International Journal for Parasitology-Parasites and Wildlife最新文献

Myxobolus nagaraensis is a myxozoan parasite first reported in freshwater gobies (Rhinogobius spp.) from the Nagara River, Gifu Prefecture, Japan. Myxospores of M. nagaraensis form plasmodia in the visceral cavities of gobies, commonly presenting as distended abdomens. Although Rhinogobius is a common fish genus in Japan, details of M. nagaraensis, including genetic information, remain unknown. We compared the nucleotide sequences of the ribosomal RNA gene (rDNA) of M. nagaraensis from three different host species (R. fluviatilis, R. nagoyae, and R. similis) caught in three different rivers in Japan (Sakai, Sagami, and Kaname). The ITS region (ITS-1, 5.8S rDNA, and ITS-2) and large subunit (LSU) rDNA exhibited 49 and 55 variable sites, respectively. The highest nucleotide diversity was observed in the ITS region (0.00962), whereas that of the LSU rDNA was 0.00187. Differences in host species, rather than rivers, were a significant factor for genetic variation in both the ITS region (62.58%; P < 0.001) and LSU rDNA (55.22%; P < 0.01). Significant genetic variation was observed in M. nagaraensis from R. similis compared to R. fluviatilis (P < 0.001) or R. nagoyae (P < 0.001) from the same river. Such details are valuable for understanding parasite dispersal and its ecological impact on Rhinogobius hosts.

Some species within the family Plasmodiidae (Haemosporida) have been extensively studied due to their implications for human health. However, for other haemosporidians that infect wild animals the knowledge is limited. Species within the genus Polychromophilus have thus far been documented exclusively as hemoparasites of bats. Records of Polychromophilus are primarily from Africa, Europe, and Southeast Asia, with limited information available for the Americas. Here, we assessed the state of knowledge on Polychromophilus species infecting bats worldwide and searched for the presence of Polychromophilus in blood samples of neotropical bats from Colombia. We found a total of 65 records of Polychromophilus in 46 bat species belonging to the families Emballonuridae, Hipposideridae, Miniopteridae, Rhinolophidae, Rhinonycteridae, and Vespertilionidae worldwide, except for Antarctica. In the Americas, records of the genus Polychromophilus are exclusively from Vespertilionidae bats in Brazil, Colombia, the United States, and Panama. The morphological and molecular analyses of blood from 125 bats, belonging to 39 species and captured in seven localities within the departments of Arauca and Caldas (Colombia), confirmed the presence of Polychromophilus deanei in a silver-tipped myotis, Myotis albescens (Vespertilionidae). This finding represents the first morphological and molecular confirmation of P. deanei in the Americas. Additionally, it expands the knowledge on the diversity and distribution of Polychromophilus in Neotropical bats.

Poor long-term survival (Mean = 2.16 y; 95% CI 1.68–2.65) was identified in a captive population of thorny devils (Moloch horridus) held at the Alice Springs Desert Park in the Northern Territory, Australia, over a period of 27 years. There was no significant difference in survival time (after acquisition) of wild-caught individuals compared captive born animals, or males compared to females. Limited information was available regarding the cause(s) of death for animals found dead or euthanased. Health of the live population at the time of the study (n = 14) was assessed by clinical history review, physical examination, and faecal examination. Large numbers of coccidian oocysts measuring 20–24 μm in diameter were identified upon faecal examination. Molecular investigation of genomic DNA from these samples identified Isospora amphiboluri based on the sequences of partial regions of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and the nuclear small subunit of ribosomal RNA gene (SSU). Isospora amphiboluri was originally described from the bearded dragon (Pogona barbata) and has since been recorded in the inland bearded dragon (Pogona vitticeps) and the central netted dragon (Ctenophorus nuchalis). The present case expands the host range for I. amphiboluri. Histological examination of tissues was not available, and therefore the potential role of I. amphiboluri in morbidity and mortality of M. horridus is not clear. Further research is required to understand if colonization with I. amphiboluri is pathogenic in this species.

Red foxes play a crucial role in the life cycle and transmission of zoonotic pathogens, including Toxocara canis; however, comprehensive information on the prevalence of T. canis in red foxes (Vulpes vulpes) is lacking. In this meta-analysis we aimed to evaluate the global and regional prevalence of T. canis among red foxes. We searched PubMed, Scopus, and Google Scholar for studies reporting prevalence of T. canis in red foxes up to April 1, 2024. Using a random-effects model, we estimated pooled prevalences at global, regional, and national levels and assessed heterogeneity through subgroup and meta-regression analyses. The overall pooled global prevalence of T. canis infection in red foxes was 32.1% (95% CI, 28.5–35.6%), with the highest prevalence in Europe (34.6%, 30.9–38.3%) and the lowest in the Eastern Mediterranean (20.0%, 11.0–29.0%). In other regions, prevalences of Toxocara were as follows: Central Asia (33.1%, 26.8–39.4%), North America (23.6%, 10.6–36.6%), Western Pacific (21.3%, 5.2–37.4%), and Eastern Mediterranean & North Africa (20.0%, 11.0–29.0%). However, data from certain geographical regions are very limited (for example Greece, Austria, China and North Africa). Prevalence rates showed a decreasing trend over time. Subgroup analyses indicated higher prevalences in male red foxes (54.1%, 41.4–66.7%) compared to females (37.5%, 29.9–45.1%), and in juvenile red foxes (56.2%, 39.1–73.3%) compared to adults (33.4%, 23.2–43.6%). T. canis worm burdens were generally low, not exceeding an average of 4 worms per fox in most studies. Our findings reveal a substantial prevalence of T. canis infection in red fox populations worldwide (32.1%), highlighting their potentially significant role in perpetuating the transmission of infection to both companion animals and humans. Continued surveillance is essential to mitigate the risk of Toxocara transmission to companion animals and humans. However, a major remaining challenge is to assess the relative importance of the red fox as a contributor to environmental contamination with Toxocara ova. Further research is also needed to address study limitations and provide a complete global picture of T. canis epidemiology in red foxes and other wild animals, especially in underrepresented regions.

Tick-borne haemoparasites, including piroplasms and trypanosomes, are almost ubiquitous in Australian wildlife, with some associated with health impacts to individual animals and declining wildlife populations. An array of ecologically distinct piroplasm and trypanosome species occur throughout Australia although many of these species and their sylvatic ecologies are poorly characterised. Between May 2022 and October 2023, an anecdotally reported localised eastern grey kangaroo (Macropus giganteus) morbidity/mortality event occurred in coastal southern New South Wales, Australia, characterised by animals presenting with blindness, emaciation, lethargy, ataxia, and astasia. Here we used molecular techniques to identify tick-borne piroplasms (Babesia and Theileria) and trypanosomes in affected animals. Blood (n = 89) and liver (n = 19) samples were collected after the humane euthanasia of wild animals due to welfare concerns, and brief notes on the animal's health were recorded. In total, 20 (22.5%) animals were infected with tick-borne haemoparasites, including a novel Theileria sp. nov. (14, 15.7%), Babesia macropus (2, 2.2%), Trypanosoma gilletti (5, 5.6%), and Trypanosoma vegrandis (1, 1.1%). Liver samples were also screened for Wallal and Warego viruses due to animals' blindness, but were negative. This is the first report of T. gilletti and T. vegrandis in eastern grey kangaroos, although they have been previously reported in high numbers in ticks which commonly parasites this host. The novel Theileria sp. was previously reported in questing Ixodes holocyclus and in ticks from an opportunistically collected eastern grey kangaroo and red-necked wallaby (Notamacropus rufogriseus). However, we show for the first time this Theileria sp. can occur widely in eastern grey kangaroos. Ultimately, this small study did not intend, and is not able to draw inference regarding the pathogenicity of these haemoparasites to eastern grey kangaroos and it is likely that other factors, such as chronic Phalaris grass toxicity, had a role in this localised mortality/morbidity event.

The Brazilian porcupine (Coendou prehensilis, Rodentia, Erethizontidae) is an arboreal South American nocturnal rodent. Switzerland is home to one of the largest captive colonies in Europe. In June 2022, most of the animals in this colony showed severe diarrhoea, and Giardia sp. cysts were detected. All the animals were treated with metronidazole (75 mg/animal/day orally) for five days, repeating after two weeks. The diarrhoea continued, sometimes containing blood, and further analyses revealed Giardia sp. cysts and Trichuris sp. eggs with a particular undulating eggshell in pooled samples. The soil layer of some enclosures was removed to thoroughly clean and disinfect the underlying concrete floor. The animals were treated with fenbendazole (50 mg/kg/day orally) for 5 days repeating after three days. Giardia sp. cysts were not further detected. However, Trichuris sp. eggs were detected in branch bark samples and in six animals 2–3 months after treatment. The treatment with fenbendazole was repeated and no further Trichuris sp. eggs were detected. A 18S rRNA fragment consensus sequence showed 98.58% identity with Trichuris fossor. The Trichuris sp. in C. prehensilis may represent a new species, specific for arboreal porcupines. Demodex mites were observed in faecal flotations and thereafter in skin scrapings from five animals (four of them being family-related). A 16S consensus sequence showed 86.4% identity with other Demodex species. The animals were initially treated with moxidectin (0.4 and 0.8 mg/kg orally) and afterwards with sarolaner (10 mg/animal) but the treatments were not completely effective since in control scrapings, two animals evidenced few non-motile mites. An individual susceptibility and poor immunological control of the infection is suggested. Treatment with fenbendazole was effective against Giardia sp. and Trichuris sp. infections; however, reinfections may occur if the enclosures and tree branches are not deep cleaned and disinfected or replaced.

Reintroduced animals face disease risks, potentially impacting both the reintroduced and the local wildlife/domestic populations. This study focuses on the Asiatic wild asses (Equus hemionus) reintroduced to the Negev desert in southern Israel. Despite potential threats of disease spill-over to and from domesticated donkeys and horses in the area, there are no records of the gastrointestinal nematodes (GIN) of the wild ass population. We used DNA metabarcoding on fecal samples of wild asses collected across seasons and habitats, near water sources that they frequently use. Ten GIN species were detected in the feces, nine belonging to the family Strongylidae, which commonly infects and causes disease in equids worldwide, such as horses, zebras, and donkeys. Some of these Strongylidae species are also found in domesticated equids in Israel, thus raising concerns regarding potential parasite transmission between wild and domestic animals. The high prevalence of certain GIN species suggests frequent transmission, likely due to the congregation of the wild asses around water sources. While we observed statistically significant variations in some GIN species across seasons and habitats, we did not find clear overall differences between GIN communities. DNA metabarcoding proves to be a valuable tool for identifying GIN species in wild animals, with potential applications in monitoring their health and preventing disease transmission to and from domestic animals.

Dirofilaria (Nochtiella) tenuis is a mosquito-borne subcutaneous parasite of raccoons, regarded as the causative agent of most human dirofilarial infections in North America. Despite the wide geographic range of raccoons in the Americas, the presence of this parasite has not been confirmed outside its known endemic areas in the Southern United States. Based on morphological and molecular data, we present the first record of D. (N.) tenuis in wild raccoons from the Yucatan Peninsula. Adult thread-like worms recovered from subcutaneous tissues of wild raccoons were analyzed with light microscopy, histology, scanning electron microscopy (SEM), and 18S rRNA, 28S rRNA and cox1 gene sequencing for identification and phylogenetic analysis. The collected nematodes were identified as D. (N.) tenuis based on their morphology. SEM analysis revealed details about different facial ornamentations in male worms, which had not been previously described. Molecular and phylogenetic analyses confirmed morphological observations by placing our specimens within clades of the Dirofilaria genus. Our findings represent the first molecular characterization for this nematode and extend the geographical range of this parasite to Mexico. Further studies are required for a more accurate picture of the epidemiology of this filarioid across Mexico and other areas overlapping the raccoon's range.

The phenomenon of cuckoos’ brood parasitism is well known and can be investigated using applied mathematical techniques. Among adaptive features of this phenomenon are certain egg parameters that ensure their shortened incubation period (I) and thus the successful survival of their offspring. In particular, the volume of a cuckoo egg is not less than, or exceeds, that of the host species, which should, in theory, increase I. Also, cuckoo eggs have thicker shell than that of nest hosts. Here, we analyzed the available geometric dimensions of eggs in 447 species and found an inverse correlation (−0.585, p < 0.05) between I and the shell thickness-to-egg surface area ratio (T/S). A mathematical relationship was derived to calculate I depending on T/S. This premise was confirmed by comparative calculations using egg images of two parasitic species, common (Cuculus canorus) and plaintive cuckoo (Cacomantis merulinus) and their hosts: great reed warbler (Acrocephalus arundinaceus), European robin (Erithacus rubecula), rufescent prinia (Prinia rufescens), and common tailorbird (Orthotomus sutorius). An average calculated I value for cuckoo eggs was one day less than that for host eggs. Our findings unravel additional details of how cuckoos adapt to brood parasitism and specific host-parasite relationships.

Understanding the impact of parasites on wildlife populations is an important aspect of conservation management. However, research on ectoparasites in wildlife can be difficult, as examinations of live animals which are not habituated to human handling are often impossible. The European wildcat (Felis silvestris) is a strictly protected wildlife species whose population has been recovering in Germany in recent decades. Several studies from different European countries have investigated the parasitological status of European wildcat populations. However, most of these studies assessed endoparasite infections, whereas ectoparasite infestations have often been neglected. To fill this knowledge gap for wildcats in Germany, 131 dead found specimens were examined for ectoparasites by macroscopic and microscopic examination of the fur and the ear canals. Infestation with ectoparasites was present in 84.0% (110/131) of the wildcats. Ticks showed the highest prevalence with 72.5% (95/131) of wildcats infested, with 49.6% (65/131) infested with Ixodes ricinus and 36.6% (48/131) with Ixodes hexagonus/canisuga. A total of 27.5% (36/131) of the wildcats were positive for at least one flea species. Of the nine different flea species identified by morphology and/or molecular analyses, Ceratophyllidae were most common (16.8% [22/131]), with Ceratophyllus sciurorum confirmed on 12.2% (16/131) and Nosopsyllus fasciatus on 1.5% (2/131) animals, followed by Pulex irritans (5.3% [7/131]), Spilopsyllus cuniculi (3.8% [5/131]), Chaetopsylla spp. (3.1% [4/131]) (2/131 Chaetopsylla trichosa and 1/131 Chaetopsylla globiceps), Ctenocephalides felis (1.5% [2/131]), Archaeopsylla erinacei (1.5% [2/131]) and Ctenophthalmus baeticus (0.8% [1/131]). Further, 23.7% (31/131) of the wildcats harboured mites, identified as Trombicula autumnalis in 12.2% (16/131) and Otodectes cynotis in 4.8% (6/124) of cases. The only louse species detected was Felicola hercynianus with a prevalence of 2.3% (3/131). Infestation intensities ranged from 1 to 86 ticks, 1–49 fleas, 1–1896 mites, and 1–92 F. hercynianus per wildcat. This study demonstrates that a variety of ectoparasites infests wildcats in Germany, but they do not seem to have a serious impact on the general health of wildcats, as judged by the hosts' mostly good or very good nutritional condition. In addition, the potential risk to domestic cats (Felis catus) and humans posed by the wildcats’ ectoparasites, appears to be low but present.