The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Anna E. Jolles - One of the best experts on this subject based on the ideXlab platform.
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Toll-like receptor (TLR) diversity influences mycobacterial growth in African Buffalo.
Tuberculosis, 2017Co-Authors: Nikki Le Roex, Anna E. Jolles, Brianna R. Beechler, Paul D. Van Helden, Eileen G. HoalAbstract:Abstract Understanding the role of wildlife in the maintenance or spread of emerging infectious diseases is a growing priority across the world. Bovine tuberculosis (BTB) is a chronic, infectious disease caused by Mycobacterium bovis ( M. bovis ). BTB is widespread within game reserves in southern Africa, and within these ecosystems the primary wildlife host of this disease is the African Buffalo. We used a modified bacterial killing assay for mycobacteria to investigate the effect of Toll-like receptor (TLR) genetic diversity and demographic parameters on the ability of African Buffalo to restrict mycobacterial growth. Eosinophil count, time delay, bovine PPD response and avian PPD response were negatively correlated with mycobacterial growth. TLR6 diversity and the interaction of age group and sex were positively correlated with mycobacterial growth. Our results suggest that both demographic and individual immune parameters influence the ability to control mycobacterial infection in African Buffalo. TLR6 diversity is particularly interesting as this locus has also shown associations with BTB in cattle, suggesting that further research into the effects, selection and role of TLR6 variants in bovine tuberculosis will be productive.
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enemies and turncoats bovine tuberculosis exposes pathogenic potential of rift valley fever virus in a common host African Buffalo syncerus caffer
Proceedings of The Royal Society B: Biological Sciences, 2015Co-Authors: Brianna R. Beechler, Vanessa O Ezenwa, Erin E Gorsich, Carrie A Manore, B Reininghaus, Dawn M Oneal, Anna E. JollesAbstract:The ubiquity and importance of parasite co-infections in populations of free-living animals is beginning to be recognized, but few studies have demonstrated differential fitness effects of single infection versus co-infection in free-living populations. We investigated interactions between the emerging bacterial disease bovine tuberculosis (BTB) and the previously existing viral disease Rift Valley fever (RVF) in a competent reservoir host, African Buffalo, combining data from a natural outbreak of RVF in captive Buffalo at a Buffalo breeding facility in 2008 with data collected from a neighbouring free-living herd of African Buffalo in Kruger National Park. RVF infection was twice as likely in individual BTB+ Buffalo as in BTB− Buffalo, which, according to a mathematical model, may increase RVF outbreak size at the population level. In addition, co-infection was associated with a far higher rate of fetal abortion than other infection states. Immune interactions between BTB and RVF may underlie both of these interactions, since animals with BTB had decreased innate immunity and increased pro-inflammatory immune responses. This study is one of the first to demonstrate how the consequences of emerging infections extend beyond direct effects on host health, potentially altering the dynamics and fitness effects of infectious diseases that had previously existed in the ecosystem on free-ranging wildlife populations.
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evaluation of the sensitivity and specificity of an enzyme linked immunosorbent assay for diagnosing brucellosis in African Buffalo syncerus caffer
Journal of Wildlife Diseases, 2015Co-Authors: Erin E Gorsich, R G Bengis, Vanessa O Ezenwa, Anna E. JollesAbstract:Brucellosis is a disease of veterinary and public health importance worldwide. In sub-Saharan Africa, where the bacterium Brucella abortus has been identified in several free-ranging wildlife species, successful disease control may be dependent on accurate detection in wildlife reservoirs, including African Buffalo (Syncerus caffer). We estimated the sensitivity and specificity of a commercial enzyme-linked immunosorbent assay (ELISA) (IDEXX Brucellosis Serum Ab test, IDEXX Laboratories, Westbrook, Maine, USA) for B. abortus based on a data set of 571 serum samples from 258 Buffalo in the Kruger National Park, South Africa. We defined a pseudogold standard test result as those Buffalo that were consistently positive or negative on two additional serologic tests, namely, the rose bengal test (RBT) and the complement fixation test (CFT). The ELISA's cutoff value was selected using receiver operating characteristics analysis, the pseudogold standard, and a threshold criterion that maximizes the total sensitivity and specificity. Then, we estimated the sensitivity and specificity of all three tests using Bayesian inference and latent class analysis. The ELISA had an estimated sensitivity of 0.928 (95% Bayesian posterior credibility interval [95% BCI] = 0.869–0.974) and specificity of 0.870 (95% BCI = 0.836–0.900). Compared with the ELISA, the RBT had a higher estimated sensitivity of 0.986 (95% BCI = 0.928–0.999), and both the RBT and CFT had higher specificities, estimated to be 0.992 (95% BCI = 0.971–0.996) and 0.998 (95% BCI = 0.992–0.999), respectively. Therefore, no single serologic test perfectly detected the antibody. However, after adjustment of cutoff values for South African conditions, the IDEXX Brucellosis Serum Ab Test may be a valuable additional screening test for brucellosis in Kruger National Park's African Buffalo.
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innate immunity in free ranging African Buffalo syncerus caffer associations with parasite infection and white blood cell counts
Physiological and Biochemical Zoology, 2012Co-Authors: Brianna R. Beechler, Vanessa O Ezenwa, Heather M Broughton, Austin Bell, Anna E. JollesAbstract:AbstractMammalian immunology has been studied in great detail in laboratory animals, but few of the tools and less of the insight derived from these studies have been placed in the context of natural, outbred wildlife populations subject to variable environments. We investigated patterns of innate immunity in free-ranging African Buffalo in relation to host traits (age, reproductive status, body condition, white blood cell counts) and disease status (bovine tuberculosis [BTB], gastrointestinal nematodes, coccidia, ticks). We evaluated and used an in vitro assay measuring bactericidal competence of blood to assess a component of innate immunity in 200 female Buffalo captured at Kruger National Park, South Africa, in June/July and October 2008. Animals with BTB had higher bactericidal competence of blood. Animals with higher neutrophil counts had higher bactericidal competence, whereas animals with lower lymphocyte counts had higher bactericidal competence. This pattern was driven by animals captured at the...
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hidden consequences of living in a wormy world nematode induced immune suppression facilitates tuberculosis invasion in African Buffalo
The American Naturalist, 2010Co-Authors: Vanessa O Ezenwa, Rampal S Etienne, Gordon Luikart, Albano Bejapereira, Anna E. JollesAbstract:Abstract: Most hosts are infected with multiple parasites, and responses of the immune system to co‐occurring parasites may influence disease spread. Helminth infection can bias the host immune response toward a T‐helper type 2 (Th2) over a type 1 (Th1) response, impairing the host’s ability to control concurrent intracellular microparasite infections and potentially modifying disease dynamics. In humans, immune‐mediated interactions between helminths and microparasites can alter host susceptibility to diseases such as HIV, tuberculosis (TB), and malaria. However, the extent to which similar processes operate in natural animal populations and influence disease spread remains unknown. We used cross‐sectional, experimental, and genetic studies to show that gastrointestinal nematode infection alters immunity to intracellular microparasites in free‐ranging African Buffalo (Syncerus caffer). Buffalo that were more resistant to nematode infection had weaker Th1 responses, there was significant genotypic variati...
Julius Beneoluchi Odili - One of the best experts on this subject based on the ideXlab platform.
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African Buffalo Optimization Algorithm for Tuning Parameters of a PID Controller in Automatic Voltage Regulators
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:In this paper, we present the African Buffalo Optimization (ABO) approach for the metaheuristic tuning of the Proportional, Integral & Derivative (PID) Controller parameters of Automatic Voltage Regulators in electrical power generation and transmission. ABO simulates the movement of African Buffalos as they migrate from place to place all over Africa in search of grazing pastures. The Buffalos use just two basic vocalizations, namely the waaa and the maaa to organize the entire herd in their migration and search for food a nd water. Though a recently-designed algorithm, the ABO has been effective and efficient in solving a number of search optimization problems. The highpoints of the ABO include its use of few parameters, constant interactions among the Buffalos and the deployment of the exploration and exploitations mechanisms of the algorithm in every iteration. The simulation outcome of the application of ABO to tune the parameters of a PID-Controller parameters of Automatic Voltage Regulators has been very competitive when compared similar outcomes of other metaheuristics tuners: BFO-PID, PSO-PID, GA-PID, PID-PSO, PID Tuner and ACO-PID.
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African Buffalo Optimization Approach to the Design of PIDController in Automatic Voltage Regulator System
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M.Abstract:In the past few decades, researchers have focused so much attention on the application of bio-inspired techniques for solving real-life problems in science, engineering and industrial processes. This paper presents the African Buffalo Optimization (ABO) approach to tuning the Proportional, Integral and Derivative (PID) parameters of an Automatic Voltage Regulator. The ABO is a simulation of the movement of African Buffalos in the vast African landscape in search of lush grazing pastures using two basic sounds, namely the waaa and the maaa vocalizations. The ABO has so far been effective and efficient in providing solutions to a number of optimization problems as a result of its use of relatively fewer parameters, straightforward fitness function as well as regular communications using the star communication topology. Simulation results from the application of the ABO to tuning the parameters of an AVR has proven to be very competitive when compared with the results of other bio-inspired optimization techniques such as the GA-PID, ACO-PID, PSO-PID, BFO-PID, PID-PSO and PID Tuner.
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Convergence Analysis of the African Buffalo Optimization Algorithm
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:This paper presents the convergence analysis of the newly-developed African Buffalo Optimization algorithm. African Buffalo Optimization is a simulation of the organizational skills of the African Buffalos using two basic sounds: /waaa/ and /maaa/ as they transverse the African landscape in search of grazing pastures. The African Buffalo Optimization has proven to be quite successful since its development hence the need to examine its convergence behavior. The analysis of the convergence of Nature-inspired optimization algorithms is necessary to help researchers and practitioners understand the workings of the algorithms in the algorithms’ attempts at solutions. After a number of evaluations, this study discovered that the convergence of African Buffalo Optimization is a function of the population size, communication topology, parameter-set, landscape topology and the objective function being optimized.
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African Buffalo Optimization (ABO): A New MetaheuristicAlgorithm
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M.Abstract:This paper proposes a new meta-heuristic approach to solving numerical and graph-based problems. The African Buffalo algorithm evolved from an understanding of the animal's survival instincts and the search techniques they utilize in the African forests and savannahs; the search for the optimal path to pasture is aligned to their cooperative, intelligent, and social nature. The African Buffalo Optimization (A.B.0) algorithm simulates the African Buffalos' behaviour by encapsulation in a mathematical model; which solves a number of discrete optimization problems using graph-based route planning, job scheduling and it extends Swarm Intelligence paradigms. When compared to the Ant Colony Optimization algorithm, Simulated Annealing and Genetic Algorithm, the results obtained from African Buffalo Optimization show that the algorithm works well and can be extended to solving problems like: path planning, scheduling, vehicle routing in addition to other constraint-driven problems.
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Solving Traveling Salesman’s Problem Using African Buffalo Optimization, Honey Bee Mating Optimization & Lin-Kerninghan Algorithms
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:This paper compares the performances of the African Buffalo Optimization (ABO), hybrid Honey Bee Mating Optimization (HBMO) and the Lin-Kernighan (LKH) algorithms for solving the problems of the Symmetric Travelling Salesman’s Problems. The three techniques have been applied successfully to solve the popular problem of an anonymous travelling salesman who is searching for the most optimized route to visiting all his customers in different locations of a large city or in a number of cities. This study focusses on these three methods with the aim of ascertaining the most efficient and effective. Results obtained from using these algorithms to solve the benchmark dataset on TSP available in TSPLIB95 serve as the comparative data. The outcome of this experiment shows that the newly-developed African Buffalo Optimization has very encouraging performance in terms of capacity to obtain optimal or near-optimal results consistently and in the most cost-effective manner.
Marinda C Oosthuizen - One of the best experts on this subject based on the ideXlab platform.
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tick borne haemoparasites in African Buffalo syncerus caffer from two wildlife areas in northern botswana
Parasites & Vectors, 2015Co-Authors: Dewald Eygelaar, Ferran Jori, Nicola E Collins, Mokganedi Mokopasetso, Kgomotso P Sibeko, Ilse Vorster, Milana Troskie, Marinda C OosthuizenAbstract:Background: The African Buffalo (Syncerus caffer) is a host for many pathogens known to cause economically important diseases and is often considered an important reservoir for livestock diseases. Theileriosis, heartwater, babesiosis and anaplasmosis are considered the most important tick-borne diseases of livestock in sub-Saharan Africa, resulting in extensive economic losses to livestock farmers in endemic areas. Information on the distribution of tick-borne diseases and ticks is scarce in Northern Botswana. Nevertheless, this data is necessary for targeting surveillance and control measures in livestock production at national level. Methods: In order to address this gap, we analyzed 120 blood samples from Buffalo herds for the presence of common tick-borne haemoparasites causing disease in livestock, collected in two of the main wildlife areas of Northern Botswana: the Chobe National Park (CNP, n = 64) and the Okavango Delta (OD, n = 56). Results: Analysis of the reverse line blot (RLB) hybridization assay results revealed the presence of Theileria, Babesia, Anaplasma and Ehrlichia species, either as single or mixed infections. Among the Theileria spp. present, T. parva (60%) and T. mutans (37%) were the most prevalent. Other species of interest were Anaplasma marginale subsp. centrale (30%), A. marginale (20%), Babesia occultans (23%) and Ehrlichia ruminantium (6%). The indirect fluorescent antibody test (IFAT) indicated 74% of samples to be positive for the presence of T. parva antibodies. Quantitative real-time PCR (qPCR) detected the highest level of animals infected with T. parva (81% of the samples). The level of agreement between the tests for detection of T. parva positive animals was higher between qPCR and IFAT (kappa = 0.56), than between qPCR and RLB (kappa = 0.26) or the latter and IFAT (kappa = 0.15). Conclusions: This is the first report of tick-borne haemoparasites in African Buffalo from northern Botswana, where animals from the CNP showed higher levels of infection than those from OD. Considering the absence of fences separating wildlife and livestock in the CNP and the higher levels of some parasite species in Buffalo from that area, surveillance of tick-borne diseases in livestock at the interface in the CNP should be prioritized.
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phylogeny of theileria buffeli genotypes identified in the south African Buffalo syncerus caffer population
Veterinary Parasitology, 2014Co-Authors: Mamohale E Chaisi, Nicola E Collins, Marinda C OosthuizenAbstract:Theileria buffeli/orientalis is a group of benign and mildly pathogenic species of cattle and Buffalo in various parts of the world. In a previous study, we identified T. buffeli in blood samples originating from the African Buffalo (Syncerus caffer) in the Hluhluwe–iMfolozi Game Park (HIP) and the Addo Elephant Game Park (AEGP) in South Africa. The aim of this study was to characterise the 18S rRNA gene and complete internal transcribed spacer (ITS1-5.8S-ITS2) region of T. buffeli samples, and to establish the phylogenetic position of this species based on these loci. The 18S rRNA gene and the complete ITS region were amplified from DNA extracted from blood samples originating from Buffalo in HIP and AEGP. The PCR products were cloned and the resulting recombinants sequenced. We identified novel T. buffeli-like 18S rRNA and ITS genotypes from Buffalo in the AEGP, and novel Theileria sinensis-like 18S rRNA genotypes from Buffalo in the HIP. Phylogenetic analyses indicated that the T. buffeli-like sequences were similar to T. buffeli sequences from cattle and Buffalo in China and India, and the T. sinensis-like sequences were similar to T. sinensis 18S rRNA sequences of cattle and yak in China. There was extensive sequence variation between the novel T. buffeli genotypes of the African Buffalo and previously described T. buffeli and T. sinensis genotypes. The presence of organisms with T. buffeli-like and T. sinensis-like genotypes in the African Buffalo could be of significant importance, particularly to the cattle industry in South Africa as these animals might act as sources of infections to naive cattle. This is the first report on the characterisation of the full-length 18S rRNA gene and ITS region of T. buffeli and T. sinensis genotypes in South Africa. Our study provides invaluable information towards the classification of this complex group of benign and mildly pathogenic species.
Ahmad Noraziah - One of the best experts on this subject based on the ideXlab platform.
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Convergence Analysis of the African Buffalo Optimization Algorithm
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:This paper presents the convergence analysis of the newly-developed African Buffalo Optimization algorithm. African Buffalo Optimization is a simulation of the organizational skills of the African Buffalos using two basic sounds: /waaa/ and /maaa/ as they transverse the African landscape in search of grazing pastures. The African Buffalo Optimization has proven to be quite successful since its development hence the need to examine its convergence behavior. The analysis of the convergence of Nature-inspired optimization algorithms is necessary to help researchers and practitioners understand the workings of the algorithms in the algorithms’ attempts at solutions. After a number of evaluations, this study discovered that the convergence of African Buffalo Optimization is a function of the population size, communication topology, parameter-set, landscape topology and the objective function being optimized.
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African Buffalo Optimization Algorithm for PID parameters tuning of Automatic Voltage Regulators
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:To obtain stability of electric power generating system, there is the need for an Automatic Voltage Regulator (AVR) component. The effectiveness of the AVR is traceable to the proper tuning of the Proportional, Integral and Derivative (PID) parameters within the AVR. Our innovation is the successful use of the African Buffalo Optimization Algorithm to tune PID parameters for optimum efficiency and effectiveness.
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Solving Traveling Salesman’s Problem Using African Buffalo Optimization, Honey Bee Mating Optimization & Lin-Kerninghan Algorithms
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:This paper compares the performances of the African Buffalo Optimization (ABO), hybrid Honey Bee Mating Optimization (HBMO) and the Lin-Kernighan (LKH) algorithms for solving the problems of the Symmetric Travelling Salesman’s Problems. The three techniques have been applied successfully to solve the popular problem of an anonymous travelling salesman who is searching for the most optimized route to visiting all his customers in different locations of a large city or in a number of cities. This study focusses on these three methods with the aim of ascertaining the most efficient and effective. Results obtained from using these algorithms to solve the benchmark dataset on TSP available in TSPLIB95 serve as the comparative data. The outcome of this experiment shows that the newly-developed African Buffalo Optimization has very encouraging performance in terms of capacity to obtain optimal or near-optimal results consistently and in the most cost-effective manner.
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African Buffalo Optimization Algorithm for Tuning Parameters of a PID Controller in Automatic Voltage Regulators
2020Co-Authors: Julius Beneoluchi Odili, Kahar M. N. M., Ahmad NoraziahAbstract:In this paper, we present the African Buffalo Optimization (ABO) approach for the metaheuristic tuning of the Proportional, Integral & Derivative (PID) Controller parameters of Automatic Voltage Regulators in electrical power generation and transmission. ABO simulates the movement of African Buffalos as they migrate from place to place all over Africa in search of grazing pastures. The Buffalos use just two basic vocalizations, namely the waaa and the maaa to organize the entire herd in their migration and search for food a nd water. Though a recently-designed algorithm, the ABO has been effective and efficient in solving a number of search optimization problems. The highpoints of the ABO include its use of few parameters, constant interactions among the Buffalos and the deployment of the exploration and exploitations mechanisms of the algorithm in every iteration. The simulation outcome of the application of ABO to tune the parameters of a PID-Controller parameters of Automatic Voltage Regulators has been very competitive when compared similar outcomes of other metaheuristics tuners: BFO-PID, PSO-PID, GA-PID, PID-PSO, PID Tuner and ACO-PID.
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African Buffalo optimization for global optimization
Current Science, 2018Co-Authors: Julius Beneoluchi Odili, Ahmad NoraziahAbstract:In this study we apply the African Buffalo optimization (ABO) to solve benchmark global optimization problems. Such problems which are artificial representation of different search landscapes ranging from unimodal to multimodal, separable to non-separable, constrained to unconstrained search landscapes have become a veritable instrument to test the search capacities of optimization algorithms. After a number of experimental procedures involving 28 benchmark problems, results from ABO prove to be rather competitive leading to the conclusion that it is a worthy addition to the body of swarm intelligence techniques.
Brianna R. Beechler - One of the best experts on this subject based on the ideXlab platform.
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bovine tuberculosis disturbs parasite functional trait composition in African Buffalo
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Brianna R. Beechler, Peter Buss, Kate S Boersma, Courtney A C Coon, Erin E Gorsich, Brian S Henrichs, Adam M Siepielski, Johannie M Spaan, Robert S SpaanAbstract:Novel parasites can have wide-ranging impacts, not only on host populations, but also on the resident parasite community. Historically, impacts of novel parasites have been assessed by examining pairwise interactions between parasite species. However, parasite communities are complex networks of interacting species. Here we used multivariate taxonomic and trait-based approaches to determine how parasite community composition changed when African Buffalo ( Syncerus caffer ) acquired an emerging disease, bovine tuberculosis (BTB). Both taxonomic and functional parasite richness increased significantly in animals that acquired BTB than in those that did not. Thus, the presence of BTB seems to catalyze extraordinary shifts in community composition. There were no differences in overall parasite taxonomic composition between infected and uninfected individuals, however. The trait-based analysis revealed an increase in direct-transmitted, quickly replicating parasites following BTB infection. This study demonstrates that trait-based approaches provide insight into parasite community dynamics in the context of emerging infections.
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detection of pathogen exposure in African Buffalo using non specific markers of inflammation
Frontiers in Immunology, 2018Co-Authors: Caroline K Glidden, Brianna R. Beechler, Peter Buss, Bryan Charleston, Linmari De Klerklorist, Francois Frederick Maree, Timothy Muller, Eva Perezmartin, Katherine Anne Scott, Ockert Louis Van SchalkwykAbstract:ABSTRACT Detecting exposure to new or emerging pathogens is a critical challenge to protecting human, domestic animal and wildlife health. Yet current techniques to detect infections typically target known pathogens of humans or economically important animals. In the face of the current surge in infectious disease emergence, non-specific disease surveillance tools are urgently needed. Tracking common host immune responses indicative of recent infection may have potential as a non-specific diagnostic approach for disease surveillance. The challenge to immunologists is to identify the most promising markers, which ideally should be highly conserved across pathogens and host species, become upregulated rapidly and consistently in response to pathogen invasion, and remain elevated beyond clearance of infection. This study combined an infection experiment and a longitudinal observational study to evaluate the utility of non-specific markers of inflammation (NSMI; two acute phase proteins (haptoglobin and serum amyloid A), two pro-inflammatory cytokines (IFN and TNF-)) as indicators of pathogen exposure in a wild mammalian species, African Buffalo (Syncerus caffer). Specifically, in the experimental study we asked (1) How quickly do Buffalo mount NSMI responses upon challenge with an endemic pathogen, foot-and-mouth disease virus; (2) for how long do NSMI remain elevated after viral clearance and; (3) how pronounced is the difference between peak NSMI concentration and baseline NSMI concentration? In the longitudinal study, we asked (4) Are elevated NSMI associated with recent exposure to a suite of bacterial and viral respiratory pathogens in a wild population? Among the four NSMI that we tested, haptoglobin showed the strongest potential as a surveillance marker in African Buffalo: Concentrations quickly and consistently reached high levels in response to experimental infection, remaining elevated for almost a month. Moreover, elevated haptoglobin was indicative of recent exposure to two respiratory pathogens assessed in the longitudinal study. We hope this work motivates studies investigating suites of non-specific markers of inflammation as indicators for pathogen exposure in a broader range of both pathogen and host species, potentially transforming how we track disease burden in natural populations.
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Toll-like receptor (TLR) diversity influences mycobacterial growth in African Buffalo.
Tuberculosis, 2017Co-Authors: Nikki Le Roex, Anna E. Jolles, Brianna R. Beechler, Paul D. Van Helden, Eileen G. HoalAbstract:Abstract Understanding the role of wildlife in the maintenance or spread of emerging infectious diseases is a growing priority across the world. Bovine tuberculosis (BTB) is a chronic, infectious disease caused by Mycobacterium bovis ( M. bovis ). BTB is widespread within game reserves in southern Africa, and within these ecosystems the primary wildlife host of this disease is the African Buffalo. We used a modified bacterial killing assay for mycobacteria to investigate the effect of Toll-like receptor (TLR) genetic diversity and demographic parameters on the ability of African Buffalo to restrict mycobacterial growth. Eosinophil count, time delay, bovine PPD response and avian PPD response were negatively correlated with mycobacterial growth. TLR6 diversity and the interaction of age group and sex were positively correlated with mycobacterial growth. Our results suggest that both demographic and individual immune parameters influence the ability to control mycobacterial infection in African Buffalo. TLR6 diversity is particularly interesting as this locus has also shown associations with BTB in cattle, suggesting that further research into the effects, selection and role of TLR6 variants in bovine tuberculosis will be productive.
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enemies and turncoats bovine tuberculosis exposes pathogenic potential of rift valley fever virus in a common host African Buffalo syncerus caffer
Proceedings of The Royal Society B: Biological Sciences, 2015Co-Authors: Brianna R. Beechler, Vanessa O Ezenwa, Erin E Gorsich, Carrie A Manore, B Reininghaus, Dawn M Oneal, Anna E. JollesAbstract:The ubiquity and importance of parasite co-infections in populations of free-living animals is beginning to be recognized, but few studies have demonstrated differential fitness effects of single infection versus co-infection in free-living populations. We investigated interactions between the emerging bacterial disease bovine tuberculosis (BTB) and the previously existing viral disease Rift Valley fever (RVF) in a competent reservoir host, African Buffalo, combining data from a natural outbreak of RVF in captive Buffalo at a Buffalo breeding facility in 2008 with data collected from a neighbouring free-living herd of African Buffalo in Kruger National Park. RVF infection was twice as likely in individual BTB+ Buffalo as in BTB− Buffalo, which, according to a mathematical model, may increase RVF outbreak size at the population level. In addition, co-infection was associated with a far higher rate of fetal abortion than other infection states. Immune interactions between BTB and RVF may underlie both of these interactions, since animals with BTB had decreased innate immunity and increased pro-inflammatory immune responses. This study is one of the first to demonstrate how the consequences of emerging infections extend beyond direct effects on host health, potentially altering the dynamics and fitness effects of infectious diseases that had previously existed in the ecosystem on free-ranging wildlife populations.
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innate immunity in free ranging African Buffalo syncerus caffer associations with parasite infection and white blood cell counts
Physiological and Biochemical Zoology, 2012Co-Authors: Brianna R. Beechler, Vanessa O Ezenwa, Heather M Broughton, Austin Bell, Anna E. JollesAbstract:AbstractMammalian immunology has been studied in great detail in laboratory animals, but few of the tools and less of the insight derived from these studies have been placed in the context of natural, outbred wildlife populations subject to variable environments. We investigated patterns of innate immunity in free-ranging African Buffalo in relation to host traits (age, reproductive status, body condition, white blood cell counts) and disease status (bovine tuberculosis [BTB], gastrointestinal nematodes, coccidia, ticks). We evaluated and used an in vitro assay measuring bactericidal competence of blood to assess a component of innate immunity in 200 female Buffalo captured at Kruger National Park, South Africa, in June/July and October 2008. Animals with BTB had higher bactericidal competence of blood. Animals with higher neutrophil counts had higher bactericidal competence, whereas animals with lower lymphocyte counts had higher bactericidal competence. This pattern was driven by animals captured at the...