Search Results (20)

Ticks are a major concern for both animal and human health, as they are primary vectors of infectious pathogens. This study focused on ticks found in a nature reserve in southern Italy, highly frequented for recreational activities and inhabited by wild boars. Using molecular techniques, 214 ticks, including questing ticks and those removed from wild boars, were examined for tick-borne pathogens (TBPs), with a focus on zoonotic pathogens. Six tick species were identified: Hyalomma lusitanicum, Rhipicephalus pusillus, Rh. sanguineus s.l., Rh. bursa, Rh. turanicus, and Dermacentor marginatus, several of which are known vectors of zoonotic pathogens. Overall, 14% of ticks were positive for TBPs, mainly bacteria of Rickettsia genus. Molecular analyses detected Rickettsia slovaca, R. massiliae, Candidatus R. shennongii, R. conorii, R. felis, and R. barbariae. Additionally, single detections of Coxiella burnetii and Theileria annulata were recorded. Phylogenetic analyses were conducted on Rickettsia sequences. The range of ticks and TBPs present in this area highlights potential public health concerns. New associations between tick species and TBPs were documented, though vector roles need further investigation. The study highlights the importance of monitoring tick populations in both rural and urban environments to protect public health and prevent tick-borne disease spreading. Full article

Tick-borne diseases (TBDs) are a considerable public health problem worldwide. The occurrence of Anaplasma spp., Borrelia burgdorferi s.l., Coxiella burnetii, Rickettsia spp., and tick-borne encephalitis virus (TBEv) was investigated via PCR and sequencing in 683 ticks collected from 105 roe deer, 61 wild boars, 49 fallow deer, and 2 chamois, in the Liguria region, northwest Italy, between 2019 and 2022. The ticks were morphologically identified. Four different tick species were found: Ixodes ricinus (66.8% of the collected ticks), Dermacentor marginatus (15.8%), Rhipicephalus sanguineus s.s. (15.7%), and Haemaphysalis punctata (0.9%). Six ticks (0.9%) were only identified as Rhipicephalus spp. Of the 222 pools analyzed, 27.9% were positive. Most pools (n = 58, 26.1% of pools analyzed) were positive for Rickettsia spp., and several species were found: Rickettsia slovaca was the dominant species (15.3%), followed by R. monacensis (8.1%), while R. helvetica (1.8%), R. massiliae (0.5%), and R. raoultii (0.5%) were found only sporadically. Anaplasma phagocytophilum was identified in three pools and B. burgdorferi s.l. in one pool. All samples were negative for C. burnetii and TBEv. Significant associations were found between I. ricinus and roe deer, D. marginatus and wild boar, and between R. monacensis and I. ricinus. The prevalence of Rickettsia spp. differed significantly between tick and host species. This updated picture of tick species and TBPs in wild ungulates in Liguria, where the population of these animals is increasing, shows a widespread presence of potentially zoonotic Rickettsia spp. Continuous monitoring and public information on preventive measures are needed. Full article

Tick-borne rickettsioses (TBRs) are distributed worldwide and are recognized as important emerging vector-borne zoonotic diseases in Europe. The aim of this study was to identify tick-associated Rickettsia among ticks removed from humans, and to track how tick populations and their associated pathogens have changed over the years. For this purpose, we conducted a tick surveillance study in northwestern Spain between 2018 and 2022. Ticks were morphologically identified and analyzed for the presence of rickettsial pathogens through the amplification of the citrate synthase (gltA) and the outer membrane protein A (ompA) genes. PCR products were sequenced and subjected to phylogenetic analyses. We collected 7397 ticks, with Ixodes ricinus being the species most frequently isolated. Based on the PCR results, Rickettsia DNA was detected in 1177 (15.91%) ticks, and 10 members of Rickettsia were identified: R. aeschlimannii, R. conorii subsp. conorii, R. conorii subsp. raoultii, R. massiliae, R. monacensis, R. sibirica subsp. mongolitimonae, R. slovaca, R. helvetica, Candidatus R. barbariae, and Candidatus R. rioja. Some of these Rickettsia have gone previously undetected in the study region. There is clear geographic and seasonal expansion not only of tick populations, but also of the associated Rickettsia. The comparison of our data with those obtained years ago provides a clear idea of how the spatiotemporal distributions of ticks and their associated Rickettsiae have changed over the years. Full article

Karachay-Cherkessia is the region in the Russian Federation that has been overlooked in terms of research on the human bacterial pathogens transmitted by ticks. In this study, we investigated the infection status of ticks with Rickettsia, Borrelia, Coxiella burmetii, Anaplasma phagocytophilum, and Ehrlichia chaffeensis/Ehrlichia muris associated with natural focal infections in Karachay-Cherkessia. A total amount of 159 ticks from three species across three genera (Ixodes ricinus, Dermacentor marginatus, Hyalomma scupense) removed from humans were collected for analysis. Additionally, we used 53 individual ticks and 40 tick pools from the vegetation of three species (I. ricinus, D. marginatus, and Rhipicephalus bursa). Screening of the studied pathogens was performed by using commercial qPCR kits. Sanger sequencing utilizing partial sequences of gltA and ompA genes was employed to identify the Rickettsia species. Our findings revealed the presence of DNA from five species within the spotted fever group Rickettsia, namely Rickettsia raoultii, R. slovaca, R. helvetica, R. monacensis, and R. aeschlimannii. Moreover, two distinct genotypes were identified within R. aeschlimannii, R. helvetica, and R. monacensis. Additionally, DNA from Borrelia burgdoferi s.l., B. miyamotoi, and A. phagocytophilum was detected in the tested ticks. This study provides valuable insights into the prevalence and the diversity of bacterial pathogens transmitted by ticks in the Karachay-Cherkessia region. Full article

Rickettsial infections of the central nervous system (CNS) are manifested by severe neurological symptoms and represent a serious life-threatening condition. Despite the considerable health danger, only a few studies have been conducted focusing on the pathogenesis induced by Rickettsia sp. in CNS. To investigate the signaling pathways associated with the neurotoxic effects of rickettsiae, we employed an experimental model of cerebrocortical neurons combined with molecular profiling and comprehensive bioinformatic analysis. The cytopathic effect induced by Rickettsia akari and Rickettsia slovaca was demonstrated by decreased neuronal viability, structural changes in cell morphology, and extensive fragmentation of neurites in vitro. Targeted profiling revealed the deregulation of genes involved in the neuroinflammatory and neurotoxic cell response pathways. Although quantitative analysis showed differences in gene expression response, functional annotation revealed that the biological processes are largely shared between both Rickettsia species. The identified enriched pathways are associated with cytokine signaling, chemotaxis of immune cells, responses to infectious agents, interactions between neurons, endothelial and glial cells, and regulation of neuronal apoptotic processes. The findings of our study provide new insight into the etiopathogenesis of CNS infection and further expand the understanding of molecular signaling associated with neuroinvasive Rickettsia species. Full article

The Soprano pipistrelle bat, Pipistrellus pygmaeus, is a common species in large parts of Sweden. Many of its natural habitats are near human habitations. This creates opportunities for ticks infesting these bats to encounter humans and possibly transmit zoonotic pathogens by tick bites. The bats are often infested with Carios vespertilionis, a tick species that, in addition to bats, has been recorded to bite humans on occasion. This study aimed to investigate if C. vespertilionis acts as a reservoir for Anaplasma phagocytophilum, Neoehrlichia mikurensis, Tick-borne encephalitis virus, and species of Babesia and Rickettsia and to improve currently used conventional PCR protocols for molecular species determination of Rickettsia spp. Ninety-two C. vespertilionis ticks were collected from underneath a bat-box harbouring P. pygmaeus. Pathogen-specific PCR assays showed that 58.4% were positive for Rickettsia spp. and negative for the other pathogens analysed. Phylogenetic analyses indicate that the species belong to R. parkeri, R. conorii, R. slovaca, R. sibirica subsp. mongolotimonae, R. rickettsii, and a hitherto uncultured Rickettsia sp. Several of these species are considered pathogenic to humans. Given the ecology and behaviour of C. vespertilionis, it may be a vector of these rickettsiae among bats and occasionally humans. To determine the Rickettsia species with certainty, and to determine if C. vespertilionis may be a reservoir and vector of the Rickettsia spp., further studies are needed. Full article

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

Tickborne bacterial pathogens have been described worldwide as risk factors for both animal and human health. Spotted fevers caused by Rickettsiae may cause non-specific symptoms, which make clinical diagnosis difficult. The aim of the current study was to evaluate and review the diversity of SFG Rickettsiae in ticks collected in 41 counties in Romania. A total of 2028 questing and engorged ticks collected in Romania belonging to five species were tested by PCR amplification of Rickettsia spp. gltA and 17-D gene fragments: Ixodes ricinus (n = 1128), Dermacentor marginatus (n = 507), D. reticulatus (n = 165), Rhipicephalus rossicus (n = 128) and Haemaphysalis punctata (n = 100). Five Rickettsia species were identified following DNA sequence analysis: R. helvetica, R. monacensis, R. slovaca, R. raoultii, and R. hoogstraalii. The most common species detected was R. monacensis. Moreover, R. hoogstraalii was detected for the first time in Romania and in R. rossicus ticks. The detection of R. raoultii and R. monacensis in questing larvae of Hae. punctata suggests the possible transovarial transmission of these Rickettsia species in ticks. The detection of R. hoogstraalii for the first time in Romania increases the reported SFG Rickettsia diversity in the country. Full article

Epidemiological knowledge on pathogens in ticks feeding on birds in Moldova is scarce. To reduce this gap of information, a total of 640 migrating and native birds of 40 species were caught from 2012 to 2015 and examined for the presence of ticks in the Republic of Moldova. Altogether, 262 ticks belonging to five tick species (Ixodes ricunus n = 245, Ixodes frontalis n = 12, Haemaphysalis punctata n = 2, Hyalomma marginatum n = 2 (only males), Dermacentor marginatus n = 1) were collected from 93 birds. Of these ticks, 250 (96%) were at the stage of a nymph and 9 at the stage of a larva (3%). One imago of I. frontalis and two imagoes of Hy. marginatum were found. Generally, ticks infested 14.1% of the assessed birds belonging to 12 species. DNA was extracted from individual ticks with subsequent PCR targeting Rickettsia spp., Borrelia spp. in general, as well as relapsing fever-associated Borrelia spp., in particular, Anaplasma phagocytophilum, Neoehrlichia mikurensis, Babesia spp. and Coxiella burnetii. The bird species Turdus merula showed the heaviest infestation with ticks and the highest incidence of infected ticks. Altogether, 32.8% of the assessed ticks (n = 86) were positive for one of the pathogens. DNA of Borrelia spp. was found in 15.2% (40/262) of the investigated ticks; in 7.6% of ticks (20/262), DNA of rickettsiae was detected; 6.9% (18/262) of the ticks were positive for A. phagocytophilum DNA; in 1.5% of the ticks (4/262), DNA of Neoehrlichia mikurensis was detected, followed by 1.5% (4/262) Babesia microti and 1.5% (4/262) Borrelia miyamotoi. Within the B. burgdorferi complex, B. garinii (n = 36) was largely predominant, followed by B. valaisiana (n = 2) and B. lusitaniae (n = 2). Among the detected Rickettsia spp., R. monacensis (n = 16), R. helvetica (n = 2) and R. slovaca (n = 1) were identified. In conclusion, the study provided some new information on the prevalence of ticks on birds in Moldova, as well as the presence of DNA of pathogens in the ticks. By doing so, it provided an additional piece in the puzzle of the global epidemiology of tick-transmitted infectious diseases from a geographic side from where respective surveillance data are scarce. Full article

During recent decades, a tick-borne rickettsial syndrome, characterized by eschar and painful lymphadenopathy after Dermacentor marginatus-bite, has been described as an emerging rickettsiosis in Europe. Our group named it DEBONEL (Dermacentor-borne-necrosis-erythema-lymphadenopathy), regarding the vector and the main infection signs. Other groups called it TIBOLA (tick-borne-lymphadenophathy) and, later, SENLAT (scalp-eschar-and-neck-lymphadenopathy-after-tick-bite), expanding, in the latter, the etiological spectrum to other pathogens. Objective: To investigate the etiology of DEBONEL agents in our area, and to compare their epidemiological/clinical/microbiological characteristics. During 2001–2020, 216 patients clinically diagnosed of DEBONEL (the largest series from one center) in La Rioja (northern Spain) were examined. Rickettsia spp. were amplified in 14/104 (13.46%) blood samples, 69/142 (48.59%) eschar swabs, 7/7 (100%) biopsies, and 71/71 (100%) D. marginatus from patients. For samples in which Rickettsia was undetected, no other microorganisms were found. ‘Candidatus Rickettsia rioja’, Rickettsia slovaca, Rickettsia raoultii, and Rickettsia DmS1 genotype were detected in 91, 66, 4, and 3 patients, respectively. DEBONEL should be considered in patients with clinical manifestations herein described in areas associated to Dermacentor. The most frequently involved agent in our environment is ‘Ca. R. rioja’. The finding of Rickettsia sp. DmS1 in ticks attached to DEBONEL patients suggests the implication of other rickettsia genotypes. Full article

Tick-borne rickettsiae are emerging pathogens that are becoming widespread in Europe. Rickettsiae are endemic in Italy, but epidemiological data are currently scarce. This study aimed to improve our knowledge about rickettsial infections in tick and wild boar populations. Blood and ticks were collected from 102 wild boars in 2010 and 2018. Ticks were also collected from the vegetation in the area. All of the samples were examined using real-time PCR targeting the gltA gene to detect Rickettsia DNA. Positivity was confirmed by PCR amplifying the gltA and/or ompB genes. A total of 254 ticks and 89 blood samples were analyzed. Zoonotic rickettsiae were detected in the ticks but not in the blood samples. Rickettsia slovaca (R. slovaca) was the most prevalent in ticks and was found in 23.7% of Dermacentor marginatus (D. marginatus) and in 3.4% of Ixodes ricinus (I. ricinus). Other zoonotic species were identified, such as Rickettsia monacensis, which was detected in 12% of I. ricinus ticks, and Rickettsia helvetica which was found in 3.4% of questing I. ricinus ticks and in 1.1% of D. marginatus collected from wild boars. This study highlights a high prevalence of zoonotic rickettsiae, particularly that of R. slovaca, in northeastern Italy. As rickettsioses are underreported and underdiagnosed in human medicine, both clinicians and researchers should pay more attention to this topic. Full article

Limited information is available on the presence of rickettsial infection in animal reservoirs in Spain. Antibodies against Rickettsia slovaca and Rickettsia conorii were therefore sought in the sera of farm, domestic and wild animals (n = 223 samples) in an area of northern Spain. Indirect immunofluorescence assays showed: (A) 17/120 and 16/120 (14.2% and 13.3%) of serum samples from sheep (farm animals) reacted with R. slovaca and R. conorii antigens, respectively; (B) 10/73 and 10/73 (13.7% and 13.7%) of samples from dogs (domestic animals) did the same; (C) as did 22/30 and 20/30 (73.3% and 66.6%) of samples from deer (wild animals) (overall titre range: 1/40 to 1/1280). The prevalence of both types of infection was significantly greater in the wild animals than either the farm or domestic animals. The largest titres were recorded for R. slovaca in all three groups. Full article

There is no updated information on the spread of Rickettsiales in Italy. The purpose of our study is to take stock of the situation on Rickettsiales in Italy by focusing attention on the species identified by molecular methods in humans, in bloodsucking arthropods that could potentially attack humans, and in animals, possible hosts of these Rickettsiales. A computerized search without language restriction was conducted using PubMed updated as of December 31, 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. Overall, 36 species of microorganisms belonging to Rickettsiales were found. The only species identified in human tissues were Anaplasma phagocytophilum,Rickettsia conorii, R. conorii subsp. israelensis, R. monacensis, R. massiliae, and R. slovaca. Microorganisms transmissible by bloodsucking arthropods could cause humans pathologies not yet well characterized. It should become routine to study the pathogens present in ticks that have bitten a man and at the same time that molecular studies for the search for Rickettsiales can be performed routinely in people who have suffered bites from bloodsucking arthropods. Full article

Rickettsia spp. are the second most common pathogens detected in Ixodes ricinus ticks in Austria after Borrelia burgdorferi sensu lato. Species belonging to the spotted fever group (SFG) are the causative agents for tick-borne rickettsiosis across the world. So far, only four SFG Rickettsia spp. were detected in Austria, namely R. helvetica, R. raoultii, R. monacensis and R. slovaca. Here, we describe the identification of a new SFG Rickettsia species detected in an I. ricinus tick. Sequencing of various rickettsial genes revealed a nucleotide sequence similarity of 99.6%, 98.5%, 97.3% and 98.5% to the gltA, ompA, ompB, and sca4 genes, respectively, of known and validated species. Additionally, sequencing of the htrA gene and 23S-5S intergenic spacer region also only showed 99.6% and 99.2%, respectively, similarity to known species. Therefore, and in accordance with current criteria for Rickettsia species discrimination, we hereby describe a new species of the SFG with putative pathogenic potential. We propose the name “Candidatus Rickettsia thierseensis” based on the village Thiersee in the Austrian province of Tyrol, where the carrying tick was found. Full article

We investigated the distribution of Dermacentor spp. and their infection by zoonotic bacteria causing SENLAT (scalp eschar neck lymphadenopathy) in Turin province, northwestern Italy. We collected ticks in a mountain and in a periurban park, from vegetation and different animal sources, and we sampled tissues from wild boar. Dermacentor marginatus (n = 121) was collected in both study areas, on vegetation, humans, and animals, while D. reticulatus (n = 13) was exclusively collected on wild boar from the periurban area. Rickettsia slovaca and Candidatus Rickettsia rioja infected 53.1% of the ticks, and R. slovaca was also identified in 11.3% of wild boar tissues. Bartonella spp. and Francisella tularensis were not detected, however, Francisella-like endosymbionts infected both tick species (9.2%). Our findings provide new insights on the current distribution of Dermacentor spp. and their infection with a spotted-fever group rickettsiae in the Alps region. Wild boar seem to play a major role in their eco-epidemiology and dispersion in the study area. Although further studies are needed to assess the burden of rickettsial diseases, our results highlight the risk of contracting SENLAT infection through Dermacentor spp. bites in the region. Full article