Rangelia vitalii in a free-ranging maned wolf (Chrysocyon brachyurus) and co-infections

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.

Hepatozoon (Eucoccidiorida: Hepatozoidae) in wild mammals of the Americas: a systematic review

BACKGROUND

The study of parasites provides insight into intricate ecological relationships in ecosystem dynamics, food web structures, and evolution on multiple scales. Hepatozoon Eucoccidiorida: Hepatozoidae) is a genus of protozoan hemoparasites with heteroxenous life cycles that switch infections between vertebrates and blood-feeding invertebrates. The most comprehensive review of the genus was published 26 years ago, and currently there are no harmonized data on the epizootiology, diagnostics, genotyping methods, evolutionary relationships, and genetic diversity of Hepatozoon in the Americas.

METHODS

Here, we provide a comprehensive review based on the PRISMA method regarding Hepatozoon in wild mammals within the American continent, in order to generate a framework for future research.

RESULTS

11 out of the 35 countries of the Americas (31.4%) had data on Hepatozoon, with Carnivora and Rodentia orders having the most characterizations. Bats, ungulates, and shrews were the least affected groups. While Hepatozoon americanum, H. americanum-like, H. canis, H. didelphydis, H. felis, H. milleri, H. griseisciuri, and H. procyonis correspond to the identified species, a plethora of genospecies is pending for a formal description combining morphology and genetics. Most of the vectors of Hepatozoon in the Americas are unknown, but some flea, mite, and tick species have been confirmed. The detection of Hepatozoon has relied mostly on conventional polymerase chain reaction (PCR), and the implementation of specific real time PCR for the genus needs to be employed to improve its diagnosis in wild animals in the future. From a genetic perspective, the V4 region of the 18S rRNA gene has been widely sequenced for the identification of Hepatozoon in wild animals. However, mitochondrial and apicoplast markers should also be targeted to truly determine different species in the genus. A phylogenetic analysis of herein retrieved 18S ribosomal DNA (rDNA) sequences showed two main clades of Hepatozoon: Clade I associated with small mammals, birds, and herpetozoa, and Clade II associated with Carnivora. The topology of the tree is also reflected in the haplotype network.

CONCLUSIONS

Finally, our review emphasizes Hepatozoon as a potential disease agent in threatened wild mammals and the role of wild canids as spreaders of Hepatozoon infections in the Americas.

Gray Wolf (Canis lupus italicus) and Red Fox (Vulpes vulpes) Parasite Survey in Anthropized and Natural Areas of Central Italy

Gastrointestinal nematodes and protozoa and other parasite occurrences were evaluated in free-ranging wolf (Canis lupus italicus) and red fox (Vulpes vulpes) populations from natural and anthropized areas of Central Italy. Analyzed fecal samples were collected from 60 foxes and 40 wolves in the anthropized areas, and 41 foxes and 39 wolves in the natural areas. In foxes, hookworm infections (p < 0.0001) were more frequently recorded in the anthropized environment, while coccidia (p < 0.05) and Cryptosporidium spp. (p < 0.0001) were more frequent in the natural area. In wolves, a higher frequency of hookworms (p < 0.0001) was observed in natural areas, while coccidia were more common in the anthropized area (p < 0.05). Moreover, in the natural environment, trichuroid nematodes (p < 0.0001) were significantly more frequent in wolves than in foxes, while Cryptosporidium (p < 0.001) and Giardia duodenalis (p < 0.001) were more common in foxes. In the anthropic area, the occurrence of hookworms was found to be significantly higher in foxes (p < 0.0001), while trichuroid nematodes were more common in wolves (p < 0.0001). The obtained data are indicative of a different diffusion of specific parasite taxa in wolves and foxes living in the natural and/or anthropized environments examined herein.

Co-infection by multiple vector-borne agents in wild ring-tailed coatis (Nasua nasua) from Iguaçu National Park, southern Brazil

The present study aimed to detect molecularly the presence of co-infections by vector-borne agents (VBA) in ring-tailed coatis' (Nasua nasua) blood samples from Iguaçu National Park (INP), southern Brazil, and assess the phylogenetic positioning of the detected agents. DNA blood samples were submitted to molecular screening and characterization for Anaplasmataceae agents, Piroplasmids, Hepatozoon sp., hemotropic mycoplasmas, and Bartonella spp. In total, 42 (85.7%) coatis were positive for hemotropic Mycoplasma sp., 12 (24.5%) for Bartonella machadoae, 7 (14.3%) for Anaplasma sp. closely related to 'Candidatus Anaplasma brasiliensis', and 3 (6%) for Hepatozoon procyonis. The most prevalent co-infections observed was from bacterial VBA: while 18.3% were co-infected by hemotropic Mycoplasma sp. and Bartonella sp., 12.2% were co-infected by Anaplasma sp. and hemotropic Mycoplasma sp. Only two animals (4%) presented co-infections by three VBA (Bartonella sp., Anaplasma sp. and hemotropic Mycoplasma sp.). The coati is a wild carnivore found in INP, mainly in areas visited by tourists. These animals are frequently seen searching for food in garbage dumps or in tourists' belongings. The present study expands the host specificity range of B. machadoae, which has been isolated only from rodents until the present moment. Since the zoonotic potential and transmission routes of the detected VBA are not yet known, surveillance in this area is much needed.

First report of canine rangeliosis in domestic dogs from different regions of Santa Catarina State, Brazil

Rangeliosis is the disease caused by Rangelia vitalii, a parasite reported in dogs from southeastern and southern Brazil, Uruguay, Paraguay, and Argentina. This protozoan is transmitted by the ixodid Amblyomma aureolatum, and infects erythrocytes, leukocytes, and vascular endothelial cells of the host. The common clinical signs, such as prostration, fever, anemia, thrombocytopenia, anorexia, weight loss, and dehydration, are also found in other infections, like canine babesiosis and ehrlichiosis. The similar clinical presentation with other diseases, as well as the indistinguishable morphology with intraerythrocytic Babesia canis, complicates the disease diagnostic. In the present study, blood samples from dogs presenting clinical signs compatible with hemoparasitosis were investigated for rangeliosis. The dogs were treated at veterinary clinics in the cities of Blumenau and Lages, in the State of Santa Catarina, Brazil. Blood samples from 17 dogs were analyzed by PCR. The samples were screened by a conventional piroplasma-PCR and the positives confirmed by a specific R. vitalii-qPCR. Two animals (2/17; 11.8%) were positive for R. vitalii, one from Blumenau and the other from Lages. Both animals presented unspecific signs of hemoparasitosis, such as apathy, anemia, and anorexia. The results indicate the necessity of molecular assays for the proper identification of the hemoparasite, and to investigate the real prevalence of rangeliosis in the State of Santa Catarina.

Rangelia vitalii in free-living crab-eating foxes (Cerdocyon thous) in Uruguay

Rangelia vitalii is a protozoan parasite that causes a hemorrhagic and hemolytic disease in dogs known as rangeliosis. Current reports of the disease are concentrated in the southern and southeastern regions of Brazil, as well as in Uruguay, Argentina, and Paraguay, and mainly concern domestic dogs. South American wild canids, such as the crab-eating fox (Cerdocyon thous), the pampas fox (Lycalopex gymnocercus), and the maned wolf (Chrysocyon brachyurus) may also be affected, although existing reports are restricted to Brazil. The present study aimed to detect R. vitalii parasitism in the Uruguayan wild fox population. DNA extracted from the blood and/or spleen samples of road-killed C. thous and L. gymnocercus found in northern Uruguay were subjected to polymerase chain reaction (PCR) to amplify a 551-bp fragment of the Rangelia 18S rRNA gene. A total of 62 wild canids, including 38 C. thous and 24L. gymnocercus, were analyzed. Five crab-eating fox samples (13.2%) were positive for R. vitalii, with 99.5-100% identity between the sequences. All samples from pampas fox tested negative for R. vitalii. When compared with the R. vitalii sequences available in GenBank, a similarity of 98.9-100% was revealed. Molecular analysis results suggest that R. vitalii is circulating in the crab-eating fox population in Uruguay; however, its veterinary relevance for these foxes remains unknown.

Rangelia vitalii molecular and histological quantification in tissues comparing crab-eating foxes (Cerdocyon thous) and domestic dogs

Rangeliosis is a condition transmitted by the tick Amblyomma aureolatum and caused by the protozoan parasite Rangelia vitalii in canids. In domestic dogs, the disease causes a severe hemolytic disease, while in wild canids the piroplasm is often detected without any clinical abnormality. This study aimed to detect and quantify the number of copies of the R. vitalii Hsp70 gene (indirect parasite burden) in several organs of domestic and South American wild canids (Cerdocyon thous and Lycalopex gymnocercus) to elucidate distinct clinical presentations of rangeliosis in these species. A total of seven domestic dogs that died due to rangeliosis and 38 wild foxes were initially included, with all dogs presenting histological and molecular features of rangeliosis, while eight C. thous were positive at the molecular analysis for R. vitalii. Fragments of 22 organs collected from domestic (n = 7) and wild foxes (n = 8) were employed for histological and molecular quantification using real-time polymerase chain reaction aiming at the Hsp70 gene. Histologically, parasitophorous vacuoles were constantly detected in the dogs, while these were detected only in two C. thous. Parasitic burden was significantly higher in the digestive, cardiorespiratory, endocrine, genitourinary, and skeletal-muscle systems of domestic dogs when compared to wild foxes. In the hematopoietic system of wild canids, some organs, such as the lymph nodes and tonsils, presented significantly lower amounts of R. vitalii, while other organs (spleen, bone marrow, and blood) had results similar to those of domestic dogs. Additionally, the central nervous system of both domestic and wild canids presented a similar quantity of R. vitalii. The etiological agent is possibly maintained through an asexual reproductive process (merogony) in both domestic and wild species. Nonetheless, a limited or short-duration schizogony phase occurs in C. thous, which would designate this species as a possible reservoir host for the agent. Dogs, in contrast, would most likely act as accidental hosts, presenting a severe and more pathogenic schizogony phase, resulting in characteristic clinical and pathological rangeliosis.

A study on the morphoquantitative and cytological characteristics of the bulbar conjunctiva of the maned wolf (Chrysocyon brachyurus; Illiger, 1815)

The maned wolf, Chrysocyon brachyurus, is a near-threatened carnivore inhabiting the Brazilian Cerrado. Few studies have been conducted on this species, and even fewer have explored its ophthalmological characteristics. Vision is critical to wild canids; thus, this study aimed to provide a morphoquantitative description of the bulbar conjunctiva of the maned wolf using cytological and histological analyses. Ten healthy maned wolves from a conservational centre, including 4 females and 6 males aged 1-12 years (6.5 ± 2.8), were included in the study. The samples for cytological analysis were collected from the inferior conjunctival sac using a cytobrush, and conjunctival tissue was collected for histological analysis from the temporal canthus zone. The cytological samples were stained using the Papanicolaou method, and the histological sections were stained using haematoxylin and eosin, Periodic acid-Schiff, picrosirius red and Masson's trichrome stains. The cytological samples were studied for stain quality, and the different cell types were counted. Histological examination was used to determine tissue types in the conjunctiva and their proportions. Analyses revealed a stratified squamous epithelium with some goblet cells and eventual pigmentation in the basal layer. Loose connective tissue with the presence of some mononuclear and polymorphonuclear cells was also observed. The epithelium of the maned wolf's bulbar conjunctiva resembles that of dogs and other carnivore species; furthermore, its physiological and pathological responses were similar to those of other carnivore species.

Survey of ticks and tick-borne agents in maned wolves (Chrysocyon brachyurus) from a natural landscape in Brazil

This study evaluated ticks and tick-borne agents in 104 captures of the maned wolf Chrysocyon brachyurus (50 different individuals and 54 recaptures) in the Serra da Canastra National Park (SCNP), a Cerrado preserved area in southeastern Brazil, from 2005 to 2012. From the 104 capture events, a total of 1,206 ticks were collected on 94 occasions (90.4 %), and identified into five species: Amblyomma tigrinum (77.3 % of all collected ticks), Amblyomma sculptum (16.6 %), Amblyomma ovale (0.1 %), Amblyomma brasiliense (0.1 %), Rhipicephalus microplus (0.1 %), and Amblyomma spp. larvae (5.8 %). Molecular analyses of A. tigrinum adult ticks revealed the presence of 'Candidatus Rickettsia andeanae', Rickettsia parkeri sensu stricto, two different haplotypes of 'Ca. Midichloria sp.', and a Hepatozoon canis haplotype. Molecular analyses of maned wolf blood samples revealed two distinct haplotypes of Hepatozoon spp., one identical to the H. canis genotype that was detected in the A. tigrinum ticks, and a Hepatozoon americanum-like haplotype. None tick or blood samples yielded amplicons through PCR assays targeting the genera Ehrlichia, Anaplasma, Babesia, Rangelia, Cytauxzoon, and Theileria. Maned wolf serum samples were tested by immunofluorescence assay against antigens of five Rickettsia species (R. parkeri, R. rickettsii, R. amblyommatis, R. rhipicephali, and R. bellii) and Ehrlichia canis. Among 78 serum samples (45 captures plus 33 recaptures), 74 (95 %) were reactive to at least one Rickettsia species, with R. parkeri eliciting the highest endpoint titers. Some maned wolves that were recaptured during the study were shown to seroconvert to R. parkeri. Serum-reactiveness to E. canis was detected in 36 % (16/45) maned wolves. During the study, general clinical signs of tick-borne diseases were not found in any of the captured animals, indicating that they were under a good health status in the SCNP, despite of been exposed to ticks (mostly A. tigrinum) and some tick-borne agents (Rickettsia, Hepatozoon, Ehrlichia). The results of the present study might represent baseline data for the conservation of the maned wolf in its natural habitat, which should be used to interpret further studies about ticks and tick-borne diseases in maned wolves within human-modified landscapes.

Hepatozoon sp. gamonts as an accidental finding in synovial liquid from an injured maned wolf (Chrysocyon brachyurus) in southeastern Brazil

A free-living, adult male maned wolf (Chrysocyon brachyurus) was referred to the Governador "Laudo Natel" - FCAV/Unesp veterinary hospital after being found with skin lesions and a fracture on the right pelvic limb, which had to be amputated due to compromised integrity. Around 20 days later, bilateral accentuated swollen on humerus-radius-ulna articulation was observed. The synovial liquid was drained and sent to the laboratory for synovial cytology with Rosenfeld staining that revealed predominantly degenerated neutrophils with karyolytic chromatin associated with intracellular inclusions suggestive of Hepatozoon sp. gametocytes. Blood and synovial liquid samples were submitted to molecular analysis, aiming to amplify the Hepatozoon spp. 18S rRNA gene fragment. Despite the positioning of the found Hepatozoon sequence together with Hepatozoon canis previously detected in domestic carnivores, the BLAST analysis showed only 98% identity with H. canis. To the best of the authors' knowledge, this is the first time a Hepatozoon was detected in the synovial liquid by clinical pathology and molecular analyses.

Rangelia vitalii and Hepatozoon canis coinfection in pampas fox Lycalopex gymnocercus from Santa Catarina State, Brazil

Rangelia vitalii is a haemoparasite that infects erythrocytes, white blood cells and the cytoplasm of endothelial cells of blood capillaries of canids in South America, and has been detected in both domestic dogs and sylvatic canids. Hepatozoon canis is a parasite that infects neutrophils and monocytes of many mammalian hosts. This study reports the infection of Lycalopex gymnocercus from Santa Catarina, Brazil, with R. vitalii and H. canis. The piroplasm was observed on both blood smears and molecular tests. Many large piroplasms were detected inside the erythrocytes, with round, oval, or teardrop-shaped organism, that occurred singly or in pairs. They had an abundant, pale blue cytoplasm and decentral dark red small nucleus. The animal was also infected with H. canis that was detected only by molecular tests. The majority of haematological and biochemistry parameters were within the reference values for domestic dog and wild canids.

Potential Challenges of Controlling Leishmaniasis in Sri Lanka at a Disease Outbreak

The present works reviewed the existing information on leishmaniasis in Sri Lanka and in other countries, focusing on challenges of controlling leishmaniasis in the country, in an outbreak. Evidence from recent studies suggests that there is a possibility of a leishmaniasis outbreak in Sri Lanka in the near future. Difficulty of early diagnosis due to lack of awareness and unavailability or inadequacy of sensitive tests are two of the main challenges for effective case management. Furthermore, the absence of a proper drug for treatment and lack of knowledge about vector biology, distribution, taxonomy and bionomics, and reservoir hosts make the problem serious. The evident potential for visceralization in the cutaneous variant of L. donovani in Sri Lanka may also complicate the issue. Lack of knowledge among local communities also reduces the effectiveness of vector and reservoir host control programs. Immediate actions need to be taken in order to increase scientific knowledge about the disease and a higher effectiveness of the patient management and control programs must be achieved through increased awareness about the disease among general public and active participation of local community in control activities.