A synoptic overview of golden jackal parasites reveals high diversity of species

Is golden jackal (Canis aureus) the most important indicator species of Trichinella infection in Croatia?

Epidemiologic monitoring of wild animals is always an important step in defining potential zoonoses that can threaten humans. Particular emphasis should be given to those zoonotic agents permanently cycling within wild animal populations and represent a permanent reservoir for other wild or domesticated animals that can be direct sources of disease for humans. In Croatia, there are two European jackal populations: the Dalmatian population (DP) that has been inhabiting the islands and coastal area along the Adriatic Sea since medieval times, and the South East European population (SEEP) that is found in continental Croatia. Research on Trichinella infections in jackal populations in Croatia was conducted from 2008 to 2022. During this 15-year period, we tested 186 jackal samples and confirmed infection in 47 individuals (25.3 %). The dominant species was T. spiralis, identified in 28 samples (60 %), T. britovi was found in 13 samples (28 %), while for six samples (12 %) the PCR test was unsuccessful. In both populations, the Trichinella species of the domestic cycle (T. spiralis) was found, though in varying ratios: in DP the ratio of identified species was 10:6 in favour of T. britovi, as opposed to 22:3 in favour of T. spiralis in SEEP. The frequency of infection with parasites from the genus Trichinella was significantly different in DP (22.9 %) than in SEEP (26.7 %) (p<0.001), while the larval count in analysed tissue did not differ by type of Trichinella species (p=0.1028). Infected jackals were found in nine of ten tested counties. The results were analysed statistically and the origin of tested and positive samples shown on a map of Croatia. Based on these findings, both jackal populations can be considered to represent an exceptionally important indicators of parasites from the genus Trichinella in Croatia, both for the sylvatic and domestic cycles. There is an evident need for epidemiological monitoring for members of both populations.

A Rare Parasite in Cats: Record of a Linguatula serrata Frölich, 1789 (Porocephalida, Linguatulidae) Nymphal Infestation in a Cat in Albania, with a Synopsis and Review of the Literature on L. serrata Infestation in Cats

Linguatula serrata, commonly known as the dogs' 'tongue-worm', is an arthropod endoparasite of the class Pentastomida infesting chiefly canids as definitive hosts and herbivores as intermediate hosts. Adult L. serrata usually reside in the upper respiratory tract, such as the nasal cavity and sinuses, and the larval stages are encapsulated in various visceral organs, respectively. This report presents the first case of a L. serrata nymphal pulmonary infestation in a cat from Albania and adds to the description of the overall rare cases of this parasitic infestation in domestic cats. Discussion of this case together with a comprehensive review of the literature allows us to conclude that cats are susceptible to the infestation with L. serrata when ingesting the parasite's eggs and allow for the development of the nymphal stage of the parasite in several visceral organs. Therefore, cats may serve as accidental intermediate hosts in the life cycle of L. serrata but are unlikely to be of epidemiological relevance. There is no evidence that domestic cats can act as definitive hosts of L. serrata.

Detection of Dirofilaria immitis in golden jackals (Canis aureus L.) but not in red foxes (Vulpes vulpes L.) and European badgers (Meles meles L.) in Croatia

BACKGROUND

Dirofilariosis is a parasitic mosquito-borne disease caused by members of the genus Dirofilaria, which includes Dirofilaria immitis and Dirofilaria repens. Surveillance studies in Europe have revealed that D. immitis can also be detected in a range of wild carnivores, raising questions over the impact of infections on wild carnivore animal health but also whether these populations may act as a reservoir for infection of other species, including domestic dogs and humans.

METHODS

In the current study, we conducted surveillance for the presence of D. immitis in several wild carnivore species, including golden jackals (Canis aureus; n = 77), red foxes (Vulpes vulpes; n = 326), and European badgers (Meles meles; n = 28), collected during an annual rabies surveillance and control program from across continental and coastal regions of Croatia.

RESULTS

Macroscopic examination of the right chambers of the heart during a post-mortem examination resulted in the detection of filarial parasites in 6.5% (5/77) golden jackal carcasses. Morphological identification, confirmed by molecular screening, classified all parasites as D. immitis. No D. immitis were detected in the red foxes or European badgers examined. All infected golden jackals were adults aged from 2 to 7 years with a parasite load ranging from 2 to 7 nematodes per carcass. One animal was infected with a sexually mature pair, while a second harbored pre-mature parasites; the remaining positive jackals were infected with female parasites only. Notably, histological examination of cardiac and lung tissue revealed proliferative endarteritis in the jackal with the highest parasite burden.

CONCLUSIONS

Further studies are required to establish whether golden jackals, as well as other wild carnivore hosts, may serve as competent definitive hosts of D. immitis and act as reservoirs for infection of other species including domestic dogs and humans. Histological changes in the cardiac tissue of at least one positive jackal were suggestive of infection with pathological consequences for the host.

Double trouble: Co-infection of Angiostrongylus vasorum and Dirofilaria immitis in golden jackal (Canis aureus) in Friuli Venezia Giulia, Italy

This study reports the first co-infection of Angiostrongylus vasorum and Dirofilaria immitis, two nematodes affecting canid cardiopulmonary systems, in golden jackals (Canis aureus) in Italy. Data on golden jackal carcasses, recovered in Friuli Venezia Giulia (Italy) from 2020 to 2023, were recorded using InfoFaunaFVG wildlife monitoring network. Out of 60 necropsied golden jackals, 24 tested positive for either pathogen, with 3 animals displaying co-infection. Pathological findings included verminous pneumonia, abdominal and thoracic bleeding, and adult individuals in the heart and pulmonary arteries. The recent expansion of the golden jackal in northern Italy may favour the establishment and spread of these nematodes, posing challenges for disease containment and surveillance. Given the increasing prevalence of angiostrongylosis and cardiopulmonary dirofilariosis in Europe, health monitoring of wild canids is essential to reduce their potential impact.

Wildlife and parasitic infections: A One Health perspective in Greece

While research on the parasitic fauna of wildlife in Greece is currently limited, conducted studies have provided valuable insights into the prevalence of parasitic infections in wild carnivores, omnivores, and herbivores. This review consolidates the existing data on the endoparasites detected in wild animals in Greece, specifically focusing on those that pose established or potential zoonotic risks. Over the last 60 years, various parasite species such as Leishmania infantum, Cryptosporidium spp., Toxoplasma gondii, Sarcocystis spp., Toxocara canis, Ancylostoma caninum, Capillaria spp., Baylisascaris spp., Trichinella spp., Thelazia callipaeda, Dirofilaria immitis, Echinococcus granulosus, Mesocestoides sp., Taenia spp., Alaria alata, and Dicrocoelium dendriticum have been identified in wildlife in Greece. These findings have become increasingly relevant due to the growing interaction between humans and wild animals, which now extends to urban environments, as well as the increased contact between wild and domestic animals. This is further complicated by the geographical expansion of vector-borne diseases due to global warming and the increased movements of humans and animals. Surveillance and monitoring of parasitic infections in Greek wildlife is warranted, and it should be based on interdisciplinary investigations considering the interconnectedness of human, wild, and domestic animals, as well as environmental health, in line with the One Health approach.

Detection and complete genome characterization of a genogroup X (GX) sapovirus (family Caliciviridae) from a golden jackal (Canis aureus) in Hungary

In this study, a novel genotype of genogroup X (GX) sapovirus (family Caliciviridae) was detected in the small intestinal contents of a golden jackal (Canis aureus) in Hungary and characterised by viral metagenomics and next-generation sequencing techniques. The complete genome of the detected strain, GX/Dömsöd/DOCA-11/2020/HUN (PP105600), is 7,128 nt in length. The ORF1- and ORF2-encoded viral proteins (NSP, VP1, and VP2) have 98%, 95%, and 88% amino acid sequence identity to the corresponding proteins of genogroup GX sapoviruses from domestic pigs, but the nucleic acid sequence identity values for their genes are significantly lower (83%, 77%, and 68%). During an RT-PCR-based epidemiological investigation of additional jackal and swine samples, no other GX strains were detected, but a GXI sapovirus strain, GXI/Tótfalu/WBTF-10/2012/HUN (PP105601), was identified in a faecal sample from a wild boar (Sus scrofa). We report the detection of members of two likely underdiagnosed groups of sapoviruses (GX and GXI) in a golden jackal and, serendipitously, in a wild boar in Europe.

Wildlife parasitology: sample collection and processing, diagnostic constraints, and methodological challenges in terrestrial carnivores

Wild terrestrial carnivores play a crucial role as reservoir, maintenance, and spillover hosts for a wide parasite variety. They may harbor, shed, and transmit zoonotic parasites and parasites of veterinary importance for domestic hosts. Although wild carnivores are globally distributed and comprise many different species, some living in close proximity to human settlements, only a few studies have investigated parasites of wild terrestrial carnivores using non-specific techniques. Access to samples of wild carnivores may be challenging as some species are protected, and others are secretive, possibly explaining the data paucity. Considering the importance of wild carnivores' health and ecological role, combined with the lack of specific diagnostic methodologies, this review aims to offer an overview of the diagnostic methods for parasite investigation in wild terrestrial carnivores, providing the precise techniques for collection and analysis of fecal, blood, and tissue samples, the environmental impact on said samples, and the limitations researchers currently face in analyzing samples of wild terrestrial carnivores. In addition, this paper offers some crucial information on how different environmental factors affect parasite detection postmortem and how insects can be used to estimate the time of death with a specific highlight on insect larvae. The paper contains a literature review of available procedures and emphasizes the need for diagnostic method standardization in wild terrestrial carnivores.

First Identification of Trichinella pseudospiralis in a Golden Jackal (Canis aureus) in Romania

Trichinella spp. are etiological zoonotic agents that spread throughout the world and affect mammals, birds, and reptiles. Within this genus, Trichinella pseudospiralis is the only recognized non-encapsulated species known to infect mammals and birds. This species has been reported in the majority of European countries, and the real epidemiological scenario of this species remains to be defined because its detection in mammals is much lower than that of the capsulated species. The aim of this study was to examine the presence of Trichinella larvae isolated from the muscles of a jackal from the hunting fund of 36 Murfatlar, Constanta County, Romania. The muscle samples were examined by artificial digestion, and the larvae were identified at the species level by multiplex PCR. The presence of larvae belonging to T. pseudospiralis, a species more frequently reported in carnivorous birds, was observed. This study describes the first identification of T. pseudospiralis in a jackal. The results suggest that there is an urgent need to investigate which species of mammals and/or birds act as reservoirs for this zoonotic nematode in Romania.

A walk on the wild side: A review of the epidemiology of Toxocara canis and Toxocara cati in wild hosts

Toxocara species are cosmopolitan nematode parasites of companion, domestic and wild hosts. Of the 26 known species of Toxocara, only Toxocara canis and Toxocara cati are definitively zoonotic. The significance of wild carnivores as definitive hosts of T. canis and T. cati respectively, has received far less attention compared to domestic dogs and cats. Complex environmental changes have promoted increasing contact between wildlife, domestic animals and humans that can enhance the risk of pathogen spillover. This review lists a total of 19 species of wild canid host that have been shown to act as definitive hosts for T. canis and a total of 21 species of wild felid host. In general, the number of publications focusing on felid host species is fewer in number, reflecting the general paucity of data on T. cati. The wild canids that have received the most attention in the published literature include the red fox (Vulpes vulpes), the wolf (Canis lupus), and the golden jackal (Canis aureus). The wild felid species that has received the most attention in the published literature is the Eurasian lynx (Lynx lynx). Some non-canid and non-felid hosts also act as definitive hosts of Toxocara species. Certainly, red foxes would appear to be the most significant wild species in terms of their potential to transmit Toxocara to domestic dogs and humans via environmental contamination. This can be explained by their increasing population densities, encroachment into urban areas and their dietary preferences for a wide range of potential paratenic hosts. However, a major challenge remains to assess the relative importance of wild hosts as contributors to environmental contamination with Toxocara ova. Furthermore, one major constraint to our understanding of the significance of wildlife parasitism is a lack of access to samples, particularly from rare host species.

Sarcocystis cruzi (Hasselmann, 1923) Wenyon, 1926: redescription, molecular characterization and deposition of life cycle stages specimens in the Smithsonian Museum

Currently, 7 named Sarcocystis species infect cattle: Sarcocystis hirsuta, S. cruzi, S. hominis, S. bovifelis, S. heydorni, S. bovini and S. rommeli; other, unnamed species also infect cattle. Of these parasites of cattle, a complete life cycle description is known only for S. cruzi, the most pathogenic species in cattle. The life cycle of S. cruzi was completed experimentally in 1982, before related parasite species were structurally characterized, and before the advent of molecular diagnostics; to our knowledge, no archived frozen tissues from the cattle employed in the original descriptions remain for DNA characterization. Here, we isolated DNA from a paraffin-embedded kidney of a calf experimentally infected with S. cruzi in 1980; we then sequenced portions of 18S rRNA, 28S rRNA, COX1 and Acetyl CoA genes and verified that each shares 99–100% similarity to other available isolates attributed to S. cruzi from naturally infected cattle. We also reevaluated histological sections of tissues of calves experimentally infected with S. cruzi in the original description, exploiting improvements in photographic technology to render clearer morphological detail. Finally, we reviewed all available studies of the life cycle of S. cruzi, noting that S. cruzi was transmitted between bison (Bison bison) and cattle (Bos taurus) and that the strain of parasite derived from bison appeared more pathogenic than the cattle strain. Based on these newfound molecular, morphological and physiological data, we thereby redescribed S. cruzi and deposited reference material in the Smithsonian Museum for posterity.

The first report on Hepatozoon canis in dogs and wolves in Poland: clinical and epidemiological features

BACKGROUND

Canine hepatozoonosis caused by Hepatozoon canis is a common infection in dogs, with frequent case reports from the Mediterranean region and more recently from several Central European countries, such as Hungary and Germany. Despite the high prevalence of H. canis in red foxes, no infections have been reported to date in dogs in Poland. We describe here the first autochthonous cases of H. canis infection in dogs, including their clinical features, and report the prevalence of H. canis in grey wolves from different regions of Poland.

METHODS

Thin smears prepared from blood samples collected from dogs were evaluated by microscopic examination. A total of 60 wolves and 47 dogs were tested. Infections were confirmed by PCR and sequencing.

RESULTS

Gamonts of H. canis were found in > 50% of the neutrophils of two dogs and in < 10% of the neutrophils in another five dogs. Molecular typing by PCR sequencing of the 18S ribosomal RNA gene fragment confirmed infections in 11 dogs from different regions of Poland, in 2.7% of dogs attending veterinary practices in central Poland and in 35% of wolves from various geographical regions of Poland. Clinical features manifested mostly in older dogs, and the most common signs were anaemia and apathy. Young dogs usually remained asymptomatic.

CONCLUSIONS

This is the first report of H. canis infection in dogs and wolves in Poland. Although the exact vector of the parasite is not known, veterinary practitioners should be aware of this new parasitosis and should consider appropriate diagnostics to confirm/exclude this infection. Further studies are needed to understand the transmission routes of H. canis in domestic and wild canids in Poland.

A coprological survey on helminths of Jackal Canis aureus Linnaeus 1758 in Kashmir Himalaya

A coprological examination was carried out between February 2017 and January 2019 to determine the prevalence of gastrointestinal helminths in jackals of Kashmir Himalaya, India. Fecal floatation and sedimentation technique revealed helminths in 215 scats out of 879 examined scats, with overall helminth prevalence of 24.45%. In the study, five different species of helminths were detected in scats of jackal: Toxocara canis (22.86%), Ancylostoma caninum (20.47%), Dipylidium caninum (17.17%), Trichuris vulpis (19.34%), and taeniid eggs (13.65%). One helminth species was found in (0.11%) of the jackal scats, two were in (1.25%), three were in (4.77%), four were in (16.38%), and five were in (1.92%). Toxocara canis, a nematode with great zoonotic significance, was most common helminth found in scats of jackal during the study. We observed significant seasonal fluctuation (p < 0.05) in the prevalence of gastrointestinal helminths, with summer having high frequency followed by autumn, spring, and winter having lowest prevalence. The study area's jackal population's preponderance of zoonotic helminth species suggests a high risk of zoonotic infection by canine intestinal helminths. This study will aid veterinarians in better plan preventative strategies with regard to wild animal intestinal parasites.

Ups and downs of infections with the broad fish tapeworm Dibothriocephalus latus in Europe (Part II) and Asia from 1900 to 2020

The broad fish tapeworm, Dibothriocephalus latus (Diphyllobothriidea), is the most important causative agent of diphyllobothriosis, a fish-borne zoonosis, in Europe. Part I of this review focused on the occurrence of D. latus in northwestern and central Europe, particularly in Fennoscandia, the Baltic, the Alpine lakes and Danube River regions during 1900-2020. Part II summarises data on D. latus from the European and Asian parts of Russia and from Asian countries. The tapeworm has occurred throughout Russia, with the most important foci in (i) the Republic of Karelia in the northwest of European Russia, (ii) the Volga River basin in the central and southern parts of European Russia, (iii) the Ob-Irtysh rivers region in the Ural region, (iv) the Yenisei-Lena rivers region in Siberia, and (v) the Lake Baikal basin in Siberia. The incidence of diphyllobothriosis has declined in recent decades, especially in European Russia, but zoonosis is still prevalent in some regions of Siberia. Cases reported from Arctic regions, the region around Lake Baikal, and the Pacific coast, including the Amur basin, however, were probably misidentifications with D. dendriticus and/or D. nihonkaiensis. No other Asian country where D. latus findings represented either imported cases or misidentifications had natural focus of diphyllobothriosis. Patterns of distribution of D. latus occurrence were similar in all Eurasian foci between 1900 and 2020. The numbers of records were associated with historical and epidemiological milestones of particular time periods.

First Morphological and Molecular Identification of Demodex injai in Golden Jackal (Canis aureus Linnaeus, 1758) in Romania

Demodicosis is one of the most important external parasitic diseases found in carnivores. Three species of the Demodex mite inhabit the skin of dogs and related species, D. canis being the most prevalent. This paper describes the first case of infestation with D. injai in a golden jackal in Romania. An emaciated golden jackal female body found in Timiș County, western Romania, was examined at Parasitology Department of Faculty of Veterinary Medicine, Timișoara. The gross lesions were present on different regions of the body: feet, tail, axillary and inguinal areas, and skin folds as well, consisting of erythema, extensive severe alopecia with lichenification, seborrhea, and scaling. In order to establish diagnosis, microscopic examination of skin scrapes, trichogram (hair plucking), acetate tape test (impression), fungal culture, and PCR were performed. Both microscopic measurements and PCR analysis have confirmed the presence of D. injai.

Wild Mesocarnivores as Reservoirs of Endoparasites Causing Important Zoonoses and Emerging Bridging Infections across Europe

Mesocarnivores are small- or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neogale vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizootiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.

High overlap of zoonotic helminths between wild mammalian predators and rural dogs - an emerging One Health concern?

The concept of One Health emphasizes the interdependence of human, animal and environmental health and is of growing significance, in part owing to the problems related to emerging infectious diseases of wildlife origin. Wild mammalian predators are a potential risk factor for transmission of zoonotic pathogens to domesticated animals and humans. This is especially relevant in rural areas, where transmission of zoonotic pathogens can occur particularly efficiently when free-ranging dogs are present. The main aim of this study was to determine helminth infections among wild mammalian predators and evaluate the overlap between helminth faunas of wild mammals and dogs. Scat samples of predators were collected in coastal areas of Western Estonia and genetic methodology applied for the correct identification of predator species from their scat. Parasitic helminths of mammalian predators in the scat samples were analysed and compared with dog data from a previous study. High helminth prevalence (~90%) was found in dominant predator species in the area, namely the red fox (Vulpes vulpes) and golden jackal (Canis aureus). Moreover, the helminth fauna of both wild species, including potentially zoonotic helminths, overlapped largely with that of rural dogs in the same area. The results, together with the ones from earlier parasitological studies among humans in Estonia, emphasize the potential risk of pathogen transmission from wild mammalian predators to dogs and from dogs to humans, making parasitic diseases of wildlife a One Health concern.

The Scenario of Ticks and Tick-Borne Pathogens of Sheep on a Mediterranean Island

Ticks and transmitted pathogens constitute a major concern for livestock health/welfare and productivity for the Mediterranean region, often posing an important zoonotic threat. The aim of this study was to investigate the presence, infection intensity, and seasonality of ticks and tick-borne pathogens on the island of Lesvos in Greece, which was selected as a potential hotspot for their circulation. To this end, 101 sheep farms were visited over a tick activity season, and ticks, blood samples, and questionnaire data were collected. Ticks were identified by species, and DNA from both ticks and blood samples was further investigated using the polymerase chain reaction–reverse line blot (PCR–RLB) technique. In 72.3% of the farms, sheep were found to be infected by 9 ixodid species, with Rhipicephalus turanicus being the most common during the spring/early summer period. As regards tick-borne pathogens (TBPs), 84.9% of the animals were found to be infected with at least one pathogen, the most common being genera of Anaplasma and Theileria, alone or in co-infections. To further characterize the Anaplasma species found, selected samples were sequenced, revealing isolates of A. ovis, A. capra, A. marginale, and A. phagocytophilum. Of the 169 female R. turanicus ticks analyzed by PCR–RLB, 89.9% were harboring at least one TBP belonging to the genera Anaplasma, Ehrlichia, Babesia, Theileria, or Rickettsia. Overall, the data presented in this study revealed a high burden of ticks and TBPs in sheep, including zoonotic species, stressing the need for applying effective monitoring and control programs using a more holistic One Health approach.

From the Balkan towards Western Europe: Range expansion of the golden jackal (Canis aureus)-A climatic niche modeling approach

In recent decades, a rapid range expansion of the golden jackal (Canis aureus) towards Northern and Western Europe has been observed. The golden jackal is a medium-sized canid, with a broad and flexible diet. Almost 200 different parasite species have been reported worldwide from C. aureus, including many parasites that are shared with dogs and cats and parasite species of public health concern. As parasites may follow the range shifts of their host, the range expansion of the golden jackal could be accompanied by changes in the parasite fauna in the new ecosystems. In the new distribution area, the golden jackal could affect ecosystem equilibrium, e.g., through changed competition situations or predation pressure. In a niche modeling approach, we project the future climatic habitat suitability of the golden jackal in Europe in the context of whether climatic changes promote range expansion. We use an ensemble forecast based on six presence-absence algorithms to estimate the climatic suitability of C. aureus for different time periods up to the year 2100 considering different IPCC scenarios on future development. As predictor variables, we used six bioclimatic variables provided by worldclim. Our results clearly indicate that areas with climatic conditions analogous to those of the current core distribution area of the golden jackal in Europe will strongly expand towards the north and the west in future decades. Thus, the observed range expansion may be favored by climate change. The occurrence of stable populations can be expected in Central Europe. With regard to biodiversity and public health concerns, the population and range dynamics of the golden jackal should be surveyed. Correlative niche models provide a useful and frequently applied tool for this purpose. The results can help to make monitoring more efficient by identifying areas with suitable habitat and thus a higher probability of occurrence.

First Report of Alveolar Hydatid Disease (Echinococcus multilocularis) in a Golden Jackal (Canis aureus)

BACKGROUND

Alveolar hydatid disease caused by the tapeworm Echinococcus multilocularis is a parasitic disease present in the northern hemisphere. Echinococcus multilocularis is a parasite of canid and felid carnivores as definitive hosts, and small mammals, particularly rodents as intermediate hosts. Other animal species and humans can be aberrant intermediate hosts for this parasite. It is known that besides acting as definitive hosts, domestic dogs can rarely become infected with the larval form of E. multilocularis and develop alveolar echinococcosis; however, a role of wild canids as aberrant intermediate hosts has not been documented until now. To the best of our knowledge the present paper provides the first description of alveolar hydatid disease in a golden jackal (Canis aureus).

CASE PRESENTATION

Necropsy of the yearling female animal found a large, round, tumor-like mass, 20 cm in diameter, with a rough, multilobulated surface in the abdominal cavity, connected to the liver and omentum. On the cut surface this tumor-like lesion was multicystic, with a number of locular cavities filled with a clear yellowish to orange watery fluid and a large area of necrosis in the central part of the mass. Histopathology revealed multiple cystic spaces separated by fibrous sheaths and inflammatory cells-lymphocytes, plasma cells, neutrophil and eosinophil granulocytes. The cysts contained either pale, hyaline, eosinophilic laminar and occasionally amorphous, acellular, PAS-positive structures, or metacestodes with invaginated protoscolices. In several cysts round calcified bodies (calcareous corpuscles) were noted. Microscopic examination showed everted and inverted protoscolices which were attached to fragments of the brood capsule or free in hydatid fluid. By comparing consensus nucleotide sequence of 457 bp obtained by PCR reaction with sequences deposited in NCBI GenBank it is determined that it was 100% identical with E. multilocularis sequences under accession numbers MH259778.1, MH259776.1, AB668376.1, EU704124.1 and AB018440.2.

CONCLUSIONS

The present paper provides a proof that the golden jackal, besides being a definitive host, can also serve as the aberrant intermediate host for E. multilocularis.

Linguatula serrata in an imported dog in Germany: Single-case or emerging disease?

Linguatula serrata is a worm-like parasite with zoonotic potential that inhabits the nasal cavities of canids. Although most cases of linguatulosis are associated with unspecific and rather mild respiratory symptoms, cases of unusual infestations and severe courses in both animals and humans have been reported. In central and northern Europe, the pathogen used to appear only sporadically, however, within the last few years the number of detections has increased noticeably. In July 2020 an approximately nine-month-old dog, imported from Romania, was presented in a veterinary practice in Gotha, central Germany, due to persistent worsening cough. Despite antibiotic treatment the tussis became more severe until the dog expectorated multiple worm-like structures. Three of these specimens were sent to the Institute of Parasitology (Faculty of Veterinary Medicine, University of Leipzig, Leipzig) for morphological and genetic species identification. The latter was based on a 1000-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (cox1) and the complete nuclear 18S rRNA gene. The dog presented in this study suffered from a severe respiratory impairment caused by worm-like parasites inhabiting its upper respiratory tract. The detected parasites were morphologically identified as female specimens of the so-called tongue-worm L. serrata, which was confirmed by pairwise alignment and phylogenetic analysis of the produced sequences. We report an unusually severe case of L. serrata infection in an imported dog and discuss the spread of this potentially dangerous parasite in central and northern Europe.

Canine microfilaraemia in some regions of Iran

BACKGROUND

Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available.

METHODS

Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott's test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR). All of the PCR products were sequenced and phylogenetic analysis was performed.

RESULTS

In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country.

CONCLUSION

The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.

Dermal microfilariae of dogs, jackals and cats in different regions of Iran

Background

Due to the complexity of retrieving skin-dwelling microfilariae, filarioids of dogs presenting dermal microfilariae (e.g. Cercopithifilaria spp., Onchocerca lupi) are relatively unknown compared to Dirofilaria spp. and Acanthocheilonema spp. whose microfilariae circulate in the blood. Although Cercopithifilaria spp. and O. lupi filarioids are distributed worldwide, there is a paucity of information on their occurrence in Iran. The aim of this study was to investigate these filarioids in a large population of dogs from different regions of Iran.

Methods

From October 2018 to September 2020, skin biopsies were obtained from dogs housed in shelters (n = 557) and privately owned dogs (n = 26) in seven provinces of Iran (Hamedan, Kermanshah, Yazd, Mazandaran, Khuzestan, Lorestan, Esfahan), as well as from three road-killed jackals (Canis aureus) and three cats (Felis catus) in Hamedan province. The skin biopsies were first soaked in saline solution at room temperature overnight, and examined for dermal microfilariae under the microscope. Positive skin specimens and sediments were tested by PCR for a 304-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and amplicons were sequenced.

Results

Microfilariae of Cercopithifilaria spp. were found in skin biopsies of 32 of the 583 (5.5%) dogs tested, with infection rates of up to 25% in Kermanshah. No microfilariae were recovered from skin biopsy samples collected from dogs in Khorramabad and Ahvaz, nor from the examined jackals and cats. None of the privately owned dogs were found to be infected. Morphologic and morphometric characteristics of the microfilariae were consistent with C. bainae. Eighteen skin samples were positive for the cox1 gene, of which 15 sequences showed a nucleotide identity of 100% and three of 93.4% with the reference sequence of C. bainae available in GenBank (haplotype I; GenBank accession number: JF461457).

Conclusions

The data from this study broadens current knowledge on the geographical distribution of C. bainae in dogs in Middle Eastern countries. Further studies on different wild canine species in the country (e.g. jackal, fox, wolf) could provide further information on the epidemiology of these filarioids. A particular focus should be put on zoonotic O. lupi given the reports of its presence in human patients from this country.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-05141-2.

Toxoplasma gondii Genotypes Circulating in Serbia-Insight into the Population Structure and Diversity of the Species in Southeastern Europe, a Region of Intercontinental Strain Exchange

In Europe, Toxoplasma gondii lineage II is dominant, and ToxoDB#1 the most frequently occurring genotype. The abundance of lineage III genotypes varies geographically and lineage I are rare, yet present in several regions of the continent. Data on the T. gondii population structure in southeastern Europe (SEE) are scarce, yet necessary to appreciate the diversity of the species in Europe. To help fill this gap, we genotyped 67 strains from nine species of intermediate hosts in Serbia by MnPCR-RFLP, determined the population structure, and identified the genotypes using ToxoDB. A neighbor-joining tree was also constructed from the isolates genotyped on nine loci. While 42% of the total genotype population consisted of ToxoDB#1 and ToxoDB#2, variant genotypes of both lineages comprised 46% of the population in wildlife and 28% in domestic animals and humans. One genotype of Africa 4 lineage was detected in a human sample. Interestingly, the findings include one lineage III variant and one II/III recombinant isolate with intercontinental distribution, which appear to be moderately related to South American genotypes. Based on these findings, SEE is a region of underappreciated T. gondii genetic diversity and possible strain exchange between Europe and Africa.

First molecular description of Macracanthorhynchus hirudinaceus in wild boars from Italy with pathomorphological and epidemiological insights

Macracanthorhynchus hirudinaceus is a zoonotic parasite affecting suids worldwide which are the definitive hosts for this helminth species. Macracanthorhynchus hirudinaceus is of significant economic and management concern due to its pathogenicity, causing intestinal obstruction and perforation in the definitive hosts. Current study is the preliminary investigation from Sardinia, Italy, reporting the pathomorphological findings and molecular characterization of M. hirudinaceus in the wild boars (Sus scrofa meridionalis). A total of 59 wild boars were examined showing acanthocephalan infection in 8 (13.6%) animals. In total, 49 parasites were collected with a mean intensity of 6.1. Comparatively higher infection levels were observed for males (16.7%) and young boars (14.3%); however, these epidemiological differences were statistically non-significant. Histopathological examination revealed the presence of a variable number of nodules (∼5 mm) in the intestine of M. hirudinaceus infested animals surrounded by a hyperemic-hemorrhagic halo. Several parasites were recovered from the intestinal lumen attached by the means of characteristic hooks showing necrosis in muscle layers. A moderate number of plump reactive fibroblasts and lesser numbers of fibrocytes were embedded with and at the borders of the inflammatory nodules in a moderate amount of homogeneous intensely eosinophilic fibrillary material rupturing the cell membrane. For molecular characterization, six isolated worms were amplified for the partial mitochondrial cox1 gene showing distinct interindividual variations. This first pathological and molecular description from southern Europe provided new knowledge about the diffusion of M. hirudinaceus in wild boars, furthering the research into the origin and transmission status of M. hirudinaceus in endemic localities.

The golden jackal (Canis aureus) and the African swine fever pandemic: Its role is controversial but not negligible (a diet analysis study)

Background

In Europe, the African swine fever (ASF) pandemic mostly affects the environmental domain of health, which is a strongly human‐impacted ecosystem. However, the current control strategies focus solely on the wild boar and tend to disregard other epidemiologically relevant elements of the ecosystem.

Objectives

This study investigated the potential impact of the golden jackal on the surveillance effort and disease transmission.

Methods

For this reason, the authors analysed the content of 277 stomachs of this canid species within its westernmost inhabitant population, in order to determine the amount of suid remains, disposed.

Results

The findings confirmed that in a densely populated wild boar habitat, the main diet component of jackals was wild boar all the year round. The jackals disposed of 0.3–0.6 kg/km²/day offals that potentially contained suid remains. On the other hand, the scavenging activity removed the most important target objects on which the passive surveillance of ASF should be based.

Conclusions

This study cannot determine whether canid scavengers positively or negatively influence the control efforts; however, the impact of the jackal should not be disregarded. The results warn the necessity of a multidisciplinary approach to complex epidemiological situations within different ecosystems.

Intestinal helminth infections in the golden jackal (Canis aureus L.) from Vojvodina: Hotspot area of multilocular echinococcosis in Serbia

In the present study, 64 golden jackals were examined for intestinal helminths in three regions of Vojvodina, Serbia. Among the examined jackals 57.8% were infected with at least one parasite species. Using the intestinal scraping technique (SCT), eight species of intestinal helminths were found: Alaria alata (7.8%), Toxascaris leonina (9.4%), Toxocara canis (4.7%), Uncinaria stenocephala (20.3%), Echinococcus multilocularis (14.1%), Mesocestoides sp. (42.2%), Taenia pisiformis, and Taenia hydatigena (the overall prevalence of Taenia infection was 6.3%). To the best of our knowledge, this is the first report of T. leonina in jackals from Serbia. In comparison with the SCT results, coprological tests were less sensitive and specific for parasite identification, as only two nematode species (T. leonina and T. canis) as well as ancylostomatid and taeniid eggs were identified. The total prevalence of intestinal helminths was higher in males (71.9% males, 45% females), but the difference was not statistically significant (χ 2 = 3.76; P = 0.052). Co-infection with two species of intestinal helminths was found in 35% of the examined golden jackal individuals, three-species co-infection was demonstrated in 21.6%, whereas four-species co-infection was detected in 2.7% of the golden jackals examined. Echinococcus multilocularis has previously been recorded in jackals and foxes in Serbia, but only in Vojvodina. Our results corroborate the findings of previous studies, and indicate that the Vojvodina Province, more specifically the Srem region, is probably a high-risk area for E. multilocularis transmission to humans.

Positive selection on the MHC class II DLA-DQA1 gene in golden jackals (Canis aureus) from their recent expansion range in Europe and its effect on their body mass index

Background

In Europe, golden jackals (Canis aureus) have been expanding their range out of the southern and southeastern Balkans towards central Europe continually since the 1960s. Here, we investigated the level of functional diversity at the MHC class II DLA-DQA1 exon 2 in golden jackal populations from Bulgaria, Serbia, and Hungary. Specifically, we tested for positive selection on and geographic variation at that locus due to adaptation to supposedly regionally varying pathogenic landscapes. To test for potential fitness effects of different protein variants on individual body condition, we used linear modeling of individual body mass indexes (bmi) and accounted for possible age, sex, geographical, and climatic effects. The latter approach was performed, however, only on Serbian individuals with appropriate data.

Results

Only three different DLA-DQA1 alleles were detected, all coding for different amino-acid sequences. The neutrality tests revealed no significant but positive values; there was no signal of spatial structuring and no deviation from the Hardy–Weinberg equilibrium across the studied range of expansion. However, we found a signal of trans-species polymorphism and significant test results for positive selection on three codons. Our information-theory based linear modeling results indicated an effect of ambient temperature on the occurrence of individual DLA-DQA1 genotypes in individuals from across the studied expansion range, independent from geographical position. Our linear modeling results of individual bmi values indicated that yearlings homozygous for DLA-DQA1*03001 reached values typical for adults contrary to yearlings carrying other genotypes (protein combinations). This suggested better growth rates and thus a possible fitness advantage of yearlings homozygous for DLA-DQA1*03001.

Conclusions

Our results indicate a demographic (stochastic) signal of reduced DLA-DQA1 exon 2 variation, in line with the documented historical demographic bottleneck. At the same time, however, allelic variation was also affected by positive selection and adaptation to varying ambient temperature, supposedly reflecting geographic variation in the pathogenic landscape. Moreover, an allele effect on body mass index values of yearlings suggested differential fitness associated with growth rates. Overall, a combination of a stochastic effect and positive selection has shaped and is still shaping the variation at the studied MHC locus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12862-021-01856-z.

Paleoparasitology and archaeoparasitology in Iran: A retrospective in differential diagnosis

OBJECTIVE

This paper reviews paleo- and archaeoparasitology publications to date, from Iran. The primary focus is the importance of differential diagnosis and the crucial role of interdisciplinary collaborations among parasitologists and other specialists.

METHODS

All relevant articles and theses published in Iran through October 2020 are included and evaluated, with particular emphasis on the diagnostic process.

RESULTS

Archaeoparasitic studies in Iran have identified a number of parasites that provide insight into the past. Misidentification, however, due to incomplete differential diagnosis, remains an issue, as does incomplete description and problematic images.

CONCLUSIONS

Identification of paleoparasites to the species level must be supported with accurate morphology and morphometry. Rigorous differential diagnosis is essential. Caution must be exercised when interpreting observations of ova recovered from coprolites. In these instances, precise identification of host animals and aligning parasite ranges with host specificity is critical. The possibility of incidental parasite presence must be evaluated, including non-specificity of parasite tropisms, transport hosting, or contamination. Lastly, differential diagnosis must include consideration of intentional consumption of parasites. Thus, parasitological findings must be placed in geographical, historical, and cultural contexts.

SIGNIFICANCE

Archaeoparasitological research in Iran has elucidated the presence of faunal and human disease in the past and has, through this reevaluation of the published works, contributed to precise description and diagnosis of ova of roundworms, tapeworms, thorny-headed worms, and recognition of larval stages of tapeworms in recovered remains of mites.

Subcutaneous ticks: a first report in a golden jackal, and their absence in non-canid carnivores

BACKGROUND

Ticks are hematophagous arthropods which normally attach to the surface of the host's skin. Their aberrant presence in the subcutaneous tissue of a few carnivores, predominantly foxes, has been reported. However, there have been no reports of this phenomenon in other carnivores such as mustelids or golden jackals. Our aim was to investigate the host spectrum for this aberrant localization of ticks.

METHODS

Between 2015 and 2020, a total of 198 carcasses of 12 species of carnivore were examined by parasitological necropsy. When a subcutaneous tick was found, the nodule was removed, carefully dissected, and stored in ethanol. The morphological identification of the subcutaneous tick was carried out to species level.

RESULTS

A single subcutaneous tick was found in one carcass, that of a golden jackal (Canis aureus). The tick was identified as a female Ixodes ricinus. All the other carcasses were negative for the presence of subcutaneous ticks.

CONCLUSION

To our knowledge, this is the first report of a subcutaneous tick in a golden jackal. This finding broadens the host spectrum of subcutaneous ticks, and reinforces the idea that, among carnivores, this phenomenon only occurs in canids.

The occurrence of Echinococcus spp. in golden jackal (Canis aureus) in southwestern Hungary: Should we need to rethink its expansion?

Alveolar echinococcosis and cystic echinococcosis are severe zoonotic diseases caused by Echinococcus multilocularis and Echinococcus granulosus s.l. in Europe. To present knowledge, in the European continent, the most important definitive hosts of these parasites belong to the Canidae family. The golden jackal as an opportunistic mesopredator frequently preys on rodents including arvicolids and other easily available food resources, such as viscera and other carrion. By these reasons, the golden jackal can promote the maintenance of both Echinococcus multilocularis and Echinococcus granulosus s.l. Our investigation was conducted in the southwestern part of Hungary where one of the densest golden jackal populations exists. We examined altogether 173 golden jackal small intestines to determine the presence of Echinococcus multilocularis and Echinococcus granulosus s.l. After the molecular diagnostic procedure, we found 27 Echinococcus multilocularis-positive (prevalence: 15.6%; mean intensity: 664 worms) and three Echinococcus granulosus s.l. infected hosts (prevalence: 1.7%; mean intensity: 554.3 worms). We suggest the invasion of the golden jackal in Europe can enhance the spread of both Echinococcus multilocularis and Echinococcus granulosus s.l. This novel epidemiological situation can influence the geographical distribution of these helminths and the characteristics of their endemic in different host species, as well as in humans.

Biotic and abiotic factors influencing the prevalence, intensity and distribution of Eucoleus aerophilus and Crenosoma vulpis in red foxes, Vulpes vulpes from Romania

To understand the importance of host’ habitat choice in determining parasite burden, we studied the distribution of two helminth parasites of the red fox (Vulpes vulpes) in south-eastern Europe (Romania): Crenosoma vulpis and Eucoleus aerophilus, both widely distributed respiratory nematodes parasitic in various carnivores. Even though the life cycle and biology of the two nematodes follow a different pattern, both parasites appear to be co-distributed and often co-infect foxes with variable prevalences across their range. Between July 2016 and August 2018, 550 red foxes, V. vulpes were collected by hunters in different localities from 22 counties of Romania and examined by necropsy. All parasites found in the trachea and bronchial system were collected and preserved in 70% ethanol. We characterised red fox/parasite habitats using seven predictors (fragmentation, altitude, presence/absence of water surface, per cent cover of arable land/grassland/urbanized areas/forest cover/wetlands). Prevalence, abundance, intensity, and sex ratio were calculated and statistically analysed using the R software. Out of the 550 examined foxes, 76.2% were infected with lungworms. The overall prevalence was 32.0% for C. vulpis and 72.5% for E. aerophilus. The mean intensity of infection was 13.70 for C. vulpis 6.15 for E. aerophilus. For both nematodes, the prevalence was significantly higher in males than in females, and there was no influence of hosts’ age. No statistical differences were found for intensity and mean intensity in the case of infection with C. vulpis and E. aerophilus between age and sex categories. The abundance of C. vulpis showed a strong positive relationship with the presence of wetlands and habitat fragmentation. We found a significant correlation between the abundance of E. aerophilus and altitude, with foxes from higher elevations showing higher prevalences.

•

Crenosoma vulpis and Eucoleus aerophilus are widely distributed respiratory nematodes.

•

Prevalence, abundance, intensity were calculated and statistically analysed using R software Grs.

•

There was a significant correlation between the abundance of E. aerophilus and altitude.

•

The abundance of C. vulpis showed a strong positive relationship with the presence of wetland.

Rapid spread and emergence of heartworm resulting from climate and climate-driven ecological changes in Hungary

In Europe, Dirofilaria immitis persists mainly in the southern countries with a Mediterranean climate. Because spreading of heartworms from these countries towards the northern ones could be observed in the past decades, necropsy records of 4076 Hungarian dogs were reviewed for heartworm infections. The first autochthonous canine D. immitis case was detected on the Great Hungarian Plain in 2007. Until 2011, the number of heartworm infection cases was low, and these cases were restricted to a small part of the Great Hungarian Plain. Since 2012, the number of cases has increased considerably, and the rapid expansion of the parasite's geographic range could also be observed. Our retrospective study has revealed that most of the Hungarian territory became a heartworm endemic region, and the prevalence of infection greatly multiplied over the past 12 years. The establishment, rapid spread, and emergence of D. immitis may be mainly explained by the warming climate in Hungary. However, the partly climate-driven spread of the most important reservoir host in wildlife, the golden jackal (Canis aureus) from the Mediterranean Balkan Peninsula might have also played a significant role. This study is an example of the rapid spread and emergence of pathogens resulting from climate and climate-driven ecological changes. Because a continuous increase in the temperature and further dispersal of golden jackals in Europe are projected, further spread and emergence of heartworm can be expected. Similar spread and emergence of D. immitis could be observed in North America. It cannot be excluded that similar reasons (global warming and rapid dispersal and population growth of the most important wild canine reservoir host) are in the background on both continents.

Prevalence of Toxocara and Toxascaris infection among human and animals in Iran with meta-analysis approach

BACKGROUND

Toxocariasis is a worldwide zoonotic parasitic disease caused by species of Toxocara and Toxascaris, common in dogs and cats. Herein, a meta-analysis was contrived to assess the prevalence of Toxocara/Toxascaris in carnivore and human hosts in different regions of Iran from April 1969 to June 2019.

METHODS

The available online articles of English (PubMed, Science Direct, Scopus, and Ovid) and Persian (SID, Iran Medex, Magiran, and Iran Doc) databases and also the articles that presented in held parasitology congresses of Iran were involved.

RESULTS

The weighted prevalence of Toxocara/Toxascaris in dogs (Canis familiaris) and cats (Felis catus) was 24.2% (95% CI: 18.0-31.0%) and 32.6% (95% CI: 22.6-43.4%), respectively. Also, pooled prevalence in jackal (Canis aureus) and red fox (Vulpes vulpes) was 23.3% (95% CI: 7.7-43.2%) and 69.4% (95% CI: 60.3-77.8%), correspondingly. Weighted mean prevalence of human cases with overall 28 records was 9.3% (95% CI: 6.3-13.1%). The weighted prevalence of Toxocara canis, Toxocara cati, and Toxascaris leonina was represented as 13.8% (95% CI: 9.8-18.3%), 28.5% (95% CI: 20-37.7%) and 14.3% (95% CI: 8.1-22.0%), respectively.

CONCLUSION

Our meta-analysis results illustrate a considerable prevalence rate of Toxocara/Toxascaris, particularly in cats and dogs of northern parts of Iran. The presence of suitable animal hosts, optimum climate and close contact of humans and animals would have been the reason for higher seroprevalence rates of human cases in our region. Given the significance clinical outcomes of human Toxocara/Toxascaris, necessary measures should be taken.

Echinococcus multilocularis and Echinococcus granulosus in canines in North-Khorasan Province, northeastern Iran, identified using morphology and genetic characterization of mitochondrial DNA

Background

Canids are definitive hosts of Echinococcus multilocularis and Echinococcus granulosus. This study aimed to survey these two Echinococcus species in canids of North-Khorasan Province, northeastern Iran, using morphological criteria and genetic characterization of mitochondrial DNA.

Methods

The carcasses of 106 canids, namely 61 jackals (Canis aureus), 23 foxes (Vulpes vulpes), 19 dogs (Canis familiaris) and three wolves (Canis lupus) were collected from the study area in 2013–2014 and examined for Echinococcus species. Morphological features were assessed by microscopy of adult worms. For molecular characterization, DNA was extracted, mostly from the adult worms but also from eggs. DNA fragments of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) mitochondrial genes were amplified and sequenced. Sequences were aligned and compared with reference sequences. Intraspecific and interspecific diversity were calculated and phylogenetic analysis was performed.

Results

Overall, 9.4% of the canids (eight jackals and two foxes) were found infected with E. multilocularis by molecular methods, of which seven cases were also confirmed using morphological description of the adult worms. Echinococcus granulosus was found in 6.6% of the canines (four dogs, two jackals and one wolf) as determined by both molecular methods and adult cestode morphology. All E. granulosus isolates were identified as the G1 genotype. Comparative sequence analysis indicated 0–0.7% and 0% intraspecific divergence within E. granulosus isolates and 0% and 0–0.2% within E. multilocularis isolates for cox1 and nad1, respectively.

Conclusions

This study revealed the presence of E. multilocularis and E. granulosus in canids of North-Khorasan Province of Iran. Jackals were found infected with both E. multilocularis and E. granulosus, but infection with the former species was higher.

Insights on Spirocerca lupi, the Carcinogenic Dog Nematode

Spirocerca lupi is a nematode transmitted by dung beetles that infects domestic and wild canids in tropical and subtropical regions and is associated with neoplasia. It produces a distinctive pathology with the formation of esophageal nodules classified as inflammatory, preneoplastic, or neoplastic with metastasis to distant organs. Aberrant central nervous system migration of this nematode is also responsible for severe neurological manifestations. Reports of spirocercosis have increased over the last two decades showing spread of this canine helminth in five continents. S. lupi from different geographical locations is genetically distinct with two genotypes, genotype I from Africa, Asia, and Australia, and genotype II from Europe, and recently separated from Spirocerca vulpis, a new species described in red foxes from Europe.

Detection and genotyping of Toxoplasma gondii in wild canids in Serbia

To gain insight into the population structure of the protozoan parasite Toxoplasma gondii in wildlife in Serbia, multiplex nested PCR- RFLP was performed on T. gondii DNA positive samples of heart tissue of three wild canid species, including red foxes (Vulpes vulpes), golden jackals (Canis aureus) and grey wolves (Canis lupus). Out of 110 samples (28 red foxes, 72 golden jackals, 10 wolves), 30 (27.3%) were positive for T. gondii DNA, of which 24 were genotyped (nine red foxes, 13 golden jackals and two wolves). The results showed a large dominance of lineage II (n = 20, 83.4%) over lineage III (n = 4, 16.7%) strains. Lineage II comprised four archetypes, 14 variants and one which remained undetermined, while within lineage III there were three archetypes and one variant strain. However, a notable difference in diversity was observed among the examined canids, with eight (88.9%) of the nine strains detected in red foxes distinct, vs. six (46.1%) distinct strains of the 13 detected in golden jackals. Since anthropogenic food sources are a major reservoir of archetypal lineage II and III T. gondii strains, the results suggest that the golden jackal may be outcompeting the red fox, forcing it to hunt wild mammals and birds for sustenance, thereby increasing its chances of infection with variant strains. In addition to presenting the first data on the T. gondii population structure in wild canids in Serbia, this is the first report ever on T. gondii genotypes in golden jackals, a species with an increasing presence in Europe and another important reservoir of domestically circulating T. gondii strains.

Comparative Ecology of Bartonella and Brucella Infections in Wild Carnivores

Phylogenetic sister clades Bartonella and Brucella within the order Rhizobiales present some common biological characteristics as well as evident differences in adaptations to their mammalian reservoirs. We reviewed published data on Bartonella and Brucella infections in wild carnivores to compare the ecology of these bacteria in relatively similar host environments. Arthropod vectors are the main mechanism for Bartonella species transmission between mammalian hosts. The role of arthropods in transmission of Brucella remains disputed, however experimental studies and reported detection of Brucella in arthropods indicate potential vector transmission. More commonly, transmission of Brucella occurs via contact exposure to infected animals or the environment contaminated with their discharges. Of 26 species of carnivores tested for both Bartonella and Brucella, 58% harbored either. Among them were bobcats, African lions, golden jackals, coyotes, wolves, foxes, striped skunks, sea otters, raccoons, and harbor seals. The most common species of Bartonella in wild carnivores was B. henselae, found in 23 species, followed by B. rochalimae in 12, B. clarridgeiae in ten, and B. vinsonii subsp. berkhoffii in seven. Among Brucella species, Br. abortus was reported in over 30 terrestrial carnivore species, followed by Br. canis in seven. Marine carnivores, such as seals and sea lions, can host Br. pinnipedialis. In contrast, there is no evidence of a Bartonella strain specific for marine mammals. Bartonella species are present practically in every sampled species of wild felids, but of 14 Brucella studies of felids, only five reported Brucella and those were limited to detection of antibodies. We found no reports of Bartonella in bears while Brucella was detected in these animals. There is evident host-specificity of Bartonella species in wild carnivores (e.g., B. henselae in felids and B. vinsonii subsp. berkhoffii in canids). A co-adaptation of Brucella with terrestrial wild carnivore hosts is not as straightforward as in domestic animals. Wild carnivores often carry the same pathogens as their domesticated relatives (cats and dogs), but the risk of exposure varies widely because of differences in biology, distribution, and historical interactions.

Respiratory and Cardiopulmonary Nematode Species of Foxes and Jackals in Serbia

As part of routine monitoring of foxes (Vulpes vulpes) and jackals (Canis aureus) on the territory of Vojvodina province (northern Serbia), an analysis of respiratory and cardiopulmonary parasitic nematodes was conducted. Both host species harbored Eucoleus aerophilus, E. boehmi and Crenosoma vulpis, whereas Angiostrongylus vasorum was found only in foxes. A high prevalence of infection (72.6 %) was noted for E. aerophilus in foxes. The remaining parasite species occurred less frequently in both host species. In all species where it could be quantified, a high degree of parasite aggregation within host individuals was noted. Single species infections were most common, whereas two and three species infections occurred less frequently in both host species. The distribution of abundance of E. aerophilus was affected by host sex, with abundances higher in male foxes. Sampling site and year influenced abundance variation in E. boehmi.

Golden jackals (Canis aureus) as hosts for ticks and tick-borne pathogens in Serbia

The golden jackal (Canis aureus) is a medium-sized canid species native to Europe. This species is characterized by rapid large-scale expansion. A similar trend is also observed in Serbia, where the species is now distributed in more than a half of the territory. Although jackals prefer habitats in human-dominated landscapes, these animals have not been studied well enough from an eco-epidemiological point of view, and little is known about their potential for carrying zoonotic pathogens. In a study conducted during a three-year period (01/2010-02/2013), a total of 216 hunted or road-killed golden jackals were collected from 10 localities in Serbia. Ticks, when present, were removed, and after necropsy, spleen samples were collected from each animal. All tick and spleen samples were tested for the DNA of bacterial and protozoan tick-borne pathogens (Borrelia species, Bartonella species, Rickettsia species, Anaplasma species, Coxiella burnetii, Francisella species and Babesia species) by multiplex real-time PCR, conventional PCR and sequencing analyses. The DNA of Babesia canis was detected in nine out of 216 (4.2%) spleen samples, and two samples (0.9%) tested positive for Anaplasma phagocytophilum. In 118 ticks collected from jackals, the DNA of two Babesia species (Ba. canis and Ba. microti), three Borrelia species (Bo. garinii, Bo. valaisiana, and Bo. lusitaniae) and A. marginale was detected. From the aspect of public health surveillance, the potential role of the golden jackal in the maintenance of vector-borne zoonotic pathogens in Serbia must be considered, and further eco-epidemiological studies should be performed to determine the precise role of this animal species in zoonotic disease transmission cycles.

High mitochondrial sequence divergence in synanthropic flea species (Insecta: Siphonaptera) from Europe and the Mediterranean

Background

Adult fleas are haematophagous ectoparasites of warm-blooded vertebrates, particularly mammals. Among them, the cat flea (Ctenocephalides felis) and the human flea (Pulex irritans) have high veterinary-medical significance, owing to their cosmopolitan distribution and role in the transmission of important vector-borne pathogens. While the taxonomy of Ct. felis has been investigated on a morphological basis during the past decades, its molecular-phylogenetic analyses have been only recently conducted. This study expands the knowledge on Ct. felis from hitherto less studied geographical regions, and includes representatives from additional flea families, less investigated with molecular approaches.

Methods

Fleas were collected in four countries of the Mediterranean Basin (Croatia, Italy, Malta and Israel), as well as in Hungary, from domestic and wild carnivores, rodents and humans. The DNA extracts of representative fleas (n = 148), belonging to ten species of eight genera, were used for PCR amplification of part of their cytochrome c oxidase subunits 1, 2 (cox1, cox2) and 18S rRNA genes, followed by sequencing and phylogenetic analyses.

Results

The majority (65.6%) of Ct. felis felis cox2 sequences showed 99.4–100% similarity to each other (haplogroup A), whereas those from Malta and Israel had 98.1–98.7% sequence similarity (haplogroup B), and a third sequence from Israel (haplotype C) had as low as 96.3% sequence similarity in comparison with a reference sequence from group “A”. Except for the shape of the head, no consistent morphological differences (e.g. in chaetotaxy) were found between haplogroups “A” and “C”. Haplotypes of Ct. canis were genetically more homogenous, with 99.6–100% sequence similarity to each other. However, when P. irritans collected from humans was compared to those from three species of wild carnivores, these only had 96.6% cox2 similarity. The mouse flea, Leptopsylla segnis and the northern rat flea, Nosopsyllus fasciatus were both shown to have haplotypes with low intraspecific cox2 similarities (96.2 and 94.4%, respectively). Taken together, differences between mitochondrial lineages within four flea species exceeded that observed between two Chaetopsylla spp. (which had 97.3% cox2 similarity). The topologies of cox1 and cox2 phylogenetic trees were in line with relevant sequence comparisons. Conversely, 18S rRNA gene analyses only resolved differences above the species level.

Conclusions

Ctenocephalides felis felis, P. irritans, L. segnis and N. fasciatus were shown to have such a high level of mitochondrial gene heterogeneity, that the uniformity of these flea taxa should be reconsidered. Although the present results are limited (especially in the case of L. segnis and N. fasciatus), there appears to be no geographical or host restriction, which could explain the divergence of these genetic lineages.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2798-4) contains supplementary material, which is available to authorized users.