Keds, the enigmatic flies and their role as vectors of pathogens

Molecular and morphological analysis revealed a new Lipoptena species (Diptera: Hippoboscidae) in southern Spain harbouring Coxiella burnetii and bacterial endosymbionts

Hippoboscid flies (Diptera: Hippoboscidae) are obligate bloodsucking ectoparasites of animals. In Europe, limited research has been conducted on this family until the recent introduction of the deer ked Lipoptena fortisetosa Maa, 1965. A new species of the genus Lipoptena, Lipoptena andaluciensis sp. nov., was found in southern Spain after extensive sampling with carbon-dioxide baited suction traps. A total of 52 females and 32 males were collected at 29 out of 476 sites examined over eight months in 2023. Lipoptena andaluciensis sp. nov. was characterized morphologically and molecularly. The new Lipoptena species can be differentiated from the closely related L. fortisetosa by size, chaetotaxy of the dorsal and ventral thorax, abdominal plates, and genitalia. Based on DNA-barcoding, our specimens showed the highest similarity with Melophagus ovinus (Linnaeus, 1758) (88.4 %) and with L. fortisetosa (86-88 %). Individual screening of Lipoptena specimens (n = 76) for seven important zoonotic pathogens such as bacteria (Anaplasmataceae family: Bartonella spp., Borrelia spp., Coxiella burnetii and Rickettsia spp.) and protozoans (Babesia spp. and Theileria spp.) by conventional PCR and RT-PCR was performed. DNA of C. burnetii was detected in one specimen, while two other specimens harboured Anaplasmataceae (Wolbachia spp., 100 % homology and another endosymbiont probably related to Arsenophonus sp., 95.3 % homology, respectively), all representing the first records of these bacteria in the Lipoptena spp. from Europe. Carbon dioxide traps probed its effectiveness as a reliable passive method for keds surveillance. Our study highlights the existence of a new Lipoptena species, presumably widely distributed in southern Spain. The role of this species in the transmission cycle of pathogens of medical-veterinary relevance needs to be considered in the area.

Ornithomya biloba, Pseudolynchia garzettae and Pseudolynchia canariensis (Diptera: Hippoboscidae): three new United Kingdom colonists and potential disease vectors

In the northern hemisphere, many species' ranges are shifting northwards with climate change. Here I present evidence, from the first large-scale citizen science study of the Hippoboscidae in the United Kingdom, for the colonisation of the United Kingdom by three species of Diptera in the family Hippoboscidae, which are obligate ectoparasites of birds. The Swallow Louse Fly, Ornithomya biloba; the Nightjar Louse Fly, Pseudolynchia garzettae and the Pigeon Louse Fly, Pseudolynchia canariensis were previously considered to be vagrants from more southerly latitudes but the presence of a pair taken possibly in the act of copulation, gravid females and the increase in numbers of the various species provides good evidence of local breeding activity. I discuss the potential for further northwards range shift and whether the presence of three new species of parasite may have implications for the spread of avian disease within the region. I also include a concise key to the genus Pseudolynchia and images of P. canariensis, P. garzettae and O. biloba to aid further identification of these species in the region.

Detection of Bartonella schoenbuchensis (sub)species DNA in different louse fly species in Saxony, Germany: The proof of multiple PCR analysis necessity in case of ruminant-associated bartonellae determination

BACKGROUND

Hippoboscid flies are bloodsucking arthropods that can transmit pathogenic microorganisms and are therefore potential vectors for pathogens such as Bartonella spp. These Gram-negative bacteria can cause mild-to-severe clinical signs in humans and animals; therefore, monitoring Bartonella spp. prevalence in louse fly populations appears to be a useful prerequisite for zoonotic risk assessment.

METHODS

Using convenience sampling, we collected 103 adult louse flies from four ked species (Lipoptena cervi, n = 22; Lipoptena fortisetosa, n = 61; Melophagus ovinus, n = 12; Hippobosca equina, n = 8) and the pupae of M. ovinus (n = 10) in the federal state of Saxony, Germany. All the samples were screened by polymerase chain reaction (PCR) for Bartonella spp. DNA, targeting the citrate synthase gene (gltA). Subsequently, PCRs targeting five more genes (16S, ftsZ, nuoG, ribC and rpoB) were performed for representatives of revealed gltA genotypes, and all the PCR products were sequenced to identify the Bartonella (sub)species accurately.

RESULTS AND CONCLUSIONS

The overall detection rates for Bartonella spp. were 100.0%, 59.1%, 24.6% and 75.0% in M. ovinus, L. cervi, L. fortisetosa and H. equina, respectively. All the identified bartonellae belong to the Bartonella schoenbuchensis complex. Our data support the proposed reclassification of the (sub)species status of this group, and thus we conclude that several genotypes of B. schoenbuchensis were detected, including Bartonella schoenbuchensis subsp. melophagi and Bartonella schoenbuchensis subsp. schoenbuchensis, both of which have previously validated zoonotic potential. The extensive PCR analysis revealed the necessity of multiple PCR approach for proper identification of the ruminant-associated bartonellae.

Molecular detection and characterization of bovine viral diarrhea virus type 2 and bluetongue virus 9 in forest flies (Hippobosca equina) collected from livestock in southern Kazakhstan

Keds are hematophagous ectoparasites of animals belonging to the family Hippoboscidae (Diptera: Hippoboscoidea). Because of their importance as vectors of some pathogens of medical and veterinary importance, they have received special attention. There are numerous studies demonstrating the presence of various parasites and pathogenic bacteria in keds. At the same time, there are very few reports on ked-related viruses. The aim of this study was to perform a molecular survey of viral pathogens in the forest fly (Hippobosca equina) from southern Kazakhstan. In this study, 104H. equina were collected from livestock in Turkistan oblast (southern region of Kazakhstan), which has the largest concentration of livestock in the country. Insect homogenates were screened by PCR for pestiviruses, orbiviruses, flaviviruses, orthobunyaviruses, phleboviruses, orthopoxviruses, capripoxviruses, parapoxviruses, and asfiviruses. The causative agents of two livestock diseases, bovine viral diarrhea virus (BVDV) (3/104; 2.88%; 95% confidence interval (CI): 0.6-8.2%) and bluetongue virus (BTV) (1/104; 0.96%; 95% CI: 0.02-5.24%), were identified and subjected to further analysis. The BTV strain was isolated and all ten genomic RNA segments were sequenced using the Sanger technique. The isolated BTV strain showed >99.6% identity in all genomic segments with the BTV-9 strains belonging to the 'western' topotype. Partial analysis of the 5'-untranslated region demonstrated that both BVDV strains are closely related to Pestivirus B. Flaviviruses, phleboviruses, orthobunyaviruses, poxviruses, and asfiviruses were not detected. This is the first report describing BVDV type 2 in Kazakhstan. The study also confirms the presence of BTV serotype 9 in southern Kazakhstan. The data presented here can help improve preventive measures to control the spread of viral diseases in livestock by using forest flies as an object of epidemiological studies. However, further studies are needed to investigate the vector capacity of H. equina and its suitability for xenodiagnosis of veterinary relevant pathogens.

The contribution of citizen science in the surveillance of wildlife and related arthropods

Environmental and anthropogenic factors may significantly affect the diffusion of wild animals, enhancing the interface of human–wildlife interactions and driving the spread of pathogens and vector-borne diseases between animals and humans. However, in the last decade, the involvement of citizens in scientific research (the so-called citizen science approach, henceforth abbreviated as CS) provided a network of large-scale and cost-effective surveillance programmes of wildlife populations and their related arthropod species. Therefore, this review aims to illustrate different methods and tools used in CS studies, by arguing the main advantages and considering the limitations of this approach. The CS approach has proven to be an effective method for establishing density and distribution of several wild animal species, in urban, peri-urban and rural environments, as well a source of information regarding vector–host associations between arthropods and wildlife. Extensive efforts are recommended to motivate citizens to be involved in scientific projects to improve both their and our knowledge of the ecology and diseases of wildlife. Following the One Health paradigm, collaborative and multidisciplinary models for the surveillance of wildlife and related arthropod species should be further developed by harnessing the potentiality of the CS approach.

Analysis of the bacterial communities associated with pupae and winged or wingless adults of Lipoptena fortisetosa collected from cervids in Italy

The hippoboscid Lipoptena fortisetosa Maa, 1965 is a hematophagous ectoparasite of cervids that can bite humans. This fly is expanding its geographical range and is of concern for animal and human health since it can potentially harbour harmful microorganisms. This study was aimed at characterizing the bacterial communities of L. fortisetosa in its different life-cycle stages. Pupae and wingless adults were collected from cervids hunted in Tuscan-Emilian Apennines (central Italy) and pooled into groups of 10 by life stage (30 individual pupae; 1420 individual wingless adults). Winged flies were caught by sweep netting and separated into five pools of 10 insects. After DNA extraction, the bacterial content of each pool was analysed using 16 S metabarcoding. Results revealed that the composition and relative abundance of different taxa greatly differed in the three analysed groups. Wingless adults showed a high abundance of Bartonella (33.07%), which is almost absent in winged flies and pupae. Among the detected pathogens, four genera of concern for human health were found: Bartonella, Moraxella, Mycobacterium and Rickettsia. Interestingly reads similar to Bartonella bovis, Moraxella osloensis and Arsenophonus lipopteni Operational Taxonomic Unit (OTUs) were detected. These findings suggest the possible role of L. fortisetosa as a reservoir of pathogenic microorganisms, confirming the need for further investigation to ascertain its vectorial capacity.

Molecular pathogen screening of louse flies (Diptera: Hippoboscidae) from domestic and wild ruminants in Austria

BACKGROUND

Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The potential role of hippoboscids as vectors of human and veterinary pathogens is being increasingly investigated, but the presence and distribution of infectious agents in louse flies is still unknown in parts of Europe. Here, we report the use of molecular genetics to detect and characterize vector-borne pathogens in hippoboscid flies infesting domestic and wild animals in Austria.

METHODS

Louse flies were collected from naturally infested cattle (n = 25), sheep (n = 3), and red deer (n = 12) across Austria between 2015 and 2019. Individual insects were morphologically identified to species level and subjected to DNA extraction for molecular pathogen screening and barcoding. Genomic DNA from each louse fly was screened for Borrelia spp., Bartonella spp., Trypanosomatida, Anaplasmataceae, Filarioidea and Piroplasmida. Obtained sequences of Trypanosomatida and Bartonella spp. were further characterized by phylogenetic and haplotype networking analyses.

RESULTS

A total of 282 hippoboscid flies corresponding to three species were identified: Hippobosca equina (n = 62) collected from cattle, Melophagus ovinus (n = 100) from sheep and Lipoptena cervi (n = 120) from red deer (Cervus elaphus). Molecular screening revealed pathogen DNA in 54.3% of hippoboscids, including infections with single (63.39%), two (30.71%) and up to three (5.90%) distinct pathogens in the same individual. Bartonella DNA was detected in 36.9% of the louse flies. Lipoptena cervi were infected with 10 distinct and previously unreported Bartonella sp. haplotypes, some closely associated with strains of zoonotic potential. DNA of trypanosomatids was identified in 34% of hippoboscids, including the first description of Trypanosoma sp. in H. equina. Anaplasmataceae DNA (Wolbachia spp.) was detected only in M. ovinus (16%), while < 1% of the louse flies were positive for Borrelia spp. and Filarioidea. All hippoboscids were negative for Piroplasmida.

CONCLUSIONS

Molecular genetic screening confirmed the presence of several pathogens in hippoboscids infesting domestic and wild ruminants in Austria, including novel pathogen haplotypes of zoonotic potential (e.g. Bartonella spp.) and the first report of Trypanosoma sp. in H. equina, suggesting a potential role of this louse fly as vector of animal trypanosomatids. Experimental transmission studies and expanded monitoring of hippoboscid flies and hippoboscid-associated pathogens are warranted to clarify the competence of these ectoparasites as vectors of infectious agents in a One-Health context.

Molecular investigation on infection by haemosporidians in three Western Palearctic species of swift (Apodidae) and their ectoparasitic louse flies

Swifts (Apodidae) are an unusual group of birds that spend most of their lives in flight, landing only when breeding. Although this aerial lifestyle greatly reduces their likelihood of being bitten by vectors and infected by vector-born parasites, swifts can still be heavily infested during breeding by nest-based vectors such as louse flies (Hippoboscidae). Here, we investigated host, vector, and vector-borne parasite relationships in the three most widespread swift species in the Western Palearctic (WP): common swifts (Apus apus), pallid swifts (A. pallidus), and alpine swifts (Tachymarptis melba), their nest-based louse flies (Crataerina pallida and C. melbae) and avian haemosporidians (genera Haemoproteus, Plasmodium, and Leucocytozoon). Studies of haemosporidian infections in Apodidae remain limited, with clear evidence of infection found to date in just four Neotropical and one Australasian species. The possible role of louse flies in transmitting haemosporidian infections has never been tested in swifts. We assessed the occurrence of haemosporidian infection by PCR screenings of DNA from blood samples from 34 common swifts and 44 pallid swifts from Italy, and 45 alpine swifts from Switzerland. We also screened 20 ectoparasitic louse flies present on 20 birds and identified them by both morphological features and cytochrome oxidase subunit 1 (COI) barcodes. Our results provide no evidence of haemosporidian infection in the 123 swifts tested or in the two louse fly species we identified. Our findings are consistent with available knowledge showing no haemosporidian occurrence in WP swift species and that the most likely infection route for these highly aerial species (via louse fly ectoparasites during nesting) is unlikely.

Identification of ectoparasitic insects among domestic goats in Bulgaria

Background and Aim

Ectoparasitic entomoses cause serious economic losses to small-scale farmers. Parasites have both direct and indirect impacts on hosts. Domestic goats are a common target of infestation with ectoparasitic insects. This study aimed to identify the species of ectoparasitic insects in domestic goats in Bulgaria.

Materials and Methods

The study was performed in 34 farms from 29 settlements in 16 regions of Bulgaria. A total of 4599 goats from eight breeds, naturally infested with ectoparasitic insects were included in the study. The goats were inspected with a magnifying glass for the presence of skin changes (alopecia, dandruff, crusts, and nodules), eggs and adult ectoparasites. The detected insects were collected individually with tweezers and preserved in containers with 70% ethanol. Over the study period, 5,651 insects were collected; their species, sex, and developmental stage were identified by their morphological features and biometric measurements.

Results

Six species from 5 genera were detected: Linognathus stenopsis Burmeister, 1838; Linognathus africanus Kellog and Paine, 1911; Bovicola caprae Gurlt, 1843; Pulex irritans Linnaeus, 1758; Hippobosca equina Linnaeus, 1758; and Lipoptena cervi Linnaeus, 1758. Linognathus stenopsis were the most prevalent, followed by B. caprae and P. irritans. In detected lice populations, female insects were more numerous; female: male ratios ranged from 2.2 to 7.2 and imagines prevailed over the nymphs. In fleas, male imagines were more numerous than females (1:0.8).

Conclusion

The study demonstrated that the species L. stenopsis, L. africanus, B. caprae, and P. irritans were encountered in more than 40% of surveyed farms, situated in 68.75% of regions in Bulgaria. The most intense infestation was by species from the Linognathus genus (907 insects), whereas the highest extensity of infestation was registered for P. irritans (32.3%). This study detected P. irritans as the only flea species.

Detection of Pathogens and Ticks on Sedentary and Migratory Birds in Two Corsican Wetlands (France, Mediterranean Area)

Birds are one of the most species-diverse vertebrate groups and are susceptible to numerous hematophagous ectoparasites. Migratory birds likely contribute to the circulation of these ectoparasites and their associated pathogens. One of the many migration paths crosses the Mediterranean islands including Corsica and its wetlands, which are migration stopovers. In our study, we collected blood samples and hematophagous ectoparasites in migratory and sedentary bird populations in two coastal lagoons: Biguglia and Gradugine. A total of 1377 birds were captured from which 762 blood samples, 37 louse flies, and 44 ticks were collected. All the louse flies were identified as Ornithomya biloba and all the ticks were from the Ixodes genus: Ixodes sp. (8.5%), I. accuminatus/ventalloi (2.9%), I. arboricola/lividus (14.3%), I. frontalis (5.7%) and I. ricinus (68.6%). Five pathogens were detected: Anaplasma phagocytophilum, Erhlichia chaffeensis, and Rickettsia helvetica in ticks, and Trypanosoma sp. in louse flies. Ehrlichia chaffeensis and the West Nile virus were both detected in bird blood samples in Corsica. This is the first report of these tick, louse fly and pathogen species isolated on the bird population in Corsica. Our finding highlights the importance of bird populations in the presence of arthropod-borne pathogens in Corsican wetlands.

Bird Louse Flies Ornithomya spp. (Diptera: Hippoboscidae) as Potential Vectors of Mammalian Babesia and Other Pathogens

Background: Birds and mammals share various ectoparasites, which are responsible for the transmission of a wide range of pathogens. The louse flies (family Hippoboscidae) are ectoparasitic dipterans feeding strictly on the blood of mammals and birds. Both sexes of the louse flies are obligatory hematophagous and are known to act as the vectors of infectious agents. Materials and Methods: A total of 20 specimens of Ornithomya sp. were collected by hand on birds caught in nets or by hand from humans in two localities in Eastern Slovakia in 2021. The DNA samples were individually screened by species-specific PCRs for the presence of selected vector-borne pathogens. Results: Taxonomic identification folowed by molecular analyses revealed two louse fly species of Ornithomya spp. (O. avicularia and O. biloba). The molecular screening provided negative PCR results for Anaplasma phagocytophilum, Borrelia burgdorferi s.l., Rickettsia spp., Bartonella spp., and Hepatozoon canis. In contrast, positive PCR results were obtained for Babesia spp., Wolbachia spp., and Trypanosoma corvi. Conclusions: Of epidemiological importance is that the louse flies can presumably spread Babesia and other pathogens by host switching which facilitates the transmission and spread of numerous pathogens.

The genome of sheep ked (Melophagus ovinus) reveals potential mechanisms underlying reproduction and narrower ecological niches

BACKGROUND

Melophagus ovinus is considered to be of great veterinary health significance. However, little is known about the information on genetic mechanisms of the specific biological characteristics and novel methods for controlling M. ovinus.

RESULTS

In total, the de novo genome assembly of M. ovinus was 188.421 Mb in size (330 scaffolds, N50 Length: 10.666 Mb), with a mean GC content of 27.74%. A total of 13,372 protein-coding genes were functionally annotated. Phylogenetic analysis indicated that the diversification of M. ovinus and Glossina fuscipes took place 72.76 Mya within the Late Cretaceous. Gene family expansion and contraction analysis revealed that M. ovinus has 65 rapidly-evolving families (26 expansion and 39 contractions) mainly involved DNA metabolic activity, transposases activity, odorant receptor 59a/67d-like, IMD domain-containing protein, and cuticle protein, etc. The universal and tightly conserved list of milk protein orthologues has been assembled from the genome of M. ovinus. Contractions and losses of sensory receptors and vision-associated Rhodopsin genes were significant in M. ovinus, which indicate that the M. ovinus has narrower ecological niches.

CONCLUSIONS

We sequenced, assembled, and annotated the whole genome sequence of M. ovinus, and launches into the preliminary genetic mechanisms analysis of the adaptive evolution characteristics of M. ovinus. These resources will provide insights to understand the biological underpinnings of this parasite and the disease control strategies.

Hippobosca equina L. (Hippoboscidae: Hippobosca)-An Old Enemy as an Emerging Threat in the Palearctic Zone

Arthropods of the Hippoboscoidea superfamily are parasites of animals from various systematic groups. Mass appearances of these insects and their attacks on people are increasingly being recorded. Their parasitism has a negative effect on host well-being, as it causes feelings of agitation and irritation as well as skin itching and damage. It may result in weight loss and development of diseases in the long-term perspective. Parasites can be a potential epidemiological threat for their hosts as well. One of such parasites is a cosmopolitan species of the Hippoboscinae subfamily-Hippobosca equina. Studies have confirmed the presence of Corynebacterium pseudotuberculosis equi, Bartonella spp., and Anaplasma spp. in the organism of these insects. The frequency of anaphylactic reactions caused by H. equina attacks has been increasing. The aim of the present paper was to summarize the up-to-date knowledge of Hippobosca equina Linnaeus, 1758 due to its significance in medical and veterinary sciences as a potential vector of pathogens. Given the increasing expansion of ectoparasites, mainly related to climate change, ensuring animal welfare and human health is a priority.

First determination of DNA virus and some additional bacteria from Melophagus ovinus (sheep ked) in Tibet, China

Melophagus ovinus (sheep ked) is one of the common ectoparasites in sheep. In addition to causing direct damage to the host through biting and sucking blood, sheep ked is a potential vector of helminths, protozoa, bacteria, and viruses. Sheep M. ovinus samples from three regions in Tibet were selected for DNA extraction. The 16S rDNA V3-V4 hypervariable region was amplified, after genomic DNA fragmentation, Illumina Hiseq libraries were constructed. The 16S rRNA sequencing and viral metagenomics sequencing were separately conducted on the Illumina Novaseq 6000 platform and molecular biology software and platforms were employed to analyze the sequencing data. Illumina PE250 sequencing results demonstrated that the dominant bacteria phylum in M. ovinus from Tibet, China was Proteobacteria, where 29 bacteria genera were annotated. The dominant bacterial genera were Bartonella, Wolbachia, and Arsenophonus; Bartonella chomelii, Wolbachia spp., and Arsenophonus spp. were the dominant bacterial species in M. ovinus from Tibet, China. We also detected Kluyvera intermedia, Corynebacterium maris DSM 45190, Planomicrobium okeanokoites, and Rhodococcus erythropolis, of which the relative abundance of Kluyvera intermedia was high. Illumina Hiseq sequencing results demonstrated that 4 virus orders were detected in M. ovinus from Tibet, China, and 3 samples were annotated into 29 families, 30 families, and 28 families of viruses, respectively. Virus families related to vertebrates and insects mainly included Mimiviridae, Marseilleviridae, Poxviridae, Ascoviridae, Iridoviridae, Baculoviridae, Hytrosaviridae, Nudiviridae, Polydnaviridae, Adomaviridae, Asfarviridae, Hepeviridae, Herpesviridae, and Retroviridae; at the species level, the relative abundance of Tupanvirus_soda_lake, Klosneuvirus_KNV1, and Indivirus_ILV1 was higher. African swine fever virus and many poxviruses from the family Poxviridae were detected, albeit their relative abundance was low. The dominant bacterial phylum of M. ovinus from Tibet, China was Proteobacteria, and the dominant bacterial genera were Bartonella, Wolbachia, and Arsenophonus, where 23 out of 29 annotated bacteria genera were first reported in M. ovinus. Kluyvera intermedia, Corynebacterium maris DSM 45190, Planomicrobium okeanokoites, and Rhodococcus erythropolis were detected for the first time. All DNA viruses detected in this study have been reported in M. ovinus for the first time.

Updated taxonomic keys for European Hippoboscidae (Diptera), and expansion in Central Europe of the bird louse fly Ornithomyacomosa (Austen, 1930) with the first record from Slovakia

The available keys for European Hippoboscidae are outdated and do not cover all species currently known from Europe. Therefore, identification keys to the eleven genera and 31 species of the European hippoboscids are provided here. Ornithomyacomosa (Austen, 1930) (Diptera: Hippoboscidae) is recorded for the first time from the territory of Slovakia based on one female found on a sand martin, Ripariariparia (Linnaeus, 1758). The list of keds and louse flies recorded from the territory of Slovakia is increased to 20 species. New host records for Slovakia are presented.

Low host specificity of Hippobosca equina infestation in different domestic animals and pigeon

This study aimed to highlight the low host specificity of Hippobosca equina (H. equina) that poses a danger in diseases transmission between different animal species as well as, identification of the collected flies using light microscope and molecular characterization of H. equina in Egypt. Two hundred and forty flies were collected weekly from different animal species from El-Faiyum, Al Qalyubia and Kafr El-Sheikh Governorates, Egypt at the period from May to September of 2020. Insects were phenotypically and genetically identified then classified into 170 (70.8%) males and 70 (29.2%) females. The highest prevalence of H. equina was noticed from mid-June to the end of August. The sequencing of COI gene of five H. equina fly collected from different hosts as (horse, pigeon, cattle, buffalo, and donkey) were submitted to the GenBank under the accession numbers of MZ452239, MZ452240, MZ461943, MZ461944, and MZ461945, respectively. For insect infestation control, fipronil and deltamethrin is monthly sprayed for animals, birds and their circumference give a best result in our control study in the field. Deltamethrin showed a success in the elimination process and control measures of external parasites of pigeon.

Avian Louse Flies and Their Trypanosomes: New Vectors, New Lineages and Host–Parasite Associations

Louse flies (Hippoboscidae) are permanent ectoparasites of birds and mammals. They have a cosmopolitan distribution with more than 200 described species. The aim of this study was to reveal host–vector–parasite associations between louse flies, birds, and trypanosomes. A total of 567 louse fly specimens belonging to 7 species were collected from birds at several localities in Czechia, including the rare species Ornithophila metallica and Ornithoica turdi. There was a significant difference in the occurrence of Ornithomya avicularia and Ornithomya fringillina on bird hosts according to their migratory status, O. fringillina being found more frequently on long-distance migrants. Trypanosomes were found in four species, namely, Ornithomya avicularia, O. fringillina, O. biloba, and Ornithoica turdi; the later three species are identified in this paper as natural trypanosome vectors for the first time. The prevalence of trypanosomes ranged between 5 and 19%, the highest being in O. biloba and the lowest being in O. fringillina. Phylogenetic analysis of the SSU rRNA gene revealed that a vast majority of trypanosomes from hippoboscids belong to the avian T. corvi/culicavium group B. Four new lineages were revealed in group B, with louse flies being probable vectors for some of these trypanosome lineages. We also confirmed the transcontinental distribution of several trypanosome lineages. Our results show that hippoboscids of several genera are probable vectors of avian trypanosomes.

Antennal Morphology and Fine Structure of Flagellar Sensilla in Hippoboscid Flies with Special Reference to Lipoptena fortisetosa (Diptera: Hippoboscidae)

Simple Summary

In insects, host searching usually involves different kinds of stimuli, both visual and chemical, that may act in combination. External cues are perceived through specific sensory organs (sensilla), mainly present on the antennae. Understanding how ectoparasites belonging to the Hippoboscidae locate their hosts is crucial, since these flies infest animals and can attack humans, with veterinary and medical implications. The aim of this research was to study the antennae of four hippoboscid species, Lipoptena cervi (Linnaeus, 1758), Lipoptena fortisetosa Maa, 1965, Hippobosca equina Linnaeus, 1758, and Pseudolynchia canariensis (Macquart, 1840), investigating the morphology and the sensory structures present on these appendages. A typical conformation of the antennae with the envelopment of the third segment (flagellum) inside the first two have been observed. Moreover, two types of sensilla have been detected and their role in the perception of host odours and CO₂ have been hypothesized. Other antennal structures seem to be involved in the detection of temperature and humidity variations. Our findings confirm that these hippoboscids use chemoreception for host location, giving insights into this complex process in this poorly investigated group.

Abstract

Lipoptena cervi (Linnaeus), Lipoptena fortisetosa Maa, Hippobosca equina Linnaeus, and Pseudolynchia canariensis (Macquart) are hematophagous ectoparasites that infest different animal species and occasionally bite humans. Hosts are located by a complex process involving different kinds of stimuli perceived mainly by specific sensory structures on the antennae, which are the essential olfactory organs. General antennal morphology, together with distribution and ultrastructure of sensilla, have been studied in detail with scanning and transmission electron microscopy approaches. Observations have revealed some common features among the four studied hippoboscids: (a) typical concealment of the flagellum inside the other two segments; (b) characteristic trabecular surface of the flagellum; (c) peculiar external microtrichia; (d) presence on the flagellum of basiconic sensilla and grooved peg coeloconic sensilla; (e) unarticulated arista. The ultrastructure of L. fortisetosa revealed that microtrichia and the flagellar reticulated cuticle are not innervated. Different roles have been hypothesized for the described antennal structures. Microtrichia and the reticulated cuticle could convey volatile compounds towards the flagellar sensory area. Peculiar sensory neurons characterize the unarticulated arista which could be able to detect temperature variations. Coeloconic sensilla could be involved in thermoreception, hygroreception, and carbon dioxide reception at long distances, while the poorly porous basiconic sensilla could play a role in the host odour perception at medium–short distances.

The role of sheep ked (Melophagus ovinus) as potential vector of protozoa and bacterial pathogens

The sheep ked (Melophagus ovinus) hematophagous insect may act as a potential vector of vector-borne pathogens. The aim of this study was to detect the presence of Trypanosoma spp., Bartonella spp., Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato in sheep ked collected from sheep in Poland. In total, Trypanosoma spp. was detected in 58.91% of M. ovinus, whereas Bartonella spp. and B. burgdorferi s.l. were found in 86.82% and 1.55% of the studied insects, respectively. A. phagocytophilum was not detected in the studied material. In turn, co-infection by Trypanosoma spp. and Bartonella spp. was detected in 50.39%, while co-infection with Trypanosoma spp. and Bartonella spp. and B. burgdorferi s.l. was found in 1.55% of the studied insects. The conducted study showed for the first time the presence of B. burgdorferi s. l. in M. ovinus, as well as for the first time in Poland the presence of Trypanosoma spp. and Bartonella spp. The obtained results suggest that these insects may be a potential vector for these pathogens, but further-more detailed studies are required.

Zoonotic Bartonella species in Eurasian wolves and other free-ranging wild mammals from Italy

Bartonellae are emerging vector-borne pathogens infecting humans, domestic mammals and wildlife. Ninety-seven red foxes (Vulpes vulpes), 8 European badgers (Meles meles), 6 Eurasian wolves (Canis lupus), 6 European hedgehogs (Erinaceus europaeus), 3 beech martens (Martes foina) and 2 roe deer (Capreolus capreolus) from Italian Nature Conservatory Parks were investigated for Bartonella infection. Several Bartonella species (9.84%; 95% CI: 4.55-15.12), including zoonotic ones, were molecularly detected among wolves (83.3%; 95% CI: 51-100.00), foxes (4.12%; 95% CI: 0.17-8.08), hedgehogs (33.33%; 95% CI: 0.00-71.05) and a roe deer. Bartonella rochalimae was the most common Bartonella species (i.e. in 4 foxes and 2 wolves) detected. Candidatus B. merieuxii and B. vinsonii subsp. berkhoffii were identified for the first time in wolves. Furthermore, Bartonella schoenbuchensis was identified in a roe deer and a new clone with phylogenetic proximity to B. clarridgeiae was detected in European hedgehogs. Zoonotic and other Bartonella species were significantly more frequent in Eurasian wolves (p < .0001), than in other free-ranging wild mammals, representing a potential reservoir for infection in humans and domestic animals.

Molecular Detection of Selected Pathogens with Zoonotic Potential in Deer Keds (Lipoptena fortisetosa)

Deer keds are obligatory hematophagous ectoparasites of birds and mammals. Cervids serve as specific hosts for these insects. However, ked infestations have been observed in non-specific hosts, including humans, companion animals, and livestock. Lipoptena fortisetosa is a weakly studied ectoparasite, but there is evidence to indicate that it continues to spread across Europe. The existing knowledge on deer keds' impact on wildlife is superficial, and their veterinary importance is enigmatic. Lipoptena fortisetosa is a species with vectorial capacity, but potential pathogen transmission has not been assessed. The objective of this study was to evaluate the prevalence of selected pathogens in L. fortisetosa collected from cervids and host-seeking individuals in the environment. Out of 500 acquired samples, 307 (61.4%) had genetic material from at least one tested pathogen. Our research suggests that L. fortisetosa may be a potential vector of several pathogens, including A. phagocytophilum, Babesia spp., Bartonella spp., Borellia spp., Coxiella-like endosymbionts, Francisiella tularensis, Mycoplasma spp., Rickettsia spp., and Theileria spp.; however, further, more extensive investigations are required to confirm this. The results of the study indicate that keds can be used as biological markers for investigating the prevalence of vector-borne diseases in the population of free-ranging cervids.

Vector-Borne Pathogens with Veterinary and Public Health Significance in Melophagus ovinus (Sheep Ked) from the Qinghai-Tibet Plateau

Melophagus ovinus (sheep ked) is a hematophagous ectoparasite that mainly parasitizes sheep. In addition to causing inflammation, wool loss, and skin damage to the animal hosts, M. ovinus also serves as a vector for a variety of pathogens and is highly likely to participate in the life and transmission cycle of pathogenic organisms. Herein, we investigated the presence and molecular characterization of vector-borne pathogens in M. ovinus from Qinghai-Tibet Plateau, China. A total of 92 M. ovinus pools collected from the Qinghai province of China were screened for the presence of selected vector-borne pathogens. The overall positive rate of A. ovis, A. bovis, A. phagocytophilum, and T. ovis in M. ovinus was 39.1%, 17.4%, 9.8%, and 89.1%, respectively. All of the samples were negative for Border disease virus (BDV), other Anaplasma species, Babesia spp., Rickettsia spp., and Borrelia spp. Co-infection of different Anaplasma species and T. ovis occurred in 51.2% of all samples with T. ovis. The positive rates of A. ovis, A. bovis, and A. phagocytophilum in different regions and altitudes of the sampling sites were significantly different. Sequence and phylogenetic analysis of target genes confirmed their identity with corresponding pathogens. Our results elucidate the occurrence and molecular characterization of Anaplasma spp. and Theileria spp. in M. ovinus, which could act as potential zoonotic reservoirs. To the best of our knowledge, this is the first report of the detection of A. bovis and A. phagocytophilum DNA in M. ovinus. This study gives the first extensive molecular survey of vector-borne pathogens with veterinary and public health significance in M. ovinus from the Qinghai-Tibet Plateau, China.

Ecotyping of Anaplasma phagocytophilum from Wild Ungulates and Ticks Shows Circulation of Zoonotic Strains in Northeastern Italy

Simple Summary

Tick-borne infectious diseases represent a rising threat both for human and animal health, since they are emerging worldwide. Among the bacterial infections, Anaplasma phagocytophilum has been largely neglected in Europe. Despite its diffusion in ticks and animals, the ecoepidemiology of its genetic variants is not well understood. The latest studies identify four ecotypes of Anaplasma phagocytophilum in Europe, and only ecotype I has shown zoonotic potential. The aim of the present study was to investigate the genetic variants of Anaplasma phagocytophilum in wild ungulates, the leading reservoir species, and in feeding ticks, the main vector of infection. The analyzed samples were collected in northeastern Italy, the same area where the first Italian human cases of anaplasmosis in the country were reported. Using biomolecular tools and phylogenetic analysis, ecotypes I and II were detected in both ticks (Ixodes ricinus species) and wild ungulates. Specifically, ecotype II was mainly detected in roe deer and related ticks; and ecotype I, the potentially zoonotic variant, was detected in Ixodes ricinus ticks and also in roe deer, red deer, chamois, mouflon, and wild boar. These findings reveal not only the wide diffusion of Anaplasma phagocytophilum, but also the presence of zoonotic variants.

Abstract

Anaplasma phagocytophilum (A. phagocytophilum) is a tick-borne pathogen causing disease in both humans and animals. Human granulocytic anaplasmosis (HGA) is an emerging disease, but despite the remarkable prevalence in European ticks and wild animals, human infection appears underdiagnosed. Several genetic variants are circulating in Europe, including the zoonotic ecotype I. This study investigated A. phagocytophilum occurrence in wild ungulates and their ectoparasites in an area where HGA has been reported. Blood samples from wild ungulates and ectoparasites were screened by biomolecular methods targeting the mps2 gene. The groEL gene was amplified and sequenced to perform genetic characterization and phylogenetic analysis. A total of 188 blood samples were collected from different wild ungulates species showing an overall prevalence of 63.8% (88.7% in wild ruminants and 3.6% in wild boars). The prevalence of A. phagocytophilum DNA in ticks (manly Ixodes ricinus), and keds collected from wild ruminants was high, reflecting the high infection rates obtained in their hosts. Among ticks collected from wild boars (Hyalomma marginatum and Dermacentor marginatus) no DNA was detected. Phylogenetic analysis demonstrated the presence of ecotype I and II. To date, this is the first Italian report of ecotype I in alpine chamois, mouflon, and wild boar species. These findings suggest their role in HGA epidemiology, and the high prevalence detected in this study highlights that this human tick-borne disease deserves further attention.

Exposure of Humans to Attacks by Deer Keds and Consequences of Their Bites-A Case Report with Environmental Background

Simple Summary

Lipoptena species, also named the deer ked or deer fly, are commonly encountered in temperate areas of Europe, northern China, and North America. Although wild animals seem to be the preferred hosts of these parasitic arthropods, it is increasingly being noted that humans are also directly threatened by their bites. Skin lesions evolving after Lipoptena bites are painful and often lead to the development of inflammation of the skin. Lipoptena species also pose a threat to the health of the host by transferring pathogenic factors, e.g., Bartonella schoenbuchensis, Borrelia burgdorferi, and Anaplasma phagocytophilum. For this reason, knowledge of symptoms caused by Lipoptena bites is worth promoting among not only scientists but also the general public.

Abstract

Insects of the genus Lipoptena, e.g., Lipoptena cervi and Lipoptena fortisetosa, are hematophagic ectoparasites mainly attacking deer, roe deer, moose, horses, and cattle. Humans may also be incidental hosts for these insects. The species are vectors of numerous pathogens, including Bartonella schoenbuchensis, Borrelia burgdorferi, and Anaplasma phagocytophilum. Due to the short time of feeding on humans, usually painless bites, and an initially small trace at the site of the bite, the symptoms reported by the patient may not be associated with deer ked infestation and infection with pathogens transmitted by these arthropods. The aim of the study was to describe the consequences of L. cervi bites in humans with detailed documentation of the development of skin lesions. The knowledge about skin lesions arising after deer ked bites may be useful in clinical practice for monitoring patients for the presence of pathogens transmitted by the parasites.

Parasitic diseases of equids in Iran (1931-2020): a literature review

Parasitic infections can cause many respiratory, digestive and other diseases and contribute to some performance conditions in equids. However, knowledge on the biodiversity of parasites of equids in Iran is still limited. The present review covers all the information about parasitic diseases of horses, donkeys, mules and wild asses in Iran published as articles in Iranian and international journals, dissertations and congress papers from 1931 to July 2020. Parasites so far described in Iranian equids include species of 9 genera of the Protozoa (Trypanosoma, Giardia, Eimeria, Klossiella, Cryptosporidium, Toxoplasma, Neospora, Theileria and Babesia), 50 helminth species from the digestive system (i.e., 2 trematodes, 3 cestodes and 37 nematodes) and from other organs (i.e., Schistosoma turkestanica, Echinococcus granulosus, Dictyocaulus arnfieldi, Parafilaria multipapillosa, Setaria equina and 3 Onchocerca spp.). Furthermore, 16 species of hard ticks, 3 mite species causing mange, 2 lice species, and larvae of 4 Gastrophilus species and Hippobosca equina have been reported from equids in Iran. Archeoparasitological findings in coprolites of equids include Fasciola hepatica, Oxyuris equi, Anoplocephala spp. and intestinal strongyles. Parasitic diseases are important issues in terms of animal welfare, economics and public health; however, parasites and parasitic diseases of equines have not received adequate attention compared with ruminants and camels in Iran. The present review highlights the knowledge gaps related to equines about the presence, species, genotypes and subtypes of Neospora hughesi, Sarcocystis spp., Trichinella spp., Cryptosporidium spp., Giardia duodenalis, Blastocystis and microsporidia. Identification of ticks vectoring pathogenic parasites, bacteria and viruses has received little attention, too. The efficacy of common horse wormers also needs to be evaluated systematically.

First report on Bartonella henselae in dromedary camels (Camelus dromedarius)

Bartonellosis is one of the clinically underdiagnosed emerging bacterial diseases among domestic livestock, particularly in camels. Until now, the natural infection of camels with Bartonella species was not investigated in Tunisia. In the attempt of filling this gap in knowledge, a total of 412 dromedary camels (Camelus dromedarius) as well as 300 associated ticks (Hyalomma dromedarii (160; 53.4%), H. impeltatum (131; 43.6%) and H. excavatum (9; 3%) were screened for the presence of Bartonella spp. by PCR followed by a sequencing step through the amplification of the rpoB gene. Positive samples were then tested and further characterized by the combined use of the ftsZ and gltA genes. Fifteen camels (3.6%) were found to be positive to Bartonella spp. However, there was no evidence of Bartonella DNA in any of the analyzed ticks. Risk factors' analysis shows that camels derived from arid and semi-arid bioclimatic areas were more infected than those originated from desert area. Molecular characterization and phylogenetic analysis revealed the occurrence of novel B. henselae genotypes closely related to those isolated from humans, cats, and lions. By combining the characteristics of each single gene with those of concatenated sequences, we report here the first molecular detection of B. henselae in the dromedary camel suggesting a possible involvement of camelids as hosts or reservoirs in the transmission cycle of this emerging bacterium in arid and saharan areas.