Molecular detection of apicomplexan protozoa in Hokkaido brown bears (Ursus arctos yesoensis) and Japanese black bears (Ursus thibetanus japonicus)

Cytauxzoon paradoxurus n. sp., a novel Cytauxzoon species identified in common palm civets in Singapore

BACKGROUND

The common palm civet (Paradoxurus musangus) is a species native to Southeast Asia. Highly adapted to urbanised environments, these civets can often be found in proximity to humans and companion animals, raising the concern of pathogen transmission at the human-wildlife and wildlife-domestic animal interface. Whilst there have been reports of various bacteria and viruses detected in civets, little is known about the protozoa that they may harbour. In this study, we screened the common palm civets in Singapore for tick-borne protozoan parasites known as piroplasms.

METHODS

Over a 2-year period, blood samples were opportunistically collected from 135 wild common palm civets following a physical examination. The sex and weight of each civet were recorded, and any ectoparasites detected were identified through DNA barcoding. DNA extracts of blood samples were screened using a PCR assay targeting the 18S rRNA gene of piroplasmids.

RESULTS

A novel Cytauxzoon species was detected in 29 civets (21.5%), and a statistically significant association was found between infection and the civet's weight. Two cat flea (Ctenocephalides felis) specimens were discovered on two sampled civets; however, Cytauxzoon DNA was not detected in either the flea or the sampled civet. Phylogenetic analysis of the Cytauxzoon 18S rRNA gene sequences from 29 civets revealed that this piroplasmid is most closely related to a Cytauxzoon sp. detected in meerkats in South Africa but molecularly distinct from the six currently described Cytauxzoon species.

CONCLUSIONS

This detection documents the first molecular confirmation of Cytauxzoon sp. infection in Southeast Asia and the first report of Cytauxzoon sp. in a viverrid host. Further studies are required to determine the vector involved in the transmission of this novel Cytauxzoon species, as no ticks were found on the sampled civets. The discovery of Cytauxzoon paradoxurus n. sp. highlights the importance of expanded biosurveillance to better understand the diversity of piroplasms harboured by wildlife in the region and its potential for cross-species transmission.

Diversity of Cytauxzoon spp. (Piroplasmida: Theileriidae) in Wild Felids from Brazil and Argentina

Domestic and wild felids are frequently parasitized by apicomplexan protozoa in the genus Cytauxzoon. Expanding species diversity has recently been described within this genus, with potential implications for epidemiology and pathogenesis. In light of these findings, this study assessed the genetic diversity of Cytauxzoon spp. in wild felids (n = 66) from different eco-regions of Brazil and Argentina. Of the 66 blood samples analyzed, 53 (80.3%) were 18S rRNA gene PCR-positive for Cytauxzoon spp., including 43 jaguars (Panthera onca) and 10 ocelots (Leopardus pardalis). Panthera onca specimens (100%, 43/43) were most frequently infected, followed by Leopardus pardalis (76.9%; 10/13). Cytauxzoon spp. were not detected in Leopardus braccatus (n = 1) or Puma concolor (n = 9). Phylogenetic analyses of fragments of the 18S rRNA, cytB, and cox-1 gene sequences from jaguars were closely related to Cytauxzoon felis. In contrast, sequences from ocelots were more closely associated with Cytauxzoon brasiliensis. Distance and haplotype analysis further confirmed the circulation of at least two distinct genovariants of C. felis among jaguars, as evidenced by their close positioning and low genetic divergence (0-0.14% for 18S rRNA, 0.37-0.56% for cytB, and 0.08-0.74% for cox-1). Additionally, sequence data from ocelots suggested that multiple genovariants of C. brasiliensis are circulating among these cats in different Brazilian eco-regions. Our study provides evidence of two distinct Cytauxzoon organisms parasitizing free-ranging and captive jaguars and ocelots, respectively, in Brazil and Argentina.

A novel genotype of Babesia microti-like group in Ixodes montoyanus ticks parasitizing the Andean bear (Tremarctos ornatus) in Ecuador

Babesia species (Piroplasmida) are hemoparasites that infect erythrocytes of mammals and birds and are mainly transmitted by hard ticks (Acari: Ixodidae). These hemoparasites are known to be the second most common parasites infecting mammals, after trypanosomes, and some species may cause malaria-like disease in humans. Diagnosis and understanding of Babesia diversity increasingly rely on genetic data obtained through molecular techniques. Among hard ticks, several Ixodes species are known vectors of Babesia microti-like species in the Northern Hemisphere. Recently, Ixodes and Amblyomma ticks have been recorded parasitizing the Andean bear (Tremarctos ornatus) in Ecuador. Previous reports have suggested babesiosis in a fatal case of this threatened bear species in that country. This study aimed to detect Piroplasmida DNA in hard ticks collected from Andean bears at two sites in Ecuador. This species plays a critical role as an ecological engineer and a seed disperses, contributing significantly to the maintenance and health of Andean ecosystems. Twelve ticks screened with conventional PCR and Piroplasmida DNA was amplified from one Ixodes montoyanus tick collected from a free-living female Andean bear at Llanganates National Park. Two Babesia sequences were characterized: one for the 18 S ribosomal rRNA gene and another for the cytochrome c oxidase 1 gene. Phylogenetic analyses for both loci placed these sequences within the B. microti-like clade. This study reports a novel B. microti-like genotype identified in an I. montoyanus parasitizing a female Andean bear, contributing to the knowledge of the diversity of this group in South America. Given their conservation status, future epidemiological surveillance of Babesia and other tick-borne infectious agents in Andean bears is needed.

Description and molecular characterisation of Babesia ailuropodae n. sp., a new piroplasmid species infecting giant pandas

BACKGROUND

Babesia spp. are protozoan parasites that infect the red blood cells of domesticated animals, wildlife and humans. A few cases of giant pandas (a flagship species in terms of wildlife conservation) infected with a putative novel Babesia sp. have been reported. However, comprehensive research on the morphological and molecular taxonomic classification of this novel Babesia sp. is still lacking. This study was designed to close this gap and formally describe this new Babesia sp. infecting giant pandas.

METHODS

Detailed morphological, molecular and phylogenetic analyses were conducted to characterise this Babesia sp. and to assess its systematic relationships with other Babesia spp. Blood samples from giant pandas infected with Babesia were subjected to microscopic examination. The 18S ribosomal RNA (18S rRNA), cytochrome b (cytb) and mitochondrial genome (mitogenome) of the new Babesia sp. were amplified, sequenced and assembled using DNA purified from blood samples taken from infected giant pandas. Based on the newly generated 18S rRNA, cytb and mitogenome sequences, phylogenetic trees were constructed.

RESULTS

Morphologically, the Babesia sp. from giant pandas exhibited various forms, including round to oval ring-shaped morphologies, resembling those found in other small canine Babesia spp. and displaying typical tetrads. Phylogenetic analyses with the 18S rRNA, cytb and mitogenome sequences revealed that the new Babesia sp. forms a monophyletic group, with a close phylogenetic relationship with the Babesia spp. that infect bears (Ursidae), raccoons (Procyonidae) and canids (Canidae). Notably, the mitogenome structure consisted of six ribosomal large subunit-coding genes (LSU1-6) and three protein-coding genes (cytb, cox3 and cox1) arranged linearly.

CONCLUSIONS

Based on coupled morphological and genetic analyses, we describe a novel species of the genus Babesia, namely, Babesia ailuropodae n. sp., which infects giant pandas.

Molecular investigation and clinical management of Hepatozoon Canis infection in an Indian jackal - a case report

BACKGROUND

Hepatozoonosis is a common tick-borne illness reported from all over the world. The infection has been well documented in dogs and cats, and has also been identified in wild canids and felids. India is home to many canid species; however, the incidence of Hepatozoonosis in wild canids is rarely reported. A wide variety of protocols have been discussed for the clinical management of the infection in companion animals; however, the suitability of treatment protocols in wild canids is understudied. The current case report highlights the clinical management of Hepatozoonosis in an Indian jackal and molecular investigation to provide vital insights into the epidemiology of the disease.

CASE PRESENTATION

A paraplegic Indian jackal was rescued from Melghat Tiger Reserve, Maharashtra, India. The animal had extensive decubital ulcers on the left pin bone and could not walk; however, the animal was active and dragged the hindlimb during locomotion. The vital parameters, blood and serum investigations were normal. Post physiotherapy, massage and infrared therapy, the animal could walk but started knuckling, resulting in injuries. Eight weeks into rehabilitation, the animal had a steep fall in haemoglobin concentration, platelet count, weight loss and was diagnosed with Hepatozoonosis. Considering the altered vital parameters, the jackal was rationally treated with Doxycyclin @ 20 mg/Kg O.D. (Once Daily) for 45 days along with supportive therapy. The jackal recovered after the treatment and led a normal life.

CONCLUSION

Mono-drug regime using Doxycycline was effective in the alleviation of H.canis infection in jackal. The drug was effective in alleviating the clinical presentation without alteration of vital parameters. The molecular investigation provided qualitative inputs in understanding the epidemiology of Hepatozoon in wild canids.