Rickettsial agents in Egyptian ticks collected from domestic animals

Molecular detection of Coxiella burnetii in ticks infesting wild and domestic animals in the Eastern region of Punjab, Pakistan

Tick-borne pathogens are significant for human, veterinary, and wildlife health. Coxiella burnetii is an example that is widely distributed across various hosts and can cross species boundaries. In Pakistan, there is a scarcity of data regarding C. burnetii at the intersection of wildlife and livestock. Ticks were collected from ruminants and wildlife from the districts of Kasur, Pakpattan, and Okara in Pakistan. Five tick species totaling 571 ticks were collected, with the following distribution: 56.4% Hyalomma anatolicum, 22.4% Rhipicephalus microplus, 10.5% Hyalomma marginatum, 7.9% Rhipicephalus sanguineus, and 2.8% Rhipicephalus turanicus. Fifty tick pools were screened for C. burnetii to amplify a segment of the IS1111 using real-time PCR assays. Ticks collected from sheep and goats had a greater rate of positivity for C. burnetii (40% and 38%, respectively) compared to Indian long-eared hedgehogs with a prevalence of 2%. Coxiella burnetii was prominent in Rhipicephalus microplus (92.3%) and Hyalomma anatolicum (88.9%), followed by Rhipicephalus turanicus (66.6%), Rhipicephalus sanguineus (33.3%), and Hyalomma marginatum (25.0%). Ticks from Pakpattan district displayed the highest prevalence of C. burnetii (88.9%), whereas the lowest was observed in ticks from Kasur district (77.3%). There was no significant association between tick gender and C. burnetii infection. Female host animals were more likely to harbor ticks containing C. burnetii, with a prevalence rate of 81.8%. The research underscores the urgent need for comprehensive studies on C. burnetii in Pakistan, especially at the interface of wildlife and livestock. The high prevalence rates observed in certain tick species and geographic regions emphasize the importance of targeted public health interventions. Future research should focus on elucidating the transmission dynamics and implementing effective control measures to mitigate the impact of these pathogens on human, veterinary, and wildlife health in the region.

Assessment of cattle tick infestation: Molecular insights into Rhipicephalus annulatus and the efficacy of garlic oil and nanoemulsion as acaricidal agents

Ticks, particularly Rhipicephalus annulatus, pose significant threats to livestock, causing economic losses and transmitting various infectious diseases. This study aimed to evaluate the potential acaricidal properties of garlic oil and its nanoemulsion against ticks infesting cattle, Rhipicephalus annulatus through the evaluation of mortality rate and morphological changes of the treated ticks. The study also included prevalence, risk factors, and molecular confirmation of tick species. Genetic characterization confirmed the identity of R. annulatus. Our results revealed a high prevalence of R. annulatus (46.9%) with a higher risk in male cattle (50%) than females (44.9%) and a nonsignificant high infection (49.1%) in animals ≤ 1 year old. The acaricidal efficiency of garlic oil and its nanoemulsion was concentration and time-dependent. The high concentration of garlic oil (20 mg/L) induced complete mortality within 48 hours. The nanoemulsion formulation enhanced efficacy, particularly at 5 mg/L, which exhibited rapid and substantial acaricidal activity. Scanning electron microscopy revealed morphological alterations induced by garlic oil and its nanoemulsion, including changes to the anterior capitulum, dorsal, and ventral cuticles. The study contributes to the exploration of effective, safe, and eco-friendly alternatives for tick control. Further research is warranted to validate their efficacy under diverse conditions and assess practical strategies.

Hard Tick Species Parasitism Levels in Domestic Ruminants with Their Distribution and Role as Vectors: A Detailed Global Meta-analysis and Systematic Review

PURPOSE

This comprehensive global meta-analysis reviews the parasitism levels of tick genera and species, life stages, seasonality, attachment sites, the global mean ranks of tick species parasitism rates and records, and their distribution and role as vectors.

METHODS

From the 418 papers identified, 390 papers were selected to become part of the study.

RESULTS

The genera recorded as infesting domestic ruminants were Rhipicephalus (42 species), Haemaphysalis (32 species), Hyalomma (19 species), Amblyomma (18 species), Ixodes (10 species), Dermacentor (8 species), Margaropus and Nosomma (1 species). Globally, domestic ruminants are more infested by adult females and males than by the nymphal and larval stages of the tick species. The global tick species parasitism levels at the attachment sites of domestic ruminants were, in order, tail and anal region, neck and dewlap, scrotum or udder, ear region, thigh and abdomen, and dorsal surface.

CONCLUSIONS

Among 131 species of eight genera of hard ticks recorded infesting domestic ruminants, 42 species had mean ranks of tick species parasitism rates up to 10%, and 37 species had mean ranks of tick species parasitism up to 10 records. Briefly, the higher the indexes of tick species parasitism rates and records, the more important their role as vectors. In addition, the majority of them are found among tick species-infested humans with nearly high ranks of tick species parasitism rates and records that double their medical, veterinary, and zoonotic importance to be the most common vectors and reservoirs of bacterial, protozoan, and viral pathogenic microorganisms, causing severe infectious diseases, and as a result, can be more dangerous to humans and domestic ruminants.

Distribution of different Rickettsia species in countries of the WHO Eastern Mediterranean (WHO-EMRO) region: An overview

SUBJECT

Rickettsia is a zoonotic bacterial pathogen transmitted by vectors and has extensive reservoirs in animal and human populations. Rickettsiosis is a public health problem all over the world. However, comprehensive information on the geographical distribution of different Rickettsia species, infection status of reservoirs, vectors, and human cases is lacking in most parts of the world. Therefore, this study aimed to investigate the geographical distribution of different Rickettsia species and their vectors in countries of the WHO-EMRO region.

METHODS

In this review study, a search was conducted for reports and published studies on Rickettsia species from WHO-EMRO region countries in various databases from 1995 to 2022. Finally, the reported status of human cases, reservoirs, and vectors associated with each species in different countries was documented.

RESULTS

Reports of infections related to the detection of Rickettsia species were only available for 15 out of 22 WHO-EMRO member countries. A total of twenty-four Rickettsia species, including R. sibrica, R. lusitaniae, R. africae, R. prowazekii, R. felis, R. typhi, R. rickettsii, R. aeschlimannii, R. conorii, R. massiliae, R. helvetica, R. monacensis, R. rhipicephali, R. bellii, R. asembonensis, R. hoogstraalii, R. andeanae, R. raoultii, R. asiatica, R. slovaca, R. australis, R. barbariae, Candidatus R. amblyommii, and Candidatus R. goldwasserii, were reported from WHO-EMRO member countries. Furthermore, human cases infected with six different Rickettsia species, including R. sibrica, R. prowazekii, R. felis, R. typhi, R. rickettsii, R. aeschlimannii, R. conorii, R. massiliae, and R. helvetica, were reported from these countries.

CONCLUSION

The vast diversity of Rickettsia vectors has contributed to the ongoing discovery of new Rickettsia species. Therefore, further research on the reservoir hosts of Rickettsia infections in the understudied WHO-EMRO region is crucial. This research sheds light on Rickettsia disease's epidemiology and transmission dynamics in this region.

First report of spotted fever group Rickettsia aeschlimannii in Hyalomma turanicum, Haemaphysalis bispinosa, and Haemaphysalis montgomeryi infesting domestic animals: updates on the epidemiology of tick-borne Rickettsia aeschlimannii

Tick-borne Rickettsia spp. have long been known as causative agents for zoonotic diseases. We have previously characterized Rickettsia spp. in different ticks infesting a broad range of hosts in Pakistan; however, knowledge regarding Rickettsia aeschlimannii in Haemaphysalis and Hyalomma ticks is missing. This study aimed to obtain a better understanding about R. aeschlimannii in Pakistan and update the knowledge about its worldwide epidemiology. Among 369 examined domestic animals, 247 (66%) were infested by 872 ticks. Collected ticks were morphologically delineated into three genera, namely, Rhipicephalus, Hyalomma, and Haemaphysalis. Adult females were the most prevalent (number ₌ 376, 43.1%), followed by nymphs (303, 34.74%) and males (193, 22.13%). Overall, genomic DNA samples of 223 tick were isolated and screened for Rickettsia spp. by the amplification of rickettsial gltA, ompA, and ompB partial genes using conventional PCR. Rickettsial DNA was detected in 8 of 223 (3.58%) ticks including nymphs (5 of 122, 4.0%) and adult females (3 of 86, 3.48%). The rickettsial gltA, ompA, and ompB sequences were detected in Hyalomma turanicum (2 nymphs and 1 adult female), Haemaphysalis bispinosa (1 nymph and 1 adult female), and Haemaphysalis montgomeryi (2 nymphs and 1 adult female). These rickettsial sequences showed 99.71-100% identity with R. aeschlimannii and phylogenetically clustered with the same species. None of the tested Rhipicephalus microplus, Hyalomma isaaci, Hyalomma scupense, Rhipicephalus turanicus, Hyalomma anatolicum, Rhipicephalus haemaphysaloides, Rhipicephalus sanguineus, Haemaphysalis cornupunctata, and Haemaphysalis sulcata ticks were found positive for rickettsial DNA. Comprehensive surveillance studies should be adopted to update the knowledge regarding tick-borne zoonotic Rickettsia species, evaluate their risks to humans and livestock, and investigate the unexamined cases of illness after tick bite among livestock holders in the country.

Microorganisms associated with hedgehog arthropods

Hedgehogs are small synanthropic mammals that live in rural areas as well as in urban and suburban areas. They can be reservoirs of several microorganisms, including certain pathogenic agents that cause human and animal public health issues. Hedgehogs are often parasitized by blood-sucking arthropods, mainly hard ticks and fleas, which in turn can also carry various vector-born microorganisms of zoonotic importance. Many biotic factors, such as urbanization and agricultural mechanization, have resulted in the destruction of the hedgehog's natural habitats, leading these animals to take refuge near human dwellings, seeking food and shelter in parks and gardens and exposing humans to zoonotic agents that can be transmitted either directly by them or indirectly by their ectoparasites. In this review, we focus on the microorganisms detected in arthropods sampled from hedgehogs worldwide. Several microorganisms have been reported in ticks collected from these animals, including various Borrelia spp., Anaplasma spp., Ehrlichia spp., and Rickettsia spp. species as well as Coxiella burnetii and Leptospira spp. As for fleas, C. burnetii, Rickettsia spp., Wolbachia spp., Mycobacterium spp. and various Bartonella species have been reported. The detection of these microorganisms in arthropods does not necessarily mean that they can be transmitted to humans and animals. While the vector capacity and competence of fleas and ticks for some of these microorganisms has been proven, in other cases the microorganisms may have simply been ingested with blood taken from an infected host. Further investigations are needed to clarify this issue. As hedgehogs are protected animals, handling them is highly regulated, making it difficult to conduct epidemiological studies on them. Their ectoparasites represent a very interesting source of information on microorganisms circulating in populations of these animals, especially vector-born ones.

Anaplasma Species in Africa-A Century of Discovery: A Review on Molecular Epidemiology, Genetic Diversity, and Control

Anaplasma species, belonging to the family Anaplasmataceae in the order Rickettsiales, are obligate intracellular bacteria responsible for various tick-borne diseases of veterinary and human significance worldwide. With advancements in molecular techniques, seven formal species of Anaplasma and numerous unclassified species have been described. In Africa, several Anaplasma species and strains have been identified in different animals and tick species. This review aims to provide an overview of the current understanding of the molecular epidemiology and genetic diversity of classified and unclassified Anaplasma species detected in animals and ticks across Africa. The review also covers control measures that have been taken to prevent anaplasmosis transmission on the continent. This information is critical when developing anaplasmosis management and control programs in Africa.

An Update of Evidence for Pathogen Transmission by Ticks of the Genus Hyalomma

Current and likely future changes in the geographic distribution of ticks belonging to the genus Hyalomma are of concern, as these ticks are believed to be vectors of many pathogens responsible for human and animal diseases. However, we have observed that for many pathogens there are no vector competence experiments, and that the level of evidence provided by the scientific literature is often not sufficient to validate the transmission of a specific pathogen by a specific Hyalomma species. We therefore carried out a bibliographical study to collate the validation evidence for the transmission of parasitic, viral, or bacterial pathogens by Hyalomma spp. ticks. Our results show that there are very few validated cases of pathogen transmission by Hyalomma tick species.

Distribution and Prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African Ticks: A Systematic Review and Meta-Analysis

In Africa, ticks continue to be a major hindrance to the improvement of the livestock industry due to tick-borne pathogens that include Anaplasma, Ehrlichia, Rickettsia and Coxiella species. A systemic review and meta-analysis were conducted here and highlighted the distribution and prevalence of these tick-borne pathogens in African ticks. Relevant publications were searched in five electronic databases and selected using inclusion/exclusion criteria, resulting in 138 and 78 papers included in the qualitative and quantitative analysis, respectively. Most of the studies focused on Rickettsia africae (38 studies), followed by Ehrlichia ruminantium (27 studies), Coxiella burnetii (20 studies) and Anaplasma marginale (17 studies). A meta-analysis of proportions was performed using the random-effects model. The highest prevalence was obtained for Rickettsia spp. (18.39%; 95% CI: 14.23–22.85%), R. africae (13.47%; 95% CI: 2.76–28.69%), R. conorii (11.28%; 95% CI: 1.77–25.89%), A. marginale (12.75%; 95% CI: 4.06–24.35%), E. ruminantium (6.37%; 95% CI: 3.97–9.16%) and E. canis (4.3%; 95% CI: 0.04–12.66%). The prevalence of C. burnetii was low (0%; 95% CI: 0–0.25%), with higher prevalence for Coxiella spp. (27.02%; 95% CI: 10.83–46.03%) and Coxiella-like endosymbionts (70.47%; 95% CI: 27–99.82%). The effect of the tick genera, tick species, country and other variables were identified and highlighted the epidemiology of Rhipicephalus ticks in the heartwater; affinity of each Rickettsia species for different tick genera; dominant distribution of A. marginale, R. africae and Coxiella-like endosymbionts in ticks and a low distribution of C. burnetii in African hard ticks.

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.

Predicting the potential distribution of the cattle fever tick Rhipicephalus annulatus (Acari: Ixodidae) using ecological niche modeling

Rhipicephalus annulatus is a tick species of veterinary importance due to its potential to transmit babesiosis to cattle. This species has a Holarctic distribution with some Afrotropical records and is one-host species of veterinary importance. This study was carried out from September 2021 to February 2022 at 6 Egyptian collection sites, and a total of 1150 cattle were scanned randomly to collect ticks. A total of 1095 tick specimens were collected and identified as R. annulatus using taxonomic keys. Males were found on all parts of the cattle except the head and around the eyes, but females were found on all parts; in addition, the highest number of specimens was gathered from the udder, (neck and chest), and belly. Maximum entropy (MaxEnt) modeling was used to predict the potential global distribution of R. annulatus. The MaxEnt model performed better than random with an average test area under the curve (AUC) value of 0.96, and model predictions were significantly better than random and gave (AUC) ratios above the null expectations in the partial receiver operating characteristic (pROC) analyses (P < 0.001). Based on correlation analyses, a set of 9 variables was selected for species from 15 bioclimatic and 5 normalized difference vegetation index (NDVI) variables. The study showed that the current distribution of R. annulatus is estimated to occur across Asia, Africa, Europe, South America, and North America. Annual mean temperature (Bio1) and median NDVI had the highest effect on the distribution of this species. The environmentally suitable habitat for R. annulatus sharply increased with increasing annual mean temperature (Bio1). These results can be used for making effective control planning decisions in areas suitable to this vector of many diseases worldwide.

Unraveling the epidemiological relationship between ticks and rickettsial infection in Africa

Tick-borne rickettsioses are emerging and re-emerging diseases of public health concern caused by over 30 species of Rickettsia. Ticks are obligate hematophagous arthropods with over 700 species of Ixodid ticks known worldwide. The escalating geographical dispersal of tick vectors and concomitant increase in the incidences of tick-borne diseases have fueled interest in the ecology of tick-borne pathogens. This review focuses on aspects of the Rickettsia pathogen, including biology, taxonomy, phylogeny, genetic diversity, epidemiology of the disease, and the role of vertebrate host in the perpetuation of rickettsioses in Africa. Our review also highlights some of the species of Rickettsia that are responsible for disease, the role of tick vectors (both hard and soft ticks) and the species of Rickettsia associated with diverse tick species across the continent. Additionally, this article emphasizes the evolutionary perspective of rickettsiae perpetuation and the possible role of amplifying vertebrate host and other small mammals, domestic animals and wildlife in the epidemiology of Rickettsia species. We also specifically, discussed the role of avian population in the epidemiology of SFG rickettsiae. Furthermore, we highlighted tick-borne rickettsioses among travelers due to African tick-bite fever (ATBF) and the challenges to surveillance of rickettsial infection, and research on rickettsiology in Africa. Our review canvasses the need for more rickettsiologists of African origin based within the continent to further research towards understanding the biology, characterization, and species distribution, including the competent tick vectors involved in their transmission of rickettsiae across the continent in collaboration with established researchers in western countries. We further highlighted the need for proper funding to encourage research despite competing demands for resources across the various sectors. We finalize by discussing the similarities between rickettsial diseases around the world and which steps need to be taken to help foster our understanding on the eco-epidemiology of rickettsioses by bridging the gap between the growing epidemiological data and the molecular characterization of Rickettsia species.

Detection of Ticks and Tick-Borne Pathogens of Urban Stray Dogs in South Africa

This study aimed to identify ticks infesting dogs admitted to the Potchefstroom Animal Welfare Society (PAWS) and to detect tick-borne pathogens they are harbouring. A total of 592 ticks were collected from 61 stray dogs admitted to PAWS originating from several suburbs in and near Potchefstroom, South Africa. The dog ticks were identified as Haemaphysalis elliptica (39%) and Rhipicephalus sanguineus (61%) by both morphological and DNA analyses. Of these ticks, H. elliptica consisted of 67.5% (156/231) and 32.5% (75/231) female and male ticks, respectively, whilst R. sanguineus consisted of 48.5% (175/361) and 51.5% (186/361) female and male ticks, respectively. Microscopic examination of blood smears from engorged female ticks indicated overall occurrences of 0.5% (1/204) for Babesia spp. from R. sanguineus, 1% (2/204) of Anaplasma spp. from H. elliptica, and 22% (45/204) of Rickettsia spp. from both H. elliptica and R. sanguineus. Using pooled samples molecular detection of tick-borne pathogens indicated overall occurrences of 1% (1/104) for A. phagocytophilum in H. elliptica, 9.6% (10/104) of Rickettsia spp. in H. elliptica and R. sanguineus, 5.8% (6/104) of Ehrlichia canis in H. elliptica and R. sanguineus, and 13.5% (14/104) of Coxiella spp. in both H. elliptica and R. sanguineus. Additionally, PCR detected 6.5% (2/31) of Coxiella spp. DNA from H. elliptica eggs. Our data indicate that urban stray dogs admitted at PAWS are infested by H. elliptica and R. sanguineus ticks which are harbouring several pathogenic organisms known to cause tick-borne diseases.

Epidemiology and genetic characteristics of tick-borne bacteria in dromedary camels of the world

This review presents updated knowledge on the main tick-borne bacteria infecting one-humped camels (Camelus dromedarius) around the world. Camels are increasingly the subject of several scientific investigations, showing that they are receptive and carriers of several zoonotic bacteria. An appraisal is also given of the relative public health importance of these bacterial infections according to One Health concept. Microscopic, serologic and molecular findings are appropriately generated in order to exploit epidemiological data, and phylogeographic specificities associated to each vector-borne bacterium. Indeed, camels and their ticks harbour similar species and genotypes of pathogenic bacteria commonly identified in other animals, e.g., Anaplasma spp.,Ehrlichia spp., Borrelia spp., Rickettsia spp., Coxiella burnetii, Bartonella spp. and hemotrophic mycoplasmas. This evidence suggests an epidemiological role of camels in the spread of these pathogens in their natural habitats. However, these infections are commonly asymptomatic in camels resulting in underestimation of the impact of these infections. Furthermore, camels have recently been proven to have their own specific unclassified strains, such as Candidatus Anaplasma camelii and Candidatus Bartonella camelii, implying that possible interactions may lead to the emergence of pathogenic and zoonotic bacteria. In camel-rearing areas of the world, spatial and temporal spread of these infections, due to climatic and ecological changes and human activities such as development projects and urbanization, is expected. Hence the data presented herein provides a basis for strategic frameworks for the research and the development of novel diagnosis and control strategies worldwide, which are needed to protect camels, other livestock, and people in contact with dromedaries from threats that arthropod-borne pathogens can pose.

Detection of zoonotic vector-borne pathogens in domestic dogs in Giza, Egypt

The public health implications of zoonotic vector-borne pathogens are numerous because domestic animals, such as dogs, live in close proximity to humans. Blood was collected from 116 domestic dogs in Cairo, Egypt from three different settings at the human-animal interface. The three settings the dogs came from were: privately owned animals seeking care at the Cairo University Faculty of Veterinary Medicine Clinic, non-laboratory reared research dogs maintained at the Cairo University Faculty of Veterinary Medicine, and an urban private animal rescue in Shabramont, Giza, Egypt. Enrolled animals were visually inspected for presence of flea or tick ectoparasites, Rhipicephalus sanguineus sensu lato ticks were recovered from 56 enrolled animals and a flea identified as Ctenocephalides felis was recovered from one animal. To test for past and/or current infection with vector-borne pathogens, conventional PCR and IDEXX SNAP® 4Dx® Plus were performed on whole blood. Pathogen targets included: Anaplasma spp., Ehrlichia spp., Babesia spp., Borrelia spp., Bartonella spp., Dirofilaria spp., and Rickettsia spp. Among dogs sampled across all locations, one dog was positive for Babesia sp. infection and one dog was positive for Anaplasma sp. infection as detected by PCR and confirmed by Sanger sequencing. Three additional dogs were positive for infection but had incomplete sequences obtained: two for Ehrlichia sp. and one for Borrelia sp. The SNAP® test results for all sampled dogs included: eight dogs positive for Anaplasma spp., 14 dogs positive for Ehrlichia spp., and five additional dogs positive for both Anaplasma spp. and Ehrlichia spp. SNAP® test results by sampling location showed that 66% of the dogs at the animal rescue were positive for Anaplasma spp. and/or Ehrlichia spp., 17% of the privately owned dogs at the Faculty of Veterinary medicine were positive for Anaplasma spp. and/or Ehrlichia spp., and none of the research dogs were positive for any of the targets on the SNAP® test. This high proportion of seropositivity in the animals sampled indicates a vector population which is not well controlled and a need for continued owner education and promotion of consistent use of preventive medications and the risk for zoonotic transmission.

Distribution of Tick-Borne Pathogens in Domestic Animals and Their Ticks in the Countries of the Mediterranean Basin between 2000 and 2021: A Systematic Review

Tick-borne pathogens (TBPs) include a wide range of bacteria, parasites and viruses that cause a large spectrum of animal, human and zoonotic tick-borne diseases (TBDs). The object of this review was to establish an inventory and an analysis of TBPs found in domestic animals in the countries of the Mediterranean Basin. This geographic area occupies a central position between several continents and is an area of movement for animals, humans and pathogens of interest and their vectors, which is important in terms of animal and human health. In this systematic review, we included a total of 271 publications produced between 2000–2021 concerning TBPs in domestic animals. Among this literature, we found a total of 90 pathogen species (known as TBPs) reported in the 20 countries of the area; these were detected in tick species from domestic animals and were also directly detected in domestic animals. In all, 31 tick species were recorded and 12 domestic animal species, the latter comprising nine livestock and three pet species. More than 50% of the publications were from Western Europe. Island data were extracted and assessed, as islands of the Mediterranean Basin were represented in 16% of the publications and 77.8% of the TBPs reported. Our results show the importance of islands in the monitoring of TBPs, despite the low percentage of publications.

Serological and molecular surveys of Anaplasma spp. in Egyptian cattle reveal high A. marginale infection prevalence

BACKGROUND

Bovine anaplasmosis is an infectious disease with worldwide distribution. It spreads by various routes mainly through tick bites.

AIMS

This study aimed to investigate bovine related Anaplasma spp. in cattle from three northern governorates of Egypt by serological and molecular assays, to evaluate the associated risk factors and to analyze the phylogeny of revealed A. marginale isolates.

METHODS

During 2020, a total of 650 blood samples were collected from asymptomatic cattle in the governorates of Kafr El-Sheikh (n=240), Menofia (n=230), and Al-Gharbia (n=180). Sera samples were examined using the Anaplasma antibody test kit, cELISA v2. Blood genomic DNA of seropositive cattle was then examined by PCRs specific to A. marginale, A. centrale, and A. bovis. Selected positive samples were subjected to nucleotide sequencing. Risk factors (i.e. geographical area, breed, type of production, sex, age, herd size, season, husbandry system, tick infestation, and application of acaricides) were evaluated by logistic regression approach.

RESULTS

In total, 130 cattle (20%, 95% CI: 17.1-23.3) were recorded seropositive for Anaplasma species. Major risk factors associated with seropositivity were being crossbred, dairy cattle, aged more than 5 years, summer season, herd size of below 300, pasture grazing, tick infestation, and not being subjected to regular treatment with acaricides. By using species-specific PCR, only A. marginale was detected. Nucleotide sequencing showed the occurrence of two different msp4 genotypes.

CONCLUSION

This study shows the high prevalence of A. marginale in cattle of Kafr El-Sheikh, Al-Gharbia, and Menofia. However, the connection between Anaplasma species and their tick vectors remains unknown in Egypt and merits further investigations. Since these infections primarily spread through ixodid tick bites, effective ectoparasite control strategies, regular examination of cattle and successful chemoprophylaxis are recommended.

Pathogens in ticks collected in Israel: I. Bacteria and protozoa in Hyalomma aegyptium and Hyalomma dromedarii collected from tortoises and camels

Ticks were collected from 30 Greek tortoise (Testudo graeca), and 10 Arabian camels (dromedary) (Camelus dromedarius) in Israel. All those collected from Greek tortoises belonged to Hyalomma aegyptium, while all specimens collected from the camels belonged to Hyalomma dromedarii. Out of 84 specimens of H. aegyptium, 31 pools were examined by PCR, while from 75 H. dromedarii specimens nine pools were studied. Out of 31 pools of H. aegyptium 26 were positive for pathogens or endosymbiont; 14 for one, 11 for two and one for three pathogens. Out of nine pools prepared from H. dromedarii, seven were positive for pathogens (two for C. burnetii and five for Leishmania infantum). In H. aegyptium, Rickettsia africae, Rickettsia aeschlimannii, Rickettsia endosymbiont, Coxiella burnetii, Hemolivia mauritanica, Babesia microti, Theileria sp., and Leishmania infantum was detected, while in H. dromedarii C. burnetii and L. infantum were found. None of the ticks were positive for Anaplasma/Ehrlichia, Listeria monocytogenes, Bartonella spp., Hepatozoon spp. and Toxoplasma gondii. H Rickettsia endosymbionts, C. burnetii, B. microti, Theileria sp. and L. infantum are reported for the first time in H. aegyptium, and C. burnetii and L. infantum for the first time in H. dromedarii.

Prevalence of Coxiella burnetii in bovine placentas in Hungary and Slovakia: Detection of a novel sequence type - Short communication

Cotyledons (n = 167) from 30 Hungarian and 5 Slovakian dairy cattle herds were analysed for Coxiella burnetii by real-time PCR targeting the IS1111 gene. Eighty (88.9%) out of the 90 cotyledons from retained placentas and 31 (40.3%) out of the 77 cotyledons from normally separated placentas tested positive. Seventeen out of the 80 positive samples (21.3%) originating from retained placentas were found to be highly loaded with C. burnetii with a cycle threshold (Ct) value lower than or equal to 27.08, ranging between 11.92 and 27.08. The rest of the positive samples from retained fetal membranes and from normally separated placentas were moderately loaded with C. burnetii DNA. Five out of the ten samples showing the strongest positivity (Ct 11.92-18.28) from retained placentas were genotyped by multispacer sequence typing based on ten loci, which revealed sequence type (ST) 61, a type that had not been detected in Hungary and Slovakia previously. Retained placenta was more likely in cows with C. burnetii PCR-positive cotyledons (odds ratio: 12.61, P = 0.0023). The high C. burnetii DNA load found in retained fetal membranes may be a potential risk factor for human infection and may also be associated with the retention of fetal membranes.

Molecular epidemiology of certain vector-borne bacterial microorganisms in domestic animals and their ectoparasites in Egypt

Vector-borne bacterial diseases (VBBD) are a diverse group of tropical and subtropical zoonotic diseases. This study investigated the possibility of domestic animals to carry certain vector-borne bacterial microorganisms (VBBMs), as well as the presence of these targeted DNAs in their ectoparasites in different localities of Egypt using molecular analyses. For this study, 234 animal hosts (112 cattle, 38 sheep, 28 goats, 26 buffaloes, 22 donkeys, and 8 horses) in addition to 115 ectoparasites (95 ticks and 20 lice) were investigated for the molecular detection of Bartonella spp., Borrelia spp., and Rickettsia spp., targeting 16S-23S rRNAITS, 16S rRNA, and gltA genes, respectively. The results indicated that the overall prevalence of VBBD was observed in 17 animals (7.26%), of which 16 (6.84%) were positive for Bartonella spp. and one (0.43%) was positive for Borrelia theileri. All blood samples were negative for the DNA of Rickettsia spp. In addition, the results demonstrated that all ectoparasites were free from VBBDNA. Furthermore, of the animals examined for ectoparasite infestation, 28 (11.97%) and 5 (2.14%) represented Rhipicephalus annulatus ticks and Haematopinus tuberculatus lice, respectively, which infested animals. Analysis of epidemiological factors revealed that gender, age, and ectoparasitic infestation of animals had a significant effect on Bartonella infection, whereas no significant difference between animal species was observed. Hence, we report a potential novel Bartonella sp. from cattle and buffaloes, including a new genotype of Bo. theileri from cattle, in Egypt.

Hard ticks (Acari: Ixodidae) infesting domestic animals in Egypt: diagnostic characters and a taxonomic key to the collected species

Ticks are important vectors of emerging health problems in humans and animals. We conducted several field surveillances to investigate the fauna of hard ticks on domestic animals in seven governorates of Egypt during 2018-2019. A total of 3265 individual tick specimens were collected and identified to the species level; the specimens belong to 11 species within three genera (Amblyomma, Hyalomma, and Rhipicephalus). Tick infestation was highest in dromedary camels (70%), followed by dogs (52.5%), cattle (50%), buffaloes (38%), and horses (12%). Ten species were collected from dromedary camels, 2 from cattle, and one species from dogs, buffaloes, and horses. Diagnostic characters with high-quality photographic images of the 11 tick species were provided. New measurements of the body regions such as spiracles and body grooves were also obtained to provide further details on morphological variations among the diverse tick species. This study provided detailed descriptions of the genital apertures of five Hyalomma species. Morphological variations of male Hyalomma impeltatum, and genital apertures of female Hyalomma dromedarii and Hyalomma excavatum were also examined in this study. Finally, we provided additional details on local geographic distributions, hosts, endemicity status, and disease relationships of the eleven tick species.

Multiple vector-borne pathogens of domestic animals in Egypt

Vector Borne Diseases (VBDs) are considered emerging and re-emerging diseases that represent a global burden. The aim of this study was to explore and characterize vector-borne pathogens in different domestic animal hosts in Egypt. A total of 557 blood samples were collected from different animals using a convenience sampling strategy (203 dogs, 149 camels, 88 cattle, 26 buffaloes, 58 sheep and 33 goats). All samples were tested for multiple pathogens using quantitative PCR and standard PCR coupled with sequencing. We identified Theileria annulata and Babesia bigemina in cattle (15.9 and 1.1%, respectively), T. ovis in sheep and buffaloes (8.6 and 7.7%, respectively) and Ba. canis in dogs (0.5%) as well as Anaplasma marginale in cattle, sheep and camels (20.4, 3.4 and 0.7%, respectively) and Coxiella burnetii in sheep and goats (1.7 and 3%; respectively). New genotypes of An. centrale, An. ovis, An. platys-like and Borrelia theileri were found in cattle (1.1,3.4, 3.4 and 3.4%, respectively), An. platys-like in buffaloes (7.7%), An. marginale, An. ovis, An. platys-like and Bo. theileri in sheep (3.4, 1.7, 1.7 and 3.4%, respectively), An. platys, An. platys-like and Setaria digitata in camels (0.7, 5.4 and 0.7%, respectively) and Rickettsia africae-like, An. platys, Dirofilaria repens and Acanthocheilonema reconditum in dogs (1.5, 3.4, 1 and 0.5%, respectively). Co-infections were found in cattle, sheep and dogs (5.7, 1.7, 0.5%, respectively). For the first time, we have demonstrated the presence of several vector-borne zoonoses in the blood of domestic animals in Egypt. Dogs and ruminants seem to play a significant role in the epidemiological cycle of VBDs.

Four Tick-Borne Microorganisms and Their Prevalence in Hyalomma Ticks Collected from Livestock in United Arab Emirates

Ticks and associated tick-borne diseases in livestock remain a major threat to the health of animals and people worldwide. However, in the United Arab Emirates (UAE), very few studies have been conducted on tick-borne microorganisms thus far. The purpose of this cross-sectional DNA-based study was to assess the presence and prevalence of tick-borne Francisella sp., Rickettsia sp., and piroplasmids in ticks infesting livestock, and to estimate their infection rates. A total of 562 tick samples were collected from camels, cows, sheep, and goats in the Emirates of Abu Dhabi, Dubai, and Sharjah from 24 locations. DNA was extracted from ticks and PCR was conducted. We found that Hyalomma dromedarii ticks collected from camels had Francisella sp. (5.81%) and SFG Rickettsia (1.36%), which was 99% similar to Candidatus Rickettsia andeanae and uncultured Rickettsia sp. In addition, Hyalomma anatolicum ticks collected from cows were found to be positive for Theileria annulata (4.55%), whereas H. anatolicum collected from goats were positive for Theileria ovis (10%). The widespread abundance of Francisella of unknown pathogenicity and the presence of Rickettsia are a matter of concern. The discovery of T. ovis from relatively few samples from goats indicates the overall need for more surveillance. Increasing sampling efforts over a wider geographical range within the UAE could reveal the true extent of tick-borne diseases in livestock. Moreover, achieving successful tick-borne disease control requires more research and targeted studies evaluating the pathogenicity and infection rates of many microbial species.

The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited-A Systematic Review

The zoonosis Q fever is caused by the obligate intracellular bacterium Coxiella burnetii. Besides the main transmission route via inhalation of contaminated aerosols, ticks are discussed as vectors since the first isolation of the pathogen from a Dermacentor andersonii tick. The rare detection of C. burnetii in ticks and the difficult differentiation of C. burnetii from Coxiella-like endosymbionts (CLEs) are questioning the relevance of ticks in the epidemiology of Q fever. In this review, literature databases were systematically searched for recent prevalence studies concerning C. burnetii in ticks in Europe and experimental studies evaluating the vector competence of tick species. A total of 72 prevalence studies were included and evaluated regarding DNA detection methods and collection methods, country, and tested tick species. Specimens of more than 25 different tick species were collected in 23 European countries. Overall, an average prevalence of 4.8% was determined. However, in half of the studies, no Coxiella-DNA was detected. In Southern European countries, a significantly higher prevalence was observed, possibly related to the abundance of different tick species here, namely Hyalomma spp. and Rhipicephalus spp. In comparison, a similar proportion of studies used ticks sampled by flagging and dragging or tick collection from animals, under 30% of the total tick samples derived from the latter. There was no significant difference in the various target genes used for the molecular test. In most of the studies, no distinction was made between C. burnetii and CLEs. The application of specific detection methods and the confirmation of positive results are crucial to determine the role of ticks in Q fever transmission. Only two studies were available, which assessed the vector competence of ticks for C. burnetii in the last 20 years, demonstrating the need for further research.

Ectoparasites of hedgehogs: From flea mite phoresy to their role as vectors of pathogens

Hedgehogs are synanthropic mammals, reservoirs of several vector-borne pathogens and hosts of ectoparasites. Arthropod-borne pathogens (i.e., Rickettsia spp., Borrelia spp., and Anaplasmataceae) were molecularly investigated in ectoparasites collected on hedgehogs (n = 213) from Iran (161 Hemiechinus auritus, 5 Erinaceus concolor) and Italy (47 Erinaceus europaeus). In Iran, most animals examined (n = 153; 92.2%) were infested by ticks (Rhipicephalus turanicus, Hyalomma dromedarii), and 7 (4.2%) by fleas (Archeopsylla erinacei, Ctenocephalides felis). Of the hedgehogs infested by arthropods in Italy (i.e., 44.7%), 18 (38.3%) were infested by fleas (Ar. erinacei), 7 (14.9%) by ticks (Haemaphysalis erinacei, Rh. turanicus, Rhipicephalus sanguineus sensu lato), and 6 (12.8%) by mites (Caparinia tripilis, Acarus nidicolous, Ornithonyssus spp.). Phoretic behavior of C. tripilis on Ar. erinacei was detected in two flea specimens from Italy. At the molecular analysis Rickettsia spp. was detected in 93.3% of the fleas of Italy. In Iran, Rickettsia spp. was detected in 8.0% out of 212 Rh. turanicus ticks, and in 85.7% of the Ar. erinacei fleas examined. The 16S rRNA gene for Ehrlichia/Anaplasma spp. was amplified in 4.2% of the 212 Rh. turanicus ticks. All sequences of Rickettsia spp. from fleas presented 100% nucleotide identity with Rickettsia asembonensis, whereas Rickettsia spp. from Rh. turanicus presented 99.84%–100% nucleotide identity with Rickettsia slovaca, except for one sequence, identical to Rickettsia massiliae. The sequences of the 16S rRNA gene revealed 99.57%–100% nucleotide identity with Anaplasma spp., except for one, identical to Ehrlichia spp. A new phoretic association between C. tripilis mites and Ar. erinacei fleas has been herein reported, which could be an important route for the spreading of this mite through hedgehog populations. Additionally, spotted fever group rickettsiae were herein detected in ticks and fleas, and Anaplasma/Ehrlichia spp. in ticks, suggesting that hedgehogs play a role as reservoirs for these vector-borne pathogens.

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New phoretic association of Caparinia tripilis mites on Archaeopsylla erinacei fleas.

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Occurrence of spotted fever group rickettsiae in Rhipicephalus turanicus from hedgehogs.

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Occurrence of Anaplasmataceae in Rhipicephalus turanicus from hedgehogs.

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High Prevalence of Rickettsia asembonensis in Archaeopsylla erinacei fleas from hedgehogs.

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Hedgehogs are suggested as reservoirs of vector-borne pathogens.

Molecular Investigation on Tick-Borne Hemoparasites and Coxiella burnetii in Dromedary Camels (Camelusdromedarius) in Al Dhafra Region of Abu Dhabi, UAE

Camels represent an important resource for inhabitants of the most arid regions of the world and their survival is mainly related to environment conditions including the risk of parasitic diseases, which may represent a significant cause of losses in livestock production of these areas. Camels may be parasitized by several hematophagous arthropods, which can be vectors of several diseases including zoonosis. This study aimed to investigate in dromedary camels and their ticks the importance of tick-borne hemoparasites that might be responsible for a recent and obscure morbidity of camels in Al Dhafra region of Abu Dhabi, UAE. Blood samples and ticks from 93 naturally infected camels belonging to 36 herds, affected by variable acute clinical syndromes lasting from 3 to 5 days, were analyzed through molecular techniques for specific DNA presence of different blood pathogens: Anaplasmamarginale/Anaplasmaovis, Anaplasma phagocytophilum, Coxiella burnetii,Babesia spp., and Theileria spp. DNA. All the 72 ticks collected belonged to the Hyalomma dromedarii species and were negative for blood pathogens. n = 15 camels (16.1%) were found positive to the following tick-borne hemoparasites: A. phagocytophilum 11 (11.8%), Coxiella burnetii 3 (3.2%), and Babesia/Theileria spp. 2 (2.1%). One singular camel showed coinfection of C. burnetii and A. phagocytophiulm. Genetic profile of C. burnetii showed a high phylogenetic relatedness to European, Asian and African C. burnetii strains. This is the first laboratory investigation on tick-borne pathogens in camels in UAE, and the first report of A. phagocytophilum and C. burnetii. Moreover, since the detected pathogens are recognized pathogens for humans, this study highlights the zoonotic risk for humans working in camel husbandry.

Ticks and Tick-Borne Diseases of Livestock in the Middle East and North Africa: A Review

Ticks are important vectors of an array of viral, bacterial and protozoan pathogens resulting in a wide range of animal and human diseases. There is limited information in the literature about tick species in the Middle East and North Africa (MENA) countries, even though they have suitable climate and vegetation for ticks and their hosts. We reviewed the occurrence of tick species and the pathogens they transmit from the MENA on published papers from 1901-2020. We found taxonomic records of 55 tick species infesting livestock representing the following eight genera: Ornithodoros, Otobius, Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes, and Rhipicephalus. In addition, 15 pathogens were recorded causing diseases of significance, with Crimean-Congo hemorrhagic fever, theileriosis, babesiosis and anaplasmosis being widely distributed diseases in the region. In recent decades, there has been increasing trends in disease occurrence and movement associated with global movement of humans and global trade of animals. We suggest that disease control and prevention could be achieved effectively through good integration between public health, veterinary medicine and animal management, and ecological approaches. We recommend further research in the areas of tick ecology and tick born-disease transmission. Furthermore, we suggest evaluation and improvement of disease control policies in the region.

First survey of ticks, tick-borne pathogens (Theileria, Babesia, Anaplasma and Ehrlichia) and Trypanosoma evansi in protected areas for threatened wild ruminants in Tunisia

The aim of the study was to identify ticks present in the environment and wild Tunisian ruminants and to detect tick-borne pathogens and Trypanosoma evansi DNA in these specimens. Sampling was done throughout each season from the environment in three protected areas around Tunisia: El Feidja, Haddaj and Oued Dekouk. Ticks were collected also, from one fawn of Barbary red deer and eight naturally deceased wild ruminants (one Barbary red deer, five Scimitar-horned oryx, one Addax antelope and one Dorcas gazelle), all of which lived in various protected areas. PCR and nested PCRs were performed to detect the presence of Theileria spp., Babesia spp., Trypanosoma evansi, Ehrlichia spp., Anaplasma spp., Anaplasma bovis and Anaplasma phagocytophilum DNA in these tick specimens. A total of 352 ticks were collected, belonging to six different species: Hyalomma excavatum (80.6%), Hyalomma dromedarii (10.2%), Hyalomma marginatum (0.5%), Rhipicephalus bursa (0.5%), Rhipicephalus sanguineus sensu lato (5.1%) and Ixodes ricinus (2.8%). Pathogens have been detected in 25% of H. dromedarii, 9.1% of H. excavatum and 5% of R. sanguineus sensu lato. The percentage of detection of T. evansi was 0.2%. Ehrlichia spp.-Anaplasma spp. were detected in 10.1% of ticks. Anaplasma spp. and A. bovis were detected in 7.6%, and 0.8% of examined ticks, respectively. None of the Theileria spp., Babesia spp., or A. phagocytophilum DNA was detected in the tested ticks. To our knowledge, the present study represents the first identification of these six tick species and the first detection of rickettsial pathogens and T. evansi in North African wild ruminants' species. These results extend the knowledge about the diversity of ticks and tick-borne pathogens in wildlife and justify further investigations of the possible role of R. sanguineus sensu lato in the transmission of T. evansi.

Sample pooling methods for efficient pathogen screening: Practical implications

Due to the large number of negative tests, individually screening large populations for rare pathogens can be wasteful and expensive. Sample pooling methods improve the efficiency of large-scale pathogen screening campaigns by reducing the number of tests and reagents required to accurately categorize positive and negative individuals. Such methods rely on group testing theory which mainly focuses on minimizing the total number of tests; however, many other practical concerns and tradeoffs must be considered when choosing an appropriate method for a given set of circumstances. Here we use computational simulations to determine how several theoretical approaches compare in terms of (a) the number of tests, to minimize costs and save reagents, (b) the number of sequential steps, to reduce the time it takes to complete the assay, (c) the number of samples per pool, to avoid the limits of detection, (d) simplicity, to reduce the risk of human error, and (e) robustness, to poor estimates of the number of positive samples. We found that established methods often perform very well in one area but very poorly in others. Therefore, we introduce and validate a new method which performs fairly well across each of the above criteria making it a good general use approach.

First detection of Anaplasma ovis in sheep and Anaplasma platys-like variants from cattle in Menoufia governorate, Egypt

Tick-borne diseases are of global economic importance, especially due to the costs associated with disease treatment and productivity losses in livestock. In this study, 244 livestock animals (cattle N = 92, buffaloes N = 86 and sheep N = 66) from Menoufia, Egypt were tested for Anaplasma, Ehrlichia and Babesia species using PCR. Results revealed detection of A. ovis (9.1%) in sheep while Anaplasma spp. (14.1%), A. marginale (15.2%), B. bigemina (6.5%) and B. bovis (5.4%) in cattle. On the other hand, Anaplasma spp. (1.2%), A. marginale (1.2%) and B. bovis (1.2%), were detected in buffaloes. Significantly higher detection rates were observed in cattle for Anaplasma spp. (P = .020), A. marginale (P = .001) and B. bigemina (P = .022) than in buffaloes. Sequence analysis of Anaplasma spp. isolates from cattle, revealed A. platys-like strains. Phylogenetic analyses of the A. platys-like isolates revealed variation among the strains infecting cattle. The A. marginale buffalo isolate, on the other hand, showed some level of divergence from the cattle isolates. This study reports the first detection of A. ovis in sheep and A. platys-like strains in cattle in Menoufia and Egypt at large. The results of the current study provide valuable information on the epidemiology and genetic characteristics of tick-borne pathogens infecting livestock in Egypt.

Prevalence of Coxiella burnetii in Central and Eastern European dairy herds

The aim of the present study was to assess the prevalence of Coxiella burnetii in dairy herds in Central and Eastern European countries based on ELISA and PCR tests. A total of 370 bulk tank milk samples were collected in 2019 originating from Croatia (n = 13), Czech Republic (n = 138), Hungary (n = 126), Serbia (n = 24), Slovakia (n = 53) and Slovenia (n = 16). Prevalence of C. burnetii differed according to the country of origin with Croatia showing 100.00%, the Czech Republic 98.55%, Hungary 97.61%, Serbia 70.83%, Slovakia 90.56% and Slovenia showing 62.50% average percentages of the positive herds. C. burnetii specific ELISA showed 100.00% positivity in all examined countries if herds consisted of equal or above 250 milking cows. The growing number of farms managing large number of animals, where cattle density is high correlates with the increasing prevalence of C. burnetii in the region.

Bartonella vinsonii subsp. arupensis infection in animals of veterinary importance, ticks and biopsy samples

Testing for vector-borne pathogens in livestock is largely reliant upon blood and tissue. The role of biopsy samples remains poorly explored for detecting tick-borne bacteria in animals. In a 2-year survey, animals of veterinary importance from farms throughout the northern part of Greece were routinely checked for the presence of biopsy samples. Where detected, either a portion or a biopsy was collected together with whole blood samples and any ticks at the site of the biopsy sample. Molecular testing was carried out by real-time PCR targeting the internal transcribed spacer gene of Bartonella species. A total of 68 samples (28 blood samples, 28 biopsy samples and 12 ticks (nine Rhipicephalus bursa and three Rhipicephalus turanicus)) were collected from goats (64 samples) and cattle (four samples). Eight (11.8%) of the 68 samples were positive for Bartonella species. Of the biopsy and whole blood samples, four (14.3%) of each type were positive for Bartonella species. None of the ticks tested positive for Bartonella species. All pairs of positive biopsy samples/whole blood samples originated from the same animals. Positive samples were identified as Bartonella vinsonii subsp. arupensis. Although many more samples from a much wider spectrum of animal species is required before concluding upon the merit of biopsy samples in the study of tick-borne diseases, the significance of our finding warrants further study, both for clinical consequences in small ruminants and for those humans who are farming infected animals.

Norway rat (Rattus norvegicus) ectoparasites in livestock production systems from central Argentina: Influencing factors on parasitism

Haematophagous ectoparasites are worldwide vectors of many zoonotic bacterial diseases, both emerging and re-emerging, whose incidences are rising. Livestock development alters different environmental characteristics such as the microclimate of a site, changing the availability, density and susceptibility of the hosts to pathogens and vectors, indirectly influencing the spread and persistence of a disease within an ecosystem. The Norway rat (Rattus norvegicus), the most abundant vertebrate pest species found on livestock farms from Argentina, is a reservoir for several important zoonotic bacteria and may harbor ectoparasite species, which act as their vectors. Even though the Norway rat is widely known for its role as an ectoparasite host, the ecological characteristics of their ectoparasite communities and the related factors with parasitism on livestock farms have never been described. In the present study, we describe the ectoparasite community in Norway rats from central Argentina livestock farms, while also depicting the influencing factors on both ectoparasite occurrence and abundance. Ectoparasites were collected from rats captured in 20 sites from Buenos Aires province, between the winter of 2016 and the summer of 2018. A total of 1441 ectoparasite individuals were collected from 159 Norway rat individuals [Total ectoparasite prevalence = 69.2%; Mean ectoparasite specimen abundance (± CI) = 9.06 ± 2.32 ectoparasite individuals per rat; Mean ectoparasite specimen intensity (±CI) = 13.10 ± 3.08 ectoparasite individuals per infested rat found]. Ectoparasite assemblage consisted of four cosmopolitan species, recognized for their sanitary relevance: mites (Laelapidae: Laelaps nuttalli and Laelaps echidninus), lice (Polyplacidae: Polyplax spinulosa) and fleas (Pulicidae: Xenopsylla cheopis). We observed higher Norway rat abundance in sites related to higher ectoparasite occurrence and abundance frequencies on the rats. Additionally, ectoparasites were more abundant on rats in warm seasons and on male individuals, over female rats. Moreover, the geographical location of the studied sites influenced the ectoparasite assemblage structure observed on the rats. This study broadens the knowledge on the role of Norway rats as zoonotic ectoparasites hosts and analyzes the drivers influencing ectoparasite occurrence and abundance on the most populated region of Argentina, which is also the region with the most intensive livestock farming. Therefore, this survey may assist in evaluating potential risks for humans and generate effective sanitary control strategies for ectoparasite-borne infectious diseases.

Upscaling the Surveillance of Tick-borne Pathogens in the French Caribbean Islands

Despite the high burden of vector-borne disease in (sub)tropical areas, few information are available regarding the diversity of tick and tick-borne pathogens circulating in the Caribbean. Management and control of vector-borne disease require actual epidemiological data to better assess and anticipate the risk of (re)emergence of tick-borne diseases in the region. To simplify and reduce the costs of such large-scale surveys, we implemented a high-throughput microfluidic real-time PCR system suitable for the screening of the main bacterial and parasitic genera involved in tick-borne disease and potentially circulating in the area. We used the new screening tool to perform an exploratory epidemiological study on 132 adult specimens of Amblyomma variegatum and 446 of Rhipicephalus microplus collected in Guadeloupe and Martinique. Not only the system was able to detect the main pathogens of the area-Ehrlichia ruminantium, Rickettsia africae, Anaplasma marginale, Babesia bigemina and Babesia bovis-but the system also provided evidence of unsuspected microorganisms in Caribbean ticks, belonging to the Anaplasma, Ehrlichia, Borrelia and Leishmania genera. Our study demonstrated how high-throughput microfluidic real-time PCR technology can assist large-scale epidemiological studies, providing a rapid overview of tick-borne pathogen and microorganism diversity, and opening up new research perspectives for the epidemiology of tick-borne pathogens.

Performance Analysis of Anaplasma Antibody Competitive ELISA Using the ROC Curve for Screening of Anaplasmosis in Camel Populations in Egypt

Anaplasmosis is a tick-born and potential zoonotic disease caused by Anaplasma (A.) phagocytophilum, A. ovis, A. platys and A. capra. Anaplasma marginale affecting bovines and camels causing significant economic losses. Camels as an integral part of the socio-economic lifestyle of nomads in semi-arid to arid ecosystems are prone to suffer from subclinical Anaplasma infections. This study aimed to determine the performance and adaptation of commercial competitive Anaplasma ELISA (cELISA) as a tool for screening the seroprevalence of anaplasmosis whitin the camel populations in Egypt. This study was based on the serological investigation of 437 camel sera collected between 2015 and 2016 during a Q fever prevalence study in Egypt using commercially available cELISA for the detection of antibodies specific for Anaplasma in bovine serum. The receiver operating characteristic (ROC) curve, an analysis method for optimizing cutoff values in cELISAs, was used to estimate the sensitivity and specificity using 76 true as serological positive (n = 7) and negative (n = 60) for Anaplasma antibodies. ROC curve analysis was done for 7 true positive and 60 true negative bovine samples and 7 true positive and 29 true negative camel samples serum. Real time PCR and/or conventional PCR was applied to confirm Anaplasma spp. specific-DNA in camel serum as an indication of a true positive and true negative for ROC analysis. Chi square analysis was performed to estimate the association between risk factors and anaplasmosis in camels. The cutoff value was determined as 0.42 (p value ≤ 0.001). Data simulation with randomly generated values revealed a cutoff value of 0.417 (p ≤ 0.001) with resulting 58.1% Se and 97.8% Sp. Seven true positive and 29 true negative camel serum samples was confirmed by PCR. Using the estimated cut off, the seroprevalence in the Nile Valley and Delta and the Eastern Desert domain was 47.4% and 46.4%, respectively. The potential risk factors as domains and origin of animals were less significantly associated with the prevalence of anaplasmosis (domains: χ(2) = 41.8, p value ≤ 0.001 and origin: χ(2) = 42.56, p value ≤ 0.001). Raising awareness especially for veterinarians and animal owners will significantly contribute to the best understanding of anaplasmosis in camels in Egypt. Alternative (in silico) validation techniques and preliminary prevalence studies are mandatory towards the control of neglected anaplasmosis in the camel population.

Prevalence, distribution on host's body, and chemical control of camel ticks Hyalomma dromedarii in the United Arab Emirates

Background and Aim

Camel farming remains a part of the culture of the Arabian Peninsula although modern methods have greatly increased camel densities in the entire region. In the United Arab Emirates (UAE), camel production is threatened by tick parasitism. However, no study has considered assessing the magnitude of the problem in the UAE. We conducted a study evaluating tick richness, abundance, and spatial distribution of ticks on camels in farms near Al Ain, UAE. In addition, we conducted a survey of farm owners to determine the control methods used to eliminate camel ticks.

Materials and Methods

Tick counts were made on 502 camels (Camelus dromedarius). For each examined animal, visual counts of ticks were made on the entire body segregating the counts by head, neck, forelegs, hump, abdomen, back legs, and tail area. In addition, a total of 70 camel owners from the study area were randomly selected and surveyed about the tick control methods.

Results

Hyalomma dromedarii was the only species found during the study. The prevalence of ticks was 98% among the sampled animals. The mean intensity (tick load) was 25.8±2.4 ticks/host and the maximum number of ticks per animal was 102. Ticks were found in five vicinities that are on the border with Oman. The highest number of ticks on the body of the camel occurred on the tail area followed by the abdomen. Cypermethrin was the most commonly used acaricide (46.9%).

Conclusion

The high abundance of ticks reported in this study calls for the establishment of a good management strategy. In addition, finding ticks in vicinities in the UAE that are on the border with Oman suggests a cross-border movement between the two countries. Therefore, studying this movement is important to understand its role in the global circulation of some H. dromedarii tick-borne diseases and the movement of acaricide resistance alleles among tick populations.

Seroprevalence and Molecular Detection of Bovine Anaplasmosis in Egypt

Bovine anaplasmosis is a tick-borne disease with zoonotic potential, caused by the obligate intracellular bacterium Anaplasma marginale. The disease is distributed worldwide in tropical and subtropical regions. The economic losses from anaplasmosis in animals is of significant importance because it causes severe morbidity and mortality in cattle. Recovered animals may become persistent carriers. Epidemiological information on the actual status of bovine anaplasmosis in Egypt is scarce. Thus, this study aimed to determine anti-Anaplasma antibody and DNA in serum samples using ELISA and PCR, respectively. In total, 758 bovine sera were collected from cattle farms located in 24 Egyptian governorates in 2015 to 2016. Sera were analyzed with the commercially available 'Anaplasma antibody competitive ELISA v2' kit and 'AmpliTest Anaplasma/Ehrlichia spp. real time TaqMan TM PCR. Anaplasma spp. antibodies were detected in 140 (18.5%) (CI: 15.8-21.4%) of the investigated sera by ELISA, and Anaplasma/Ehrlichia-DNA was detected in 40 (5.3%) (CI: 3.8-7.1%) of the positive sera by real time PCR. Co-detection of both Anaplasma spp. and Coxiella burnetii-specific antibodies was proven in 30 (4%) of the investigated sera. The results of this work confirm the significant prevalence of bovine anaplasmosis in Egypt. Raising awareness in decision makers of the public health, veterinarians and animal owners is required to reduce the spread of infection.

Zoonotic parasites of dromedary camels: so important, so ignored

With a global population of about 35 million in 47 countries, dromedary camels play a crucial role in the economy of many marginal, desert areas of the world where they survive under harsh conditions. Nonetheless, there is scarce knowledge regarding camels' parasite fauna which can reduce their milk and meat productions. In addition, only scattered information is available about zoonotic parasites transmitted to humans via contamination (e.g. Cryptosporidium spp., Giardia duodenalis, Balantidium coli, Blastocystis spp. and Enterocytozoon bieneusi), as foodborne infections (e.g. Toxoplasma gondii, Trichinella spp. and Linguatula serrata) or by arthropod vectors (Trypanosoma spp.). Herein, we draw attention of the scientific community and health policy-making organizations to the role camels play in the epidemiology of parasitic zoonotic diseases also in the view of an increase in their farming in desert areas worldwide.

Selective whole genome amplification and sequencing of Coxiella burnetii directly from environmental samples

Whole genome sequencing (WGS) is a widely available, inexpensive means of providing a wealth of information about an organism's diversity and evolution. However, WGS for many pathogenic bacteria remain limited because they are difficult, slow and/or dangerous to culture. To avoid culturing, metagenomic sequencing can be performed directly on samples, but the sequencing effort required to characterize low frequency organisms can be expensive. Recently developed methods for selective whole genome amplification (SWGA) can enrich target DNA to provide efficient sequencing. We amplified Coxiella burnetii (a bacterial select agent and human/livestock pathogen) from 3 three environmental samples that were overwhelmed with host DNA. The 68- to 147-fold enrichment of the bacterial sequences provided enough genome coverage for SNP analyses and phylogenetic placement. SWGA is a valuable tool for the study of difficult-to-culture organisms and has the potential to facilitate high-throughput population characterizations as well as targeted epidemiological or forensic investigations.

Molecular identification and prevalence of tick-borne pathogens in zebu and taurine cattle in North Cameroon

Background

Public interest for tick-borne pathogens in cattle livestock is rising due to their veterinary and zoonotic importance. Consequently, correct identification of these potential pathogens is crucial to estimate the level of exposition, the risk and the detrimental impact on livestock and the human population.

Results

Conventional PCR with generic primers was used to identify groups of tick-borne pathogens in cattle breeds from northern Cameroon. The overall prevalence in 1260 blood samples was 89.1%, with 993 (78.8%) positive for Theileria/Babesia spp., 959 (76.1%) for Anaplasma/Ehrlichia spp., 225 (17.9%) for Borrelia spp., and 180 (14.3%) for Rickettsia spp. Sanger sequencing of a subset of positively-tested samples revealed the presence of Theileria mutans (92.2%, 130/141), T. velifera (16.3%, 23/141), Anaplasma centrale (10.9%, 15/137), A. marginale (30.7%, 42/137), A. platys (51.1%, 70/137), Anaplasma sp. ‘Hadesa’ (10.9%, 15/137), Ehrlichia ruminantium (0.7%, 1/137), E. canis (0.7%, 1/137), Borrelia theileri (91.3%, 42/46), Rickettsia africae (59.4%, 19/32) and R. felis (12.5%, 4/32). A high level of both intra- and inter-generic co-infections (76.0%) was observed. To the best of our knowledge, B. theileri, T. mutans, T. velifera, A. platys, Anaplasma sp. ‘Hadesa’, R. felis and E. canis are reported for the first time in cattle from Cameroon, and for R. felis it is the first discovery in the cattle host. Babesia spp. were not detected by sequencing. The highest number of still identifiable species co-infections was up to four pathogens per genus group. Multifactorial analyses revealed a significant association of infection with Borrelia theileri and anemia. Whereas animals of older age had a higher risk of infection, the Gudali cattle had a lower risk compared to the other local breeds.

Conclusion

Co-infections of tick-borne pathogens with an overall high prevalence were found in all five study sites, and were more likely to occur than single infections. Fulani, Namchi and Kapsiki were the most infected breed in general; however, with regions as significant risk factor. A better-adapted approach for tick-borne pathogen identification in co-infected samples is a requirement for epidemiological investigations and tailored control measures.

Molecular detection and genetic characterization of the potentially pathogenic Coxiella burnetii and the endosymbiotic Candidatus Midichloria mitochondrii in ticks infesting camels (Camelus dromedarius) from Tunisia

Tick-borne bacteria are considered to be emerging in camels, but data about their occurrence in Tunisian dromedaries and their infesting ticks remain scarce. In this study, 412 camel blood samples and 327 partially engorged ticks were collected and tested for the presence of Coxiella burnetii and/or related strains, and Rickettsiales bacteria. Coxiella burnetii was detected in 9 Hyalomma impeltatum and 3 H. dromedarii with an overall prevalence rate of 3.6% (12/327). Candidatus Midichloria mitochondrii DNA was identified in 16 H. impeltatum and 10 H. dromedarii with an overall prevalence rate of 8% (26/327). Six ticks (2%) were found to be co-infected with these two bacteria. No positive DNA camel blood sample was observed for both bacteria. Genotyping and phylogenetic analysis of obtained C. burnetii partial sequences based on the IS1111 and htpB genes revealed 99-100% similarity to the pathogenic C. burnetii strains isolated from humans, ruminants and ticks, and that were genetically distant to those isolated from all endosymbiotic related strains (Coxiella-like bacteria). The analysis of the rickettsial partial sequences of the 16S rRNA gene showed 100% similarity to Ca. M. mitochondrii strains infecting Ixodid ticks and dogs. This is the first time that C. burnetii and Ca. M. mitochondrii have been detected in ticks from Tunisia, which raises the possibility of the involvement of Hyalomma tick species in the active diffusion of these bacteria among camels, other domestic animals and humans.

Improving specific detection and updating phylogenetic data related to Anaplasma platys-like strains infecting camels (Camelus dromedarius) and their ticks

In camels and their infesting ectoparasites, specific detection of pathogenic Anaplasma platys and genetically related strains (A. platys-like strains) remains problematic. This requires sequencing of the hemi-nested PCR products specific to A. platys and related strains. In this study, a PCR/RFLP method, earlier developed for specific detection of A. platys-like strains in animal species other than camels, was adapted in order to subtype A. platys-like strains isolated from camels and their ticks and to differentiate them from pathogenic A. platys without going through a sequencing step. This approach was used for investigating the infections with A. platys and related strains in 412 Camelus dromedarius camels and 334 feeding ticks from five Tunisian governorates. Microscopic examination using Giemsa-stained blood smears was performed in order to specify which types of cells were infected. Ticks were identified as Hyalomma dromedarii (n = 164, 49%), H. impeltatum (n = 161, 48.3%) and H. excavatum (n = 9, 2.7%). A. platys was not detected in any of the tested camels or ticks. The overall prevalence of A. platys-like strains was 5.6% (23/412) in camels and microscopic examination of infected cells showed a tropism for neutrophil granulocytes. One tick identified as H. dromedarii out of 327 analyzed ticks was found to be infected with A. platys-like strains (0.3%). Alignment, identity comparison and phylogenetic analysis of the 16S rRNA partial sequences obtained in this study suggest that Tunisian dromedaries and feeding ticks are infected with different Anaplasma strains genetically related to A. platys. Sequence analysis and phylogenetic study based on the groEL gene confirm the RFLP results and show that camel strains formed a separate sub-cluster relatively close to A. platys-like strains infecting Tunisian cattle. This adapted RFLP assay allows fast and specific detection of pathogenic A. platys and A. platys-like strains in camels and infesting ticks and has the intrinsic potential of revealing co-infections with these two types of bacteria in the same sample, reducing the time and costs associated with cloning and sequencing during molecular diagnosis.

Evaluation of vaccine candidates purified from the adult ticks of Ornithodoros savignyi (Acari: Argasidae) and Hyalomma dromedarii (Acari: Ixodidae) against tick infestations

Ticks cause anemia, toxicosis, growth delay, and transmit infectious diseases in animals and humans. The current study aimed to evaluate the immunoprophylactic properties of two vaccine candidates to develop vaccine against tick infestations. These two vaccine candidates were specific fraction from the adults of the soft tick Ornithodoros savignyi and cross-reactive fraction from the adults of the hard tick Hyalomma dromedarii. Both specific and cross-reactive fractions were isolated by Cyanogen Bromide-activated Sepharose-4B affinity column chromatography. Both candidates proved their cross-reactivity by enzyme linked immunosorbent assay and Western blot. Characterization of the two vaccines by SDS-PAGE showed that the O. savignyi specific fraction consists of four bands; 97, 85, 66 and 11.5 kDa compared with nine bands associated with its crude antigen (196-11.5 kDa). The H. dromedarii cross-reactive vaccine candidate consists of three bands; 97, 66 and 45 kDa compared to eight bands of its crude antigen (196-21 kDa). Two common bands of 97 and 66 kDa between two candidates showed immunogenic cross-reactivity with the developed antisera of both infestations by Western blot. Immunization of rabbits intramuscularly with two doses of the fractions separately (40 µg/kg) led to immunological and parasitological changes. Immunologically; the level of immunoglobulins in vaccinated rabbits increased significantly compared with control infested non-vaccinated rabbits. These immunoglobulins are probably responsible for the protective effect of both candidates. Parasitologically, immunized rabbits showed protection against infestation by adult ticks as proved by significant feeding rejection percentage and significant reduction in egg and engorgement weights of H. dromedarii. While insignificant protection was observed against O. savignyi ticks infestation in feeding rejection and reduction in engorgement weight. In conclusion, this study suggests promising immunoprophylactic potentials of the purified fractions against tick infestations in rabbits through induction of IgG responses. The protective effect of both vaccine candidates deserves further evaluation in other hosts and against other tick infestations.

Molecular characterization of Anaplasma and Ehrlichia in ixodid ticks and reservoir hosts from Palestine: a pilot survey

Tick-borne anaplasmosis and ehrlichiosis are clinically important emerging zoonoses usually overlooked by veterinarians and physicians alike. This study aimed at detecting and genetically characterizing Ehrlichia and Anaplasma species in ixodid ticks and their animal hosts from the West Bank, Palestine. A total of 723 ixodid ticks belonging to three genera (Rhipicephalus, Hyalomma, Haemaphysalis) were collected from dogs, sheep, goats and camels. In addition, 189 blood samples were collected from dogs, sheep, camels, horses and a goat from the West Bank, Palestine. All tick and blood samples were investigated for the presence of Anaplasma and Ehrlichia targeting a 345 bp fragment of the 16S rRNA gene followed by sequence analysis. The infection rate of Anaplasma spp. in ticks was 6.5% (47/723). Anaplasma platys was identified in 28% (13/47) of them. Whereas, based on a partial sequence (851 bp) of msp4 gene, 38% (18/47) were identified as A. ovis. The species of the remaining 16 positive samples (16/47, 34%) could not be identified. Simultaneously, the infection rate of Ehrlichia spp. in the ticks was 0.6% (4/723). Three of which were E. canis and one was Ehrlichia spp. The infection rate of A. platys in dogs' blood samples was 10% (13/135), while it was 1.5% (2/135) for E. canis. The infection rate of Anaplasma in sheep blood samples was 40% (19/47), out of which 26% (5/19) were caused by A. ovis as revealed by msp4-PCR. Implementation of purely-spatial analysis by saTScan for all cases of Anaplasma revealed two statistically significant clusters in two districts; Tubas town and Majdal-Bani-Fadil village on the western hills of the Jordan Valley. Most cases of Anaplasma (83%) were from rural areas where life cycle components (vector, host and reservoir) abundantly interact. This study is the first in Palestine to reveal the presence of Anaplasma and Ehrlichia in ticks, dogs and sheep providing crucial platform for future epidemiological surveys and control strategies in the country and region.

Presence of Rickettsia aeschlimannii, 'Candidatus Rickettsia barbariae' and Coxiella burnetii in ticks from livestock in Northwestern Algeria

Livestock and their ectoparasites are involved in the epidemiology of several zoonotic diseases. Studies regarding the molecular detection of infectious agents in ticks from Northwestern Algeria are scarce. Thus, the presence of spotted fever group Rickettsia spp., Anaplasmataceae microorganisms and Coxiella burnetii was investigated in ticks collected from ruminants in Sidi Bel Abbes and Saida provinces. Rickettsia aeschlimannii was detected in one Hyalomma excavatum pool and one H. marginatum pool. Moreover, 'Candidatus Rickettsia barbariae' was found in one H. excavatum and six Rhipicephalus bursa pools. Lastly, Coxiella burnetii was amplified in two H. excavatum and two R. bursa pools. No Anaplasmataceae bacterium was detected. This study demonstrates the presence of the tick-associated microorganism 'Candidatus R. barbariae' in the North of Africa, and corroborates the presence of the zoonotic pathogens R. aeschlimannii and C. burnetii in Algeria.

Vector-borne bacteria in blood of camels in Iran: New data and literature review

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Information about vector-borne bacteria of camels is scarce.

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Anaplasmataceae, SFG rickettsiae, Bartonella and Borrelia were investigated in blood of 200 dromedary camels of Iran.

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PCR results revealed 30 animals (15%) to be infected with Anaplasmataceae bacteria.

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BlastN® analysis of positive samples revealed identity with “Candidatus Anaplasma camelii” isolates.

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This paper reviews the current knowledge on camels’ tick-borne bacteria including microscopy, serology and molecular studies.

Despite close association between camels and humans, molecular based studies on vector-borne pathogens infecting camels are scarce compared to other animals in Iran. The current study was carried out to investigate the occurrence of vector-borne bacteria in the blood of dromedaries by molecular tools. A total of 200 peripheral blood samples were collected from apparently healthy animals. Microscopic examination was performed on Giemsa-stained blood smears, and drops of blood were spotted on Whatman FTA^® cards for molecular analyses. Genomic DNA was extracted from the cards, and PCR amplification followed by sequencing of positive samples was carried out for the detection of Anaplasmataceae, spotted fever group (SFG) rickettsiae, Bartonella spp. and Borrelia spp. Intra-cytic forms of any blood pathogens could not be detected by light microscopy. PCR results revealed 30 animals (15%) to be infected with Anaplasmataceae bacteria. Analyses of sequences revealed a strain of Anaplasma sp. identical to Candidatus Anaplasma camelii isolated from camels, cattle and deer in Asia and Africa. Neither SFG rickettsiae, nor Borrelia or Bartonella species were found. Further studies for determining epidemiological role of camels and its zoonotic potential are recommended. This paper reviews the current knowledge on camels’ tickborne bacteria including microscopy, serology and molecular studies.

Molecular and immunological characterization of Hyalomma dromedarii and Hyalomma excavatum (Acari: Ixodidae) vectors of Q fever in camels

BACKGROUND AND AIM

Q fever Coxiella burnetii is a worldwide zoonotic disease, and C. burnetii was detected in mammals and ticks. Ticks play an important role in the spread of C. burnetii in the environment. Therefore, the aims of this study were to detect Q fever C. burnetii in camels and ixodid ticks by molecular tools and identification of Hyalomma dromedarii and Hyalomma excavatum using molecular and immunological assays.

MATERIALS AND METHODS

A total of 113 blood samples from camels and 190 adult ticks were investigated for the infection with C. burnetii by polymerase chain reaction (PCR) and sequencing the targeting IS30A spacer. The two tick species H. dromedarii and H. excavatum were characterized molecularly by PCR and sequencing of 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit-1 (CO1) genes and immunologically by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot.

RESULTS

A total of 52 camels (46%) were positive for Q fever infection. Only 10 adult ticks of H. dromedarii were infected with C. burnetii. The IS30A sequence was around 200 bp in length for C. burnetii in H. dromedarii ticks with a similarity of 99% when compared with reference data in GenBank records. The length of 16S rDNA and CO1 was 440 and 850 bp, respectively, for both H. dromedarii and H. excavatum. The phylogenetic status of H. dromedarii was distant from that of H. excavatum. SDS-PAGE revealed seven different bands in the adult antigens of either H. dromedarii or H. excavatum with molecular weights ranged from 132.9 to 17.7 KDa. In western blot analyses, the sera obtained from either infested camel by H. dromedarii or infested cattle by H. excavatum recognized four immunogenic bands (100.7, 49.7, 43.9, and 39.6 kDa) in H. dromedarii antigen. However, the infested camel sera identified two immunogenic bands (117 and 61.4 kDa) in H. excavatum antigen. Furthermore, the sera collected from cattle infested by H. excavatum recognized three immunogenic bands (61.4, 47.3, and 35 kDa) in H. excavatum antigen.

CONCLUSION

Molecular analyses indicated that both camels and ticks could be sources for infection of animals and humans with Q fever. Furthermore, the molecular analyses are more accurate tools for discriminating H. dromedarii and H. excavatum than immunological tools.