Phylogenetic insights on Mediterranean and Afrotropical Rhipicephalus species (Acari: Ixodida) based on mitochondrial DNA

Tick-borne pathogens from ruminant ticks in a Mediterranean ecosystem from Eastern Spain

Vector-borne diseases represent various sicknesses that are increasingly significant in human and veterinary health. Among the zoonotic agents transmitted by ticks, infections caused by the intracellular pathogens from the Anaplasmataceae family and piroplasmids (Babesia/Theileria spp.) are particularly notable due to the substantial economic losses they cause in the livestock sector. A study was carried out to assess the prevalence of these pathogens in ticks from ruminants in the province of Valencia (Eastern Iberian Peninsula). Between 2019 and 2022, 1674 ticks were collected from 163 domestic and wild ruminants. The tick species were identified using molecular and morphological features and included Rhipicephalus spp. (Rhipicephalus bursa and Rhipicephalus sanguineus) (88.7%), Haemaphysalis sulcata (5.9%), Ixodes ricinus (3.6%) and Dermacentor marginatum (1.2%). The Spanish ibex (Capra pyrenaica) was found to be at greater risk of infestation by Haemaphysalis compared to other ruminants. Polimerase Chain Reaction (PCR) analysis was performed on 108 individual ticks from different hosts, with 16.7% testing positive for members of the Anaplasmataceae family and 39.8% for Theileria spp. Sequencing of 10 positive samples from each pathogen group revealed the presence of Anaplasma ovis, Anaplasma platys, Ehrlichia spp., Theileria ovis and Theileria capreoli. No Anaplasma phagocytophilum or Babesia spp. were detected. Further research is essential for improved management of ticks and the diseases they transmit in the study area.

The complete mitochondrial genome analysis of Haemaphysalis hystricis Supino, 1897 (Ixodida: Ixodidae) and its phylogenetic implications

In order to study the sequence characteristics, gene order, and codon usage of the mitochondrial genome of Haemaphysalis hystricis, and to explore its phylogenetic relationship, a total of 36 H. hystricis isolated from dogs were used as sample in this study. The mitochondrial genome of a H. hystricis was amplified with several pairs of specific primers by PCR, and was sequenced by first generation sequencing. The mitochondrial genome of H. hystricis was 14,719 bp in size, and it contained 37 genes including 13 protein coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and AT-rich region. Each PCG sequence had different lengths, the sequence longest and shortest gene were nad5 (1,652 bp) and atp8 (155 bp), respectively, among the 13 PCGs. All PCGs used ATN as their initiation codon, 10 of 13 PCGs used TAN as their termination codon, and 3 of which had incomplete termination codon (TA/T). Most of the 22 tRNAs with different sizes could form the classical cloverleaf structures expect for tRNA-Ala, tRNA-Ser1, tRNA-Ser2, and tRNA-Glu, and there were base mismatch (U-U and U-G) in all the 22 tRNAs sequences. Two rRNAs, namely rrnL and rrnS, had different lengths, rrnL located between tRNA-Leu1 and tRNA-Val, and rrnS located between tRNA-Val and tRNA-Ile, respectively. Two AT (D-loop) control areas with different lengths were in the mitochondrial genome, the NCRL was located between tRNA-Leu2 and tRNA-Cys, and the NCRS was located between rrnS and tRNA-Ile. The complete mitochondrial genome sequence of H. hystricis was AT preferences, and the gene order is the same as that of other Haemaphysalis family ticks. However, phylogenetic analysis showed that H. hystricis was most closely related to Haemaphysalis longicornis among the selected ticks. The mitochondrial genome not only enriches the genome database, provides more novel genetic markers for identifying tick species, and studying its molecular epidemiology, population genetics, systematics, but also have implications for the diagnosis, prevention, and control of ticks and tick-borne diseases in animals and humans.

Molecular Detection of Anaplasma marginale in Amblyomma mixtum Infesting Cattle in the Major Livestock-Producing States of Mexico

Bovine anaplasmosis is a tick-borne disease caused by Anaplasma marginale, although mechanical transmission by biting flies also occurs. Infection with A. marginale can reach 26% mortality and morbidity is associated with reduced beef and milk production, causing economic losses for livestock producers. Between March 2022 and July 2023, 1920 ticks were collected from 52 cattle production units in major cattle-producing states in Mexico, including Chiapas, Jalisco, Michoacán, Tabasco, and Veracruz. Of all the ticks collected, 35.57% were morphologically identified as Amblyomma mixtum. Samples of A. mixtum from each state, totaling 271, were tested for A. marginale via polymerase chain reaction (PCR). A. marginale was detected molecularly in 15.3% of A. mixtum samples. A. mixtum from Chiapas had the highest prevalence of A. marginale (24.0%), followed by Tabasco and Veracruz (20.0% each), Jalisco (15.2%), and Michoacán (6.6%). Phylogenetic analysis supported the morphological identification of A. mixtum and confirmed the genetic identity of A. marginale. This research is the first report on the molecular detection of A. marginale in A. mixtum ticks in Mexico. Results suggest that this 3-host tick species might be a potential vector. A. mixtum is Mexico's second most economically significant tick feeding on cattle after Rhipicephalus microplus. This information about A. marginale prevalence in A. mixtum expands our understanding of bovine anaplasmosis epidemiology in Mexico. Further research is needed to assess the role of A. mixtum as a vector of A. marginale.

Unveiling Tick Diversity in Cattle in Cameroon: Emergence of Rhipicephalus microplus, Replacing the Original Rhipicephalus spp

Ticks are well-known vectors of pathogens, posing considerable risks to livestock health and productivity. In Cameroon, where livestock production is vital, established tick species such as Amblyomma variegatum and Hyalomma truncatum are prevalent in key cattle-rearing areas. The recent introduction of the invasive, acaricide-resistant Rhipicephalus microplus further complicates control efforts. In this study, we deliver baseline data on the composition of tick species and their shifts within agroecological zone I (AEZ I) and agroecological zone III (AEZ III) of Cameroon, providing a foundation for targeted vector control strategies to ultimately reduce the risk of pathogen transmission. From 1100 ticks collected across two Cameroonian agroecological zones, H. truncatum (39.9%), A. variegatum (31%), and R. microplus (10.64%) were the most prevalent species, along with Rhipicephalus lunulatus (4.45%), Hyalomma rufipes (1.45%), Hyalomma marginatum (1.09%), Hyalomma dromedarii (0.45%), and Rhipicephalus sanguineus (0.9%). Molecular identification using cytochrome C oxidase subunit 1 (cox1) and 16s led to the identification of five additional species, Hyalomma nitidum (0.73%), Rhipicephalus simus (3.54%), Rhipicephalus sulcatus (2.64%), Rhipicephalus praetextatus (2.1%), and Rhipicephalus pusillus (1.1%). R. microplus emerged as the most dominant Rhipicephalus spp. in AEZ I, comprising 67.5% of the total Rhipicephalus ticks. In conclusion, we demonstrate the further spread of R. microplus, which represents a major source of vector-borne diseases, affecting both humans and animals.

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.

Description of Rhipicephalus hibericus sp. nov. (Ixodoidea: Ixodidae), a species of the Rhipicephalus sanguineus group in southwestern Europe

We describe all the life stages of Rhipicephalus hibericus n. sp., provide the types, and present molecular support for a new species of the Rhipicephalus sanguineus sensu lato group, present in southwestern Europe, that has been historically confused with Rhipicephalus turanicus Pomerantzev, 1940. A new name is proposed for this taxon because it was impossible to ascribe to types of already described species in the group, deposited for more than 100 years in natural history institutions. The males have a dorsum showing deep and coarse punctations (absent in Rhipicephalus sanguineus sensu stricto) and adanal plates with large punctations (absent in R. sanguineus s.s.); the tail of the spiracular plate is as wide as the closest festoon (half the width in R. sanguineus s.s.). Females have large punctations in dorsal fields, a wide spiracular plate, and a "V" shaped genital opening; such a combination of characters cannot be found in other species of the group. Immatures are described from specimens collected on hosts (Rodentia and Eulipotyphla). Both larvae and nymphs are markedly smaller than R. sanguineus s.s. Nymphs display long, backward-projected auriculae; larvae are almost half the size of R. sanguineus s.s. The new species can hybridize with R. sanguineus s.s. in laboratory colonies producing an unfertile F2, laying brown and dry eggs that did not hatch. Phylogenetic analysis of partial coxI gene sequences placed R. hibericus in a well-supported clade with other sequences of R. sanguineus s.l. from Portugal, as a sister clade of R. sanguineus s.s. The new species does not belong to the R. turanicus group of species. Both 12S and 16S partial gene sequences were not as precise in the correct phylogenetic placement of R. hibericus, in part probably due to the existence of erroneously identified sequences in GenBank©. This description, together with the previous reinstatement of Rhipicephalus secundus and Rhipicephalus rutilus, and the description of the neotypes of R. sanguineus s.s. should help researchers to adequately identify their collections. Our findings demonstrate that R. turanicus is absent in southwestern Europe. Old collections should be re-examined to provide the actual range of the new species.

Tick infestation in spur-thighed tortoise population: a pilot study for unraveling epidemiological patterns and demographic consequences

Ectoparasites, such as ticks, modulate host population dynamics by impacting demographic traits. They transmit infectious agents among their hosts, posing a critical threat to animal and public health. This study aimed to characterize and analyze the Hyalomma aegyptium infestation on one of its main hosts, the spur-thighed tortoise, its effects on demographic traits, and to determine the diversity of infectious agents present in both ticks and tortoises in the Maamora forest (northwestern Morocco). Our results show that 100% of the tortoises were parasitized by adult ticks in spring, an infestation intensity of 4 ticks/tortoise (5.1 and 3.6 ticks/tortoise in males and females, respectively; 4.2 and 3.3 ticks/tortoise in gravid and non-gravid females, respectively) and an abundance ranging from 1 to 12. Although without significant differences, male tortoises had higher tick abundances than females. The interaction of tortoise sex and body condition was significantly related to tick abundance, male body condition decreased with higher tick abundance in contrast to females. Nevertheless, the interaction of body condition and reproductive stage of females was not significantly related to tick abundance. Gravid females were significantly associated with tick abundance, showing a slightly higher infestation than non-gravid females. Molecular analysis of pooled tick samples revealed the presence of Ehrlichia ewingii, Candidatus Midichloria mitochondrii, and Rickettsia africae, with a minimum infection rate of 0.61 to 1.84%. However, blood sample analysis of the tortoises was infectious agent-free, pinpointing a lack of significant health problems. Given the possible effect on the transmission of zoonotic diseases by spur-thighed tortoises associated with their frequent collection as pets, it should be surveyed to control possible human health problems. In conservation terms, as a long-lived species, the role of tick infestation in demographic traits might be included in the management and conservation programs of spur-thighed tortoises.

Low Genetic Diversity of the Only Clade of the Tick Rhipicephalus microplus in the Neotropics

This study addresses the variability of the mitochondrial cytochrome oxidase subunit I (COI) and 16S rDNA (16S), and nuclear internal transcriber spacer ITS2 (ITS2) genes in a set of field-collected samples of the cattle tick, Rhipicephalus microplus (Canestrini, 1888), and in geo-referenced sequences obtained from GenBank. Since the tick is currently considered to be a complex of cryptic taxa in several regions of the world, the main aims of the study are (i) to provide evidence of the clades of the tick present in the Neotropics, (ii) to explore if there is an effect of climate traits on the divergence rates of the target genes, and (iii) to check for a relationship between geographical and genetic distance among populations (the closest, the most similar, meaning for slow spread). We included published sequences of Rhipicephalus annulatus (Nearctic, Afrotropical, and Mediterranean) and R. microplus (Afrotropical, Indomalayan) to fully characterize the Neotropical populations (total: 74 16S, 44 COI, and 49 ITS2 sequences included in the analysis). Only the clade A of R. microplus spread in the Nearctic-Neotropics. Both the K and Lambda's statistics, two measures of phylogenetic signal, support low divergence rates of the tested genes in populations of R. microplus in the Neotropics. These tests demonstrate that genetic diversity of the continental populations does not correlate either with the geographic distance among samples or with environmental variables. The low variability of these genes may be due to a combination of factors like (i) the recent introduction of the tick in the Neotropics, (ii) a large, effective, and fast exchange of populations, and (iii) a low effect of climate on the evolution rates of the target genes. These results have implications for the ecological studies and control of cattle tick infestations.

Their young bite better: On- and off-host selection pressure as drivers for evolutionary-developmental modification in Rhipicephalus ticks

Distinct life stages may experience different selection pressures influencing phenotypic evolution. Morphological evolution is also constrained by early phenotypes, since early development forms the phenotypic basis of later development. This work investigates evolutionary-developmental modification in three life stages and both sexes of 24 Rhipicephalus species using phylogenetic comparative methods for geometric morphometrics of basis capituli (basal mouthpart structure used for host attachment), and scutum or conscutum areas (proxy for overall body size). Findings indicate species using large hosts at early life stages have distinct basis capituli shapes, correlated with host size, enabling attachment to the tough skins of large hosts. Host-truncate species (one- and two-host) generally retain these adaptive features into later life stages, suggesting neoteny is linked to the evolution of host truncation. In contrast, species using small hosts at early life stages have lost these features. Developmental trajectories differ significantly between host-use strategies (niches), and correlate with distinct clades. In two-host and three-host species using large hosts at early life stages, developmental change is heterotopically accelerated (greater cell mass development) before the first off-host period where selection probably favours large individuals able to better resist dehydration when questing (waiting) for less abundant, less active hosts. In other species, development is heterotopically reduced (neotenic), possibly because dehydration risk is bypassed by prolonged host attachment (one-host species - heterotopic neoteny), or is allometrically repatterned possibly by using highly abundant and active hosts (three-host species using small hosts at early life stages - allometric repatterning). These findings highlight complex trade-offs between on- and off-host factors of free-living ectoparasite ecology, which mediate responses to diverse selection pressures varied by life stage and host-use strategy. It is proposed that these trade-offs shape evolutionary-developmental morphology and diversity of Rhipicephalus ticks.

Epidemiologic profile of hard ticks and molecular characterization of Rhipicephalus microplus infesting cattle in central part of Khyber Pakhtunkhwa, Pakistan

Tick infestation is a major public and animal health concern causing significant financial losses, especially in tropical and subtropical regions of the world. This study aimed at investigating the epidemiologic profile of ticks infesting cattle and molecular identification of R. microplus in the centrally ignored part of Khyber Pakhtunkhwa, Pakistan. A total of 600 cattle from 20 farms were examined for the tick infestation, among them 358 (59.7%) cattle were infested with ticks. A total of 2118 nymph, larvae and adult tick stages were collected and morphologically identified followed by molecular confirmation of Rhipicephalus microplus. Host-based demographic and ecological parameter analysis revealed significantly higher tick infestation in adult, female, exotic, freely grazing, and with irregular/no acaricides treated cattle. The univariate logistic analysis showed that host age, gender, breed, acaricides use, and feeding method were significantly (P < 0.05) associated, whereas multivariate analysis revealed only host breed and feeding method were potential risk factors (P < 0.05) for tick infestation. Microscopy-based examination identified four different species of ticks including R. microplus (44.5%), Hyalomma anatolicum (38.5%), and Hyalomma marginatum (10.5%) and Hyalomma excavatum (6.5%). Tick infestation pattern showed that 55.9% of cattle was found co-infested with R. microplus and H. anatolicum followed by R. microplus and H. anatolicum and H. marginatum (29.3%) then R. microplus, H. anatolicum, H. marginatum, and H. excavatum (11.2%). Sequencing of the second internal transcribed spacer (ITS2-) and 16S rRNA gene fragments also confirmed the molecular identification of Rhipicephalus microplus. Phylogenetic analysis of ITS-2 revealed all sequences clustered in single clade of the R. microplus while the 16S rRNA nucleotide sequences showed that R. microplus in this study was clustered together in clade A along with other isolates from Pakistan, China, and India. The high tick infestation suggests the need for designing strategic and integrated control measures for ticks in order to ensure good health of domestic animals in this region of Pakistan.

A cross-sectional survey of hard ticks and molecular characterization of Rhipicephalus microplus parasitizing domestic animals of Khyber Pakhtunkhwa, Pakistan

BACKGROUND

In tropical and subtropical countries, tick infestation causes major public health problems and considerable financial losses to the livestock industry. This study was aimed to assess the species composition of richness and analyze the phylogeny of Rhipicephalus microplus in the District Bannu of Khyber Pakhtunkhwa, Pakistan.

METHODS

Collected ticks were identified morphologically and DNA extracted from R. microplus was amplified and subjected to sequencing.

RESULTS

A total of 3,600 animals were examined among them 1,494 animals were found to be infested with ticks, including 669 cows, 476 buffaloes, 163 goats, and 186 sheep (p = 0.001). Tick infestation was significantly high (43.58%) in animals of age group (<1 year) (p-value = 0.027). Female animals were more (44.05%) infested with ticks than males (34.43%) (p = 0.001). The intensity of infestation was significantly higher in summer (77.49%) (p = 0.001). A total of 5,557 ticks were collected comprising three genera and six species. R. microplus was predominantly prevalent (n = 1,474; 26.52%), followed by Rhipicephalus annulatus (n = 1,215; 21.86%), Hyalomma anatolicum (n = 1,139; 20.49%), Hyalomma marginatum (n = 1,086; 19.54%), and Rhipicephalus turanicus (n = 761; 13.69%), while the least common was Haemaphysalis aciculifer (n = 80; 1.43%) (p = 0.001). Morphologically identified R. microplus species were also analyzed genetically by using two genetic markers 16S ribosomal RNA (16S rRNA) and internal transcribed spacer 2 (ITS2) genes. The phylogenetic study revealed that R. microplus is genetically diversified and clustered in clade B with R. microplus species from China, India, and Pakistan.

CONCLUSION

Ticks infestation was significantly correlated with various factors including age, sex, season, and animal type. R. microplus genetically resembled species reported from India and China. However, major knowledge gaps concerning various species of ticks exist and many areas are still unexplored in Pakistan. Therefore, it is necessary to explore the epidemiological and molecular aspects of various tick species in other regions of southern Khyber Pakhtunkhwa.

Adaptive radiation and speciation in Rhipicephalus ticks: A medley of novel hosts, nested predator-prey food webs, off-host periods and dispersal along temperature variation gradients

Rhipicephalus are a species-diverse genus of ticks, mainly distributed in the Afrotropics with some species in the Palearctic and Oriental regions. Current taxonomic consensus comprise nine informal species groups/lineages based on immature morphology. This work integrates biogeographic, ecological and molecular lines of evidence to better understand Rhipicephalus evolution. Phylogenetic analysis based on four genes (12S, 16S, 28S-D2 and COI) recovered five distinct clades with nine descendant clades that are generally congruent with current taxonomy, with some exceptions. Historical biogeography is inferred from molecular divergence times, ancestral distribution areas, host-use and climate niches of four phylogenetically significant bioclimatic variables (isothermality, annual, seasonal and diurnal temperature range). Novel hosts enabled host-linked dispersal events into new environments, and ticks exploited new hosts through nested predator-prey connections in food webs. Diversification was further induced by climate niche partitioning along gradients in temperature range during off-host periods. Ancestral climate niche estimates corroborated dispersal events by indicating hypothetical ancestors moved into environments with different annual and seasonal temperature ranges along latitudinal gradients. Host size for immature and adult life stages was important for dispersal and subsequent diversification rates. Clades that utilise large, mobile hosts (ungulates and carnivores) early in development have wider geographic ranges but slower diversification rates, and those utilising small, less mobile hosts (rodents, lagomorphs and afroinsectivores) early in development have smaller ranges but higher diversification rates. These findings suggest diversification is driven by a complex set of factors linked to both host-associations (host size, ranges and mobility) and climate niche partitioning along annual and seasonal temperature range gradients that vary with latitude. Moreover, competitive interactions can reinforce these processes and drive speciation. Off-host periods facilitate adaptive radiation by enabling host switches along nested predator-prey connections in food webs, but at the cost of environmental exposure that partitions niches among dispersing progenitors, disrupting geneflow and driving diversification. As such, the evolution and ecological niches of Rhipicephalus are characterised by trade-offs between on- and off-host periods, and these trade-offs interact with nested predator-prey connections in food webs, host-use at different life stages, as well as gradients in annual and seasonal temperature ranges to drive adaptive radiation and speciation.

Mitochondrial sequences of Rhipicephalus and Coxiella endosymbiont reveal evidence of lineages co-cladogenesis

Rhipicephalus ticks are competent vectors of several pathogens, such as Spotted Fever Group Rickettsiae (SFGR) and many Babesia species. Within this genus, different R. sanguineus s.l. lineages show an unequal vector competence and resistance regarding some pathogenic strains. Current literature supports that tick endosymbionts may play an essential role in the transmission ability of a vector. Indeed, the microbial community of Rhipicephalus seems to be dominated by Coxiella-like endosymbionts (CLE). Still, their co-evolutionary associations with the complicated phylogeny of Rhipicephalus lineages and their transmissible pathogens remain unclear. We performed a phylogenetic congruence analysis to address whether divergent R. sanguineus s.l. lineages had a different symbiont composition. For that, we applied a PCR based approach to screen part of the microbial community present in 279 Rhipicephalus ticks from the Iberian Peninsula and Africa. Our analyses detected several qPCR-positive signals for both SFGR and Babesia species, of which we suggest R. sanguineus-tropical lineage as a natural vector of Babesia vogeli and R. sanguineus-temperate lineage of SFGR. The acquisition of 190 CLE sequences allowed to evaluate co-phylogenetic associations between the tick and the symbiont. With this data, we observed a strong but incomplete co-cladogenesis between CLE strains and their Rhipicephalus tick lineages hosts.

Detection of tick-borne pathogens in Rhipicephalus sanguineus sensu lato and dogs from different districts of Portugal

Dogs are highly exposed to pathogens transmitted by ectoparasites. The Mediterranean climate of Southern Europe, together with the presence of stray and/or neglected pets in close proximity with humans, contribute for tick expansion and stand for increased risk to infections in humans due to the zoonotic potential of many of these agents. The aim of this study was to perform a molecular survey in dogs (suspected of tick-borne disease and/or infested with ticks), as well as in ticks collected from those animals, from 12 districts of Portugal to investigate the occurrence of Rickettsia spp. and other tick-borne pathogens (Babesia, Ehrlichia, Anaplasma and Hepatozoon). Additionally, a serological survey of spotted fever group Rickettsia in Portuguese dogs was performed using an in-house immunofluorescence assay (IFA). A total of 200 whole-blood samples and 221 Rhipicephalus sanguineus s. l. ticks were collected from dogs. A total of 14 (7 %) blood samples and 10 (4.5 %) ticks yielded presumptively positive 420-bp amplicons using the Rickettsia spp. partial ompB nested PCR. Screening of the ompB-positive samples using the gltA gene showed 8 positive ticks. All Rickettsia ompB and gltA sequences had the highest identity with R. massiliae. The Rickettsia-positive dogs were further tested for other tick-borne pathogens and were found to be infected with Babesia spp. (n = 5), but not with Ehrlichia, Anaplasma or Hepatozoon. Of the 149 dog serum specimens tested in the serological assay, 103 (69 %) were positive for IgG antibodies against spotted fever group Rickettsia. Antibodies were found in dogs from all the studied districts, in 55 (53 %) of the stray and in 48 (47 %) of the owned dogs. Our study detected and characterized for the first time R. massiliae in dogs from Portugal, broadening the geographical range of this canine pathogen and adding knowledge to the impact of this disease in dogs.

Integrative taxonomy and species delimitation of Rhipicephalus turanicus (Acari: Ixodida: Ixodidae)

Rhipicephalus turanicus ticks are widely distributed across the Palearctic and Afrotropics. These two continental populations display differences in morphological characters that raise the question of a potential species boundary. However, the taxonomic status of these morphologically divergent lineages is uncertain because R. turanicus from Cyprus and Zambia have been shown to interbreed and produce fertile hybrids. We employ integrative taxonomy that considers data from mtDNA sequences (12S and 16S rDNA), geographic distribution, traditional (qualitative) morphology, as well as shape outlines of female spiracles and male adanal plates measured in a geometric morphometric framework (quantitative morphology) to resolve this taxonomic issue. Molecular lines of evidence (12S and 16S rDNA) support taxonomic separation between ticks sampled in the Afrotropics and the Palearctic. This is corroborated by qualitative and quantitative morphology. Within the Palearctic, two sub-lineages were recovered based on sequence data that loosely correspond to southern Europe and the Middle East/Asia. One new species, Rhipicephalus afranicus n. sp. is described from South Africa with a geographic distribution that extends into eastern Africa. This leaves R. turanicus sensu lato comprised of two lineages located in southern Europe and the Middle East/Asia. The type locality for R. turanicus is in Uzbekistan, thus the Middle East/Asia lineage is considered R. turanicus sensu stricto. Detailed descriptions are provided for R. afranicus n. sp. and R. turanicus sensu stricto together with high resolution images. Speciation is attributed to recent Sahara desert expansion that formed a natural barrier to dispersal approximately 5-7 million years ago. However, reproductive potential between these two species suggests that divergence time and mode of speciation were not sufficient for the development of reproductive isolation. We suggest speciation was complicated by divergence and population reintegration events driven by oscillating climatic conditions contributing to reticulate evolution and maintenance of compatibility between reproductive mechanisms. This study represents an integrative (iterative) approach to delimiting Rhipicephalus spp., and provides the first application of shape outlines for female spiracles and male adanal plates measured in a geometric morphometric framework, applied to testing species boundaries between ticks.

Mitochondrial 16S rRNA gene analysis reveals occurrence of Rhipicephalus sanguineus sensu stricto from steppe and high plateaus regions, Algeria

The present study aims to perform comparative genetic characterization for R. sanguineus s.l. infesting Algerian dogs living in steppe and high plateau regions based on mitochondrial 16S rRNA gene sequencing and phylogenetic analysis. In total, 1043 ticks were collected from 147 infested dogs, including 756 ticks from 124 dogs in Djelfa and 287 ticks from 23 dogs in Bordj-Bou-Arreridj. All ticks were morphologically identified as R. sanguineus s.l., and 87 specimens were randomly selected for molecular analysis. Sequences obtained from selected ticks clustered with sequences of R. sanguineus s.l. from France, Germany, Portugal, and Spain, all of which belong to R. sanguineus s.s. The occurrence of R. sanguineus s.s. in Algeria is an interesting result given that most R. sanguineus in Africa cluster among the tropical lineage. This finding should prompt further investigation by exhaustive studies across Algerian territory. Such data can be useful to understand the dispersal route of R. sanguineus s.s. from Europe to North Africa, or whether their occurrence in Algeria is a result of historical biogeography.

Germ cells: a useful tool for the taxonomy of Rhipicephalus sanguineus s.l. and species of the Amblyomma cajennense complex (Acari: Ixodidae)

The systematics of several ticks species (Acari: Ixodidae) remains controversial. Many species, including those of the Amblyomma cajennense complex and Rhipicephalus sanguineus s.l., are given special attention since they are cryptic species complexes and are also important in human and veterinary medicine. The A. cajennense complex was recently reorganized into six valid species, among which Amblyomma patinoi and Amblyomma mixtum have been confirmed in Colombia. On the other hand, the taxonomic status of R. sanguineus s.l. is controversial since it is a cosmopolitan cryptic species complex with a high reproductive capacity and a broad range of hosts (including man). To address this challenge, the germ cells of male ticks display a diverse morphology that offers novel opportunities for taxonomy. This study describes the events of spermatogenesis in A. mixtum and R. sanguineus s.l. individuals collected during active feeding on domestic hosts in the department of Caldas, Colombia. The individuals were identified using dichotomous keys and through PCR amplification of a fragment of the mitochondrial 16S ribosomal DNA gene. The male reproductive systems of A. mixtum and R. sanguineus s.l. were fixed in 2.5% glutaraldehyde for 48 h and dehydrated in increasing dilutions of ethanol. The samples were then embedded and mounted in historesin to obtain sections of 3 μm that were stained with hematoxylin-eosin (HE), photographed, and visualized through optical microscopy. The results show that the morphology of mature germ cells displays excellent diagnostic traits that can be used for tick taxonomy.

Pathogenic Rickettsia in ticks of spur-thighed tortoise (Testudo graeca) sold in a Qatar live animal market

The dissemination of vector arthropods harbouring zoonotic pathogens through the uncontrolled transboundary trade of exotic and pet animals poses an important threat to Public Health. In the present report, we describe the introduction of pathogenic Rickettsia africae and R. aeschlimanni in ticks removed from imported tortoises in Qatar. A total of 21 ticks were collected from pet spur-thighed tortoises (Testudo graeca) from Doha, May 2018, and studied for species identification and characterization of Rickettsia spp. Morphological and molecular analysis of ticks allowed their identification as Hyalomma aegyptium. Molecular analysis of partial ompA and gltA genes showed that Rickettsia sequences found on these ticks clustered with sequences classified as R. aeschilimanii and R. africae. Since pre-adult stages of H. aegyptium also feed on humans, this tick species may play a role in the transmission of R. aeschilimanii and R. africae. We alert for the introduction of non-native pets as vehicles for tick importation, known vectors for animal and human pathogenic agents. Importation of exotic species into non-autochthonous countries deserves strict control to enforce robust surveillance and mitigate potential exotic diseases epidemics.

Seasonal Dynamics, Record of Ticks Infesting Humans, Wild and Domestic Animals and Molecular Phylogeny of Rhipicephalus microplus in Khyber Pakhtunkhwa Pakistan

Although ticks prevalent in various agro-systems of Pakistan are associated with economic losses, information is still missing about the tick's diversity, hosts they infest, seasonal dynamics and molecular phylogeny of Rhipicephalus microplus in Khyber Pakhtunkhwa (KP) Pakistan. This study for the first time enlisted ticks infesting diverse hosts including humans in various regions of KP. A total of 8,641 ticks were collected across the northern, southern and central regions of KP and were morpho-taxonomically categorized into six genera comprising 17 species, R. microplus (n = 3,584, 42%), Hyalomma anatolicum (n = 2,253, 27%), Argas persicus (n = 1,342, 16%), Hya. impeltatum (n = 586, 7%), R. turanicus (n = 161, 2%), R. haemaphysaloides (n = 142, 2%), R. annulatus (n = 132, 2%), Hae. montgomeryi (n = 123, 1.4%), Hya. marginatum (n = 110, 1.3%), R. sanguineus (n = 34, 0.4%), and Hae. longicornis (n = 31, 0.4%). Ticks infesting wild animals included Amblyomma gervaisi, Amb. exornatum, Amb. latum, Dermacentor marginatus, and Hae. indica, while ticks collected from humans included R. microplus, R. annulatus, Hya. anatolicum, Hya. marginatum, and Hae. punctata. The overall prevalence of ticks infesting domestic animals was 69.4% (536/772). Among animal hosts, cattle were found highly infested (87.2%, 157/180) followed by buffalos (79%, 91/114), domestic fowls (74.7%, 112/150), goats (68.3%, 82/120), dogs (66.7%, 32/48), horses (61.3%, 49/80), and sheep (16.3%, 13/80). Analysis revealed that the tick burden significantly differed among domestic animals and was found to be high in cattle, followed by buffalos, goats, sheep, domestic fowl, dogs, and horses. Seasonal patterns of ticks distribution showed highest prevalance in July, August, and September due to the prevailing high temperature and humidity during these months. The phylogenetic analysis of cattle tick R. microplus based on partial mitochondrial cytochrome oxidase subunit I (COX1), 16S ribosomal RNA (16S rRNA) and internal transcribed spacer 2 (ITS2) sequences, revealed that R. microplus prevalent in this region belongs to clade C which include ticks originating from Bangladesh, Malaysia, and India. Further large scale studies across the country are necessary to explore the molecular and cross breeding aspects at the geographical overlapping of various tick species and their associated pathogens to facilitate designing control strategies as well as awareness against tick infestation in the region.

Rhipicephalus sanguineus (Latreille, 1806): Neotype designation, morphological re-description of all parasitic stages and molecular characterization

The aims of this work were to re-describe all parasitic stages of Rhipicephalus sanguineus sensu stricto, to select and deposit a neotype, and to characterize some of its diagnostic molecular traits. A male of R. sanguineus s.s. collected in Montpellier, France, was designated as neotype. The diagnostic characters unique to the male of R. sanguineus s.s. are: spiracular plate elongated and subtriangular in shape with a dorsal prolongation narrow and usually visible dorsally, with the dorsal prolongation narrower than the width of the adjacent festoon; punctations of the scutum moderate in number and unequal in size; marginal groove conspicuous, deep and punctate; posteromedian groove distinct and elongated, and posterolateral grooves often sub-circular, shorter than posteromedian groove; adanal plates long, wide, and subtriangular in shape, with a clear concavity in its inner margin and posterior margin broadly rounded or truncated; accessory adanal plates with the posterior end pointed, narrower than the width of adjacent festoon. The female of R. sanguineus s.s. can be diagnosed by a combination of broadly U-shaped genital aperture, spiracular plate with a narrow dorsal prolongation visible dorsally, basis capituli hexagonal with broad lateral angles, and scutum barely longer than broad with posterior margin sinuous and punctations moderate in number and unequal in size, larger and more numerous along cervical fields. The nymph has a basis capituli sub-triangular dorsally with lateral angles slightly curved and presence of ventral processes, scutum approximately as long as broad with lateral margins nearly straights, posterior margin broadly rounded, and cervical grooves short and sigmoid in shape extending posteriorly to the level of the eyes. The larva is characterized by basis capituli broader than long with lateral angles short and slightly curved and with posterior margin slightly convex, cervical grooves short, shallow and subparallel, and scutum almost twice broader than long. The phylogenetic analysis of DNA sequences support R. sanguineus s.s. as a well-defined taxon when compared with other species of the R. sanguineus group: R. turanicus s.s., R. camicasi, R. guilhoni, R. sulcatus, R. pusillus, R. rossicus and R. leporis. Molecularly R. sanguineus s.s. also encompasses the so-called "temperate lineage" from the New World (Argentina, southern Brazil, Chile, Uruguay, and USA). The evidence currently available supports the presence of R. sanguineus s.s. in Europe (France, Italy, Spain, Switzerland and Portugal) and America (Argentina, Brazil, Chile, Uruguay and U.S.A.), but further studies are needed to determine the exact geographic range of this taxon.