not only been shown to infect a wide range of game species under experimental conditions, but has also been naturally detected in oryx, giraffe, camels and gazelle. In addition, clinical lumpy skin disease has previously been described in springbok (Antidorcas marsupialis), an African antelope species, in South Africa. This report describes the characterization of lumpy skin disease virus belonging to cluster 1.2, from field samples from springbok, impala (Aepyceros melampus) and a giraffe (Giraffa camelopardalis) in South Africa using PCR, Sanger and whole genome sequencing. Most of these samples were submitted from wild animals in nature reserves or game parks, indicating that the disease is not restricted to captive-bred animals on game farms or zoological gardens. The potential role of wildlife species in the transmission and maintenance of LSDV is further discussed and requires continuing investigation, as the virus and disease may pose a serious threat to endangered species. Full article
(This article belongs to the Special Issue Capripox Viruses: A Continuing Transboundary Threat to Animal Health)
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16 pages, 3477 KB  
Article
An Integrated Ecological Niche Modelling Framework for Risk Mapping of Peste des Petits Ruminants Virus Exposure in African Buffalo (Syncerus caffer) in the Greater Serengeti-Mara Ecosystem
by Laura Carrera-Faja, Chris Yesson, Bryony A. Jones, Camilla T. O. Benfield and Richard A. Kock
Pathogens 2023, 12(12), 1423; https://doi.org/10.3390/pathogens12121423 - 7 Dec 2023
Cited by 2 | Viewed by 2471
Abstract
Peste des petits ruminants (PPR) is a highly contagious viral disease of small ruminants that threatens livelihoods and food security in developing countries and, in some cases, wild ungulate species conservation. The Greater Serengeti-Mara Ecosystem (GSME) encompasses one of the major wildlife populations [...] Read more.
Peste des petits ruminants (PPR) is a highly contagious viral disease of small ruminants that threatens livelihoods and food security in developing countries and, in some cases, wild ungulate species conservation. The Greater Serengeti-Mara Ecosystem (GSME) encompasses one of the major wildlife populations of PPR virus (PPRV)-susceptible species left on earth, although no clinical disease has been reported so far. This study aimed to gain further knowledge about PPRV circulation in the GSME by identifying which factors predict PPRV seropositivity in African buffalo (Syncerus caffer). Following an ecological niche modeling framework to map host-pathogen distribution, two models of PPRV exposure and buffalo habitat suitability were performed using serological data and buffalo censuses. Western Maasai Mara National Reserve and Western Serengeti National Park were identified as high-risk areas for PPRV exposure in buffalo. Variables related to wildlife-livestock interaction contributed to the higher risk of PPRV seropositivity in buffalo, providing supportive evidence that buffalo acquire the virus through contact with infected livestock. These findings can guide the design of cost-effective PPRV surveillance using buffalo as a sentinel species at the identified high-risk locations. As more intensive studies have been carried out in Eastern GSME, this study highlights the need for investigating PPRV dynamics in Western GSME. Full article
(This article belongs to the Section Epidemiology of Infectious Diseases)
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30 pages, 2881 KB  
Article
Enhancing Metaheuristic Optimization: A Novel Nature-Inspired Hybrid Approach Incorporating Selected Pseudorandom Number Generators
by Marko Gulić and Martina Žuškin
Algorithms 2023, 16(9), 413; https://doi.org/10.3390/a16090413 - 28 Aug 2023
Cited by 7 | Viewed by 2596
Abstract
In this paper, a hybrid nature-inspired metaheuristic algorithm based on the Genetic Algorithm and the African Buffalo Optimization is proposed. The hybrid approach adaptively switches between the Genetic Algorithm and the African Buffalo Optimization during the optimization process, leveraging their respective strengths to [...] Read more.
In this paper, a hybrid nature-inspired metaheuristic algorithm based on the Genetic Algorithm and the African Buffalo Optimization is proposed. The hybrid approach adaptively switches between the Genetic Algorithm and the African Buffalo Optimization during the optimization process, leveraging their respective strengths to improve performance. To improve randomness, the hybrid approach uses two high-quality pseudorandom number generators—the 64-bit and 32-bit versions of the SIMD-Oriented Fast Mersenne Twister. The effectiveness of the hybrid algorithm is evaluated on the NP-hard Container Relocation Problem, focusing on a test set of restricted Container Relocation Problems with higher complexity. The results show that the hybrid algorithm outperforms the individual Genetic Algorithm and the African Buffalo Optimization, which use standard pseudorandom number generators. The adaptive switch method allows the algorithm to adapt to different optimization problems and mitigate problems such as premature convergence and local optima. Moreover, the importance of pseudorandom number generator selection in metaheuristic algorithms is highlighted, as it directly affects the optimization results. The use of powerful pseudorandom number generators reduces the probability of premature convergence and local optima, leading to better optimization results. Overall, the research demonstrates the potential of hybrid metaheuristic approaches for solving complex optimization problems, which makes them relevant for scientific research and practical applications. Full article
(This article belongs to the Collection Feature Paper in Metaheuristic Algorithms and Applications)
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24 pages, 25948 KB  
Article
Energy-Efficient LoRa Routing for Smart Grids
by Raja Kishore Repuri and John Pradeep Darsy
Sensors 2023, 23(6), 3072; https://doi.org/10.3390/s23063072 - 13 Mar 2023
Cited by 9 | Viewed by 4360
Abstract
Energy-efficient routing protocols in Internet of Things (IoT) applications are always of colossal importance as they improve the network’s longevity. The smart grid (SG) application of the IoT uses advanced metring infrastructure (AMI) to read and record power consumption periodically or on demand. [...] Read more.
Energy-efficient routing protocols in Internet of Things (IoT) applications are always of colossal importance as they improve the network’s longevity. The smart grid (SG) application of the IoT uses advanced metring infrastructure (AMI) to read and record power consumption periodically or on demand. The AMI sensor nodes in a smart grid network sense, process, and transmit information, which require energy, which is a limited resource and is an important parameter required to maintain the network for a longer duration. The present work discusses a novel energy-efficient routing criterion in an SG environment realised using LoRa nodes. Firstly, a modified LEACH protocol–cumulative low-energy adaptive clustering hierarchy (Cum_LEACH) is proposed for cluster head selection among the nodes. It uses the cumulative energy distribution of the nodes to select the cluster head. Furthermore, for test packet transmission, multiple optimal paths are created using the quadratic kernelised African-buffalo-optimisation-based LOADng (qAB_LOADng) algorithm. The best optimal path is selected from these multiple paths using a modified version of the MAX algorithm called the SMAx algorithm. This routing criterion showed an improved energy consumption profile of the nodes and the number of active nodes after running for 5000 iterations compared to standard routing protocols such as LEACH, SEP, and DEEC. Full article
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16 pages, 4693 KB  
Article
An Optimized Gradient Boost Decision Tree Using Enhanced African Buffalo Optimization Method for Cyber Security Intrusion Detection
by Shailendra Mishra
Appl. Sci. 2022, 12(24), 12591; https://doi.org/10.3390/app122412591 - 8 Dec 2022
Cited by 24 | Viewed by 3466
Abstract
The cyber security field has witnessed several intrusion detection systems (IDSs) that are critical to the detection of malicious activities in network traffic. In the last couple of years, much research has been conducted in this field; however, in the present circumstances, network [...] Read more.
The cyber security field has witnessed several intrusion detection systems (IDSs) that are critical to the detection of malicious activities in network traffic. In the last couple of years, much research has been conducted in this field; however, in the present circumstances, network attacks are increasing in both volume and diverseness. The objective of this research work is to introduce new IDSs based on a combination of Genetic Algorithms (GAs) and Optimized Gradient Boost Decision Trees (OGBDTs). To improve classification, enhanced African Buffalo Optimizations (EABOs) are used. Optimization Gradient Boost Decision Trees (OGBDT-IDS) include data exploration, preprocessing, standardization, and feature ratings/selection modules. In high-dimensional data, GAs are appropriate tools for selecting features. In machine learning techniques (MLTs), gradient-boosted decision trees (GBDTs) are used as a base learner, and the predictions are added to the set of trees. In this study, the experimental results demonstrate that the proposed methods improve cyber intrusion detection for unused and new cases. Based on performance evaluations, the proposed IDS (OGBDT) performs better than traditional MLTs. The performances are evaluated by comparing accuracy, precision, recall, and F-score using the UNBS-NB 15, KDD 99, and CICIDS2018 datasets. The proposed IDS has the highest attack detection rates, and can predict attacks in all datasets in the least amount of time. Full article
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11 pages, 615 KB  
Article
High-Specificity Test Algorithm for Bovine Tuberculosis Diagnosis in African Buffalo (Syncerus caffer) Herds
by Charlene Clarke, Netanya Bernitz, Wynand J. Goosen and Michele A. Miller
Pathogens 2022, 11(12), 1393; https://doi.org/10.3390/pathogens11121393 - 22 Nov 2022
Cited by 1 | Viewed by 1929
Abstract
Ante-mortem bovine tuberculosis (bTB) tests for buffaloes include the single comparative intradermal tuberculin test (SCITT), interferon-gamma (IFN-γ) release assay (IGRA) and IFN-γ-inducible protein 10 release assay (IPRA). Although parallel test interpretation increases the detection of Mycobacterium bovis (M. bovis)-infected buffaloes, these [...] Read more.
Ante-mortem bovine tuberculosis (bTB) tests for buffaloes include the single comparative intradermal tuberculin test (SCITT), interferon-gamma (IFN-γ) release assay (IGRA) and IFN-γ-inducible protein 10 release assay (IPRA). Although parallel test interpretation increases the detection of Mycobacterium bovis (M. bovis)-infected buffaloes, these algorithms may not be suitable for screening buffaloes in historically bTB-free herds. In this study, the specificities of three assays were determined using M. bovis-unexposed herds, historically negative, and a high-specificity diagnostic algorithm was developed. Serial test interpretation (positive on both) using the IGRA and IPRA showed significantly greater specificity (98.3%) than individual (90.4% and 80.9%, respectively) tests or parallel testing (73%). When the SCITT was added, the algorithm had 100% specificity. Since the cytokine assays had imperfect specificity, potential cross-reactivity with nontuberculous mycobacteria (NTM) was investigated. No association was found between NTM presence (in oronasal swab cultures) and positive cytokine assay results. As a proof-of-principle, serial testing was applied to buffaloes (n = 153) in a historically bTB-free herd. Buffaloes positive on a single test (n = 28) were regarded as test-negative. Four buffaloes were positive on IGRA and IPRA, and M. bovis infection was confirmed by culture. These results demonstrate the value of using IGRA and IPRA in series to screen buffalo herds with no previous history of M. bovis infection. Full article
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14 pages, 1797 KB  
Article
Identification and Characterisation of Nontuberculous Mycobacteria in African Buffaloes (Syncerus caffer), South Africa
by Charlene Clarke, Tanya J. Kerr, Robin M. Warren, Léanie Kleynhans, Michele A. Miller and Wynand J. Goosen
Microorganisms 2022, 10(9), 1861; https://doi.org/10.3390/microorganisms10091861 - 17 Sep 2022
Cited by 13 | Viewed by 3572
Abstract
Diagnosis of bovine tuberculosis (bTB) may be confounded by immunological cross-reactivity to Mycobacterium bovis antigens when animals are sensitised by certain nontuberculous mycobacteria (NTMs). Therefore, this study aimed to investigate NTM species diversity in African buffalo (Syncerus caffer) respiratory secretions and [...] Read more.
Diagnosis of bovine tuberculosis (bTB) may be confounded by immunological cross-reactivity to Mycobacterium bovis antigens when animals are sensitised by certain nontuberculous mycobacteria (NTMs). Therefore, this study aimed to investigate NTM species diversity in African buffalo (Syncerus caffer) respiratory secretions and tissue samples, using a combination of novel molecular tools. Oronasal swabs were collected opportunistically from 120 immobilised buffaloes in historically bTB-free herds. In addition, bronchoalveolar lavage fluid (BALF; n = 10) and tissue samples (n = 19) were obtained during post-mortem examination. Mycobacterial species were identified directly from oronasal swab samples using the Xpert MTB/RIF Ultra qPCR (14/120 positive) and GenoType CMdirect (104/120 positive). In addition, all samples underwent mycobacterial culture, and PCRs targeting hsp65 and rpoB were performed. Overall, 55 NTM species were identified in 36 mycobacterial culture-positive swab samples with presence of esat-6 or cfp-10 detected in 20 of 36 isolates. The predominant species were M. avium complex and M. komanii. Nontuberculous mycobacteria were also isolated from 6 of 10 culture-positive BALF and 4 of 19 culture-positive tissue samples. Our findings demonstrate that there is a high diversity of NTMs present in buffaloes, and further investigation should determine their role in confounding bTB diagnosis in this species. Full article
(This article belongs to the Special Issue Pathogen Infection in Wildlife)
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16 pages, 1728 KB  
Article
Viral Population Diversity during Co-Infection of Foot-And-Mouth Disease Virus Serotypes SAT1 and SAT2 in African Buffalo in Kenya
by Rachel M. Palinski, Barbara Brito, Frederick R. Jaya, Abraham Sangula, Francis Gakuya, Miranda R. Bertram, Steven J. Pauszek, Ethan J. Hartwig, George R. Smoliga, Vincent Obanda, George P. Omondi, Kimberly VanderWaal and Jonathan Arzt
Viruses 2022, 14(5), 897; https://doi.org/10.3390/v14050897 - 25 Apr 2022
Cited by 5 | Viewed by 4382
Abstract
African buffalo are the natural reservoirs of the SAT serotypes of foot-and-mouth disease virus (FMDV) in sub-Saharan Africa. Most buffalo are exposed to multiple FMDV serotypes early in life, and a proportion of them become persistently infected carriers. Understanding the genetic diversity and [...] Read more.
African buffalo are the natural reservoirs of the SAT serotypes of foot-and-mouth disease virus (FMDV) in sub-Saharan Africa. Most buffalo are exposed to multiple FMDV serotypes early in life, and a proportion of them become persistently infected carriers. Understanding the genetic diversity and evolution of FMDV in carrier animals is critical to elucidate how FMDV persists in buffalo populations. In this study, we obtained oropharyngeal (OPF) fluid from naturally infected African buffalo, and characterized the genetic diversity of FMDV. Out of 54 FMDV-positive OPF, 5 were co-infected with SAT1 and SAT2 serotypes. From the five co-infected buffalo, we obtained eighty-nine plaque-purified isolates. Isolates obtained directly from OPF and plaque purification were sequenced using next-generation sequencing (NGS). Phylogenetic analyses of the sequences obtained from recombination-free protein-coding regions revealed a discrepancy in the topology of capsid proteins and non-structural proteins. Despite the high divergence in the capsid phylogeny between SAT1 and SAT2 serotypes, viruses from different serotypes that were collected from the same host had a high genetic similarity in non-structural protein-coding regions P2 and P3, suggesting interserotypic recombination. In two of the SAT1 and SAT2 co-infected buffalo identified at the first passage of viral isolation, the plaque-derived SAT2 genomes were distinctly grouped in two different genotypes. These genotypes were not initially detected with the NGS from the first passage (non-purified) virus isolation sample. In one animal with two SAT2 haplotypes, one plaque-derived chimeric sequence was found. These findings demonstrate within-host evolution through recombination and point mutation contributing to broad viral diversity in the wildlife reservoir. These mechanisms may be critical to FMDV persistence at the individual animal and population levels, and may contribute to the emergence of new viruses that have the ability to spill-over to livestock and other wildlife species. Full article
(This article belongs to the Special Issue Global Foot-and-Mouth Disease Control)
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13 pages, 3244 KB  
Article
Molecular Characterization of the 2020 Outbreak of Lumpy Skin Disease in Nepal
by Pragya Koirala, Irene Kasindi Meki, Manju Maharjan, Bharani Kumar Settypalli, Salina Manandhar, Sanjay Kumar Yadav, Giovanni Cattoli and Charles Euloge Lamien
Microorganisms 2022, 10(3), 539; https://doi.org/10.3390/microorganisms10030539 - 28 Feb 2022
Cited by 38 | Viewed by 7105
Abstract
Lumpy skin disease (LSD) is a transboundary viral disease of cattle and buffaloes transmitted by blood-feeding vectors and causes high morbidity and low-to-moderate mortality. Since the first observation of LSD in Zambia in 1929, it has spread in cattle populations across African countries, [...] Read more.
Lumpy skin disease (LSD) is a transboundary viral disease of cattle and buffaloes transmitted by blood-feeding vectors and causes high morbidity and low-to-moderate mortality. Since the first observation of LSD in Zambia in 1929, it has spread in cattle populations across African countries, the Middle East, Europe, and Asia. Following the recent outbreaks of LSD in South Asian countries such as India and Bangladesh, the disease was first reported in cattle farms in Nepal in June 2020. This study investigated the Nepalese LSD outbreak and confirmed that the disease spread rapidly to three neighboring districts in a month, infecting 1300 animals. Both cattle and buffaloes showed common clinical signs of LSD, with the exception that the buffaloes presented small nodular lesions without centered ulcerations. The collected samples were first tested for the presence of LSDV by real-time PCR. We further applied molecular tools, RPO30, GPCR, EEV glycoprotein gene, and B22R, for additional characterization of the LSDV isolates circulating in Nepal. Using a PCR-based Snapback assay, we confirmed that samples collected from cattle and buffaloes were positive of LSDV. Furthermore, sequence analysis (phylogenetic and multiple sequence alignments) of four selected LSDV genes revealed that the Nepal LSDVs resemble the Bangladesh and Indian isolates and the historic isolates from Kenya. We also highlight the importance of a unique B22R gene region harboring single-nucleotide insertions in LSDV Neethling and LSDV KSGPO-240 vaccine strains, enabling us to differentiate them from the Nepalese isolates and other fields isolates. This study demonstrates the importance of disease surveillance and the need to determine the source of the disease introduction, the extent of spread, modes of transmission, and the necessary control measures. Full article
(This article belongs to the Section Virology)
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