Molecular detection of tick-borne pathogens in caracals (Caracal caracal) living in human-modified landscapes of South Africa

Description of a novel Babesia sp. genotype from a naturally infected Eurasian lynx (Lynx lynx) in Anatolia, Turkey, with remarks on its morphology and phylogenetic relation to other piroplasmid species

There are very limited data on Babesia species infecting lynx species worldwide, and almost nothing is known about babesias in the Eurasian lynx, the most widely distributed wild feline species in the Palearctic geography. This study describes a novel Babesia sp. genotype in a free-living Eurasian lynx in Turkey, named tentatively as 'Babesia sp. lynx', and its integrated genetic and morphological features. Phylogenetic analyses of piroplasmids with the novel Babesia sp. genotype in the current study indicated that this genotype falls into the 'carnivore clade A' of Babesia sensu stricto (true babesias), at the level of different genes (mainly 18S rRNA, ITS1, ITS2, and cyt b) and is monophyletic with the Babesia sp. Ankara genotype, previously observed in Turkey. Additionally, the constructed phylogenetic trees showed that the Babesia sp. lynx genotype infecting the Eurasian lynx is closely related to certain domestic and wild carnivore babesias, mainly Babesia rossi, Babesia presentii, and Babesia pisicii, at the level of different genes. This study also genetically barcoded the lynx infected with the Babesia sp. lynx and Haemaphysalis erinacei, and specimens collected from the animal revealed significant genetic variations between the sample Ha. erinacei and Babesia sp. Ankara-related Ha. erinacei that persists with sympatric populations in Central Anatolia. The lynx infected with the Babesia sp. lynx genotype was also found to be coinfected with Hepatozoon felis, an adeleorinid tick-borne protozoan parasite infecting wild and domestic felids, confirming for the first time its presence in a lynx species. Therefore, this study is the first to describe a potential novel Babesia sp. using its both morphological and phylogenetic characteristics in a lynx species. Adding the Babesia sp. lynx genotype to the phylogeny of feline piroplasmids significantly expands our knowledge of feline babesias in the Palearctic geography and their putative coevolution with their vertebrate hosts.

Poisoned chalice: Use of transformed landscapes associated with increased persistent organic pollutant concentrations and potential immune effects for an adaptable carnivore

Wildlife around cities bioaccumulate multiple harmful environmental pollutants associated with human activities. Exposure severity can vary based on foraging behaviour and habitat use, which can be examined to elucidate exposure pathways. Carnivores can play vital roles in ecosystem stability but are particularly vulnerable to bioaccumulation of pollutants. Understanding the spatial and dietary predictors of these contaminants can inform pollutant control, and carnivores, at the top of food webs, can act as useful indicator species. We test for exposure to toxic organochlorines (OCs), including dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), in a medium-sized felid, the caracal (Caracal caracal), across the peri-urban and agricultural landscapes of the city of Cape Town, South Africa. Concentrations in both blood (n = 69) and adipose tissue (n = 25) were analysed along with detailed spatial, dietary, demographic, and physiological data to assess OC sources and exposure risk. The analysis revealed widespread exposure of Cape Town's caracals to organochlorines: detection rate was 100% for PCBs and 83% for DDTs in blood, and 100% for both compounds in adipose. Caracals using human-transformed areas, such as vineyards and areas with higher human population and electrical transformer density, as well as wetland areas, had higher organochlorine burdens. These landscapes were also highly selected foraging areas, suggesting caracals are drawn into areas that co-incidentally increase their risk of exposure to these pollutants. Further, biomagnification potential was higher in individuals feeding on higher trophic level prey and on exotic prey. These findings point to bioaccumulation of OC toxicants and widespread exposure across local food webs. Additionally, we report possible physiological effects of exposure, including elevated white blood cell and platelet count, suggesting a degree of immunological response that may increase disease susceptibility. Cape Town's urban fringes likely represent a source of toxic chemicals for wildlife and require focused attention and action to ensure persistence of this adaptable mesocarnivore.

Distribution and prevalence of ticks and tick-borne pathogens of wild animals in South Africa: A systematic review

Ticks are significant ectoparasites of animals and humans. Published data indicate that most vectors that transmit livestock and human pathogens in sub-Saharan Africa, are native to the region and originate from wild animals. Currently, there is a paucity of information on the role of wild animals on the epidemiology of zoonotic tick-borne pathogens in South Africa. This systematic review focuses on the distribution of ticks and prevalence of tick-borne pathogens in different wild animals in South Africa to identify potential reservoir hosts and possible hotspots for emergence of novel tick-borne pathogens. Following several screening processes, 38 peer-reviewed studies published from 1970 to 2021, were deemed eligible. The studies reported on ticks collected from 63 host species of 21 host families, mostly Canidae, Felidae, Bovidae and Muridae. A total of 49 tick species of nine genera, i.e. Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes, Margaropus, Nuttalliella, Rhipicentor and Rhipicephalus, were reported. Nine tick species, i.e. Amblyomma marmoreum, Am. hebraeum, Haemaphysalis elliptica, Hyalomma truncatum, I. rubicundus, Rh. appendiculatus, Rh. (B.) decoloratus, Rh. evertsi evertsi and Rh. simus were the most commonly reported. Pathogens of the genera Anaplasma, Babesia, Hepatozoon and Theileria were identified in the wild animals. This review provides more insight on the ecology of ticks and tick-borne pathogens of wild animals in South Africa and gives useful information for predicting their future spread. It also demonstrates that wild animals habour a diverse range of tick species. This level of diversity entails a similarly high potential for emergence of novel tick-borne pathogens. The review further indicates that wild animals in South Africa are sentinels of tick-borne protozoans of veterinary importance and some bacterial pathogens as most ticks they habour are known vectors of pathogens of domestic animals and humans. However, studies on potential tick-borne zoonoses are under-represented and should be included in future epidemiological surveys, especially in the light of climate change and other anthropogenic threats which might result in the emergence of novel tick-borne pathogens.

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Wild animals in South Africa harbor a wide range of tick species of veterinary and medical importance.

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Forty-nine tick species belonging to 9 genera were reported from 63 wild host species of 21 families.

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Majority of the ticks occur throughout all nine provinces of South Africa.

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Wildlife in South Africa are sentinels of tick-borne protozoans and some bacterial pathogens of veterinary importance.

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The review also emphasizes the host preference of the ticks and the pathogens they transmit.

Survey of Ticks and Tick-Borne Rickettsial and Protozoan Pathogens in Eswatini

Ticks are widespread parasites of vertebrates and major vectors of pathogens to humans, domestic animals, and wildlife. In southern Africa, numerous tick species transmit diseases of economic and health importance. This study aimed to describe the occurrence of ticks and tick-borne pathogens in multiple land-use types and the possible role of ticks in the transmission of pathogen species. Using molecular techniques, we screened 1716 ticks for infection by rickettsial bacteria and protozoans. To characterize pathogen identity, we sequenced multiple loci from positive samples and analyzed sequences within a phylogenetic framework. Across the seven tick species collected as nymphs or adults, we detected Rickettsia, Anaplasma, Ehrlichia, Babesia, Hepatozoon, and Theileira species. We found that some tick species and tick-borne pathogens differed according to land use. For example, we found a higher density of Haemaphysalis elliptica and higher prevalence of Rickettsia in H. elliptica collected from savanna grasses used for livestock grazing near human settlements than savanna grasses in conservation areas. These findings highlight the importance of comprehensive surveillance to achieve a full understanding of the diversity and ecology of the tick-borne pathogens that can infect humans, domestic animals, and wildlife.

Genetic diversity of vector-borne pathogens in spotted and brown hyenas from Namibia and Tanzania relates to ecological conditions rather than host taxonomy

Background

Improved knowledge on vector-borne pathogens in wildlife will help determine their effect on host species at the population and individual level and whether these are affected by anthropogenic factors such as global climate change and landscape changes. Here, samples from brown hyenas (Parahyaena brunnea) from Namibia (BHNA) and spotted hyenas (Crocuta crocuta) from Namibia (SHNA) and Tanzania (SHTZ) were screened for vector-borne pathogens to assess the frequency and genetic diversity of pathogens and the effect of ecological conditions and host taxonomy on this diversity.

Methods

Tissue samples from BHNA (n = 17), SHNA (n = 19) and SHTZ (n = 25) were analysed by PCRs targeting Anaplasmataceae, Rickettsia spp., piroplasms, specifically Babesia lengau-like piroplasms, Hepatozoidae and filarioids. After sequencing, maximum-likelihood phylogenetic analyses were conducted.

Results

The relative frequency of Anaplasmataceae was significantly higher in BHNA (82.4%) and SHNA (100.0%) than in SHTZ (32.0%). Only Anaplasma phagocytophilum/platys-like and Anaplasma bovis-like sequences were detected. Rickettsia raoultii was found in one BHNA and three SHTZ. This is the first report of R. raoultii from sub-Saharan Africa. Babesia lengau-like piroplasms were found in 70.6% of BHNA, 88.9% of SHNA and 32.0% of SHTZ, showing higher sequence diversity than B. lengau from South African cheetahs (Acinonyx jubatus). In one SHTZ, a Babesia vogeli-like sequence was identified. Hepatozoon felis-like parasites were identified in 64.7% of BHNA, 36.8% of SHNA and 44.0% of SHTZ. Phylogenetic analysis placed the sequences outside the major H. felis cluster originating from wild and domestic felids. Filarioids were detected in 47.1% of BHNA, 47.4% of SHNA and 36.0% of SHTZ. Phylogenetic analysis revealed high genetic diversity and suggested the presence of several undescribed species. Co-infections were frequently detected in SHNA and BHNA (BHNA median 3 pathogens, range 1–4; SHNA median 3 pathogens, range 2–4) and significantly rarer in SHTZ (median 1, range 0–4, 9 individuals uninfected).

Conclusions

The frequencies of all pathogens groups were high, and except for Rickettsia, multiple species and genotypes were identified for each pathogen group. Ecological conditions explained pathogen identity and diversity better than host taxonomy.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04835-x.

Black-backed jackals (Canis mesomelas) from semi-arid rangelands in South Africa harbour Hepatozoon canis and a Theileria species but apparently not Babesia rossi

Despite the importance of disease as a wildlife management challenge in South Africa, baseline data on the epidemiology of pathogens occurring in free-ranging species has received little attention to date. Black-backed jackals (Canis mesomelas) are a wide-ranging, abundant carnivore with substantial economic importance due to their role in livestock depredation. They are known reservoirs hosts of Babesia rossi, a virulent pathogen in domestic dogs in sub-Saharan Africa. We investigated the prevalence and diversity of tick-borne pathogens (TPBs) including Babesia, Theileria, Hepatozoon, Ehrlichia and Anaplasma species, together with host-attached tick diversity, in a black-backed jackal population from the semi-arid Central Karoo, a small-livestock farming region in South Africa. Using reverse line blot hybridisation, we screened 43 blood samples and sequenced the 18S rRNA gene from positive samples to confirm and characterise pathogen identity using a phylogenetic framework. Hepatozoon canis, a ubiquitous pathogen of domestic and wild canids globally, was observed in 47% of jackals, while a Theileria sp. most similar to T. ovis, a piroplasm found in small livestock, was observed in 5% of jackals. No Babesia, Ehrlichia or Anaplasma species were identified, although a Sarcocystis sp. sequence was isolated from one jackal. Host-attached ticks (n = 20) comprised three species, Amblyomma marmoreum, Haemaphysalis elliptica/zumpti and Ixodes rubicundus, commonly known ticks in the region. In summary, prevalence of TBPs in black-backed jackals from this semi-arid rangeland region was lower than in jackal populations in more mesic regions. These jackals were apparently not infected with B. rossi. While this study is one of the first investigations into the epidemiology of TBPs infecting jackals and adds to the sparse literature, further studies which span landscape uses, climate conditions and seasonality are encouraged.

Molecular screening indicates high prevalence and mixed infections of Hepatozoon parasites in wild felines from South Africa

Genetic diversity within partial 18S rRNA sequences from Hepatozoon protozoan parasites from wild felines in South Africa was assessed and compared with data from domestic cats to assess patterns of host specificity. Lions, leopards, servals, a caracal and an African wildcat were all positive for parasites of the Hepatozoon felis-complex. However, haplotypes were not species-specific, and potential mixed infections were widespread. Additional genetic markers are needed to untangle the extremely complex situation of these parasites in both domestic cats and wild felines in South Africa.