Morphology of Pholeoixodes species associated with carnivores in the western Palearctic: Pictorial key based on molecularly identified Ixodes (Ph.) canisuga, I. (Ph.) hexagonus and I. (Ph.) kaiseri males, nymphs and larvae

Island hitchhikers: pathogen agents of Madeira and Azores ticks

Ticks are blood-sucking arthropods that can transmit pathogens to their host. As insular ecosystems can enhance tick-host interactions, this study aimed to understand tick diversity, pathogen presence, and their respective associations in the Azores and Madeira archipelagos. Unfed or partially engorged ticks (n = 120) were collected from 58 cats and dogs in the Azores (n = 41 specimens) and Madeira (n = 79 specimens) from November 2018 to March 2019. Vector identification was based on morphology and molecular criteria. For pathogen sequencing, 18S gene fragment for Babesia/Hepatozoon and gltA for Rickettsia were performed. Sequence data was explored using BLAST and BLAST and phylogenetic inference tools. In the Azores, Ixodes hexagonus, I. ventalloi, and Rhipicephalus sanguineus (n = 6; 14.6%, n = 6; 14.6%, and n = 29; 70.7% respectively) were found and in Madeira I. ricinus and R. sanguineus (n = 78, 98.7%; and n = 1, 1.3%; respectively) were identified. Tick COI markers confirmed species highlighting confirmation of R. sanguineus s.s. and genotype A of I. ventalloi. In the Azores Islands, the detected Rickettsia massiliae was linked to R. sanguineus (dogs and cats) and I. hexagonus (dogs), and in Madeira Island, R. monacensis (dogs) and Hepatozoon silvestris (cats) were found associated with I. ricinus. Further, I. ventalloi presence in the Azores expands west its known range, and Hepatozoon silvestris in Madeira may suggest that I. ricinus could have a role as a potential vector. Finally, as R. massiliae and R. monacensis presence underlines public health risks, surveillance by health authorities is crucial as pathogen-tick interactions may drive disease spread, therefore monitoring remains pivotal for disease prevention.

The hidden threat: Exploring the parasite burden and feeding habits of invasive raccoon dogs (Nyctereutes procyonoides) in central Europe

Originally from Asia, the raccoon dog Nyctereutes procyonoides is an invasive alien species in Europe, listed since 2019 on the List of invasive alien species of Union concern. The raccoon dog is considered to have negative impact on native biodiversity, as well as a crucial role in hosting and transmitting diverse parasites and pathogens of human and veterinary importance. In the present study, stomach content analyses and parasitological examinations were performed on 73 raccoon dogs from Germany. In addition, fecal samples were analyzed. The results of the study confirm the assumption that the examined raccoon dogs were infested with a various ecto- and endoparasite fauna. A total of 9 ecto- and 11 endoparasites were detected, with 6 of the endoparasites having human pathogenic potential. Trichodectes canis (P = 53.42%), Toxocara canis (P = 50.68%) and Uncinaria stenocephala (P = 68.49%) were the most abundant parasite species. The stomach contents consisted of approximately one-third vegetable and two-thirds animal components, composed of various species of amphibians, fish, insects, mammals and birds. Among them were specially protected or endangered species such as the grass frog Rana temporaria. The study shows that the raccoon dog exerts predation pressure on native species due to its omnivorous diet and, as a carrier of various parasites, poses a potential risk of infection to wild, domestic and farm animals and humans.

Molecular characterisation of three Ixodes (Pholeoixodes) species (Ixodida, Ixodidae) and the first record of Ixodes (Pholeoixodes) kaiseri from Slovakia

A study of ticks on wildlife was carried out in the area of Levice, Bratislava, Stupava, and Vrbovce (south-western Slovakia) during 2021 and 2022. Overall, 512 ticks were collected from 51 individuals of six wild mammalian species. Eight tick species were identified, namely Dermacentorreticulatus, D.marginatus, Haemaphysalisinermis, H.concinna, Ixodesricinus, I.hexagonus, and two Ixodes spp. Ixodeshexagonus were collected from northern white-breasted hedgehogs (Erinaceusroumanicus), females belonging to Ixodes spp. were collected from red fox (Vulpesvulpes) and nymphs from European badger (Melesmeles). Ixodeshexagonus and the Ixodes spp. were identified morphologically and molecularly based on sequences of fragments of two mitochondrial genes, COI and 16S rRNA. Molecular analysis of Ixodes spp. confirmed the identity of Ixodeskaiseri Arthur, 1957 and I.canisuga (Johnston, 1849). Sequence analyses show that the I.kaiseri isolate from Slovakia is identical to I.kaiseri isolates from Romania, Poland, Germany, Turkey, and Croatia. We demonstrate for the first time the presence of I.kaiseri in Slovakia using both morphological and molecular methods.

Phylogenetic analyses of Ixodes rugicollis with notes on its morphology in comparison with Ixodes cornutus

BACKGROUND

The subgenus Pholeoixodes contains Ixodes species typically associated with birds that nest in cavities or with carnivorous mammals that are burrow-dwelling. Among ticks infesting the latter, Ixodes rugicollis is regarded as the rarest species in the western Palearctic. Despite the unique morphology of this species, its identification (especially of subadult stages) is difficult, and molecular-phylogenetic data to offer other diagnostic methods and a better understanding of its taxonomy are not available.

METHODS

In this study, a female and a male of I. rugicollis were collected in Romania. The female was compared morphologically to another female of this species collected in France and to the lectotype of Ixodes cornutus (from Tajikistan), which has similar morphology and host association. Following DNA extraction, two mitochondrial (cytochrome c oxidase subunit I: cox1 and the 16S rRNA gene) and two nuclear genetic markers (18S and 28S rRNA genes) of I. rugicollis were amplified and analyzed in a phylogenetic context.

RESULTS

Females of I. rugicollis and I. cornutus differed in the shape of their palps, scutum and areae porosae and the size of peritremes, but they were similar in palpal setal length, dental formula and arrangement of anal setae. Measurements of two I. rugicollis females examined were not less different from each other than from I. cornutus. Phylogenetically, I. rugicollis clustered with other members of its subgenus. The topology of all trees showed the position of bat-associated tick species of the subgenus Eschatocephalus among Pholeoixodes species.

CONCLUSIONS

For the first time to our knowledge, this study provides high-resolution digital pictures of male and female I. rugicollis as well as corresponding molecular data. Morphological comparison of this species with I. cornutus could not resolve uncertainties in the validity of the latter species, which can only be accomplished after collecting new specimens of I. cornutus and consequent molecular comparisons. This study includes the first comprehensive molecular-phylogenetic analysis of western Palearctic Pholeoixodes species based on both nuclear and mitochondrial genetic markers and including I. rugicollis. The results of these confirm the phylogenetic position of subgenus Eschatocephalus within Pholeoixodes, justifying the need to merge them to comply with the taxonomic criterion of monophyly.

Molecular epidemiological study on ticks and tick-borne protozoan parasites (Apicomplexa: Cytauxzoon and Hepatozoon spp.) from wild cats (Felis silvestris), Mustelidae and red squirrels (Sciurus vulgaris) in central Europe, Hungary

Background

Among live wild mammals adapted to urban and peri-urban habitats in Europe, members of the families Felidae, Mustelidae and Sciuridae deserve special attention as pathogen reservoirs because all of these families include members that are kept as pets. We report here the results of our study on two important groups of tick-borne protozoan parasites in ticks and tissues of wild cats, mustelids and red squirrels.

Methods

DNA was extracted from the tissues of carnivores (wild cats, mustelids; n = 16) and red squirrels (n = 4), as well as from ixodid ticks (n = 89) collected from these hosts. These DNA extracts were screened for piroplasms and Hepatozoon spp. using conventional PCR analysis and sequencing. In addition, 53 pooled samples of 259 questing Haemaphysalis concinna ticks were evaluated for the presence of Hepatozoon DNA, followed by phylogenetic analyses.

Results

One wild cat was found to be coinfected with Cytauxzoon europaeus and a new genotype of Hepatozoon felis, and two additional wild cats were infected with H. felis from a different phylogenetic group. In mustelids, Hepatozoon martis and two further Hepatozoon genotypes were detected. The latter clustered separately, close to others reported from eastern Asia. In addition, Hepatozoon sciuri was detected in red squirrels. Morphologic and molecular analyses verified eight tick species. One wild cat was infected with a H. felis genotype that was significantly different from that in Ixodes ricinus females infesting this cat. Only three pools of questing H. concinna nymphs tested positive for Hepatozoon, one of which contained H. martis.

Conclusions

This study provides the first evidence of the occurrence of any Cytauxzoon species and of three Hepatozoon species in Hungary. In addition to H. martis, two further mustelid-associated Hepatozoon genotypes were detected, one of which was new in terms of phylogenetic and broader geographical contexts. This may be the first indication that H. felis genotypes from both of its phylogenetic groups occur in Europe. This also appears to be the first evidence of H. felis and C. europaeus coinfection in felids in Europe, and of autochthonous H. felis infection in wild cats north of the Mediterranean Basin. New tick–host associations were also observed in this study. Based on the results, H. felis and H. martis might survive transstadially in I. ricinus and H. concinna, respectively.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05271-1.

Atlas of ticks (Acari: Argasidae, Ixodidae) in Germany

An updated and increased compilation of georeferenced tick locations in Germany is presented here. This data collection extends the dataset published some years ago by another 1448 new tick locations, 900 locations of which were digitized from literature and 548 locations are published here for the first time. This means that a total of 3492 georeferenced tick locations is now available for Germany. The tick fauna of Germany includes two species of Argasidae in the genera Argas and Carios and 19 species of Ixodidae in the genera Dermacentor, Haemaphysalis, and Ixodes, altogether 21 tick species. In addition, three species of Ixodidae in the genera Hyalomma (each spring imported by migratory birds) and Rhipicephalus (occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 23 tick species are depicted in maps. The occurrence of the one remaining tick species, the recently described Ixodes inopinatus, is given at the level of the federal states. The most common and widespread tick species is Ixodes ricinus, with records in all 16 federal states. With the exception of Hamburg, Dermacentor reticulatus was also found in all federal states. The occurrence of the ixodid ticks Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus and I. inopinatus were documented in at least 11 federal states each. The two mentioned argasid tick species were also documented in numerous federal states, the pigeon tick Argas reflexus in 11 and the bat tick Carios vespertilionis in seven federal states. The atlas of ticks in Germany and the underlying digital dataset in the supplement can be used to improve global tick maps or to study the effects of climate change and habitat alteration on the distribution of tick species.