Rickettsia Aeschlimannii Research Articles

First molecular diagnosis of the human pathogen Rickettsia raoultii and other spotted fever group rickettsiae in Sudanese ixodid ticks from domestic ruminants.

Rickettsial infections are often neglected and poorly recognized by physicians in many tropical and subtropical regions. Despite a number of recent reports describing rickettsial diseases in new locations and the discovery of new rickettsiae, medical science and research have largely neglected the diagnosis and antimicrobial treatment of rickettsial infections in subtropical and tropical areas; thus, much remains to be discovered. This study aimed to detect and characterize spotted fever group (SFG) rickettsiae in ixodid ticks infesting domestic ruminants in Khartoum State. Polymerase chain reaction targeting both genes that encode for citrate synthase (gltA) and outer membrane protein (ompA) was performed for the presence of SFG rickettsia followed by sequence and phylogenetic analysis. Of the 202 ticks examined for the presence of SFG rickettsia, gltA gene was detected in 4 samples (2%). Furthermore, gltA-positive samples were used to amplify the ompA gene, in which only two samples yielded positive results. Sequence and phylogenetic analysis of the positive samples revealed four different species of SFG rickettsiae: Rickettsia aeschlimannii, Rickettsia rhipicephali, Rickettsia massiliae and Rickettsia raoultii. These results indicated the presence of SFG rickettsia in Sudanese ticks. This also indicates that humans have an opportunity to acquire these infections. It is important to keep in mind the need for careful consideration of rickettsial infections in individuals with a fever of unknown origin.

Molecular detection of Rickettsia aeschlimannii, Candidatus Rickettsia shennongii, Rickettsia sp. and Coxiella burnetii in ticks collected from camels

Tick-borne bacteria of the genera Rickettsia and Coxiella cause several emerging veterinary and human infectious diseases. Ticks of the genus Hyalomma are medically important vectors due to their potential role in the transmission of pathogens to vertebrate hosts. There is an inadequate knowledge on tick-borne Rickettsia spp. and Coxiella spp. in ticks infesting transhumant camels in Pakistan. In this study, we conducted a molecular survey for screening of Rickettsia spp. and Coxiella spp. in ticks infesting camels. Seven hard tick species including Hyalomma dromedarii, Hyalomma anatolicum, Hyalomma scupense, Hyalomma isaaci, Hyalomma turanicum, Hyalomma asiaticum, and Rhipicephalus sanguineus s.l were confirmed on camels in three distinct physiographic regions of Khyber Pakhtunkhwa, Pakistan. A subset of morphologically identified ticks were subjected to molecular assays for the genetic characterization of ticks and the detection and genetic characterization of Rickettsia and Coxiella species using standard genetic markers. Ticks screened for pathogens resulted in the detection of Rickettsia aeschlimannii and Candidatus Rickettsia shennongii and Coxiella burnetii. The molecular analysis further reveals the presences of an undetermined Rickettsia aeschlimannii-like species, that is making a distinct phylogenetic clade with R. aeschlimannii. The detection of pathogens in camel ticks poses potential health hazards as these ticks frequently bites humans. Molecular screening of Rickettsia spp. and Coxiella spp. associated with camel ticks is a preliminary step toward the surveillance of evaluating their zoonotic threats in the region.

Hyalomma marginatum - A silent stowaway after vacation at the Adriatic Sea

Hyalomma marginatum is an invasive tick species capable of transmitting pathogens that cause severe diseases such as Crimean-Congo hemorrhagic fever. In Austria, H. marginatum occurs sporadically, and migratory birds are believed to bring H. marginatum from distant regions. We report several incidents of H. marginatum imported by travelers in private cars from Croatia to Austria. One tick was positive for Rickettsia aeschlimannii. Tourist traffic may play a significant role in the northward expansion of this tick species aside from introduction by birds.

Ticks and tick-borne pathogens in selected abattoirs and a slaughter slab in Kumasi, Ghana.

Ticks are vectors of pathogens that affect the health of animals and humans. With the constant trade of livestock across borders, there is the risk of new tick species invasion accompanied by the spread of infectious tick-borne pathogens. This study sought to determine the diversity of tick species within abattoirs and a slaughter slab as well as identify the pathogens carried by these ticks. The ticks were collected from slaughtered cattle, identified and screened for pathogens using PCR and sequencing. A total of 371 ticks were collected from slaughtered cattle across the three sampling sites: Kumasi abattoir (288, 77.63%), Akwatia Line slaughter slab (52, 14.02%) and Suame abattoir (31, 8.35%). The predominant species was Amblyomma variegatum (85.44%) with Rhipicephalus sanguineus (s.l.) (0.27%) as the least occurring species. Total nucleic acid from the tick pools was screened for pathogens based on the nucleoprotein gene region in the S segment of the Crimean-Congo haemorrhagic fever virus (CCHFV) genome, the 295-bp fragment of the transposase gene of the Coxiella burnetii IS1111a element, the 560bp segment of the ssrRNA gene of Babesia and Theileria, the 345bp fragment of the Ehrlichia genus 16SrRNA gene and the rOmpA gene (OmpA) of Rickettsia. From the 52 tick pools screened, 40 (76.92%) were found positive for pathogen DNA. The pathogens identified were Rickettsia africae (69.23%), Rickettsia aeschlimannii (7.69%), C. burnetii (5.77%), uncultured Ehrlichia sp. (5.77%), Candidatus Midichloria mitochondrii (3.85%) and CCHFV (3.85%). A significant association was observed among A. variegatum, Hyalomma rufipes, Hyalomma truncatum and occurring tick-borne pathogens R. africae, R. aeschlimannii and uncultured Ehrlichia sp. (p<0.001). The findings show the occurrence of zoonotic pathogens, suggesting an increased risk of infections among the abattoir workers. There is a need to adopt control measures within the abattoirs to prevent pathogen spread.

Tick-borne diseases at the crossroads of the Middle East and central Europe

ObjectivesThe Balkan Peninsula, acting as a crossroad between central Europe and the Middle East, presents diverse ecosystems supporting various tick species capable of transmitting TBDs. This study focuses on Serbia and North Macedonia, both endemic for TBDs, aiming to investigate human-biting ticks’ prevalence, TBD prevalence, and major TBPs in blood samples. Patients and MethodsThis prospective observational study was conducted in 2022 at two medical centers, involving 45 patients from Novi Sad, Serbia, and 17 patients from Skopje, North Macedonia. All participants had either a tick still attached or had had one removed within the preceding 48 h. The study consisted in clinical evaluations of patients and testing of patient samples and ticks for tick-borne pathogens using a High-Throughput pathogen detection system based on microfluidic real-time PCR. In addition, the study assessed the genetic diversity of the identified pathogens. ResultsIxodes ricinus was the most prevalent tick species, with varying infestation rates across various body parts. Tick species and feeding times differed between Novi Sad and Skopje. TBPs were prevalent, with Rickettsia spp. dominant in Skopje and a mix including Rickettsia aeschlimannii, Rickettsia monacensis, Anaplasma phagocytophilum, and Borrelia afzelii in Novi Sad. Subclinical bacteremia occurred in 8.06% of cases, mostly involving Anaplasma spp. Clinical manifestations, primarily local hypersensitivity reactions, were observed in six patients. Phylogenetic analysis confirmed R. aeschlimannii and R. monacensis identity, highlighting genetic differences in gltA gene sequences. ConclusionsThis study sheds light on the prevalence and diversity of TBPs in tick-infested individuals from Serbia and North Macedonia, contributing valuable insights into the epidemiology of TBDs in the Balkan region.

Spatial patterns of Hyalomma marginatum-borne pathogens in the Occitanie region (France), a focus on the intriguing dynamics of Rickettsia aeschlimannii.

Hyalomma marginatum is an invasive tick species recently established in mainland southern France. This tick is known to host a diverse range of human and animal pathogens. While information about the dynamics of these pathogens is crucial to assess disease risk and develop effective monitoring strategies, few data on the spatial dynamics of these pathogens are currently available. We collected ticks in 27 sites in the Occitanie region to characterize spatial patterns of H. marginatum-borne pathogens. Several pathogens have been detected: Theileria equi (9.2%), Theileria orientalis (0.2%), Anaplasma phagocytophilum (1.6%), Anaplasma marginale (0.8%), and Rickettsia aeschlimannii (87.3%). Interestingly, we found a spatial clustered distribution for the pathogen R. aeschlimannii between two geographically isolated areas with infection rates and bacterial loads significantly lower in Hérault/Gard departments (infection rate 78.6% in average) compared to Aude/Pyrénées-Orientales departments (infection rate 92.3% in average). At a smaller scale, R. aeschlimannii infection rates varied from one site to another, ranging from 29% to 100%. Overall, such high infection rates (87.3% on average) and the effective maternal transmission of R. aeschlimannii might suggest a role as a tick symbiont in H. marginatum. Further studies are thus needed to understand both the status and the role of R. aeschlimannii in H. marginatum ticks.IMPORTANCETicks are obligatory hematophagous arthropods that transmit pathogens of medical and veterinary importance. Pathogen infections cause serious health issues in humans and considerable economic loss in domestic animals. Information about the presence of pathogens in ticks and their dynamics is crucial to assess disease risk for public and animal health. Analyzing tick-borne pathogens in ticks collected in 27 sites in the Occitanie region, our results highlight clear spatial patterns in the Hyalomma marginatum-borne pathogen distribution and strengthen the postulate that it is essential to develop effective monitoring strategies and consider the spatial scale to better characterize the circulation of tick-borne pathogens.

Diversity of Rickettsia species in collected ticks from Southeast Iran

Rickettsia occurs worldwide and rickettsiosis is recognized as an emerging infection in several parts of the world. Ticks are reservoir hosts for pathogenic Rickettsia species in humans and domestic animals. Most pathogenic Rickettsia species belong to the spotted Fever Group (SFG). This study aimed to identify and diagnose tick fauna and investigate the prevalence of Rickettsia spp. in ticks collected from domestic animals and dogs in the rural regions of Kerman Province, Southeast Iran. In this study, tick species (fauna) were identified and 2100 ticks (350 pooled samples) from two genera and species including Rhipicephalus linnaei (1128) and Hyalomma deteritum (972) were tested to detect Rickettsia genus using Real-time PCR. The presence of the Rickettsia genus was observed in 24.9% (95%CI 20.28–29.52) of the pooled samples. Sequencing and phylogenetic analyses revealed the presence of Rickettsia aeschlimannii (48.98%), Rickettsia conorii israelensis (28.57%), Rickettsia sibirica (20.41%), and Rickettsia helvetica (2.04%) in the positive samples. The results showed a significant association between county variables and the following variables: tick spp. (p < 0.001), Rickettsia genus infection in ticks (p < 0.001) and Rickettsia spp. (p < 0.001). In addition, there was a significant association between tick species and host animals (dogs and domestic animals) (p < 0.001), Rickettsia spp infection in ticks (p < 0.001), and Rickettsia spp. (p < 0.001). This study indicates a high prevalence of Rickettsia spp. (SFG) in ticks of domestic animals and dogs in rural areas of Kerman Province. The health system should be informed of the possibility of rickettsiosis and the circulating species of Rickettsia in these areas.

Beware with the backpack! New hosts and pathogens identified for Ixodes simplex ticks collected from bats in the Iberian Peninsula

To improve the knowledge on the role of bats in the maintenance and transmission of tick-borne pathogens, a molecular approach was used to characterize Anaplasma spp., Rickettsia spp., Coxiella burnetii, Borrelia burgdorferi s.l., piroplasmids, Hepatozoon spp., flaviviruses and nairoviruses in ticks collected from Iberian bats. A total of 732 bats from 25 species were captured at 38 sampling sites distributed in seven provinces of Spain between 2018 and 2022. Seventy-nine Ixodes simplex ticks were collected from 31 bats (Eptesicus isabellinus, Hypsugo savii, Myotis capaccini, Myotis emarginatus, Myotis myotis, Miniopterus schreibersii, Pipistrellus pipistrellus and Rhinolophus ferrumequinum). Sixty of 79 I. simplex were positive for at least one pathogen tested and were collected from 23 bats captured in southeast Spain. We detected the presence of Rickettsia slovaca in 12 ticks collected from M. emarginatus, H. savii, M. schreibersii and E. isabellinus; Rickettsia aeschlimannii in 1 tick from M. schreibersii; Anaplasma ovis in 3 ticks from H. savii and M. schreibersii; C. burnetii in 2 ticks from H. savii; Occidentia massiliensis in 1 tick from H. savii; piroplasmids in 12 ticks from H. savii, M. schreibersii and E. isabellinus; and a novel nairovirus in 1 tick from M. schreibersii. Furthermore, blood samples obtained from 14 of the 31 tick-infested bats were negative in all PCR analyses. This study describes new host and pathogen associations for the bat-specialist I. simplex, highlights the risk of spread of these pathogens, and encourages further research to understand the role of Iberian bats in the epidemiology of tick-borne pathogens.

Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks from Selected Regions of Namibia.

Rickettsial pathogens are among the emerging and re-emerging vector-borne zoonoses of public health importance. Reports indicate human exposure to Rickettsial pathogens in Namibia through serological surveys, but there is a lack of data on infection rates in tick vectors, hindering the assessment of the relative risk to humans. Our study sought to screen Ixodid ticks collected from livestock for the presence of Rickettsia species in order to determine infection rates in ticks and to determine the Rickettsia species circulating in the country. We collected and pooled Hyalomma and Rhipicephalus ticks from two adjacent regions of Namibia (Khomas and Otjozondjupa) and observed an overall minimum Rickettsia infection rate of 8.6% (26/304), with an estimated overall pooled prevalence of 9.94% (95% CI: 6.5-14.3). There were no statistically significant differences in the estimated pooled prevalence between the two regions or tick genera. Based on the nucleotide sequence similarity and phylogenetic analysis of the outer membrane protein A (n = 9) and citrate synthase (n = 12) genes, BLAST analysis revealed similarity between Rickettsia africae (n = 2) and Rickettsia aeschlimannii (n = 11), with sequence identities ranging from 98.46 to 100%. Our initial study in Namibia indicates that both zoonotic R. africae and R. aeschlimannii are in circulation in the country, with R. aeschlimannii being the predominant species.

First Molecular Identification of Rickettsia aeschlimannii and Rickettsia africae in Ticks from Ghana.

The threats from vector-borne pathogens transmitted by ticks place people (including deployed troops) at increased risk for infection, frequently contributing to undifferentiated febrile illness syndromes. Wild and domesticated animals are critical to the transmission cycle of many tick-borne diseases. Livestock can be infected by ticks, and serve as hosts to tick-borne diseases such as rickettsiosis. Thus, it is necessary to identify the tick species and determine their potential to transmit pathogens. A total of 1,493 adult ticks from three genera-Amblyomma, Hyalomma, and Rhipicephalus-were identified using available morphological keys and were pooled (n = 541) by sex and species. Rickettsia species were detected in 308 of 541 (56.9%) pools by genus-specific quantitative polymerase chain reaction assay (Rick17b). Furthermore, sequencing of the outer membrane protein A and B genes (ompA and ompB) of random samples of Rickettsia-positive samples led to the identification of Rickettsia aeschlimannii and Rickettsia africae with most R. africae DNA (80.2%) detected in pools of Amblyomma variegatum. We report the first molecular detection and identification of the rickettsial pathogens R. africae and R. aeschlimannii in ticks from Ghana. Our findings suggest there is a need to use control measures to prevent infections from occurring among human populations in endemic areas in Ghana. This study underscores the importance of determining which vector-borne pathogens are in circulation in Ghana. Further clinical and prevalence studies are needed to understand more comprehensively the clinical impact of these rickettsial pathogens contributing to human disease and morbidity in Ghana.

Molecular Detection of Tick-Borne Pathogens in Kumasi: With a First Report of Zoonotic Pathogens in Abattoir Workers.

Tick-borne pathogens continue to infect humans and animals worldwide. By adapting to the movement of livestock, ticks facilitate the spread of these infectious pathogens. Humans in close contact with animals that could be amplifying hosts are especially at risk of being infected with tick-borne pathogens. This study involved the collection of dry blood spots (DBSs) to determine tick-borne pathogens occurring in slaughtered livestock and abattoir workers in Kumasi. This study employed the use of conventional PCR, RT-PCR, and Sanger sequencing to detect and identify the tick-borne pathogens. The resulting data was analysed using Stata version 13. A total of 175 DBSs were collected from goats (76), cattle (54), and sheep (45) in the Kumasi abattoir (130, 74.29%) and Akwatia Line slaughter slab (45, 25.71%). The pathogens identified were mostly bacterial including Anaplasma capra (9.71%), Anaplasma phagocytophilum (1.14%), and Rickettsia aeschlimannii (0.57.%). The only parasite identified was Theileria ovis (9.14%). A significant association was seen between A. capra (p < 0.001) infection and female sheep sampled from the Akwatia Line slaughter slab. Again, there was a significant association between T. ovis (p < 0.001) infections and female sheep from the Kumasi abattoir. From the human DBS (63) screened, the pathogens identified were all bacterial including Coxiella burnetii (1.89%), Rickettsia africae (1.89%), and R. aeschlimannii (1.89%). This study reports the first detection of R. aeschlimannii in livestock as well as the occurrence of the above-mentioned pathogens in humans in Ghana. Animals can serve as amplifying hosts for infectious pathogens; hence, there is an increased risk of infections among the abattoir workers. Continuous surveillance effort is essential, and abattoir workers need to protect themselves from tick bites and infectious tick-borne pathogens.

Tissue-specific localization of tick-borne pathogens in ticks collected from camels in Kenya: insights into vector competence.

Tick-borne pathogen (TBP) surveillance studies often use whole-tick homogenates when inferring tick-pathogen associations. However, localized TBP infections within tick tissues (saliva, hemolymph, salivary glands, and midgut) can inform pathogen transmission mechanisms and are key to disentangling pathogen detection from vector competence. We screened 278 camel blood samples and 504 tick tissue samples derived from 126 camel ticks sampled in two Kenyan counties (Laikipia and Marsabit) for Anaplasma, Ehrlichia, Coxiella, Rickettsia, Theileria, and Babesia by PCR-HRM analysis. Candidatus Anaplasma camelii infections were common in camels (91%), but absent in all samples from Rhipicephalus pulchellus, Amblyomma gemma, Hyalomma dromedarii, and Hyalomma rufipes ticks. We detected Ehrlichia ruminantium in all tissues of the four tick species, but Rickettsia aeschlimannii was only found in Hy. rufipes (all tissues). Rickettsia africae was highest in Am. gemma (62.5%), mainly in the hemolymph (45%) and less frequently in the midgut (27.5%) and lowest in Rh. pulchellus (29.4%), where midgut and hemolymph detection rates were 17.6% and 11.8%, respectively. Similarly, in Hy. dromedarii, R. africae was mainly detected in the midgut (41.7%) but was absent in the hemolymph. Rickettsia africae was not detected in Hy. rufipes. No Coxiella, Theileria, or Babesia spp. were detected in this study. The tissue-specific localization of R. africae, found mainly in the hemolymph of Am. gemma, is congruent with the role of this tick species as its transmission vector. Thus, occurrence of TBPs in the hemolymph could serve as a predictor of vector competence of TBP transmission, especially in comparison to detection rates in the midgut, from which they must cross tissue barriers to effectively replicate and disseminate across tick tissues. Further studies should focus on exploring the distribution of TBPs within tick tissues to enhance knowledge of TBP epidemiology and to distinguish competent vectors from dead-end hosts.

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.

Rickettsial Infection in the COVID-19 Era: The Correlation between the Detection of Rickettsia aeschlimannii in Ticks and Storytelling Photography of a Presumable Human Rickettsiosis Case.

Rickettsia aeschlimannii infection is an emerging human tick-borne disease with only a few recorded cases. We reported a presumable autochthonous case of rickettsiosis in an Italian cattle breeder associated with a Hyalomma marginatum bite. Rickettsia aeschlimannii DNA was detected in both the tick specimen from the patient and the grazing cattle close to his farm.

First report on tick-borne pathogens detected in ticks infesting stray dogs near butcher shops.

Public health is a major concern for several developing countries due to infectious agents transmitted by hematophagous arthropods such as ticks. Health risks due to infectious agents transmitted by ticks infesting butcher-associated stray dogs (BASDs) in urban and peri-urban regions have been neglected in several developing countries. To the best of the authors' knowledge, this is the first study assessing public health risks due to ticks infesting BASDs in Pakistan's urban and peri-urban areas. A total of 575 ticks (390 from symptomatic and 183 from asymptomatic BASDs) were collected from 117 BASDs (63 symptomatic and 54 asymptomatic); the ticks belonged to 4 hard tick species. A subset of each tick species' extracted DNA was subjected to polymerase chain reaction (PCR) to amplify the 16S rDNA and cox1 sequences of the reported tick species, as well as bacterial and protozoal agents. The ticks' 16S rDNA and cox1 sequences showed 99-100% identities, and they were clustered with the sequence of corresponding species from Pakistan and other countries in phylogenetic trees. Among the screened 271 ticks' DNA samples, Anaplasma spp. was detected in 54/271 (19.92%) samples, followed by Ehrlichia spp. (n = 40/271, 14.76%), Rickettsia spp. (n = 33/271, 12.17%), Coxiella spp. (n = 23/271, 4.48%), and Hepatozoon canis (n = 9/271, 3.32%). The obtained sequences and phylogenetic analyzes revealed that the pathogens detected in ticks were Ehrlichia minasensis, Ehrlichia sp., Hepatozoon canis, Coxiella burnetii, Coxiella sp., Anaplasma capra, Anaplasma platys, Anaplasma sp., Rickettsia massiliae, "Candidatus Rickettsia shennongii" and Rickettsia aeschlimannii. Tick-borne pathogens such as E. minasensis, H. canis, A. capra, A. platys, and R. aeschlimannii, were detected based on the DNA for the first time in Pakistan. This is the first report on public health risks due to ticks infesting BASDs. These results not only provided insights into the occurrence of novel tick-borne pathogens in the region but also revealed initial evidence of zoonotic threats to both public health and domestic life.

Spotted fever group rickettsiae in hard ticks in eastern and southern Kazakhstan

Infections with spotted fever group rickettsiae represent a worldwide health problem, characterized by persistent high fever, headache, and rash in humans, domestic animals, and wildlife. To date, the occurrence of Rickettsia species in hard ticks has not been thoroughly studied, especially in eastern and southern Kazakhstan. A total of 1,245 adult ticks, comprising 734 Dermacentor marginatus, 219 Hyalomma scupense, 144 Hyalomma asiaticum, 84 Hyalomma marginatum, 48 Rhipicephalus turanicus, and 16 Haemaphysalis erinacei, collected from East Kazakhstan, Abay, Jetsu, Almaty, Jambyl, South Kazakhstan and Qyzylorda oblasts of Kazakhstan, were used to screen rickettsial agents using molecular methods. Rickettsia raoultii, Rickettsia slovaca, Rickettsia aeschlimannii and Rickettsia heilongjiangensis were identified using sequencing, and 31.5% (392/1245) of ticks carried rickettsial agents. The difference in the natural landscapes explains the variety of the collected ticks and expands our knowledge of Rickettsia species and their geographical distribution in Kazakhstan. To the best of our knowledge, this study reports the first finding of R. heilongjiangensis in Kazakhstan.

Diversity of Rickettsia spp. in ticks from wild mammals of Morocco and Mauritania

Ticks are known as vectors and reservoirs of rickettsiae and, wildlife vertebrate hosts as suitable dispersers of ticks contributing to the life cycle of rickettsial agents in nature. In the herein study, the presence of rickettsiae was investigated in ticks from wild mammals (Gerbillus and Jaculus, Vulpes rueppellii, Canis anthus, Felis lybica and Felis margarita) in Mauritania and Morocco. Morphological and molecular analysis of ticks allowed their identification as Rhipicephalus sanguineus sensu lato and Hyalomma impeltatum. A total of 126 partially engorged adult ticks, collected from 40 animals, were screened for the presence of rickettsial DNA by conventional PCR targeting the ompB gene, followed by ompA and gltA targets and bidirectional sequencing. As a result of the sequence analyses, that at least three different species of pathogenic spotted fever group rickettsiae were detected. Rickettsia parkeri-like was detected in a R. sanguineus s.l. (n=1) collected from an African wildcat from Morocco. Rickettsia aeschlimannii was detected in a H. impeltatum (n=1) collected from a gerbil rodent. Rickettsia massiliae was detected in R. sanguineus s.l. ticks (n=5) collected from two Ruppells' foxes. The herein study demonstrates that pathogenic Rickettsia species are circulating in Morocco and Mauritania wildlife.

Occurrence of Rickettsia spp. and Coxiella burnetii in ixodid ticks in Kassena-Nankana, Ghana.

Ticks are arthropods of veterinary and medical importance which spread zoonotic pathogens that link animal and human health. In this study, ticks were collected from 448 livestock between February and December 2020 in the Kassena-Nankana Districts of Ghana and screened for the presence of zoonotic pathogens DNA using PCR and sequencing approaches. In total, 1550 ticks were collected and morphologically identified. Three tick genera were identified with Amblyomma variegatum (63%) as the predominant tick species collected. DNA was extracted from 491 tick pools and screened for the presence of DNA of Rickettsia spp. based on the 115bp fragment of the 17kDa surface protein and 639bp of the Outer membrane protein A (ompA) gene and the 295bp fragment of the transposase gene of Coxiella burnetii IS1111a element. From the 491 pools screened, the DNA of Rickettsia spp. and C. burnetii was detected in 56.8 and 3.7%, respectively. Coinfections were identified in 2.4% of the tick pools. Characterization of the Rickettsia spp. in this study based on the ompA gene showed that the DNA of Rickettsia africae and Rickettsia aeschlimannii accounted for 39.7 and 14.7%, respectively, and were 100% similar to sequences in GenBank. Most R. africae and C. burnetii infections occurred in ticks collected in the wet season, whereas R. aeschlimannii occurred mostly in the dry season. These pathogens are potential public health threats, thus there is a need to implement control measures to reduce the risk of infections in vulnerable populations.

Ticks and Rickettsiae Associated with Wild Animals Sold in Bush Meat Markets in Cameroon.

Ticks are obligate blood-sucking parasites of wild animals and transmit many zoonotic microorganisms that can spread to domesticated animals and then to humans. In Cameroon, little is known about tick diversity among wildlife, especially for animals which are hunted for human consumption. Therefore, this survey was undertaken to investigate tick and Rickettsia species diversity parasitizing the wild animals sold in bush meat markets in Cameroon. In total, 686 ticks were collected and identified to the species level based on morphology, and some were genetically analyzed using the 16S rRNA gene. Eighteen tick species belonging to five genera were identified: Amblyomma spp. (Amblyomma compressum, Amblyomma flavomaculatum, and Amblyomma variegatum), Haemaphysalis spp. (Haemaphysalis camicasi, Haemaphysalis houyi, Haemaphysalis leachi, and Haemaphysalis parmata), Hyalomma spp. (Hyalomma nitidum, Hyalomma rufipes, and Hyalomma truncatum), Ixodes spp. (Ixodes rasus and Ixodes moreli), and Rhipicephalus spp. (Rhipicephalus guilhoni, Rhipicephalus moucheti, Rhipicephalus muhsamae, Rhipicephalus microplus, Rhipicephalus camicasi, and Rhipicephalus linnaei). In terms of Rickettsia important for public health, two Rickettsia spp., namely Rickettsia aeschlimannii and Rickettsia africae, were detected in Hyalomma spp. and Amblyomma spp., respectively. Distinct tick-pathogen patterns were present for divergent sequences of R. africae associated with exclusively A. variegatum vectors (type strain) versus vectors comprising A. compressum, A. flavomaculatum, and A. variegatum. This suggests possible effects of vector species population dynamics on pathogen population circulation dynamics. Furthermore, Candidatus Rickettsia africaustralis was detected for the first time in Cameroon in I. rasus. This study highlights the high diversity of ticks among wildlife sold in bush meat markets in Cameroon.

Zoonotic Pathogens Detected in Ticks in Kenyan Game Reserves

Little is known on tick-borne pathogens and their role in disease in game reserves in Kenya. Ticks were collected by sterile forceps from restrained cattle hide and placed into labeled falcon tubes. Ticks were screened for pathogens by High Resolution Melting (HRM) analysis and sequencing of specific RT-PCR products of Anaplasma, Ehrlichia, and Rickettsia species. A total of 317 ticks (281 adult ticks and 36 nymphs) comprising seven species were collected around the Tsavo National Reserve (TNR) in Taita Taveta County with Amblyomma gemma being the most commonly collected species (n = 135, 42.6%). From near Shimba Hill game reserve (SHNR), a total of 240 adult’s ticks were sampled, representing eight species, with again Amblyomma gemma being the most sampled species (n = 156, 65%). From Tsavo, a total of three pools of Rhipicephalus appendiculatus were positive for Theileria parva, two pools of Rhipicephaline evertsi for Anaplasma platys and one pool of Amblyomma variegatum nymphs for Rickettsia africae. Rickettsia africae, which causes African tick-bite fever, was detected in two pools of Am. variegatum and one pool of Amblyomma gemma collected near Shimba Hill game reserve. Rickettsia sp. and Anaplasma sp. were detected in Am. gemma and Rh. evertsi respectively. Rickettsia aeschlimannii was detected in a pool of Am. gemma. These findings highlight the risk of transmission of zoonotic pathogens to humans in regions with high human-wildlife interfaces. Of specific importance, we provide evidence of R. aeschlimannii in A. gemma for the first time, representing a potential new R. aeschlimannii vectors.