Hepatozoon martis n. sp. (Adeleorina: Hepatozoidae): Morphological and pathological features of a Hepatozoon species infecting martens (family Mustelidae)

High-throughput screening of pathogens in Ixodes ricinus removed from hosts in Lombardy, northern Italy

Ticks are important vectors of many pathogens in Europe, where the most impactful species is Ixodes ricinus. Recently, the geographical distribution of this tick species has been expanding, resulting in an increased risk of human exposure to tick bites. With the present study, we aimed to screen 350 I. ricinus specimens collected from humans and wild animals (mainly ungulates), to have a broader understanding of the tick-borne pathogens circulating in the Lombardy region, in northern Italy. To do so, we took advantage of a high-throughput real-time microfluidic PCR approach to screen ticks in a cost-effective and time-saving manner. Molecular analysis of the dataset revealed the presence of four genera of bacteria and two genera of protozoa: in ungulates, 77 % of collected ticks carried Anaplasma phagocytophilum, while the most common pathogen species in ticks removed from humans were those belonging to Borrelia burgdorferi sensu lato group (7.6 %). We also detected other pathogenic microorganisms, such as Rickettisa monacensis, Rickettsia helvetica, Neoehrlichia mikurensis, Babesia venatorum, and Hepatozoon martis. Besides, we also reported the presence of the pathogenic agent Borrelia miyamotoi in the area (1.4 % overall). The most common dual co-infection detected in the same tick individual involved A. phagocytophilum and Rickettsia spp. Our study provided evidence of the circulation of different tick-borne pathogens in a densely populated region in Italy.

Diversity of Hepatozoon species in wild mammals and ticks in Europe

BACKGROUND

Hepatozoon spp. are tick-borne parasites causing subclinical to clinical disease in wild and domestic animals. Aim of this study was to determine Hepatozoon prevalence and species distribution among wild mammals and ticks in Europe.

METHODS

Samples of wild mammals and ticks, originating from Austria, Bosnia and Herzegovina, Croatia, Belgium and the Netherlands, were tested with PCR to amplify a ~ 670-bp fragment of the small subunit ribosomal RNA gene.

RESULTS

Of the 2801 mammal samples that were used for this study, 370 (13.2%) tested positive. Hepatozoon canis was detected in samples of 178 animals (3 Artiodactyla, 173 Carnivora, 1 Eulipotyphia, 1 Lagomorpha), H. martis in 125 (3 Artiodactyla, 122 Carnivora), H. sciuri in 13 (all Rodentia), Hepatozoon sp. in 47 (among which Hepatozoon sp. Vole isolate, all Rodentia) and H. ayorgbor in 4 (all Rodentia). Regarding origin, 2.9% (6/208) tested positive from Austria, 2.8% (1/36) from Bosnia and Herzegovina, 14.6% (173/1186) from Croatia and 13.9% (190/1371) from Belgium/the Netherlands. Of the 754 ticks collected, 0.0% (0/35) Hyalomma sp., 16.0% (4/25) Dermacentor spp., 0.0% (0/23) Haemaphysalis spp., 5.3% (24/50) Ixodes and 1.4% (3/221) Rhipicephalus spp. tested positive for Hepatozoon (4.2%; 32/754), most often H. canis (n = 22).

CONCLUSIONS

Hepatozoon canis is most present in mammals (especially in Carnivora such as gray wolves and golden jackals) and ticks, followed by H. martis, which was found merely in stone martens and pine martens. None of the rodent-associated Hepatozoon spp. were detected in the ticks, suggesting the possible implication of other arthropod species or non-vectorial routes in the transmission cycle of the hemoprotozoans in rodents. Our findings of H. canis in ticks other than R. sanguineus add to the observation that other ticks are also involved in the life cycle of Hepatozoon. Now that presence of Hepatozoon has been demonstrated in red foxes, gray wolves, mustelids and rodents from the Netherlands and/or Belgium, veterinary clinicians should be aware of the possibility of spill-over to domestic animals, such as dogs.

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.

An epidemiological study in wild carnivores from Spanish Mediterranean ecosystems reveals association between Leishmania infantum, Babesia spp. and Hepatozoon spp. infection and new hosts for Hepatozoon martis, Hepatozoon canis and Sarcocystis spp

The aetiology and epidemiology of vector borne apicomplexan Babesia and Hepatozoon and kinetoplastid Leishmania infantum infections in wildlife have not been explored in wide areas of southern Spain. We investigated these infections in 151 wild carnivores, including foxes, badgers, beech martens, hedgehogs, wild cats, Egyptian mongooses, otters, genets and racoons. Overall, Hepatozoon, Babesia and L. infantum infections were detected in 68%, 48% and 23% of the wild animals surveyed, respectively. L. infantum-infected wildlife were more likely to be also infected with the apicomplexan Hepatozoon and Babesia spp. compared to the non-infected counterparts (p < .05). We report for the first time Hepatozoon martis in badgers and wild cats and H. canis in beech martens, and a Babesia sp. in wild cats from Spain. Our results also indicate the widespread distribution of H. canis in foxes (91%) and beech martens (13%), H. martis in beech martens (81%), wild cats (20%) and badgers (13%), H. felis in wild cats (60%), B. vulpes in foxes (64%), Babesia sp. type A closely related to B. vulpes, in badgers (58%) and Babesia sp. in wild cats (20%). Moreover, L. infantum infection was found in foxes (29%), beech martens (13%), badgers (8%) and 1/3 Egyptian mongooses. We also detected Cytauxzoon sp. in a wild cat and the first Sarcocystis sp. in a genet. This study provided evidence of increased risk of L. infantum infection in wildlife animals co-infected with Babesia spp. or Hepatozoon spp. and indicated that these infections are widespread in wild carnivores from Spanish Mediterranean ecosystems.

Molecular characterisation and morphological description of two new species of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina: Hepatozoidae) infecting leukocytes of African leopards Panthera pardus pardus (L.)

Background

The African leopard Panthera pardus pardus (L.) is currently listed as a vulnerable species on the IUCN (International Union for the Conservation of Nature) red list of threatened species due to ongoing population declines. This implies that leopard-specific parasites are also vulnerable to extinction. Intracellular apicomplexan haemoparasites from the genus Hepatozoon Miller, 1908 have been widely reported from wild carnivores in Africa, including non-specific reports from leopards. This paper describes two new haemogregarines in captive and wild leopards from South Africa and provides a tabular summary of these species in relation to species of Hepatozoon reported from mammalian carnivores.

Methods

Blood was collected from nine captive and eight wild leopards at various localities throughout South Africa. Thin blood smears were Giemsa-stained and screened for intraleukocytic haemoparasites. Gamont stages were micrographed and morphometrically compared with existing literature pertaining to infections in felid hosts. Haemogregarine specific primer set 4558F and 2733R was used to target the 18S rRNA gene for molecular analysis. Resulting sequences were compared to each other and with other available representative mammalian carnivore Hepatozoon sequences from GenBank.

Results

Two species of Hepatozoon were found in captive and wild leopards. Of the 17 leopards screened, eight were infected with one or both morphologically and genetically distinct haemogregarines. When compared with other species of Hepatozoon reported from felids, the two species from this study were morphometrically and molecularly distinct. Species of Hepatozoon from this study were observed to exclusively parasitize a particular type of leukocyte, with Hepatozoon luiperdjie n. sp. infecting neutrophils and Hepatozoon ingwe n. sp. infecting lymphocytes. Phylogenetic analysis showed that these haemogregarines are genetically distinct, with Hepatozoon luiperdjie n. sp. and Hepatozoon ingwe n. sp. falling in well supported separate clades.

Conclusions

To our knowledge, this is the first morphometric and molecular description of Hepatozoon in captive and wild African leopards in South Africa. This study highlights the value of using both morphometric and molecular characteristics when describing species of Hepatozoon from felid hosts.

Molecular survey of tick-borne pathogens reveals a high prevalence and low genetic variability of Hepatozoon canis in free-ranging grey wolves (Canis lupus) in Germany

Wild carnivores are important hosts for ixodid ticks and presumed reservoirs for several tick-borne pathogens (TBPs) of medical and veterinary importance. However, little is known about the role that the European grey wolf (Canis lupus) plays in the enzootic cycle of TBPs. The recent recolonization of Central European lowland, including some regions in Germany, by the grey wolf, opened up an excellent opportunity for studying the impact of the wolf population on pathogen diversity and transmission dynamics. Therefore, in the present study, we investigated spleen samples collected from 276 grey wolves in 11 federal states in Germany for common TBPs by molecular methods. In total, 127 grey wolves (46.0 %) were found to be positive for Hepatozoon canis. Only two genetic variants of this protozoan parasite (herein designated as G1 and G2) were found to circulate among the grey wolves, which can be potentially shared between populations of domestic and other wild carnivores in the country. Two grey wolves were positive for Anaplasma phagocytophilum (0.7 %), and both were co-infected with H. canis G1 genotype. The presence of other pathogens could not be confirmed by PCR and sequencing. This study represents the first one reporting H. canis in a grey wolf population worldwide, and it provides highly relevant information, which may contribute to a better understanding of the epidemiology of TBPs and the pathogen transmission dynamics among the reintroduced population of grey wolves and other carnivores.

Turkey tick news: A molecular investigation into the presence of tick-borne pathogens in host-seeking ticks in Anatolia; Initial evidence of putative vectors and pathogens, and footsteps of a secretly rising vector tick, Haemaphysalis parva

This Turkey-based study investigated the presence of various tick-borne microorganisms in a broad-range of host-seeking ticks (n = 1019) that exhibit both hunter and ambusher characteristics. All collected ticks were analyzed individually via PCR-sequencing, resulting in the identification of 18 different microorganisms: six Babesia spp., including one putative novel species (Ba. occultans, Ba. crassa, Ba. rossi, Babesia sp. tavsan1, Babesia sp. tavsan2, and Babesia sp. nov.); six SFG rickettsiae (Ri. aeschlimannii, Ri. s. mongolitimonae, Ri. slovaca, Ri. raoultii, Ri. monacensis, and Ri. hoogstraalii); two Borrelia burgdorferi sensu lato spp. (Bo. afzelii and Bo. lusitaniae); two unnamed Hepatozoon spp.; Theileria annulata; and Hemolivia mauritanica. This provided evidence for the natural transstadial survival of these tick-borne microorganisms in adult ticks (in addition a nymph) of Turkey. Surprisingly, this study determined the presence of five different microorganisms (Ba. crassa, Ba. rossi, Babesia sp. Ucbas, Hepatozoon sp., and Ri. hoogstraalii) in host-seeking Haemaphysalis parva adults, for which poor data exist on its vectorial competence. Therefore, this study provides important data indicating the potential vectorial capacity of Ha. parva. This study also revealed the presence of the close ecological and evolutionary relationships between two important vector ticks, Hyalomma marginatum and Hy. aegyptium and determined genetic variations (distinct phylogenetic divergences inside the main clades) in some pathogenic SFG rickettsiae that are found in these ticks. Additionally, the presence of two Babesia species described very recently in hares with unknown vectors, namely Babesia sp. tavsan1 and Babesia sp. tavsan2, were detected for the first time in ticks. Finally, two unnamed Hepatozoon spp. were detected in Haemaphysalis ticks and their phylogenetic positions were demonstrated. Consequently, this study provides important data on the diversity of tick-borne microorganisms in host-seeking ticks and on potentially novel microorganisms (Babesia and Hepatozoon species) and their possible vectors (Ha. parva, Ha. sulcata, Hy. aegyptium, Hy. marginatum, and Rh. turanicus).

Genetic diversity of Hepatozoon (Apicomplexa) from domestic cats in South Africa, with a global reassessment of Hepatozoon felis diversity

Genetic diversity within partial 18S rRNA sequences from Hepatozoon protozoan parasites from domestic cats in South Africa was assessed and compared against published data to assess global biogeographic patterns. Multiple distinct haplotypes of Hepatozoon felis were identified, as well as an unrelated Hepatozoon lineage. Hepatozoon felis genetic diversity globally is very high, indicating a likely complex of species. The recently described Hepatozoon apri from wild boars is closely related to some lineages of H. felis. Sarcocystis and Babesia parasites were also detected. Since Hepatozoon felis is apparently a species complex, potential differences between genetically distinct forms need to be assessed. The finding of an unrelated Hepatozoon indicates that felids can be infected by more species of Hepatozoon than currently known, and that trophic interactions may increase the number of Hepatozoon species found in carnivores. Genetic screening again is demonstrated to identify previously unrecognised parasites from vertebrate hosts.

Molecular detection of Hepatozoon felis in cats from Maio Island, Republic of Cape Verde and global distribution of feline hepatozoonosis

Background

Vector-borne diseases are emerging worldwide and have an important zoonotic relevance. In the last few years, the interest in vector-borne pathogens in cats has increased. However, studies on feline vector-borne pathogens on tropical islands are lacking. Islands differ from continental countries because they have an enclosed population of animals, with all year presence of the vectors and, most often, without vector control measures. This study focused on the molecular identification and phylogenetic analysis of vector-borne pathogens in autochthonous cats with a mixed indoor–outdoor lifestyle from Maio Island, Cape Verde archipelago.

Methods

Blood samples were collected from 80 asymptomatic cats, representing almost a quarter of the total cat population of the island. The presence of DNA of protozoa of the genus Hepatozoon and bacteria belonging to family Anaplasmataceae and to genus Bartonella was assessed by PCR and phylogenetic analysis was conducted. Statistical analysis was performed to identify risk factors associated with infection. For feline hepatozoonosis, a worldwide dataset of Hepatozoon felis sequences retrieved from mammal species and vectors along with Hepatozoon spp. sequences retrieved from felids was generated, phylogenetically analyzed and the geographical and host distribution was assessed.

Results

Hepatozoon felis genotype I was identified in 12 (15%) cats from Maio Island whereas none of the cats were PCR positive for the other pathogens tested. No significant association of H. felis infection with age, sex, location or presence of vectors was observed by statistical analysis in Cape Verde’s cats. Phylogenetic analysis on the worldwide dataset of feline Hepatozoon sequences showed two significant distinct clades for H. felis genotype I and II. Different geographical distributions were assessed: H. felis genotype I was the only genotype found in Africa and has been reported worldwide, with the exception of Japan and Brazil where only H. felis genotype II has been reported.

Conclusions

The identification of H. felis genotype I in cats in Maio Island highlights the need to further investigate the significance of H. felis genotypes and to clarify the epidemiological aspects of this infection.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3551-3) contains supplementary material, which is available to authorized users.

First Report of a Novel Hepatozoon sp. in Giant Pandas (Ailuropoda melanoleuca)

The first report of giant pandas (Ailuropoda melanoleuca) infected with a novel Hepatozoon species is presented. An intraleukocytic parasite was detected via routine blood smear from a zoo-housed giant panda at the National Zoological Park. Ribosomal DNA sequences indicated a previously undescribed Hepatozoon species. Phylogenetic and distance analyses of the sequences placed it within its own branch, clustered with Old World species with carnivore (primarily ursid and mustelid) hosts. Retrospective and opportunistic testing of other individuals produced additional positive detections (17/23, 73.9%), demonstrating 100% prevalence (14/14) across five institutions. All animals were asymptomatic at time of sampling, and health implications for giant pandas remain unknown.