Novel Genotypes of Nidicolous Argas Ticks and Their Associated Microorganisms From Spain

Molecular Detection of Borrelia spp. in Ticks of Sheep and Goats by Nested PCR Method in West Azerbaijan Province, Iran

Background: Ticks are an important vector among arthropods associated with serious medical and veterinary problems. In this research, we investigate Borrelia species in ticks isolated from the surface of livestock (sheep and goat) in different regions of West Azerbaijan province. Materials and Methods: Polymerase chain reaction (PCR) was performed using specific primers targeting Borrelia spp. genes. Borrelia spp. was identified through PCR. The positive PCR products were sent to Pishgam Company for sequencing. Sequenced data were analyzed, and phylogenetic analysis was performed using maximum likelihood method in MEGA V.10. Results: The detection rate of Borrelia spp. for 16srRNA gene 69 (n = 542; 12.7%; 95%Cl: 10.1%-15.8%), 42 (n = 542; 7.7%; 95%Cl: 5.78%-10.1%) positive on 5S-23SrRNA gene and ospA gene 4 (n = 542; 0.74%; 95%Cl: 0.29%-1.88%). Conclusion: These results are the first report in Iran to identify Borrelia spp. These results of the study showed that the Borrelia spp. in hard ticks detected by PCR and it was negative to soft ticks. it is important in public health implications at the studied areas.

Ticks in the box: Argas persicus occurrence in nest boxes of secondary cavity-nesting bird species in Italy

Migratory organisms can be vectors of parasitic host organisms that can then be transported along seasonal migratory journeys and spread across continents. Ornithophilic nidicolous ticks (e.g. soft ticks) include species responsible for the transmission of pathogens and bacteria, thus representing a health problem not only for wild species that are directly parasitized, but also for those that share the same environments or reproductive sites with them. In this regard, artificial nests for birds may turn out to be site-sources of parasites. Here, we document the occurrence of different life stages of Argas persicus ticks in nest boxes of wild birds in a natural area (not associated with poultry activities) of central coastal Italy (Maremma Regional Park, Tuscany). Between 2018 and 2022, 168 ticks were collected from nest boxes occupied by different secondary cavity-nesting birds, such as European rollers Coracias garrulus and scops owl Otus scops. Ticks were analysed morphologically, and selected specimens were also identified by mitochondrial ribosomal 16S (16S) subunit gene to ascertain their taxonomic status. All ticks were identified as Argas persicus. This finding not only suggests that this tick species has formed a viable population in this Italian region, but also further confirms the previously doubtful natural origin of the species at country level and sheds new light on its underestimated and little investigated distribution. Possible pathways of introduction and its potential impacts on local avian community are discussed.

MALDI-TOF MS as a tick identification tool in a tertiary hospital in Spain

In Spain, as in other countries, the spectrum of tick-borne diseases and their number have increased in recent years. The tick identification, at species level, can be a challenging outside research centers although this information is very usufull for decisions making. The performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in tick identification of specimens collected from patients have been seldomly reported. The aim of the present study was to desing a protein-extraction protocol and build a tick-legs reference spectra. This protocol was then validated using specimens from both patients and non-patient sources. Nine species of ticks that usually bites humans in Spain were included: Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis punctata, Hyalomma usitanicum, Hyalomma marginatum, Ixodes ricinus, Rhipicephalus bursa, Rhipicephalus pusillus and Rhipicephalus sanguineus sensu lato. Other less-frequentbiting species were also included: Haemaphysalis inermis, Haemaphysalis concinna, Hyalomma scupense,Ixodes frontalis, Ixodes hexagonus, and Argas sp. Specimens were identified by PCR and sequencing of a fragment of the 16S rRNA gene of ticks. In the tests performed with non-patient collected specimens, a 100% correlation was observed between molecular methods and MS, while in the tests performed with ticks collected from patients a 92.59% correlation was observed. Misidentification was observed only in two of I. ricinus nymphs (identified as Ctenocephalides felis). Therefore, mass- spectrometry can be confidently used as a tick identification tool in a hospital setting for the rapid identification of tick vectors.

Substantial viral and bacterial diversity at the bat-tick interface

Ticks harbour a high diversity of viruses, bacteria and protozoa. The soft tick Carios vespertilionis (Argasidae) is a common ectoparasite of bats in the Palearctic region and is suspected to be vector and reservoir of viruses and other microbial species in bat populations, some of which may act as zoonotic agents for human disease. The Soprano pipistrelle (Pipistrellus pygmaeus, Vespertilionidae) is widely distributed in Europe, where it can be found inside or close to human habitation. We used meta-transcriptomic sequencing to determine the RNA virome and common microbiota in blood-fed C. vespertilionis ticks collected from a Soprano pipistrelle bat roosting site in south-central Sweden. Our analyses identified 16 viruses from 11 virus families, of which 15 viruses were novel. For the first time in Sweden we identified Issuk-Kul virus, a zoonotic arthropod-borne virus previously associated with outbreaks of acute febrile illness in humans. Probable bat-associated and tick-borne viruses were classified within the families Nairoviridae, Caliciviridae and Hepeviridae, while other invertebrate-associated viruses included members of the Dicistroviridae, Iflaviridae, Nodaviridae, Partitiviridae, Permutotetraviridae, Polycipiviridae and Solemoviridae. Similarly, we found abundant bacteria in C. vespertilionis, including genera with known tick-borne bacteria, such as Coxiella spp. and Rickettsia spp. These findings demonstrate the remarkable diversity of RNA viruses and bacteria present in C. vespertilionis and highlight the importance of bat-associated ectoparasite surveillance as an effective and non-invasive means to track viruses and bacteria circulating in bats and ticks.

Rickettsiales in the WHO European Region: an update from a One Health perspective

BACKGROUND

The availability of molecular techniques has significantly increased our understanding of bacteria of the order Rickettsiales, allowing the identification of distinct species in both vector and host arthropods. However, the literature lacks studies that comprehensively summarize the vast amount of knowledge generated on this topic in recent years. The purpose of this study was to conduct a comprehensive analysis of the distribution of Rickettsiales in arthropod vectors, animals and humans in the WHO European Region in order to provide useful information to predict the emergence of certain diseases in specific geographical areas and to formulate hypotheses regarding the possible pathogenetic role of some rickettsial species in the etiology of human pathological conditions.

METHODS

A systematic review of the literature in the PubMed and EMBASE databases was conducted following the PRISMA methodology using the search terms "Spotted fever" OR "rickettsiosis" OR "ricketts*" AND all the countries of the WHO European Region, from 1 January 2013 to 12 February 2022. Only studies that identified rickettsiae in human, animal or arthropod samples using molecular techniques were included in the review.

RESULTS

A total of 467 articles considering 61 different species of Rickettsiales with confirmed or suspected human pathogenicity were analyzed in the review. More than 566 identifications of Rickettsiales DNA in human samples were described, of which 89 cases were assessed as importation cases. A total of 55 species of ticks, 17 species of fleas, 10 species of mite and four species of lice were found infected. Twenty-three species of Rickettsiales were detected in wild and domestic animal samples.

CONCLUSION

The routine use of molecular methods to search for Rickettsiales DNA in questing ticks and other blood-sucking arthropods that commonly bite humans should be encouraged. Molecular methods specific for Rickettsiales should be used routinely in the diagnostics of fever of unknown origin and in all cases of human diseases secondary to an arthropod bite or animal contact.

Molecular characterization and phylogenetic analysis of Argas persicus (Oken, 1818) (Acari: Argasidae) from domestic birds in eastern Algeria

Argas persicus (the fowl tick) is a species of soft tick commonly associated with poultry farms. It has a wide geographic distribution and colonizes different climate regions. Morphological identification of A. persicus has been reported worldwide, but genetic data regarding its molecular characterization is limited. The present study provides data for morphological identification and genetic characterization of A. persicus collected from domestic birds in traditional farms from east Algeria (Setif region). Additionally, A. persicus samples originating from Gansu province in China were included for comparative molecular study. In total, 1518 ticks collected from 30 infested farms were examined and morphologically identified as A. persicus. Furthermore, the 14 tick samples obtained from China were morphologically identified as A. persicus. Molecular analysis of 30 ticks from Algeria (one tick from each infested farm) and the 14 Chinese samples based on PCR, sequencing, and phylogenetic analysis of three mitochondrial genetic markers (16S rRNA, 12S rRNA, and cox1) confirmed morphological results where all samples belonged to the A. persicus group. However, phylogenetic analysis showed that all Algerian samples and two Chinese samples belong to A. persicus sensu stricto (s.s.), while the remaining Chinese samples represented A. persicus sensu lato (s.l.) (divergent lineage). The present study confirms the occurrence of A. persicus s.s. both in Algeria and China, as well as provides novel molecular data for a distinct Chinese lineage of A. persicus.

Descriptive DNA barcoding of Argas (Persicargas) arboreus and Argas (Persicargas) persicus ticks (Ixodida: Argasidae) infesting birds in Egypt

Argas ticks are primary parasites of birds with veterinary importance. Nevertheless, these ticks have received little attention regarding molecular identification studies. DNA barcoding is a powerful technique for identifying tick species besides traditional morphological identification. The present work is a first effort to divulge DNA sequences of Argas (Persicargas) arboreus from Egypt and worldwide. We used cytochrome c oxidase subunit I (COI) from A. arboreus infesting herons, and from the fowl tick Argas (Persicargas) persicus. Our results pointed out another success for the Folmer primers that are widely used in DNA barcoding, permitting the discrimination of morphologically similar A. arboreus and A. persicus.

Tick-Borne Rickettsioses in the Iberian Peninsula

Tick-borne rickettsioses (TBR) are caused by obligate, intracellular bacteria of the spotted-fever group (SFG) of the genus Rickettsia (Order Rickettsiales), transmitted by hard ticks. TBR are one of the oldest known vector-borne zoonoses and pose a threat to both human and animal health, as over the years, new SFG Rickettsia spp. have been reported worldwide with the potential to be human pathogens. In Portugal and Spain, the countries that constitute the Iberian Peninsula, reported TB rickettsiae causing human disease include Rickettsia conorii conorii, Rickettsia conorii israelensis, Rickettsia slovaca, Rickettsia raoultii, Candidatus Rickettsia rioja, Rickettsia sibirica mongolitimonae, and Rickettsia monacensis. An allochthonous case of TBR caused by Rickettsia massiliae, described in Spain, points to the need to monitor disease epidemiology, to predict risks of exposure and spread of disease, and taking into account globalization and climate changes. This review aims to provide up-to-date information on the status of TBR in the Iberian Peninsula, as well as to show the importance of a national and international collaborative epidemiology surveillance network, towards monitoring Rickettsia spp. circulation in both Portugal and Spain.

New Cell Lines Derived from European Tick Species

Tick cell lines are important tools for research on ticks and the pathogens they transmit. Here, we report the establishment of ten new cell lines from European ticks of the genera Argas, Dermacentor, Hyalomma, Ixodes and Rhipicephalus originating from Germany and Spain. For each cell line, the method used to generate the primary culture, a morphological description of the cells and species confirmation by sequencing of the partial 16S rRNA gene are presented. Further molecular analysis of the two new Ixodes ricinus cell lines and three existing cell lines of the same species revealed genetic variation between cell lines derived from ticks collected in the same or nearby locations. Collectively, these new cell lines will support research into a wide range of viral, bacterial and protozoal tick-borne diseases prevalent in Europe.

Novel symbionts and potential human pathogens excavated from argasid tick microbiomes that are shaped by dual or single symbiosis

Research on vector-associated microbiomes has been expanding due to increasing emergence of vector-borne pathogens and awareness of the importance of symbionts in the vector physiology. However, little is known about microbiomes of argasid (or soft-bodied) ticks due to limited access to specimens. We collected four argasid species (Argas japonicus, Carios vespertilionis, Ornithodoros capensis, and Ornithodoros sawaii) from the nests or burrows of their vertebrate hosts. One laboratory-reared argasid species (Ornithodoros moubata) was also included. Attempts were then made to isolate and characterize potential symbionts/pathogens using arthropod cell lines. Microbial community structure was distinct for each tick species. Coxiella was detected as the predominant symbiont in four tick species where dual symbiosis between Coxiella and Rickettsia or Coxiella and Francisella was observed in C. vespertilionis and O. moubata, respectively. Of note, A. japonicus lacked Coxiella and instead had Occidentia massiliensis and Thiotrichales as alternative symbionts. Our study found strong correlation between tick species and life stage. We successfully isolated Oc. massiliensis and characterized potential pathogens of genera Ehrlichia and Borrelia. The results suggest that there is no consistent trend of microbiomes in relation to tick life stage that fit all tick species and that the final interpretation should be related to the balance between environmental bacterial exposure and endosymbiont ecology. Nevertheless, our findings provide insights on the ecology of tick microbiomes and basis for future investigations on the capacity of argasid ticks to carry novel pathogens with public health importance.