A Technical Report on the Potential Effects of Heat Stress on Antioxidant Enzymes Activities, Performance and Small Intestinal Morphology in Broiler Chickens Administered Probiotic and Ascorbic Acid during the Hot Summer Season.

Oxidative stress negatively affects the welfare of broiler chickens leading to poor productivity and even death. This study examined the negative effect of heat stress on antioxidant enzyme activities, small intestinal morphology and performance in broiler chickens administered probiotic and ascorbic acid during the hot summer season, under otherwise controlled conditions. The study made use of 56 broiler chickens; which were divided into control; probiotic (1 g/kg); ascorbic acid (200 mg/kg) and probiotic + ascorbic acid (1 g/kg and 200 mg/kg, respectively). All administrations were given via feed from D1 to D35 of this study. Superoxide dismutase, glutathione peroxidase and catalase activities were highly significant (p < 0.0001) in the treatment groups compared to the control. Performance indicators (water intake and body weight gain) were significantly higher (p < 0.05) in the probiotic and probiotic + ascorbic acid group. The height of duodenal, jejunal and ileal villi, and goblet cell counts of broiler chickens were significantly different in the treatment groups. In conclusion, the study showed that heat stress negatively affects the levels of endogenous antioxidant enzymes, performance and the morphology of small intestinal epithelium, while the antioxidants were efficacious in ameliorating these adverse effects.

Unravelling the diversity of Anaplasma species circulating in selected African wildlife hosts by targeted 16S microbiome analysis.

Organisms in the genus Anaplasma are obligate intracellular alphaproteobacteria. Bovine anaplasmosis, predominantly caused by Anaplasma marginale, is the most prevalent tick-borne disease (TBD) of cattle worldwide. Other Anaplasma species are known to cause disease; these include A. ovis, A. platys in dogs, A. capra in goats and humans, and A. phagocytophilum in humans. The rapid advancement of next-generation sequencing technologies has led to the discovery of many novel sequences ascribed to the genus Anaplasma, with over 20 putative new species being proposed since the last formal organization of the genus. Most 16S rRNA gene surveys for Anaplasma were conducted on cattle and to a lesser extent on rodents, dogs, and ticks. Little is known about the occurrence, diversity, or impact of Anaplasma species circulating in wildlife species. Therefore, we conducted a 16S rRNA gene survey with the goal of identifying Anaplasma species in a variety of wildlife species in the Kruger National Park and neighbouring game reserves, using an unbiased 16S rRNA gene microbiome approach. An Anaplasma/Ehrlichia-group specific quantitative real-time PCR (qPCR) assay revealed the presence of Anaplasma and/or Ehrlichia species in 70.0% (21/30) of African buffalo, 86.7% (26/30) of impala, 36.7% (11/30) of greater kudu, 3.2% (1/31) of African wild dog, 40.6% (13/32) of Burchell's zebra, 43.3% (13/30) of warthog, 22.6% (7/31) of spotted hyena, 40.0% (12/30) of leopard, 17.6% (6/34) of lion, 16.7% (5/30) of African elephant and 8.6% (3/35) of white rhinoceros samples. Microbiome sequencing data from the qPCR positive samples revealed four 16S rRNA sequences identical to previously published Anaplasma sequences, as well as nine novel Anaplasma 16S genotypes. Our results reveal a greater diversity of putative Anaplasma species circulating in wildlife than currently classified within the genus. Our findings highlight a potential expansion of the Anaplasma host range and the need for more genetic information from other important genes or genome sequencing of putative novel species for correct classification and further assessment of their occurrence in wildlife, livestock and companion animals.

Distribution and Prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African Ticks: A Systematic Review and Meta-Analysis.

In Africa, ticks continue to be a major hindrance to the improvement of the livestock industry due to tick-borne pathogens that include Anaplasma, Ehrlichia, Rickettsia and Coxiella species. A systemic review and meta-analysis were conducted here and highlighted the distribution and prevalence of these tick-borne pathogens in African ticks. Relevant publications were searched in five electronic databases and selected using inclusion/exclusion criteria, resulting in 138 and 78 papers included in the qualitative and quantitative analysis, respectively. Most of the studies focused on Rickettsia africae (38 studies), followed by Ehrlichia ruminantium (27 studies), Coxiella burnetii (20 studies) and Anaplasma marginale (17 studies). A meta-analysis of proportions was performed using the random-effects model. The highest prevalence was obtained for Rickettsia spp. (18.39%; 95% CI: 14.23-22.85%), R. africae (13.47%; 95% CI: 2.76-28.69%), R. conorii (11.28%; 95% CI: 1.77-25.89%), A. marginale (12.75%; 95% CI: 4.06-24.35%), E. ruminantium (6.37%; 95% CI: 3.97-9.16%) and E. canis (4.3%; 95% CI: 0.04-12.66%). The prevalence of C. burnetii was low (0%; 95% CI: 0-0.25%), with higher prevalence for Coxiella spp. (27.02%; 95% CI: 10.83-46.03%) and Coxiella-like endosymbionts (70.47%; 95% CI: 27-99.82%). The effect of the tick genera, tick species, country and other variables were identified and highlighted the epidemiology of Rhipicephalus ticks in the heartwater; affinity of each Rickettsia species for different tick genera; dominant distribution of A. marginale, R. africae and Coxiella-like endosymbionts in ticks and a low distribution of C. burnetii in African hard ticks.

Temporal Dynamics of Anaplasma marginale Infections and the Composition of Anaplasma spp. in Calves in the Mnisi Communal Area, Mpumalanga, South Africa.

Bovine anaplasmosis, caused by Anaplasma marginale, is one of the most important tick-borne diseases of cattle. Anaplasma marginale is known to be present in the Mnisi community, Mpumalanga Province, with frequent cases of anaplasmosis reported. This study investigated the infection dynamics in calves (n = 10) in two habitats in the study area over 12 months. A duplex real-time PCR assay targeting the msp1ß gene of A. marginale and the groEL gene of A. centrale confirmed the presence of A. marginale in five calves in a peri-urban area from the first month, but in only two calves at the wildlife-livestock interface and only after six months. These results were confirmed by 16S rRNA microbiome analysis. Over 50 A. marginale msp1α genotypes were detected in the calves along with five novel Msp1a repeats. Calves in the peri-urban area were more likely to be infected with A. marginale than calves in the wildlife-livestock interface. Cattle management, acaricide treatment, and cattle density could explain differences in infection prevalence in the two areas. Our results revealed that most calves were superinfected by distinct A. marginale strains within the study period, indicating continuous challenge with multiple strains that should lead to robust immunity in the calves and endemic stability in the area.

Neoehrlichiosis in Symptomatic Immunocompetent Child, South Africa.

We describe a case of neoehrlichiosis in an immunocompetent child with acute febrile illness in South Africa. Neoehrlichiosis was diagnosed by PCR on 16S rDNA from bone marrow aspirate. Phylogenetic analysis indicated an organism closely related to Candidatus Neoehrlichia. Clinicians should be aware of possible ehrlichiosis even in immunocompetent patients.

Development and validation of a TaqMan® probe- based real-time PCR assay for detection of Ehrlichia canis.

Ehrlichiosis is a potentially fatal zoonotic tick-borne disease, caused by a pleomorphic Gram-negative bacterium. It occurs worldwide and affects humans, domestic and wild animals. Dogs infected with Ehrlichia canis develop canine monocytic ehrlichiosis (CME), a significant infectious disease of canines. TaqMan® based real-time PCR assays to detect Ehrlichia spp. affecting dogs were developed and a real-time PCR assay specific for E. canis validated. The efficiency of the assay was 93% and the 95% limit of detection was 33 E. canis plasmid copies/µl of blood (95% confidence interval: 23 - 58). The assay was specific for E. canis when tested against other haemoparasites. Consistent repeatability was observed, with an inter-run standard deviation (SD) range between 0.33 and 1.29 and an intra-run SD range between 0.04 and 1.14. Field samples were tested in parallel by both the E. canis real-time PCR assay and a reverse line blot hybridization assay. The results were in agreement for the two assays, with an exception of two out of 121 samples. Bayesian latent class analysis was used to calculate a diagnostic sensitivity of the E. canis real-time PCR assay of 90% and a specificity of 92%. This assay is a sensitive and reliable molecular detection method for E. canis and will be a useful tool for early diagnosis and timely treatment for this haemoparasite.

Haemoplasma Prevalence and Diversity in Three Invasive Rattus Species from Gauteng Province, South Africa.

Invasive Rattus species are carriers of haemotropic Mycoplasmas (haemoplasmas) globally, but data from Africa are lacking. Using a PCR-sequencing approach, we assessed haemoplasma prevalence and diversity in kidney and buccal swabs collected from three invasive Rattus species (Rattus rattus, R. norvegicus and R. tanezumi) in Gauteng Province, South Africa. Whilst the overall sequence-confirmed haemoplasma prevalence was 38.4%, infection rates in R. rattus (58.3%) were significantly higher (χ2 = 12.96; df = 2; n = 99 p < 0.05) than for R. tanezumi (14.3%). Differences between host sex (χ2 = 3.59 × 10−31; df = 1; n = 99; p = 1.00) and age (χ2 = 4.28; df = 2; n = 99; p = 0.12) were not significant. Whilst buccal (1.01%) and ectoparasite positivity (2.13%) were low, these results suggest that multiple transmission routes are possible. Three phylogenetically distinct lineages, consistent with global rat-associated strains described to date, were detected, namely, 'Candidatus Mycoplasma haemomuris subsp. Ratti', and two Rattus-specific haemoplasmas that are yet to be formally described. These results expand the known distribution of invasive rat-associated haemoplasmas and highlight the potential for pathogen co-invasion of new territories together with invading rodent hosts.

Cross border transhumance involvement in ticks and tick-borne pathogens dissemination and first evidence of Anaplasma centrale in Burkina Faso.

In West Africa, cross-border transhumance, also called seasonal migration, is known to be a very important animal production strategy, as it involves about 70 to 90% of cattle. In spite of the cattle movements, some strategic areas of transhumance remain poorly explored regarding ticks and their associated pathogens investigations. The purpose of this study is to evaluate the involvement of transhumance in the spread of cattle ticks and associated pathogens in Burkina Faso (BF) and Benin (BN), in a context of speedy invasion of West African livestock by Rhipicephalus microplus. A longitudinal survey was performed on 210 cattle from BF, monitored for ticks and tick-borne pathogens (TBP) during one seasonal transhumance. The first sampling coded "T0BF" took place in eastern BF, at the transhumance departure. A second sampling "T1BN" was carried out in northern BN, the transhumance arrival zone. A third sampling "T2BF" was done at the return of cattle in eastern BF. Ticks were morphologically identified and TBP detected with reverse line blot hybridization (RLB) assay. A total of 1027 ticks (7 species), 1006 ticks (11 species) and 1211 ticks (9 species) were respectively found at T0BF, T1BN and T2BF. Some species were collected at the three times of sampling without any significant difference in their relative abundances. However, other tick species appeared only at T1BN and/or T2BF. The TBP species found at the three points surveyed were Theileria annulata, Theileria mutans, Theileria velifera, Babesia bigemina and Anaplasma marginale. The most prevalent was T. mutans with 166/210 (79%), 159/210 (75.7%) and 78/210 (37%) cattle positive respectively at T0BF, T1BN and T2BF. Anaplasma centrale was evidenced with 0.5% and 0.9% respectively at T0BF and T2BF. To our knowledge, this represents its first report in the study area. Overall, the TBP prevalences were significantly lower at T2BF, highlighting the effect of tick populations changes induced by transhumance combined with the seasonal variation influence.

Efficacy of two commercial synthetic pyrethroids (cypermethrin and deltamethrin) on Amblyomma variegatum and Rhipicephalus microplus strains of the south-western region of Burkina Faso.

Since 2011, period of the livestock invasion by the cattle tick Rhipicephalus microplus in Burkina Faso (BF), tick-control problems were exacerbated. Based on farmer's reports, most commonly used commercial acaricides were found to be ineffective in Western South part of the country. To investigate the occurrence and extent of such acaricidal ineffectiveness, we performed the standardized larval packet test (LPT) with commercial deltamethrin (vectocid) and cypermethrin (cypertop), on two cattle tick species, the native Amblyomma variegatum and the invasive R. microplus. The resistance ratios (RR) were computed with susceptible Hounde strain of Rhipicephalus geigyi as reference. The R. microplus population showed resistance to the two acaricides tested with the highest lethal concentration (LC) values, and different resistance ratios higher than 4 (deltamethrin: RR50 = 28.18 and RR90 = 32.41; cypermethrin: RR50 = 8.79 and RR90 = 23.15). In the contrary, A. variegatum population was found to be highly susceptible to acaricides tested with low lethal concentrations and resistance ratio values (deltamethrin: RR50 = 0.5 and RR90 = 0.48; cypermethrin: RR50 = 0.68 and RR90 = 0.79). These data demonstrate high synthetic pyrethroid resistance in R. microplus strain, leading to conclude that the acaricide ineffectiveness in tick populations control remains a concern in BF.

Cattle ticks and associated tick-borne pathogens in Burkina Faso and Benin: Apparent northern spread of Rhipicephalus microplus in Benin and first evidence of Theileria velifera and Theileria annulata.

Babesiosis, theileriosis, anaplasmosis, and heartwater are tick-borne diseases that threaten livestock production in sub-Saharan Africa including Burkina Faso and Benin. For over a decade, these two bordering countries have been facing an invasion of the livestock by the tick Rhipicephalus microplus, a major vector for babesiosis, accidentally introduced in Benin in 2004. The molecular identification of tick-borne pathogens in this border area is of particular interest due to animals seasonal migration between the two countries. In this survey, epidemiological features of ticks and tick-borne pathogens in cattle were investigated to compare the eastern Burkina Faso, corresponding to a seasonal migration departure zone, and the northern Benin, which represents a seasonal migration arrival zone. Ticks and peripheral blood were collected from a total of 946 cattle in the two areas. Ticks were morphologically identified and the DNA samples from bovine blood and ticks were analysed by Reverse Line Blot (RLB) hybridization process. A total of 2856 ticks were collected on 490 cattle in Burkina Faso, eight tick species were identified, while 3583 ticks were collected on 456 cattle in North Benin with nine tick species identified. The invasive tick, R. microplus was not found in eastern Burkina Faso, but its spread farthest north in Benin is reported. Six tick-borne pathogen species were found in cattle blood both in eastern Burkina Faso and in northern Benin. Ranked in decreasing order of overall prevalences, they are: Theileria mutans (91.1%), Theileria velifera (77.8%), Babesia bigemina (10.9%), Anaplasma marginale (4.2%), Babesia bovis (3.3%), and Theileria annulata (1.8%). To the best of our knowledge, this survey represents the first report of T. velifera and T. annulata in the region. Overall, the TBP prevalences were significantly higher in northern Benin than in eastern Burkina Faso, indicating a higher parasitological risk in this area.

A shared pathogen: Babesia rossi in domestic dogs, black-backed jackals (Canis mesomelas) and African wild dogs (Lycaon pictus) in South Africa.

In sub-Saharan Africa, babesiosis in domestic dogs is caused primarily by Babesia rossi. Black-backed jackals (Canis mesomelas), which are subclinical carriers of B. rossi, were a likely reservoir host from which infection passed to domestic dogs. The role of other indigenous canids, e.g. African wild dogs (Lycaon pictus), as reservoirs of B. rossi has not been elucidated. The question also arises whether genetic differences have arisen between B. rossi infecting domestic dogs and "ancestral" B. rossi in jackals. In a previous study we found that nearly one-third (27 of 91) of jackals were infected with B. rossi; this was confirmed by 18S rDNA sequence analysis. In this study, the near full-length B. rossi 18S rRNA gene was successfully amplified from 6 domestic dogs and 3 black-backed jackals. The obtained recombinant sequences were identical (100 %) to previously described B. rossi sequences of black-backed jackals in South Africa, and 99 % similar to B. rossi from dogs in South Africa and the Sudan. Although blood specimens from 5 (10 %) of 52 free-ranging African wild dogs (from Kruger National Park, South Africa, reacted with the B. rossi probe on RLB hybridisation, the presence of B. rossi could not be confirmed by amplification and sequencing, nor by multiplex, real-time PCR. Although African wild dogs they can be infected with B. rossi without showing clinical signs, our findings suggest that they are apparently not important reservoir hosts of B. rossi.

Molecular detection and characterisation of protozoan and rickettsial pathogens in ticks from cattle in the pastoral area of Karamoja, Uganda.

Ticks and tick-borne diseases (TBDs) significantly affect cattle production and the livelihoods of communities in pastoralist areas. Data on protozoan and rickettsial pathogens in ticks infesting cattle in Uganda is scanty; while it is an indicator of the likelihood of disease transmission and occurrence. A cross-sectional study was conducted amongst cattle in the Karamoja Region, northeastern Uganda, from July through September 2017, to determine the tick species diversity, identify protozoan and rickettsial pathogens in the ticks, and characterise pathogenic species by sequence and phylogenetic analyses. About 50 % of the ticks detected from each predilection site on each animal were collected from 100 purposively-selected cattle from 20 randomly-selected herds. Twelve tick species belonging to the genera Amblyomma, Rhipicephalus and Hyalomma were identified, the most abundant being Amblyomma lepidum (93.9 %), followed by Amblyomma variegatum (2.0 %) and Rhipicephalus evertsi evertsi (1.0 %). Tick species that have not been reported in recent studies amongst cattle in Uganda were found, namely Rhipicephalus pravus, Rhipicephalus praetextatus and Rhipicephalus turanicus. The ticks were grouped into 40 pools, by species and location, and the reverse line blot (RLB) hybridisation assay was used to detect pathogens from the ticks. The most frequently detected tick-borne parasites were Theileria mutans, Theileria velifera and Theileria parva, each observed in 25 % (10/40) of the tick pools. Tick-borne pathogens, namely Babesia rossi, Babesia microti and Theileria sp. (sable) that are not common to, or not known to infect, cattle were identified from ticks. The gene encoding Ehrlichia ruminantium pCS20 region, the Ehrlichia and Anaplasma 16S rRNA gene, and T. parva p67 sporozoite antigen gene were amplified, cloned and sequenced. Seven novel E. ruminantium pCS20 variants were identified, and these grouped into two separate clusters with sequences from other parts of Africa and Asia. The T. parva p67 sequences were of the allele type 1, and parasites possessing this allele type are commonly associated with East Coast fever in eastern Africa. Analysis of the Ehrlichia and Anaplasma 16S rRNA gene sequences showed that they were closely related to Rickettsia africae and to a new Ehrlichia species variant recently found in China. Our R. africae 16S rRNA sequences grouped with R. africae isolates from Nigeria, Egypt and Benin. The information on tick species diversity and pathogens in the various tick species provides an indicator of potential transmission amongst cattle populations, and to humans, and can be useful to estimate disease risk and in control strategies.

Ticks and tick-borne pathogens infecting livestock and dogs in Tchicala-Tcholoanga, Huambo Province, Angola.

The diversity of ticks and tick-borne pathogens (TBPs) infesting domestic animals in Tchicala-Tcholoanga, Angola, in 2016 was investigated. Seventeen tick species were recorded, Amblyomma pomposum being the most abundant on cattle (40%), goats (38%) and sheep (35%); Rhipicephalus turanicus was the most abundant on dogs (46%). This study presents new records of Haemaphysalis paraleachi, R. compositus, R. kochi and R. sulcatus in Angola, the first georeferenced population of Ha. leachi in southern Africa and the second record of R. microplus in Angola. Using the reverse line blot (RLB) hybridisation assay, fifteen TBP species were detected in blood samples from cattle (n = 88), goats (n = 82), sheep (n = 85) and dogs (n = 85). F The most frequently detected species were Theileria velifera in cattle (78%), Theileria ovis in sheep (80%) and Babesia vogeli in dogs (35%). Species-specific quantitative PCR assays detected Babesia bigemina in 43% (35/80) of blood samples of cattle, while E. ruminantium was detected in 4% (3/70) of blood samples and in 7% of A. pomposum ticks. Anaplasma platys was detected from cattle (18%) and sheep (6%) during RLB analysis. These findings constitute pioneering research in Angola.

Babesia bicornis, Theileria bicornis and Theileria equi in metapopulations of two black rhinoceros (Diceros bicornis) subspecies in South Africa and their potential impact on conservation.

The two black rhinoceros subspecies (Diceros bicornis bicornis and D. b. minor) in South African conservation areas are managed as separate metapopulations. Since infection with Babesia bicornis can be fatal in black rhinoceroses, occurrence of this and other piroplasms in the two metapopulations was determined to assess possible risk. Blood specimens were collected from 156 black rhinoceroses: 80 from D. b. bicornis and 76 from D. b. minor. DNA was extracted; the V4 hypervariable region of the parasite 18S rRNA gene was amplified and subjected to the Reverse Line Blot (RLB) hybridization assay. There was a significant difference in occurrence of piroplasms: 18/80 (23%) in D. b. bicornis and 39/76 (51%) in D. b. minor. Theileria bicornis occurred in significantly more of the D. b. minor population (36/76; 47%) than the D. b. bicornis population (1/80; 1%); with B. bicornis the difference was not significant: D. b. bicornis 5/80 (6%) and D. b. minor 9/76 (11%). Three individuals were infected with Theileria equi. Results were confirmed using molecular characterization of the near full-length parasite 18S rRNA gene of 13 selected specimens. We identified four (Tb1, Tb2, Tb3 and Tb4) 18S rDNA sequence types for T. bicornis, two for B. bicornis (Bb1 and Bb2) and one for T. equi (Teq1). We furthermore identified T. bicornis haplotypes H1, H3 and H4 in 10 rhinoceroses; H3 was the most common haplotype identified. Rhinoceroses inhabiting more arid areas are apparently free of T. bicornis and B. bicornis, probably due to the absence or scarcity of vectors. When individuals are relocated for metapopulation management purposes, appropriate prophylactic action should be taken to minimise the risk of babesiosis, which could be fatal.

Anaplasma phagocytophilum and Other Anaplasma spp. in Various Hosts in the Mnisi Community, Mpumalanga Province, South Africa.

DNA samples from 74 patients with non-malarial acute febrile illness (AFI), 282 rodents, 100 cattle, 56 dogs and 160 Rhipicephalus sanguineus ticks were screened for the presence of Anaplasma phagocytophilum DNA using a quantitative PCR (qPCR) assay targeting the msp2 gene. The test detected both A. phagocytophilum and Anaplasma sp. SA/ZAM dog DNA. Microbiome sequencing confirmed the presence of low levels of A. phagocytophilum DNA in the blood of rodents, dogs and cattle, while high levels of A. platys and Anaplasma sp. SA/ZAM dog were detected in dogs. Directed sequencing of the 16S rRNA and gltA genes in selected samples revealed the presence of A. phagocytophilum DNA in humans, dogs and rodents and highlighted its importance as a possible contributing cause of AFI in South Africa. A number of recently described Anaplasma species and A. platys were also detected in the study. Phylogenetic analyses grouped Anaplasma sp. SA/ZAM dog into a distinct clade, with sufficient divergence from other Anaplasma species to warrant classification as a separate species. Until appropriate type-material can be deposited and the species is formally described, we will refer to this novel organism as Anaplasma sp. SA dog.

Collaboration Spanning Two Continents: An Online Master's Degree in Tropical Animal Health.

A joint international program in Tropical Animal Health was launched in 2016 by the Institute of Tropical Medicine, Antwerp, Belgium, and the Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria. This program is flexible in time, place, and curriculum, allowing part-time students to apply the program's learning outcomes directly in their daily work environment. This article focuses on the major challenges and issues related to developing an international joint program in general and how these challenges were addressed. Challenges such as incompatibility of admission procedures, merging academic calendars, and quality assurance mechanisms were mitigated partly by the type of collaboration and partly by using a joint e-learning platform. The e-learning format proved to be a solution for particular challenges such as mobility issues, joint development of course material, and administrative processes. Furthermore, we present the results of a survey on the experiences of graduates and facilitators in this unique joint, web-based program.

Evaluation of the relative roles of the Tabanidae and Glossinidae in the transmission of trypanosomosis in drug resistance hotspots in Mozambique.

BACKGROUND: Tsetse flies (Diptera: Glossinidae) and tabanids (Diptera: Tabanidae) are haematophagous insects of medical and veterinary importance due to their respective role in the biological and mechanical transmission of trypanosomes. Few studies on the distribution and relative abundance of both families have been conducted in Mozambique since the country's independence. Despite Nicoadala, Mozambique, being a multiple trypanocidal drug resistance hotspot no information regarding the distribution, seasonality or infection rates of fly-vectors are available. This is, however, crucial to understanding the epidemiology of trypanosomosis and to refine vector management. METHODS: For 365 days, 55 traps (20 NGU traps, 20 horizontal traps and 15 Epsilon traps) were deployed in three grazing areas of Nicoadala District: Namitangurine (25 traps); Zalala (15 traps); and Botao (15 traps). Flies were collected weekly and preserved in 70% ethanol. Identification using morphological keys was followed by molecular confirmation using cytochrome c oxidase subunit 1 gene. Trap efficiency, species distribution and seasonal abundance were also assessed. To determine trypanosome infection rates, DNA was extracted from the captured flies, and submitted to 18S PCR-RFLP screening for the detection of Trypanosoma. RESULTS: In total, 4379 tabanids (of 10 species) and 24 tsetse flies (of 3 species), were caught. NGU traps were more effective in capturing both the Tabanidae and Glossinidae. Higher abundance and species diversity were observed in Namitangurine followed by Zalala and Botao. Tabanid abundance was approximately double during the rainy season compared to the dry season. Trypanosoma congolense and T. theileri were detected in the flies with overall infection rates of 75% for tsetse flies and 13% for tabanids. Atylotus agrestis had the highest infection rate of the tabanid species. The only pathogenic trypanosome detected was T. congolense. CONCLUSIONS: Despite the low numbers of tsetse flies captured, it can be assumed that they are still the cyclical vectors of trypanosomosis in the area. However, the high numbers of tabanids captured, associated to their demonstrated capacity of transmitting trypanosomes mechanically, suggest an important role in the epidemiology of trypanosomosis in the Nicoadala district. These results on the composition of tsetse and tabanid populations as well as the observed infection rates, should be considered when defining strategies to control the disease.

Anaplasma marginale outer membrane protein vaccine candidates are conserved in North American and South African strains.

Bovine anaplasmosis is a globally economically important tick-borne disease caused by the obligate intraerythrocytic rickettsia, Anaplasma marginale. A live Anaplasma centrale blood-based vaccine is available, but it does not protect against all A. marginale field strains and may also transmit other blood-borne pathogens. Five potential outer membrane protein (OMP) vaccine candidates have been well-characterised in A. marginale strains from the USA, however, their levels of conservation in other countries must be ascertained in order to inform their use in a vaccine with regional or global efficacy. This study assessed the amino acid variation in vaccine candidate OMPs in South African strains of A. marginale, and also compared the immunogenic properties between South African and US strains. OMP genes Am779, Am854, omp7, omp8 and omp9 were amplified and sequenced from a set of genetically diverse South African samples with different msp1α-genotypes. OMPs Am854 and Am779 were highly conserved, with 99-100 % amino acid identity, while Omp7, Omp8 and Omp9 had 79-100 % identity with US strains. As has been shown previously, Omp7-9 possess conserved N- and C- termini, a central variable region, and a highly conserved CD4 T-cell epitope, FLLVDDA(I/V)V, in the N-terminal region. Western blot analysis of recombinant OMPs indicates strong antigenic conservation between South African and US strains of A. marginale, suggesting that they are good candidates for use in a novel global vaccine cocktail, although further work on the best formulation and delivery methods will be necessary.

Babesia Species of Domestic Cats: Molecular Characterization Has Opened Pandora's Box.

This is the first comprehensive review of the literature pertaining to Babesia species reported from domestic cats. Description of the four species (Babesia felis, Babesia cati, Babesia herpailuri, and Babesia pantherae) named based on morphology and/or host specificity is documented. Feline babesiosis is of major veterinary concern only in South Africa. Reports of the rare occurrence of feline babesiosis cases in Europe (France, Germany, Poland, and Spain) and Asia (Israel, India, and Pakistan) are documented. Molecular characterization has revealed that cats can harbor a variety of Babesia species. The previous practice of referring to all piroplasms, especially small ones, seen on feline blood smears as B. felis is therefore no longer tenable. The near-full-length 18S rRNA gene sequences entered into GenBank in 2001 (accession no. AF244912) are designated as definitive for B. felis sensu stricto. All published literature relating to molecular characterization of feline Babesia species that could be traced was critically assessed. Four Babesia species are now known to be involved in causing feline babesiosis in South Africa: the closely related B. felis s.s. and Babesia leo (clade I), Babesia lengau (clade II), and Babesia species cat Western Cape (clade VI, Babesia s.s.). Clade VI also includes Babesia canis presentii and Babesia hongkongensis reported from cats in Asia. Six other Babesia species have been reported from domestic cats: the dog-associated B. canis s.s., Babesia gibsoni, and B. vogeli, as well as Babesia lohae, Babesia microti, and Babesia vulpes. Phylogenetic relationships of all named species were assessed and are presented as trees. The relatively high prevalence of B. vogeli in clinically healthy cats (16% in Brazil, 13% on St Kitts, and 8.1% in Portugal) suggests that immunocompetent cats can harbor the infection with no discernible untoward effects. Reports of occurrence of B. felis and other Babesia species in domestic cats should be accepted only if they are supported by credible molecular provenance.