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.https://www.frontiersin.org/journals/veterinary-science#am2020Veterinary Tropical Disease

Genetic testing of canine degenerative myelopathy in the South African Boxer dog population

Canine degenerative myelopathy (DM) is a progressive disease process that is diagnosed late in life and mainly affects the pelvic limbs. Factors that make an ante-mortem definitive diagnosis of DM include: an insidious onset and clinical manifestation that mimics other disease processes of the pelvic limbs (hip dysplasia, cranial cruciate ligament rupture, etc.) or there may even be concurrent disease processes, old-age onset and lack of reliable diagnostic methods. Until recently, South African dog owners had to submit samples to laboratories overseas for genetic testing in order to confirm an affected dog (homozygous A/A) and to aid in the ante-mortem diagnosis of DM. Only affected dogs have been confirmed to manifest the clinical signs of DM. This study aimed to verify whether genetic testing by a local genetic laboratory was possible in order to detect a missense mutation of the superoxide dismutase gene (SOD1) that is implicated in causing the clinical signs of DM. The study also aimed to detect and map the inheritance of this disease process in a local Boxer dog population where the pedigree of the sampled population was known. Venous blood collected from Boxer dogs using a simple random sampling technique. The samples were genotyped for the SOD1:c.118G>A polymorphism. Carrier and affected Boxer dogs were detected. A pedigree that demonstrated the significance of inheriting a carrier or affected state in the population was mapped. The present study concludes that genotyping of the missense mutation in Boxer dogs is possible in South Africa. There are carrier and affected Boxer dogs in the local population, making DM a plausible diagnosis in aged dogs presenting with pelvic limb pathology

Phylogeny of Theileria buffeli genotypes identified in the South African buffalo (Syncerus caffer) population

Theileria buffeli/orientalis is a group of benign and mildly pathogenic species of cattle andbuffalo in various parts of the world. In a previous study, we identified T. buffeli in blood sam-ples originating from the African buffalo (Syncerus caffer) in the Hluhluwe–iMfolozi GamePark (HIP) and the Addo Elephant Game Park (AEGP) in South Africa. The aim of this studywas 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 speciesbased on these loci. The 18S rRNA gene and the complete ITS region were amplified fromDNA extracted from blood samples originating from buffalo in HIP and AEGP. The PCR prod-ucts 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-like18S 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 Chinaand India, and the T. sinensis-like sequences were similar to T. sinensis 18S rRNA sequencesof 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. sinensisgenotypes. The presence of organisms with T. buffeli-like and T. sinensis-like genotypes inthe African buffalo could be of significant importance, particularly to the cattle industry inSouth Africa as these animals might act as sources of infections to naïve cattle. This is thefirst 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 informationtowards the classification of this complex group of benign and mildly pathogenic species.South African National Research Foundation (NRFICD2006072000009) and UP Research Development Programme.http://www.elsevier.com/locate/vetparhb201

Piroplasm parasites of white rhinoceroses (Ceratotherium simum) in the Kruger National Park, and their relation to anaemia

As part of a larger survey to map the geographical distribution of Babesia and Theileria parasites in the southern African rhinoceros population, white rhinoceroses were sampled during routine immobilisations in the Kruger National Park. Polymerase chain reaction (PCR) and reverse line blot (RLB) hybridisation assays were used to screen for the presence of piroplasms and complete blood counts were used to assess associated changes in clinical parameters. Of the 195 rhinoceroses sampled, 71 (36.4 %) tested positive for the presence of Theileria bicornis, with no significant change in the haematological parameters measured, while 18 (9.2 %) tested positive for Theileria equi. None of the rhinoceroses sampled tested positive for Babesia bicornis, a parasite associated with mortalities in black rhinoceroses.Grant: National Research Foundation, Funding: Wildlife Group of the South African Veterinary Associationhttp://www.journals.co.za/ej/ejour_savet.htmlab201

Confirmation of occurrence of Babesia vogeli in a dog in Windhoek, central Namibia

Although there is evidence of high seroprevalence of antibodies to Babesia spp. in dogs in central Namibia, clinical babesiosis is rarely diagnosed. Rhipicephalus sanguineus sensu lato, the vector of Babesia vogeli, is common in Namibia while Haemaphysalis elliptica, the vector of the highly virulent but morphologically indistinguishable Babesia rossi, has rarely been recorded, mainly in northern Namibia. On the basis of vector occurrence, clinical cases of canine babesiosis in Windhoek, central Namibia, have been ascribed to B. vogeli. DNA extracted from a blood smear made from a sick dog was subjected to the reverse line blot hybridisation assay. The polymerase chain reaction amplicons hybridised with the B. vogeli–specific probe, but not with the Babesia canis– and B. rossi–specific probes. Although attempts at cloning and sequencing of the full-length 18S rRNA gene were unsuccessful, we can confirm that B. vogeli occurs in central Namibia.http://www.jsava.co.zaam2016Veterinary Tropical Disease

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

DATA AVAILABILITY STATEMENT : Data are contained within the article.Thermal stress is an environmental factor that negatively affects poultry production globally. It elicits behavioural and physiological changes in broiler chickens, hence the need to find ways of ameliorating its detrimental effects which are mainly expressed as oxidative stress. This study was designed as an intervention on the effect of heat stress during the hot summer season in broiler chickens’ production using probiotic and ascorbic acid as anti-stress agents. From the results, probiotic and/or ascorbic acid were effective in enhancing the antioxidant enzyme activities and performance of the broiler chickens. This study stands as a basis for application in animal production trials with a larger sample size.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.The University of Pretoria Doctoral Research Bursary and the Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, South Africa.https://www.mdpi.com/journal/animalshj2024Anatomy and PhysiologyParaclinical SciencesVeterinary Tropical DiseasesSDG-02:Zero Hunge

Sequence variation identified in the 18S rRNA gene of Theileria mutans and Theileria velifera from the African buffalo (Syncerus caffer)

The African buffalo (Syncerus caffer) is a natural reservoir host for both pathogenic and nonpathogenic Theileria species. These often occur naturally as mixed infections in buffalo. Although the benign and mildly pathogenic forms do not have any significant economic importance, their presence could complicate the interpretation of diagnostic test results aimed at the specific diagnosis of the pathogenic T. parva in cattle and buffalo in South Africa. The 18S rRNA gene has been used as the target in a quantitative real-time PCR (qPCR) assay for the detection of T. parva infections. However, the extent of sequence variation within this gene in the non-pathogenic Theileria spp. of the Africa buffalo is not well known. The aim of this study was, therefore, to characterize the full-length 18S rRNA genes of T. mutans, Theileria sp. (strain MSD) and T. velifera and to determine the possible influence of any sequence variation on the specific detection of T. parva using the 18S rRNA qPCR. The reverse line blot (RLB) hybridization assay was used to select samples which either tested positive for several different Theileria spp., or which hybridized only with the Babesia/Theileria genus-specific probe and not with any of the Babesia or Theileria speciesspecific probes. The full-length 18S rRNA genes from 14 samples, originating from 13 buffalo and one bovine from different localities in South Africa, were amplified, cloned and the resulting recombinants sequenced. Variations in the 18S rRNA gene sequences were identified in T. mutans, Theileria sp. (strain MSD) and T. velifera, with the greatest diversity observed amongst the T. mutans variants. This variation possibly explained why the RLB hybridization assay failed to detect T. mutans and T. velifera in some of the analysed samples.South African National Research Foundation (NRF ICD2006072000009) and UP Research Development Programme.http://www.elsevier.com/locate/vetparhb2013ab201

Histomorphology, ultrastructure and fatty acid composition of the adipose tissue in pansteatitis, the potentials in understanding the underlying mechanism and diagnosis of pansteatitis in the Nile crocodile

BACKGROUND : In an effort to characterize the fat body and other adipose tissue in the Nile crocodile and the effects of pansteatitis on the structure and composition of the adipose tissue, we evaluated the regional variation in structure and fatty acid composition of healthy farmed crocodiles and those affected by pansteatitis. METHODS : Adipose tissue samples were collected from the subcutaneous, visceral and intramuscular fat and the abdominal fat body of ten 4-year old juvenile crocodiles from Izinthaba Crocodile Farm, Pretoria, South Africa while pansteatitis samples were collected from visceral and intramuscular fat of crocodiles that had died of pansteatitis at the Olifant River, Mpumalanga, also in South Africa. Histomorphology, ultrastrustucture and fatty acid composition by fatty acid methyl ester (FAME) analysis were conducted. RESULTS : Histological examination showed regional variations in the adipose tissue especially in the collagen content of the ECM, tissue perfusion and division into lobes and lobules by fibrous capsule. Considerable fibrosis, mononuclear cell infiltration especially by macrophages and lymphocytes and toxic changes in the nucleus were observed in the pansteatitis samples. Regional variation in lipid composition especially in Myristoleic (C14:1), Erucic acid (C22:1n9), and Docosadienoic acid (C22:2n6) was observed. Most of the saturated and trans fatty acids were found in significant quantities in the pansteatitis samples, but had very low levels of the cis fatty acid and the essential fatty acids with C18 backbone. CONCLUSION : This study demonstrates that there exists some regional variation in histomorphology and fatty acid composition in the healthy adipose tissue of the Nile crocodile. It also showed that pansteatitis in the Nile crocodile might have been triggered by sudden change in energy balance from consumption of dead fish; and probable exposure to toxic environmental conditions with the evidence of up scaled monounsaturated long chain fatty acids composition and toxic changes in the leucocytes observed in pansteatitis in the present study.http://www.sherpa.ac.uk/romeo/issn/1476-511X/am2017Anatomy and PhysiologyParaclinical SciencesVeterinary Tropical Disease

Black-backed jackals (Canis mesomelas) are natural hosts of Babesia rossi, the virulent causative agent of canine babesiosis in sub-Saharan Africa

BACKGROUND : Babesia rossi, which is transmitted by Haemaphysalis spp. and is highly virulent to domestic dogs, occurs only in sub-Saharan Africa. Since dogs are not native to the region, it has been postulated that the natural host of B. rossi is an indigenous African canid. Although various attempts at artificial infection indicated that black-backed jackals (Canis mesomelas) could become subclinically infected with B. rossi, data on occurrence of B. rossi in free-ranging jackals was lacking. A long-term behaviour study in which free-ranging black-backed jackals were radio-collared offered the opportunity of collecting blood specimens from a large number of free-ranging jackals. METHODS : Genomic DNA was extracted from the EDTA blood samples (n = 107). PCR products were subjected to Reverse Line Blot hybridization using Theileria and Babesia genera-specific as well as 28 species-specific oligonucleotide probes, including Babesia canis, Babesia rossi, Babesia vogeli and Babesia gibsoni. The near full-length parasite 18S rRNA gene was amplified from two selected samples (free-ranging jackals), cloned and a total of six recombinants were sequenced. RESULTS : Of 91 free-ranging jackals, 77 (84.6%) reacted with the Babesia genus-specific probe; 27 (29.7%) also reacted with the B. rossi probe. Of 16 captive jackals, 6 (37.5%) reacted with the B. rossi probe, while one further sample reacted with the Babesia genus-specific probe only. After cloning, 6 recombinants yielded identical sequences identical to that of B. rossi (L19079) and differing by 2 base pairs from B. rossi (DQ111760) in GenBank. The observed sequence similarities were confirmed by phylogenetic analyses using neighbour joining and maximum parsimony. CONCLUSIONS : Black-backed jackals are natural hosts of B. rossi.Laboratory expenses were funded by the Foundational Biodiversity Information Programme, National Research Foundation of South Africa (Grant 98110 to BLP).http://www.parasitesandvectors.comam2017Veterinary Tropical Disease

Genetic analysis of pre-weaning survival and inbreeding in the Boxer dog breed of South Africa

Members of the Federation of Boxer Clubs in Southern Africa (FBCSA) have participated in official recording for many years. The aim of the study was to estimate genetic parameters and trends for pre-weaning survival and to assess inbreeding in the South African Boxer, based on performance and pedigree data. Fitness records were included from 2138 litters recorded between 1988 and 2012 and pedigree information of 32 029 Boxer dogs recorded from 1950 to 2012. The average litter size was 6.14 ± 2.43. More male puppies were born per litter (3.23 ± 1.79) than female puppies (2.91 ± 1.72), with an increase in the proportion of males in larger litter sizes. Heritability values of 0.23 ± 0.08 and 0.25 ± 0.08 were estimated for litter size (LS) and number of puppies alive at two weeks after birth (NA), respectively. Litters larger than five tended to have more puppies born dead or with low survivability. Number of puppies born dead or that died within two weeks after birth increased from 0.43/litter at first parity to 0.82/litter at fifth parity, with a substantial increase of 2.25/litter with low survivability at seventh parity. Average inbreeding levels of the Boxer breed were above 10%, with an inbreeding rate of 0.14%/year since 1982. These results indicate that FBCSA should focus on lowering the levels of inbreeding by avoiding mating closely related animals. The complete recording of fitness traits is encouraged for effective genetic management of the breed.http://www.sasas.co.zaam201