Neglected intravascular pathogens, Babesia vulpes and haemotropic Mycoplasma spp. in European red fox ( Vulpes vulpes ) population

Detection and characterization of hemotropic Mycoplasmas in Iberian wolves (Canis lupus signatus) of Cantabria, Spain

Hemoplasmas (hemotropic mycoplasmas) are uncultivable wall-less bacteria able to infect mammalian erythrocytes. Hemoplasmas can cause anemia, especially in immunocompromised hosts, predisposing to secondary infections and even leading to death. Between 2017 and 2023, spleen samples of 131 wild Iberian wolves (Canis lupus signatus) of Cantabria (Spain) were screened for Mycoplasma spp. using a real-time PCR able to amplify a 360 bp fragment of the 16S rRNA gene and confirmed by direct Sanger sequencing. Additional conventional PCRs were performed to screen for coinfections by different Mycoplasma species and to discriminate between Mycoplasma haemocanis/haemofelis (Mhc/Mhf). Overall, 24/131 (18.3%) animals were PCR-positive. Biological and environmental factors potentially promoting hemoplasma infection in this species were analyzed. Two different hemoplasma species were detected: Mhc/Mhf (18/131; 13.7%) and Candidatus Mycoplasma haematoparvum (CMhp) (3/131; 2.3%), each with one nucleotide sequence type (ntST); three other sequences were not classified. No Mhc/Mhf and CMhp coinfection were observed. The 12 Mhc/Mhf suitable for ribonuclease P RNA sequencing were confirmed as Mhc. Mhc ntST was 100% identical to a Mhc sequence previously obtained in domestic dogs (Canis lupus familiaris), and in wild Iberian wolves of northwestern Spain (Asturias and Galicia) at a similar prevalence to the one found herein, suggesting a high Mhc genetic homogeneity in this wild population. CMhp ntST was 100% identical to CMhp sequences from domestic dogs. To our knowledge, this is the first description of CMhp in the Iberian wolf. The high genetic similarity observed in Mhc and CMhp sequences, as well as their high similarity with domestic dog sequences, suggest its recent introduction, a high level of intraspecific transmission within the wild wolf population, and likely, interspecific transmission between wolves and domestic dogs.

Phylogenetic inferences based on distinct molecular markers reveals a novel Babesia (Babesia pantanalensis nov. sp.) and a Hepatozoon americanum-related genotype in crab-eating foxes (Cerdocyon thous)

Piroplasmids and Hepatozoon spp. Are apicomplexan protozoa that may cause disease in several canid species. The present study aimed to expand the knowledge on the diversity of piroplasmids and Hepatozoon in crab-eating foxes (Cerdocyon thous; n = 12) sampled in the Pantanal of Mato Grosso do Sul State, central-western Brazil. PCR assays based on the 18S rRNA were used as screening. Three (25%) and 11 (91.7%) were positive for piroplasmids and Hepatozoon spp., respectively. Co-infection was found in three C. thous. Phylogenetic analyses based on the near-complete 18S rRNA, cox-1 and hsp70 genes evidenced the occurrence of a novel of Babesia spp. (namely Babesia pantanalensis nov. sp.) closely related to Rangelia vitalii and Babesia sp. 'Coco'. This finding was supported by the genetic divergence analysis which showed (i) high divergence, ranging from 4.17 to 5.62% for 18 S rRNA, 6.16% for hps70 and 4.91-9.25% for cox-1 and (ii) the genotype network (which displayed sequences separated from the previously described Piroplasmida species by median vectors and several mutational events). Also, phylogenetic analysis based on the 18S rRNA gene of Hepatozoon spp. positioned the sequences obtained herein in a clade phylogenetically related to Hepatozoon sp. 'Curupira 2', Hepatozoon sp. detected in domestic and wild canids from Uruguay and Hepatozoon americanum. The present study described Babesia pantanalensis nov sp. and Hepatozoon closely related to H. americanum in crab-eating foxes from Brazil. Moreover, the coinfection by piroplasmids and Hepatozoon sp. for the first time in crab-eating foxes strongly suggesting that this wild canid species potentially acts as a bio-accumulate of hemoprotozoan in wild environment.

The role of wildlife in the epidemiology of tick-borne diseases in Slovakia

Tick-borne diseases (TBD) represent an important challenge for human and veterinary medicine. In Slovakia, studies on the epidemiology of tick-borne pathogens (TBP) regarding reservoir hosts have focused on small mammals and to a lesser extent on birds or lizards, while knowledge of the role of the remaining vertebrate groups is limited. Generally, wild ungulates, hedgehogs, small- and medium-sized carnivores, or squirrels are important feeding hosts for ticks and serve as reservoirs for TBP. Importantly, because they carry infected ticks and/or are serologically positive, they can be used as sentinels to monitor the presence of ticks and TBP in the environment. With their increasing occurrence in urban and suburban habitats, wild ungulates, hedgehogs or foxes are becoming an important component in the developmental cycle of Ixodes ricinus and of TBP such as Anaplasma phagocytophilum or Babesia spp. On the other hand, it has been postulated that cervids may act as dilution hosts for Borrelia burgdorferi (sensu lato) and tick-borne encephalitis virus. In southwestern Slovakia, a high prevalence of infection with Theileria spp. (100%) was observed in some cervid populations, while A. phagocytophilum (prevalence of c.50%) was detected in cervids and wild boars. The following pathogens were detected in ticks feeding on free-ranging ungulates, birds, and hedgehogs: A. phagocytophilum, Rickettsia spp., Coxiella burnetii, Neoehrlichia mikurensis, B. burgdorferi (s.l.), and Babesia spp. The growing understanding of the role of wildlife as pathogen reservoirs and carriers of pathogen-infected ticks offers valuable insights into the epidemiology of TBP, providing a foundation for reducing the risk of TBD.

Arthropod-Borne Pathogens in Wild Canids

Wild canids, as well as other wild animal species, are largely exposed to bites by ticks and other hematophagous vectors where the features favoring their presence and spread are found in wooded and semi-wooded areas. Much of the information about arthropod-borne infections concerns domestic and companion animals, whereas data about these infections in wild canids are not exhaustive. The present study is a narrative review of the literature concerning vector-borne infections in wild canids, highlighting their role in the epidemiology of arthropod-borne bacteria and protozoa.

Large-scale survey for canine vector-borne parasites in free-ranging dogs and foxes from six diverse bioclimatic regions of Chile

Chile is a large country with a marked range of climate conditions that make it an ideal scenario for the study of vector-borne parasites (VBPs); however, knowledge about their distribution is limited to a few confined areas of this country. The presence of Hepatozoon spp., piroplasmids, Leishmania spp. and filarioids was investigated through molecular and serological methods in blood and serum samples of 764 free-ranging rural dogs, 154 Andean foxes (Lycalopex culpaeus), and 91 South American grey foxes (Lycalopex griseus) from six bioclimatic regions across Chile. Hepatozoon spp. DNA was exclusively detected in foxes (43% prevalence), including sequences closely related to Hepatozoon felis (24.1%; only Andean foxes), Hepatozoon americanum (16.2%; only grey foxes), and Hepatozoon canis (1.25%; in one grey fox). Risk factor assessment identified a higher probability of Hepatozoon infection in juvenile foxes. DNA of piroplasmids was detected in 0.7% of dogs (Babesia vogeli) but in no fox, whilst antibodies against Babesia sp. were detected in 24% of the dogs and 25% of the foxes, suggesting a wider circulation of canine piroplasmids than previously believed. A positive association between the presence of antibodies against Babesia and high Rhipicephalus sanguineus sensu lato burden was observed in dogs. Leishmania spp. DNA and antibodies were detected in 0.8% and 4.4% of the dogs, respectively. Acanthocheilonema reconditum was the only blood nematode detected (1.5% of the dogs and no fox). Differences in prevalence among bioregions were observed for some of the VBPs. These results expand our knowledge about the occurrence of vector-borne parasites in Chile, some of which are firstly reported herein. This information will facilitate the diagnosis of vector-borne diseases in domestic dogs and improve the control measures for both domestic and wild canids.

Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile

Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.

Molecular survey of Babesia spp. in red foxes (Vulpes Vulpes), Asian badgers (Meles leucurus) and their ticks in China

Babesia species (Apicomplexa: Piroplasmorida) are tick-borne protozoan hemoparasites, which pose a significant threat to domestic animals, wildlife and humans. This study aimed to determine and characterize Babesia species in red foxes (Vulpes vulpes), Asian badgers (Meles leucurus) and their ticks. Blood, heart, liver, spleen, lung, kidney, large intestine and small intestine were collected from 19 wild carnivores (12 red foxes and 7 Asian badgers). All ticks were removed from these animals and identified according to morphological and molecular characteristics. The samples were tested for the presence of Babesia species using the 18S rRNA gene. Molecular analyses showed that the DNA of Babesia vogeli and Babesia vulpes was present in red fox organs/tissues and blood samples. A total of 54 hard ticks (38 Ixodes canisuga, 6 Haemaphysalis erinacei, 9 Ixodes kaiseri and 1 Dermacentor marginatus) were collected from red foxes and 12 (I. kaiseri) from Asian badgers. All ticks were adults. Among them, one I. kaiseri parasiting a red fox contained the DNA of B. vulpes while one I. canisuga was positive for Babesia sp. belonging to the clade "Babesia sensu stricto". Molecular and phylogenetic analyses indicated the presence of a novel genotype, Babesia sp. "badger China". Babesia sp. badger type A and type B from Asian badgers were different from those in European badgers. Co-infection with three Babesia genotypes was found in one Asian badger. This study provides the first data on Babesia infection in red foxes, Asian badgers and their ticks in China. Babesia vogeli was detected for the first time in red foxes in Asia. Co-infection and genetic diversity of Babesia genotypes in Asian badgers were also demonstrated.

Worldwide occurrence of haemoplasmas in wildlife: Insights into the patterns of infection, transmission, pathology and zoonotic potential

Haemotropic mycoplasmas (haemoplasmas) have increasingly attracted the attention of wildlife disease researchers due to a combination of wide host range, high prevalence and genetic diversity. A systematic review identified 75 articles that investigated haemoplasma infection in wildlife by molecular methods (chiefly targeting partial 16S rRNA gene sequences), which included 131 host genera across six orders. Studies were less common in the Eastern Hemisphere (especially Africa and Asia) and more frequent in the Artiodactyla and Carnivora. Meta-analysis showed that infection prevalence did not vary by geographic region nor host order, but wild hosts showed significantly higher prevalence than captive hosts. Using a taxonomically flexible machine learning algorithm, we also found vampire bats and cervids to have greater prevalence, whereas mink, a subclade of vesper bats, and true foxes all had lower prevalence compared to the remaining sampled mammal phylogeny. Haemoplasma genotype and nucleotide diversity varied little among wild mammals but were marginally lower in primates and bats. Coinfection with more than one haemoplasma species or genotype was always confirmed when assessed. Risk factors of infection identified were sociality, age, males and high trophic levels, and both prevalence and diversity were often higher in undisturbed environments. Haemoplasmas likely use different and concurrent transmission routes and typically display enzootic dynamics when wild populations are studied longitudinally. Haemoplasma pathology is poorly known in wildlife but appears subclinical. Candidatus Mycoplasma haematohominis, which causes disease in humans, probably has it natural host in bats. Haemoplasmas can serve as a model system in ecological and evolutionary studies, and future research on these pathogens in wildlife must focus on increasing the geographic range and taxa of studies and elucidating pathology, transmission and zoonotic potential. To facilitate such work, we recommend using universal PCR primers or NGS protocols to detect novel haemoplasmas and other genetic markers to differentiate among species and infer cross-species transmission.

Hemoplasmas Are Endemic and Cause Asymptomatic Infection in the Endangered Darwin's Fox (Lycalopex fulvipes)

Mycoplasma haemocanis is prevalent in the endangered Darwin's fox (Lycalopex fulvipes) in its main stronghold, Chiloé Island (Chile). The origin of the infection, its dynamics, its presence in other fox populations and the potential consequences for fox health remain unexplored. For 8 years, hemoplasmal DNA was screened and characterized in blood from 82 foxes in Chiloé and two other fox populations and in 250 free-ranging dogs from Chiloé. The prevalence of M. haemocanis in foxes was constant during the study years, and coinfection with "Candidatus Mycoplasma haematoparvum" was confirmed in 30% of the foxes. Both hemoplasma species were detected in the two mainland fox populations and in Chiloé dogs. M. haemocanis was significantly more prevalent and more genetically diverse in foxes than in dogs. Two of the seven M. haemocanis haplotypes identified were shared between these species. Network analyses did not show genetic structure by species (foxes versus dogs), geographic (island versus mainland populations), or temporal (years of study) factors. The probability of infection with M. haemocanis increased with fox age but was not associated with sex, season, or degree of anthropization of individual fox habitats. Some foxes recaptured years apart were infected with the same haplotype in both events, and no hematological alterations were associated with hemoplasma infection, suggesting tolerance to the infection. Altogether, our results indicate that M. haemocanis is enzootic in the Darwin's fox and that intraspecific transmission is predominant. Nevertheless, such a prevalent pathogen in a threatened species represents a concern that must be considered in conservation actions.IMPORTANCE Mycoplasma haemocanis is enzootic in Darwin's foxes. There is a higher M. haemocanis genetic diversity and prevalence in foxes than in sympatric dogs, although haplotypes are shared between the two carnivore species. There is an apparent tolerance of Darwin's foxes to Mycoplasma haemocanis.

Molecular Survey on Vector-Borne Pathogens in Alpine Wild Carnivorans

In Europe, free-ranging wildlife has been linked to the emergence of several vector-borne diseases such as rodents for Borrelia burgdorferi s.l. In particular, wild carnivorans are one of the most important sources of emerging zoonotic pathogens worldwide, although little information is available regarding the epidemiology of vector-borne parasites in these animals. Thus, the aim of this paper was to investigate the prevalence of Babesia spp., Anaplasma spp., Ehrlichia spp., Hepatozoon spp. and Leishmania infantum in alpine wild canids and mustelids from Italy. For this study, spleen samples of 157 foxes (Vulpes vulpes), 45 badgers (Meles meles), and 33 wolves (Canis lupus) collected between 2009 and 2017 in Northwest Italy were examined by using conventional PCR. Logistic regression was used to identify possible risk factors for pathogen infections. DNA of any of the tested pathogens was found in more than 90% of the analyzed animals. In particular, Babesia spp. showed significantly higher prevalence in foxes (89.7%) and badgers (89.6%) than in wolves, while the latter were considerably more infected with Hepatozoon canis (75.8%) than foxes (5.1%). None of the badger tested positive for Hepatozoon spp., although they showed high prevalence of Leishmania infantum (53.3%). Sequencing results revealed the presence, among others, of Babesia vulpes, Babesia sp. isolate badger type A and B, and Anaplasma phagocytophilum. Moreover, previously unreported pathogen/host associations were observed, such as Babesia capreoli in wolves and badgers. The prevalence of vector-borne pathogens observed in the present study is one of the highest reported so far, suggesting the importance of free-ranging carnivorans in the epidemiology and maintenance of the sylvatic cycle of the pathogens. Moreover, several of these pathogens are of particular importance regarding human (A. phagocytophilum, L. infantum) and pet health (L. infantum, B. vulpes).

Establishment of Babesia vulpes n. sp. (Apicomplexa: Babesiidae), a piroplasmid species pathogenic for domestic dogs

BACKGROUND

Canine babesiosis is a severe disease caused by several Babesia spp. A number of names have been proposed for the canine-infecting piroplasmid pathogen initially named Theileria annae Zahler, Rinder, Schein & Gothe, 2000. It was shown to be a member of the Babesia (sensu lato) group infecting carnivores and is also closely related to the Babesia microti group. Subsequently, the same parasite species was reclassified as a member of the genus Babesia and the name Babesia vulpes Baneth, Florin-Christensen, Cardoso & Schnittger, 2015 was proposed for it. However, both names do not meet the requirements of the International Code of Zoological Nomenclature (no accompanying descriptions, no deposition of type-specimens) and cannot be recognized as available names from the nomenclatural point of view. The purpose of this study was to further characterize this parasite in order to confirm its validity, to provide its description and to introduce zoological nomenclature for it with the name Babesia vulpes n. sp.

RESULTS

Morphological description of the parasite in canine erythrocytes demonstrated that it takes the shape of small (1.33 × 0.98 µm), round to oval forms reminiscent of the pyriform and ring shapes of other small canine Babesia spp., such as Babesia gibsoni Patton, 1910 and Babesia conradae Kjemtrup, Wainwright, Miller, Penzhorn & Carreno, 2006. However, these parasite forms were overall smaller than those measured for the latter two species and no tetrad (Maltese cross) form was reported. Furthermore, phylogenetic analysis using the cytochrome c oxidase subunit 1 (COX1) amino acid sequences substantiates the species identity of this parasite as previously demonstrated based on phylogenetic analysis of the 18S rRNA and β-tubulin genes. The holotype of the parasite species was designated and deposited in an accessible public collection.

CONCLUSIONS

This study ratifies the name Babesia vulpes n. sp. proposed for the parasite previously referred to as Theileria annae Zahler, Rinder, Schein & Gothe, 2000, Babesia annae (Zahler, Rinder, Schein & Gothe, 2000) or Babesia vulpes Baneth, Florin-Christensen, Cardoso & Schnittger, 2015, or mentioned as "Babesia microti-like piroplasm", "Babesia Spanish dog isolate" and Babesia cf. microti.

The role of healthy dog carriers of Babesia microti-like piroplasms

BACKGROUND

While in Europe Babesia canis has been traditionally held responsible for canine piroplasmosis, Babesia microti-like piroplasm (Bml) infection is being ever more observed in dogs, with the first clinical cases reported in northwestern Spain. This study examines the epidemiological role of healthy dogs living in endemic areas of Bml infection in Spain. The data obtained were used to describe the clinical status and map the geographical distribution of Bml infection in healthy dogs in northwestern Spain.

RESULTS

Blood samples and ticks were taken from 756 healthy dogs representatively across the whole Galicia region (northwestern Spain): stray (n = 211), hunting dogs (n = 333) and pets (n = 212). Blood samples were tested by microscopy parasite observation, nested PCR-RFLP and sequencing. Piroplasm infection prevalences in healthy dogs from northwestern Spain were 17.1% (129/756) by PCR and 3.4% (26/756) by microscopy observation. The species found by PCR were: 2.2% (17/756) for B. canis and 15.1% (114/756) for Bml. Co-infection with B. canis and Bml was noted in 2 dogs. The higher prevalences detected were Bml in hunting dogs (25.5%; 85/333) and B. canis in stray dogs (6.6%; 14/211). In fox-hunting dogs from any area and dogs from the A Coruña Province, significantly higher prevalences of Bml infection were detected (P < 0.001). Upon physical examination, tick infestation was observed: 130 ticks in 18 hunting and three pet dogs. These were subsequently identified as Rhipicephalus sanguineus (s.l.) (49.2%), Ixodes hexagonus (38.5%), Ixodes ricinus (6.9%) and Dermacentor reticulatus (5.4%). Among the more prevalent ticks infesting healthy carrier dogs were I. hexagonus, followed by D. reticulatus and I. ricinus.

CONCLUSIONS

Babesia canis and Bml were the only piroplasm species found infecting healthy dogs in Galicia, the prevalence of Bml being higher than of B. canis. Factors correlated with a higher Bml infection risk were being a hunting dog and living in the A Coruña Province. Healthy dogs travelling to other countries could act as carriers and probably contribute to the spread of Bml infection in dogs and wild carnivores throughout Europe.

High diversity of hemotropic mycoplasmas in Iberian wild carnivores

Two-hundred and thirty-one wild carnivores belonging to 10 species of in Spain were analyzed for the presence of DNA of hemotropic mycoplasmas (hemoplasmas) by means of a universal real-time PCR targeting a 16S rRNA gene fragment. Positive reactions were found for wolf (Canis lupus: 6/37), fox (Vulpes vulpes: 1/41), Eurasian badger (Meles meles: 49/85), pine marten (Martes martes: 11/23), stone marten (Martes foina: 6/9), least weasel (Mustela nivalis: 4/4), European wildcat (Felis s. silvestris: 1/2) and common genet (Genetta genetta: 7/27). Sixty-four readable sequences were obtained, resulting in 14 nucleotide sequence types (ntST). The highest diversity was detected in badger (6 ntST) and pine marten (5 ntST). The sequencing of a fragment of the RNase P gene showed that all positive reactions in wolves corresponded to Mycoplasma haemocanis. Three ntST showed an identity between 98-100% with Candidatus M. haemominutum, C. M. turicensis and C. M. haematoparvum, respectively. Four ntST were closely related to C. M. haemomeles and/or diverse genotypes reported from raccoons (Procyon lotor) in the USA. One ntST from a badger showed only 88% similarity to the closest published sequence and was phylogenetically unrelated to any other hemoplasma sequence reported. Three ntST were 99-100% similar to two different sequences reported in Spanish bats. This study confirms the widespread nature and the high genetic diversity of hemoplasma infection in carnivores. Wild carnivores might be natural hosts of some hemoplasmas infecting dogs and cats.

Ticks are more suitable than red foxes for monitoring zoonotic tick-borne pathogens in northeastern Italy

BACKGROUND

Northeastern Italy is a hotspot for several tick-borne pathogens, transmitted to animals and humans mainly by Ixodes ricinus. Here we compare the results of molecular monitoring of ticks and zoonotic TBPs over a six-year period, with the monitoring of red foxes (Vulpes vulpes) in an endemic area.

RESULTS

In the period 2011-2016, 2,578 ticks were collected in 38 sites of 20 municipalities of Belluno Province. Individual adults (264), pooled larvae (n = 330) and nymphs (n = 1984) were screened for tick-borne encephalitis virus, Borrelia burgdorferi (s.l.), Rickettsia spp., Babesia spp., Anaplasma phagocytophilum and "Candidatus Neoehrlichia mikurensis" by specific SYBR green real-time PCR assays and sequencing. The spleens of 97 foxes, culled in the period 2015-2017 during sport hunting or population control programs, were also screened. Overall, nine different pathogens were found in I. ricinus nymph and adult ticks: Rickettsia helvetica (3.69%); R. monacensis (0.49%); four species of the B. burgdorferi (s.l.) complex [B. afzelii (1.51%); B. burgdorferi (s.s.) (1.25%); B. garinii (0.18%); and B. valaisiana (0.18%)]; A. phagocytophilum (3.29%); "Candidatus N. mikurensis" (1.73%); and Babesia venatorum (0.04%). Larvae were collected and screened in the first year only and two pools (0.6%) were positive for R. helvetica. Tick-borne encephalitis virus was not found in ticks although human cases do occur in the area. The rate of infection in ticks varied widely according to tick developmental stage, site and year of collection. As expected, adults were the most infected, with 27.6% harboring at least one pathogen compared to 7.3% of nymphs. Pathogens with a minimum infection rate above 1% were recorded every year. None of the pathogens found in ticks were detectable in the foxes, 52 (54%) of which were instead positive for Babesia cf. microti (also referred to as Babesia microti-like, "Theileria annae", "Babesia annae" and "Babesia vulpes").

CONCLUSIONS

The results show that foxes cannot be used as sentinel animals to monitor tick-borne pathogens in the specific epidemiological context of northeastern Italy. The high prevalence of Babesia cf. microti in foxes and its absence in ticks strongly suggests that I. ricinus is not the vector of this pathogen.