Novel polymorphisms in the octopamine receptor gene of amitraz resistant population of Rhipicephalus sanguineus sensu lato, in south India.

The brown dog tick or Rhipicephalus sanguineus sensu lato is an ixodid tick, responsible for the dissemination of pathogens that cause canine infectious diseases besides inflicting the direct effects of tick bite. The hot humid climate of Kerala, a south Indian state, is favorable for propagation of tick vectors and acaricides are the main stay of tick control. Though the resistance against synthetic pyrethroids is reported among these species, the status of amitraz resistance in R. sanguineus s. l. in the country is uncertain due to the lack of molecular characterisation data and scarce literature reports. Hence the present study was focused on the phenotypic detection and preliminary genotypic characterisation of amitraz resistance in the R. sanguineus s. l. A modified larval packet test (LPT) on a susceptible isolate was performed to determine the discriminating dose (DD). Further LPT-DD on 35 tick isolates was carried out to detect amitraz resistance robustly, along with that full dose response bioassays on the resistant isolates were performed. The results indicated that amitraz resistance is prevalent with 49 per cent of the samples being resistant. Amplification of exon 3 of octopamine receptor gene from both the susceptible and resistant larval isolates was carried out. Amplicons of ten pooled amitraz susceptible and ten pooled amitraz resistant representative samples were sequenced and analysed, unveiling a total of three novel non-synonymous mutations in the partial coding region at positions V32A, N41D and V58I in phenotypically resistant larval DNA samples. In silico analysis by homology modelling and molecular docking of the mutated and unmutated receptors showed that these mutations had reduced the binding affinity to amitraz. However, lack of mutations in the octopamine receptor gene in three of the pooled low order resistant R. sanguineus s. l. larval samples could be suggestive of other mechanisms associated with amitraz resistance in the region. Hence, further association studies should be carried out to confirm the association of these mutations with target insensitivity in R. sanguineus s. l. ticks, along with exploring the status of metabolic resistance and other mechanisms of resistance.

The case of Mediterranean spotted fever of the traveler returned from Zambia.

We report the case of a traveler who returned from Zambia and was diagnosed with Mediterranean spotted fever (MSF), an infectious disease caused by Rickettsia conorii conorii. The patient presented to Sapporo City General Hospital with symptoms of fever, malaise, headache, and rash. The pathogen was identified by Polymerase Chain Reaction assays and subsequent analyses. The patient improved with 10-day treatment of oral doxycycline. Although some cases of MSF have been reported in sub-Saharan Africa, none have been reported in Zambia. Rhipicephalus sanguineus sensu lato, the vector of the Rickettsia conorii conorii, has been found in various areas of Zambia. Our case report highlights the potential threat of Mediterranean spotted fever in urban areas of Zambia.

Immune protection of three serine protease inhibitors vaccine in mice against Rhipicephalus sanguineus.

Bioactive molecules in tick saliva are considered to be key to successful feeding and further the transmission of tick-borne pathogens. Problems such as pathogen transmission and animal weight loss result in tick infestation can cause tremendous economic losses to the livestock industry. Therefore, the development of a universal tick vaccine is urgently needed. In this paper, three serine protease inhibitor (serpin) proteins RMS-3, L7LRK7 and L7LTU1 were analyzed with bioinformatics methods. Subsequently the proteins were expressed and purified, and inoculated into Kunming mice for immune protection analysis. The amino acid sequence similarities between RMS-3, L7LRK7 and L7LTU1 were up to 90% in Rhipicephalus sanguineus. The recombinant RMS-3 + L7LRK7 + L7LTU1 showed anticoagulant reaction function and could inhibit the activity of CD4+ lymphocytes, when inoculated into Kunming mice. Additionally, After the immunized mice were challenged with Rhipicephalus sanguineus, the percentage of larvae and nymphs that were fully engorged dropped to 40.87% (P < 0.05) and 87.68% (P > 0.05) in the RmS-3 + L7LRK7 immune group, 49.57% (P < 0.01) and 52.06% (P < 0.05) in the RmS-3 + L7LTU1 group, and 45.22% (P < 0.05) and 60.28% (P < 0.05) in the RmS-3 + L7LRK7 + L7LTU1 immune group, in comparison with the control group. These data indicate that RmS-3 + L7LRK7 + L7LTU1 has good immune protection and has the potential to be developed into a vaccine against the larvae and nymphs of R. sanguineus.

A mutation associated with resistance to synthetic pyrethroids is widespread in US populations of the tropical lineage of Rhipicephalus sanguineus s.l.

The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.), is an important vector for Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever. Current public health prevention and control efforts to protect people involve preventing tick infestations on domestic animals and in and around houses. Primary prevention tools rely on acaricides, often synthetic pyrethroids (SPs); resistance to this chemical class is widespread in ticks and other arthropods. Rhipicephalus sanguineus s.l. is a complex that likely contains multiple unique species and although the distribution of this complex is global, there are differences in morphology, ecology, and perhaps vector competence among these major lineages. Two major lineages within Rh. sanguineus s.l., commonly referred to as temperate and tropical, have been documented from multiple locations in North America, but are thought to occupy different ecological niches. To evaluate potential acaricide resistance and better define the distributions of the tropical and temperate lineages throughout the US and in northern Mexico, we employed a highly multiplexed amplicon sequencing approach to characterize sequence diversity at: 1) three loci within the voltage-gated sodium channel (VGSC) gene, which contains numerous genetic mutations associated with resistance to SPs; 2) a region of the gamma-aminobutyric acid-gated chloride channel gene (GABA-Cl) containing several mutations associated with dieldrin/fipronil resistance in other species; and 3) three mitochondrial genes (COI, 12S, and 16S). We utilized a geographically diverse set of Rh sanguineus s.l. collected from domestic pets in the US in 2013 and a smaller set of ticks collected from canines in Baja California, Mexico in 2021. We determined that a single nucleotide polymorphism (T2134C) in domain III segment 6 of the VGSC, which has previously been associated with SP resistance in Rh. sanguineus s.l., was widespread and abundant in tropical lineage ticks (>50 %) but absent from the temperate lineage, suggesting that resistance to SPs may be common in the tropical lineage. We found evidence of multiple copies of GABA-Cl in ticks from both lineages, with some copies containing mutations associated with fipronil resistance in other species, but the effects of these patterns on fipronil resistance in Rh. sanguineus s.l. are currently unknown. The tropical lineage was abundant and geographically widespread, accounting for 79 % of analyzed ticks and present at 13/14 collection sites. The temperate and tropical lineages co-occurred in four US states, and as far north as New York. None of the ticks we examined were positive for Rickettsia rickettsii or Rickettsia massiliae.

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.

Rhipicephalus sanguineus from Hungarian dogs: Tick identification and detection of tick-borne pathogens.

The brown dog tick, Rhipicephalus sanguineus is a complex of tick species with an unsettled species concept. In Europe, R. sanguineus is considered mainly a Mediterranean tick with sporadic findings in central and northern Europe. R. sanguineus is known as a vector of a range of pathogens of medical and veterinary importance, most of which not yet reported as autochthonous in Hungary. A total of 1839 ticks collected by veterinarians from dogs and cats were obtained in Hungary. The study aims at precise determination of ticks identified as R. sanguineus and detection of pathogens in collected ticks. All ticks were morphologically determined and 169 individuals were identified as R. sanguineus. A subset of 15 ticks was selected for molecular analysis (16S rDNA, 12S rDNA, COI). Phylogenetic analyses invariably placed sequences of all three markers into a single haplotype identified as R. sanguineus sensu stricto. All 169 brown dog ticks were tested for the presence of A. platys, E. canis, R. conorii, B. vogeli and H. canis. None of the investigated ticks was positive for the screened pathogens, though A. phagocytophilum sequence was detected in a single tick.

Occurrence of Dermacentor reticulatus in central-southern Poland, and potential threats to human and animal health.

INTRODUCTION AND OBJECTIVE: Dermacentor reticulatus is one of the tick species of the greatest epidemiological importance in Europe. To date, the Eastern European and Western European populations of this tick species have been separated by an area located in Poland where the species has never been found. In this study, newly discovered D. reticulatus localities in areas transformed by human activities in central-southern Poland are described. MATERIAL AND METHODS: The specimens of the ornate dog tick were identified among ticks collected from companion animals in 2010, 2012, 2013, and 2014. They were examined using PCR methods to detect Borrelia burgdorferi s.l., Rickettsia spp., Anaplasma phagocytophilum, Bartonella spp., Babesia spp., and Toxoplasma gondii. In the case of the positive results, the amplicons were sequenced and examined by a BLAST search. RESULTS: In total, 6 specimens of D. reticulatus were collected (3 females and 3 males). As declared by the owners, animal hosts stayed in the same area throughout the study period and had never travelled outside their place of residence. As many as 3/6 (50%) of D. reticulatus adults removed from dogs were infected with Rickettsia raoultii. CONCLUSIONS: The results expand the available data on the spread of the ornate dog tick and indicate that, since 2010, this tick species and Rickettsia raoultii transmitted by this tick species have probably been present in this area, which has a strongly transformed agricultural structure and and had previously been regarded as a D. reticulatus-free zone. The presence of the ornate dog tick in urban and suburban habitats in central-southern Poland poses new threats to the health of companion animals and humans associated with the transmission of pathogens by this species.

Encapsulation of carvacrol and thymol with yeast cell wall and its repellent activity against Amblyomma sculptum and Rhipicephalus sanguineus (Sensu Lato).

The main way to avoid contact with ticks and consequently tick-borne disease is the use of synthetic repellents. The search of new repellent compounds to increase the possibilities of use in strategies controls are necessary. The present study evaluated the repellent activity of two natural terpenes carvacrol and thymol in each one two different formulation (encapsulated and nonencapsulated with yeast cell wall) against the ticks Amblyomma sculptum and Rhipicephalus sanguineus sensu lato nymphs. Nymphs of A. sculptum and R. sanguineus s.l. of a single generation were used. The vertical filter paper repellency assay were performed with different concentration of both terpenes encapsulated and nonencapsulated in yeast cell wall. The repellent concentration 50% (RC50) were calculated to each compound formulation. Both carvacrol and thymol (encapsulated and nonencapsulated), had a repellent activity against A. sculptum and R. sanguineus s.l nymphs. Amblyomma sculptum was more sensitive to nonencapsulated carvacrol (RC50 values: 0.0032 to 0.0082 mg/cm2 after 1 and 15 min) (P < 0.05), while R. sanguineus s.l. was more sensitive to encapsulated carvacrol (RC50 values: 0.00008 to 0.0035 mg/cm2 after 1 and 15 min) (P < 0.05). Among tick species, R. sanguineus s.l. was more sensitive for most compounds than A. sculptum (P < 0.05). Although with distinct repellent activities, carvacrol and thymol encapsulated can be a promising alternative to synthetic repellents against A. sculptum and R. sanguineus s.l.

Parasitism on domestic cats by Amblyomma auricularium and serological evidence of exposure to Rickettsia amblyommatis.

The domestic cat is not considered a primary host for any specific tick species; however, it can be affected by some Ixodidae species, such as Rhipicephalus sanguineus sensu lato and Amblyomma spp. The study reports parasitism by Amblyomma auricularium and the detection of anti-Rickettsia spp. antibodies in domestic cats from a rural property in the Afrânio municipality, Pernambuco, Brazil. Amblyomma auricularium (24 nymphs, six females, and four males) and Amblyomma sp. (42 larvae) parasitized three cats, and 73 free-living ticks were captured in armadillo burrows: A. auricularium (36 nymphs, six females, five males) and Amblyomma sp. (26 larvae). Blood samples from cats were collected and the obtained plasma were subjected to indirect immunofluorescence assay (IFA) to detect antibodies against Rickettsia antigens. Thus, anti-Rickettsia spp. antibodies were determined (titers ranging from 128 to 512) and showed a predominant antibody response to Rickettsia amblyommatis or a very closely related genotype. This study reports the first infestation of nymphs and adults of A. auricularium on cats in a new area of occurrence in the semi-arid region of Northeastern Brazil and reports for the first time the presence of anti-Ricketsia antibodies in cats in the region, with R. amblyommatis as the probable infectious agent.

What's Eating You? Rhipicephalus Ticks Revisited.

Rhipicephalus ticks are vectors of disease in humans and animals. Rhipicephalus sanguineus sensu lato (the brown dog tick) is one of the most geographically widespread tick species worldwide, likely due to its ability to colonize human and canine dwellings over a range of habitats. They transmit a variety of diseases to dogs and humans, including canine babesiosis, canine monocytic ehrlichiosis, hepatozoonosis, Mediterranean spotted fever, and Rocky Mountain spotted fever. Tick bites manifest as intensely pruritic, erythematous papules at the site of tick attachment; symptomatic relief usually can be achieved with topical antipruritics. Prevention of tick bites is best achieved through a combination of veterinary and environmental control; protective clothing; repellents, such as N,N-diethyl-meta-toluamide (DEET) and permethrin; and prompt identification and removal of ticks.

Roaming Dogs, Intense Brown Dog Tick Infestation, and Emerging Rocky Mountain Spotted Fever in Tijuana, México.

A two decades-long epidemic of Rocky Mountain spotted fever in northern México reached the U.S. border city of Tijuana in 2021. Cases were near the city periphery in marginalized areas, some lacking infrastructure such as streets or utilities. We worked in the three census areas where human cases were reported and in 12 additional control Áreas Geoestadisticas Básicas. There were dogs, the primary tick host and Rickettsia rickettsii reservoir, in 76% of homes, with 2.2 owned dogs per home on average, approximately equal numbers of roaming dogs were seen, and 46.2% of owned dogs were allowed to roam in the street. Sixty-eight percent of people had heard of Rocky Mountain spotted fever (RMSF), and 35% self-reported tick infestation, including 19% of homes without dogs. Ticks appeared to move among houses of adjacent neighbors. Of 191 examined dogs, 61.8% were tick-infested, with 6-fold increased odds if they were allowed to roam. Although no dogs were Rickettsia polymerase chain reaction-positive, we found one R. rickettsii- and 11 Rickettsia massiliae-infected ticks. The rickettsial IgG seroprevalence by immunofluorescence antibody assay was 76.4%, associated with unhealthy body condition, adults, dogs with >10 ticks, more dogs being seen in the area, and dogs being permitted in the street. Insufficient medical and canine management resources have contributed to a case fatality rate of RMSF that has exceeded 50% in areas. High canine seroprevalence suggests risks to people and dogs; unfortunately, herd immunity is impeded by high turnover in the canine population owing to the birth of puppies and high death rates. Binational One Health workers should monitor disease spread, enact canine population management and tick eradication, and provide prevention, diagnostic, and treatment support.

Effect of an altitudinal gradient on the morphology, molecular identification and distribution of Rhipicephalus linnaei in Veracruz, Mexico.

Studies of morphological and genetic variation in vector populations across environmental gradients can help researchers to estimate species' responses to climate change scenarios and the potential risk of disease-causing pathogen expansion, which impacts negatively on human health. In this study, we analysed the effect of altitudinal gradients on the phenotypic response of the hard tick of medical and veterinary importance, Rhipicephalus sanguineus sensu lato (s.l.). Specimens of R. sanguineus s.l. were collected from host animals in one of Mexico's regions with high climatic heterogeneity (Veracruz), and geometric morphometric theory was employed to assess the response of three morphological characters to the altitudinal gradient. Additionally, genetic similarity data were provided, and ecological niche models were used to project the climatic distribution in the region. Our results demonstrate that the shape and size of ticks respond to altitude. Molecular identification indicate that all analysed samples correspond to the tropical lineage recently named Rhipicephalus linnaei. According to ecological niche models, the mean annual temperature contributes significantly to the spatial distribution of this tick species, with areas of higher suitability in the mountainous region. These changes in morphological structure and the presence of ticks at higher altitudinal gradients suggest that R. linnaei has a high potential for adaptation. Due to the variability of ecosystems in the state of Veracruz, our results could be valuable in assessing the response of this tick in a changing environment, aiding in predicting future scenarios in the distribution and abundance of this species.

Mixed-sex clusters on grass blades: breeding strategy of the ornate dog tick, Dermacentor reticulatus.

BACKGROUND: The ornate dog tick Dermacentor reticulatus is second only to the hard tick Ixodes ricinus in terms of importance as a vector of infectious organisms, especially of Babesia canis, the agent of canine babesiosis. Both the geographical range and local densities of D. reticulatus are steadily increasing in many regions of Europe. In the present study, we tested the hypothesis that D. reticulatus possesses an efficient breeding strategy that allows for a rapid increase in tick numbers and densities through the formation of mixed-sex clusters/aggregations while questing in the environment. METHODS: An observational study was carried out in the spring of 2023, at three sites in two regions in Central and North-Eastern Poland, both characterised by high tick densities. At each site, a 400-m-long transect was inspected for questing ticks. All noted ticks were collected, and tick numbers and sexes per stem were recorded. Differences in tick distribution by site and sex were analysed statistically. RESULTS: A total of 371 D. reticulatus (219 females, 152 males) ticks were collected from 270 grass stems over a combined 1200 m of transect. The majority of grass stems (74.4%) were occupied by just a single individual, with two-tick clusters the second most common category. The maximum number of D. reticulatus individuals observed on a single grass stem was six. Mixed-sex clusters were significantly more common than single-sex clusters at all three sites. With study sites combined, mixed-sex clusters accounted for 17.4% (95% confidence limit [95% CL] 13.9-21.6%) of observations, while for multiple males and multiple females, the values were 2.6% (95% CL: 1.4-4.7%) and 5.6% (95% CL: 3.7-8.3%), respectively. CONCLUSIONS: Mixed-sex clusters of D. reticulatus ticks were significantly more common than single-sex clusters, which we hypothesise reflects an efficient, likely pheromone-mediated breeding strategy of this expansive tick species.

Molecular detection of Coxiella burnetii in ticks collected from Iran.

The present study was conducted with the aim of investigating the prevalence and genetic structure of Coxiella burnetii in tick samples collected from domestic animals in Hormozgan province146 tick samples were randomly collected from cattle, sheep, goat, camel and dog herds in seven cities of Hormozgan. After the DNA was extracted from each tick sample; Nested-PCR method was used to identify the presence of C. burnetii using IS1111 transposon gene and isocitrate dehydrogenase icd gene. In addition, phylogenetic analysis and tree diagram were constructed based on IS1111 and icd genes. The results showed that out of 146 pool tick samples, 40 pool samples based on IS1111 gene and 32 pool samples based on icd gene were infected with C. burnetii. When results were stratified by livestock type, infection rates were highest in sheep ticks (37.5%, 95% CI: 21.2% - 57.29%), followed by cattle ticks (32.14%, 95% CI: 17.90% - 50.66%) and dog tick (15%, 95% CI: 70.6% - 29%). In camel and goat ticks, the infection rate was 15.90 and 23.07%, respectively. In conclusion, this study emphasizes the role of ticks as potential carriers of C. burneti. The results indicate the importance of cattle, sheep, goats, camels and dogs in Hormozgan region as effective factors in the epidemiology of Q fever and its impact on public health. In addition, a high degree of similarity (from 99% to 100%) was observed between IS1111 and icd genes in this study and recorded sequences from different regions of the world.

Larvicidal and repellent effects of essential oils on the brown dog tick (Rhipicephalus sanguineus Sensu lato) with description of new larval repellent activity test method.

The aim of this research was to investigate the larvicidal and repellent effects of essential oils (EOs) obtained from two Lamiaceae plant species, Origanum minutiflorum O. Schwarz & P.H. Davis and Dorystoechas hastata Boiss. & Heldr. ex Bentham, both endemic to Turkey, on Rhipicephalus sanguineus s.l. Latreille (Acari: Ixodidae). The study also introduces a new test method that can be used to assess the repellent effects against ticks. Both plant EOs exhibited the highest larvicidal activity against brown dog tick larvae after 24 h and LC50 and LC90 values were determined as 0.101% and 0.125% for O. minutiflorum essential oil and 0.937% and 2.1% for D. hastata essential oil, respectively. In this study, we have described a detailed protocol for a novel larval repellent activity test (LRAT) for essential oils and extracts, using simple equipment. The advantages and limitations of LRAT, when compared to other tests commonly used to determine repellent effect against ticks, are also included in this study. The LRAT was developed with modifications of the larval immersion test (LIT) and proves to be a highly efficient and easily observable method. It can be used to test any active substance that may be toxic to humans and animals. According to the LRAT, at the end of 3 h, O. minutiflorum essential oil showed a high repellent effect, varying between 84.14% and 100% at 1% concentration. This result was not statistically different from the DEET, the positive control. When comparing the larvicidal and repellent activities, O. minutiflorum essential oil was found to be more effective than D. hastata essential oil.

Multiple species of canine Rhipicephalus complex detected in Canada.

Multiple species of brown dog ticks have been described in the United States and the Caribbean: Rhipicephalus sanguineus sensu stricto (s.s.), also referred to as temperate lineage; R. linnaei (=tropical lineage); and R. rutilus (=southeastern Europe lineage) However, Rhipicephalus spp. are rarely recovered from dogs in Canada. To identify canine Rhipicephalus spp. in Canada and determine the influence of travel history on infestation, ticks morphologically identified as brown dog ticks (n = 93) collected from dogs (n = 13) in British Columbia, Ontario, and Québec, Canada were submitted with information regarding each dog's geographic location and travel history. Nucleic acid was extracted from available individual ticks (n = 86) and PCR was used to amplify sequences of a 12S rRNA mitochondrial gene fragment. Sequences were compared to published reference sequences of known species and a phylogenetic tree constructed. Twenty-three ticks (26.7%) consistent with R. linnaei were identified on seven dogs, including dogs from British Columbia and Ontario, with a median infestation intensity of 2 ticks/dog (mean = 3.3 ticks/dog). Sixty-one ticks (70.9%) consistent with R. sanguineus s.s. were found on two dogs from Québec and Ontario (median = 30.5 ticks/dog; mean = 30.5 ticks/dog). One dog from Ontario was infested with R. rutilus (n = 2) (2.3%). Species could not be determined for ticks from three dogs from Ontario and Québec. Most infested dogs (10/13; 76.9%) had a recent (< 1 month) international travel history. These data confirm that multiple species of canine Rhipicephalus are occasionally found in Canada and suggest introduction following travel is likely responsible for these infestations. Further analysis will allow for greater understanding of the range and diversity of canine Rhipicephalus spp. in North America and may reveal risk factors for infestation.

Distribution of Rhipicephalus sanguineus and Heamaphysalis elliptica dog ticks and pathogens they are carrying: A systematic review.

The role of ixodid ticks especially Rhipicephalus sanguineus and Heamaphysalis elliptica in the epidemiology of several diseases of veterinary and public health importance have been documented. This study conducted a systematic review focusing on the distribution of R. sanguineus and H. elliptica, as well as the common tick-borne pathogens they harbour. The Scopus, ScienceDirect, PubMed, and Web of Science databases were used to search for English journal articles published between January 1990 and June 2021. The articles were assessed by following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This systematic review was registered on PROSPERO [(ID no: CRD42022327372). Of the studies included in the systematic review, 247 and 19 articles had identified R. sanguineus and H. elliptica respectively, whereas 15 articles had identified both tick species. There is a reported worldwide distribution of R. sanguineus from 64 countries, whereas H. elliptica was only reported in the African continent from 6 countries. In total, 120 articles that were included in this systematic review reported detection of tick-borne pathogens from R. sanguineus (n = 118 articles) and/or H. elliptica (n = 2 articles) ticks. According to the studies tick-borne pathogens harboured by R. sanguineus included protozoa such as Babesia spp., Hepatozoon spp., Leishmania spp., and Theileria spp., as well as bacteria such as Acinetobacter spp. Anaplasma spp., Bacillus spp., Borrelia spp., Brucella spp., Coxiella spp., and Staphylococcus spp. The H. elliptica was reported to be harbouring Babesia spp., Ehrlichia spp. and Rickettsia spp. Most of the studies (50%) used the conventional polymerase chain reaction (PCR) technique for the detection of tick-borne pathogens, followed by real-time PCR (qPCR) (n = 26), and nested PCR (n = 22). This systematic review has shed light on the distribution of two common dog ticks as well as the tick-borne pathogens of veterinary and zoonotic importance they are harbouring. This data will enable surveillance studies that can report whether the distribution of these ticks and their associated tick-borne pathogens is expanding or shrinking or is stable.

Survey on tick infestation in stray dogs in localities of Malaysia.

The close relationship between dogs and humans has led to concerns regarding the transmission of zoonotic pathogens through ectoparasites such as ticks. This study aimed to investigate the occurrence of ticks and the intensity on stray dogs with specific risk factors (size, sex, neutering status, body part). Additionally, identifying the predilection sites of ticks on stray dogs was crucial for developing an effective tick control program in Malaysia. A cross-sectional study was conducted among 64 stray dogs from Kelantan and Selangor States. These dogs were subjected to integumentary examinations, collecting 431 ticks comprising Rhipicephalus sanguineus s.l. "tropical lineage" and Haemaphysalis bispinosa from 53 infested dogs. The overall occurrence of tick infestation was 82.81% (53/64), with an average intensity of 8.13 ticks (range: 1-17) per stray dog. All the potential risk factors considered in this study showed no statistically significant result (P value >0.05). The head, ear, and neck were the most preferred attachment sites for ticks. These findings underscore the importance of implementing tick control programs for stray dogs, which serve as reservoirs of ticks and tick-borne pathogens for owned dogs and humans.

Microfluidic PCR and network analysis reveals complex tick-borne pathogen interactions in the tropics.

BACKGROUND: Ixodid ticks, particularly Rhipicephalus sanguineus s.l., are important vectors of various disease-causing agents in dogs and humans in Cuba. However, our understading of interactions among tick-borne pathogens (TBPs) in infected dogs or the vector R. sanguineus s.l. remains limited. This study integrates microfluidic-based high-throughput real-time PCR data, Yule's Q statistic, and network analysis to elucidate pathogen-pathogen interactions in dogs and ticks in tropical western Cuba. METHODS: A cross-sectional study involving 46 client-owned dogs was conducted. Blood samples were collected from these dogs, and ticks infesting the same dogs were morphologically and molecularly identified. Nucleic acids were extracted from both canine blood and tick samples. Microfluidic-based high-throughput real-time PCR was employed to detect 25 bacterial species, 10 parasite species, 6 bacterial genera, and 4 parasite taxa, as well as to confirm the identity of the collected ticks. Validation was performed through end-point PCR assays and DNA sequencing analysis. Yule's Q statistic and network analysis were used to analyse the associations between different TBP species based on binary presence-absence data. RESULTS: The study revealed a high prevalence of TBPs in both dogs and R. sanguineus s.l., the only tick species found on the dogs. Hepatozoon canis and Ehrlichia canis were among the most common pathogens detected. Co-infections were observed, notably between E. canis and H. canis. Significant correlations were found between the presence of Anaplasma platys and H. canis in both dogs and ticks. A complex co-occurrence network among haemoparasite species was identified, highlighting potential facilitative and inhibitory roles. Notably, H. canis was found as a highly interconnected node, exhibiting significant positive associations with various taxa, including A. platys, and E. canis, suggesting facilitative interactions among these pathogens. Phylogenetic analysis showed genetic diversity in the detected TBPs. CONCLUSIONS: Overall, this research enhances our understanding of TBPs in Cuba, providing insights into their prevalence, associations, and genetic diversity, with implications for disease surveillance and management.

First report of dog ticks and tick-borne pathogens they are carrying in Malawi.

Ticks are vectors for transmitting tick-borne pathogens (TBPs) in animals and humans. Therefore, tick identification is necessary to understand the distribution of tick species and the pathogens they carry. Unfortunately, data on dog ticks and the TBPs they harbor in Malawi are incomplete. This study aimed to identify dog ticks and the TBPs they transmit in Malawi. One hundred thirty-two ticks were collected from 87 apparently healthy but infested domestic dogs in four districts of Malawi, which were pooled into 128 tick samples. The ticks were morphologically identified under a stereomicroscope using identification keys, and species identification was authenticated by polymerase chain reaction (PCR) through the amplification and sequencing of 12S rRNA and cytochrome c oxidase subunit I (CO1) genes. The tick species identified were Rhipicephalus sanguineus sensu lato (58.3%), Haemaphysalis elliptica (32.6%), and Hyalomma truncatum (9.1%). Screening for TBPs using species-specific PCR assays revealed that 48.4% of the ticks were infected with at least one TBP. The TBP detection rates were 13.3% for Anaplasma platys, 10.2% for Babesia rossi, 8.6% for B. vogeli, 6.3% for Ehrlichia canis, 3.9% for A. phagocytophilum, 3.1% for B. gibsoni, 2.3% for B. canis and 0.8% for Hepatozoon canis. Co-infections of up to three pathogens were observed in 48.4% of the positive samples. This is the first study to identify dog ticks and the TBPs they harbor in Malawi. These findings provide the basis for understanding dog tick distribution and pathogens they carry in Malawi. This study necessitates the examination of ticks from more study locations to have a better picture of tick challenge, and the development of ticks and tick-borne disease control methods in Malawi.