Identification of Borrelia burgdorferi sensu lato, Anaplasma and Ehrlichia species, and spotted fever group Rickettsiae in ticks from Southeastern Europe

Serological Assessment of Lyme borreliosis in Bulgaria: A Nationwide Study

Lyme borreliosis (LB), a tick-borne infection caused by bacteria in the Borrelia burgdorferi sensu lato complex, is increasingly prevalent on the Balkan Peninsula, including Bulgaria, where it is the most common tick-borne disease. This study aimed to assess the seroprevalence of LB across Bulgaria by analyzing 1892 serum samples for specific IgG antibodies using a two-tier testing protocol involving an ELISA and immunoblot methods. The results revealed an overall seroprevalence rate of 5.4%, with significant variation based on age, sex, and residence. Seroprevalence increased with age, peaking at 8.4% in individuals over 65 years. Males had a seroprevalence of 8.4% compared to 3.3% in females, and rural residents showed higher seroprevalence (10.2%) compared to urban residents (4.4%). Regional analysis indicated that seroprevalence ranged from 0.0% to 20.0%, with higher rates in northern provinces such as Gabrovo (18.9%) and Targovishte (20.0%). This study highlights the importance of two-step testing protocols for accurate diagnosis and underscores the need for increased awareness and further research to enhance public health measures and the management of LB in Bulgaria.

Simultaneous detection of seven bacterial pathogens transmitted by flies using the reverse line blot hybridization assay

BACKGROUND

Traditional methods for detecting insect-borne bacterial pathogens are time-consuming and require specialized laboratory facilities, limiting their applicability in areas without access to such resources. Consequently, rapid and efficient detection methods for insect-borne bacterial diseases have become a pressing need in disease prevention and control.

METHODS

We aligned the ribosomal 16S rRNA sequences of seven bacterial species (Staphylococcus aureus, Shigella flexneri, Aeromonas caviae, Vibrio vulnificus, Salmonella enterica, Proteus vulgaris, and Yersinia enterocolitica) by DNASTAR Lasergene software. Using DNASTAR Lasergene and Primer Premier software, we designed universal primers RLB-F and RLB-R, two species-specific probes for each pathogen, and a universal probe (catch-all). The PCR products of seven standard strains were hybridized with specific oligonucleotide probes fixed on the membrane for specific experimental procedures. To evaluate the sensitivity of PCR-RLB, genomic DNA was serially diluted from an initial copy number of 1010 to 100 copies/μl in distilled water. These dilutions were utilized as templates for the PCR-RLB sensitivity analysis. Simultaneous detection of seven fly-borne bacterial pathogens from field samples by the established PCR-RLB method was conducted on a total of 1060 houseflies, collected from various environments in Lanzhou, China.

RESULTS

The established PCR-RLB assay is capable of detecting bacterial strains of about 103 copies/μl for S. aureus, 103 copies/μl for S. flexneri, 105 copies/μl for A. caviae, 105 copies/μl for V. vulnificus, 100 copies/μl for S. enterica, 105 copies/μl for P. vulgaris, and 100 copies/μl for Y. enterocolitica. The results demonstrate that the detection rate of the established PCR-RLB method is higher (approximately 100 times) compared to conventional PCR. This method was applied to assess the bacterial carrier status of flies in various environments in Lanzhou, China. Among the seven bacterial pathogens carried by flies, S. enterica (34.57%), S. flexneri (32.1%), and Y. enterocolitica (20.37%) were found to be the predominant species.

CONCLUSIONS

Overall, this research shows that the rapid and efficient PCR-RLB detection technology could be a useful for surveillance and therefore effective prevention and control the spread of insect-borne diseases. Meanwhile, the experimental results indicate that urban sanitation and vector transmission sources are important influencing factors for pathogen transmission.

Ixodid ticks and zoonotic tick-borne pathogens of the Western Balkans

Ixodid ticks are distributed across all countries of the Western Balkans, with a high diversity of species. Many of these species serve as vectors of pathogens of veterinary and medical importance. Given the scattered data from Western Balkan countries, we have conducted a comprehensive review of available literature, including some historical data, with the aim to compile information about all recorded tick species and associated zoonotic pathogens in this region. Based on the collected data, the tick fauna of the Western Balkans encompasses 32 tick species belonging to five genera: Ixodes, Haemaphysalis, Dermacentor, Rhipicephalus and Hyalomma. A range of pathogens responsible for human diseases has also been documented, including viruses, bacteria and parasites. In this review, we emphasize the necessity for integrated surveillance and reporting, urging authorities to foster research by providing financial support. Additionally, international and interdisciplinary collaborations should be encouraged that include the exchange of expertise, experiences and resources. The present collaborative effort can effectively address gaps in our knowledge of ticks and tick-borne diseases.

History and Current Status of Mediterranean Spotted Fever (MSF) in the Crimean Peninsula and Neighboring Regions along the Black Sea Coast

Mediterranean spotted fever (MSF) is a tick-borne rickettsiosis caused by Rickettsia conorii subspecies conorii and transmitted to humans by Rhipicephalus sanguineus ticks. The disease was first discovered in Tunisia in 1910 and was subsequently reported from other Mediterranean countries. The first cases of MSF in the former Soviet Union were detected in 1936 on the Crimean Peninsula. This review summarizes the historic information and main features of MSF in that region and contemporary surveillance and control efforts for this rickettsiosis. Current data pertinent to the epidemiology of the disease, circulation of the ticks and distribution of animal hosts are discussed and compared for each of the countries in the Black Sea basin where MSF occurs.

Arthropod vectors of disease agents: their role in public and veterinary health in Turkiye and their control measures

Mosquitoes, sandflies, and ticks are hematophagous arthropods that pose a huge threat to public and veterinary health. They are capable of serving as vectors of disease agents that can and have caused explosive epidemics affecting millions of people and animals. Several factors like climate change, urbanization, and international travel contribute substantially to the persistence and dispersal of these vectors from their established areas to newly invaded areas. Once established in their new home, they can serve as vectors for disease transmission or increase the risk of disease emergence. Turkiye is vulnerable to climate change and has experienced upward trends in annual temperatures and rising sea levels, and greater fluctuations in precipitation rates. It is a potential hotspot for important vector species because the climate in various regions is conducive for several insect and acari species and serves as a conduit for refugees and immigrants fleeing areas troubled with armed conflicts and natural disasters, which have increased substantially in recent years. These people may serve as carriers of the vectors or be infected by disease agents that require arthropod vectors for transmission. Although it cannot be supposed that every arthropod species is a competent vector, this review aims to (1)illustrate the factors that contribute to the persistence and dispersal of arthropod vectors, (2)determine the status of the established arthropod vector species in Turkiye and their capability of serving as vectors of disease agents, and (3)assess the role of newly-introduced arthropod vectors into Turkiye and how they were introduced into the country. We also provide information on important disease incidence (if there's any) and control measures applied by public health officials from different provinces.

Tick-Borne Rickettsioses in the Iberian Peninsula

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.

Prevalence of Borrelia burgdorferi Sensu Lato in Ixodes ricinus Ticks Collected from Kaylaka Park in Pleven, Bulgaria

We aimed to determine the presence and distribution of Borrelia burgdorferi sensu lato (s.l.) in Ixodes ricinus ticks collected from urbanized and wild areas in Kaylaka Park (Bulgaria). A total of 546 ticks were collected over three years (2017–2019). The presence of Borrelia in 334 of the collected I. ricinus was detected by dark-field microscopy (DFM) and two nested PCRs (nPCR) targeting the borrelial 5S-23S rRNA intergenic spacer and Flagellin B (FlaB) gene. DFM was performed on a total of 215 ticks, of which 86 (40%) were positive. PCR was performed on 153 of the ticks. In total, 42.5% of the 5S-23S rRNA intergenic spacer and 49% of FlaB were positive. Considering as positive any single tick in which Borrelia sp. was detected regardless of the used method, the infection rate reached 37% (10/27) in the nymphs and 48.5% (149/307) in the adults (48.7% (77/158) females, 48.3% (72/149) males). The incidence of B. burgdorferi infection in I. ricinus did not differ statistically significantly between female, male, and nymph. This study provides evidence that Lyme disease spirochetes are present in various regions of Kaylaka Park with extremely high prevalence in their vectors.

The tick fauna in Istanbul, Turkey, from 2013 to 2017 and identification of their pathogens by multiplex PCR: an epidemiological study

Ticks may carry several pathogens as vectors and their pathogen load may vary due to differences in geography, climate and vegetation. In this study, we collected ticks from 39 districts of Istanbul (Turkey) between May and October, from 2013 to 2017, and identified them under stereo-microscope. In addition, we investigated the pathogens that the ticks carry (Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia sp. and Babesia sp.) by using multiplex polymerase chain reaction (PCR) method. We collected a total of 875 ticks from the ground and from various animals and kept them at 4 °C until experiments. We identified 248 Rhipicephalus bursa (28.3% of the total), 205 (23.4%) Rhipicephalus annulatus, 197 (22.5%) Haemaphysalis concinna, 149 (17.0%) Rhipicephalus sanguineus, 24 (2.7%) Hyalomma marginatum, 21 (2.4%) Ixodes ricinus, 13 (1.5%) Rhipicephalus kohlsi, 5 (0.6%) Hyalomma anatolicum, 5 (0.6%) Hyalomma aegyptium, 5 (0.6%) Dermacentor niveus and 3 (0.3%) Ixodes hexagonus. We included a total of 328 questing ticks in the study: 63 R. bursa, 63 R. sanguineus, 63 R. annulatus, 63 H. concinna, 24 H. marginatum, 21 I. ricinus, 13 R. kohlsi, 5 H. anatolicum, 5 H. aegyptium, 5 D. niveus and 3 I. hexagonus. Multiplex PCR indicated that 80 (24.4%) ticks were infected with Rickettsia sp., 5 (1.5%) with B. burgdorferi and 1 (0.3%) with Babesia sp. Our study indicated that Rickettsia is more common in ticks collected around Istanbul.

Novel Protozoans in Austria Revealed through the Use of Dogs as Sentinels for Ticks and Tick-Borne Pathogens

We previously isolated and cultivated the novel Rickettsia raoultii strain Jongejan. This prompted us to ask whether this strain is unique or more widely present in Austria. To assess this issue, we retrospectively screened ticks collected from dogs in 2008. Of these collected ticks, we randomly selected 75 (47 females and 28 males) Dermacentor reticulatus, 44 (21 females, 7 males, and 16 nymphs) Haemaphysalis concinna, and 55 (52 females and 3 males) ticks of the Ixodes ricinus complex. Subsequently, these ticks were individually screened for the presence of tick-borne pathogens using the reverse line blot hybridization assay. In our current study, we detected DNA from the following microbes in D. reticulatus: Anaplasma phagocytophilum, Borrelia lusitaniae, Borrelia spielmanii, Borrelia valaisiana, and R. raoultii, all of which were R. raoultii strain Jongejan. In H. concinna, we found DNA of a Babesia sp., Rickettsia helvetica, and an organism closely related to Theileria capreoli. Lastly, I. ricinus was positive for Anaplasma phagocytophilum, Borrelia afzelii, Borrelia burgdorferi sensu stricto, Borrelia garinii/Borrelia bavariensis, B. lusitaniae, B. spielmanii, B. valaisiana, Candidatus Neoehrlichia mikurensis, Rickettsia helvetica, Rickettsia monacensis, and Theileria (Babesia) microti DNA. The detection of DNA of the Babesia sp. and an organism closely related to Theileria capreoli, both found in H. concinna ticks, is novel for Austria.

Ticks and associated tick-borne pathogens from dogs and red foxes from Bulgaria

Climate changes in recent years led to a sharp rise in the tick population and an increase in the number of animals and people with tick-borne infections. The domestic and wild carnivores, especially the dogs, have a huge role for the distribution of ticks in certain areas. In this study 60 ixodid ticks collected from domestic dogs and red foxes from Bulgaria have been investigated for infection with Ehrlichia canis, Hepatozoon canis, Babesia spp., and Rickettsia spp. The results showed that the dogs were infected with two tick species - Rhipicephalus sanguineus (72%) and Ixodes ricinus (28%). The red foxes were infected with only one species - I. ricinus. Out of all R. sanguineus ticks, 43.6% were female and 56.4% male. The opposite was observed for I. ricinus - female specimens (86.7%) were significantly more prevalent than males (13.3%). Similar trend was found out for I. ricinus collected from red foxes - 66.7% of the ticks were female and 33.3% male. Infectious agents were found in 31.7% of the investigated ticks. Ehrlichia spp. was established in 79% and Rickettsia spp. in 21% of the infected ticks. Ehrlichia spp. was found only in ticks collected from dogs. The majority of the ticks infected with Ehrlichia spp. were Rh. sanguineus (93.3%) and only one tick was I. ricinus (6.7%). Four ticks were positive for Rickettsia spp., two were Rh. sanguineus and two - I. ricinus, one of the latter was found on a fox. This is the first report about detection of Ehrlichia spp. in Rh. sanguineus ticks from Bulgaria as well as Rickettsia spp. in I. ricinus ticks collected from red foxes from this country.

Serological survey of vector-borne pathogens in stray dogs from Sofia area, Bulgaria

Vector-borne diseases represent a significant part of canine infectious pathology posing serious zoonotic potential. Stray dogs are found to be an important health and ecological factor in urban areas. The objectives of the present study were to update the current knowledge on the seroprevalence of Anaplasma phagocytophilum/ Anaplasma platys, Ehrlichia canis, Borrelia burgdorferi and Dirofilaria immitis in stray dogs from Sofia, Bulgaria. A total of 448 apparently healthy and randomly selected dogs were tested with Anigen Rapid CaniV-4 Test Kit. Overall 28.57% (128/448) of all tested animals were positive for one or more of the pathogenic species. Total percentage was distributed as follows (single plus mix infections): Anaplasma spp. - 16.29% (73/448), D. immitis - 13.39% (60/448), Ehrlichia spp. - 1.34% (6/448) and B.burgdorferi - 0.67% (3/448). The current study demonstrated the circulation of Anaplasma spp. and D. immitis among stray dogs in Sofia, Bulgaria.

Monitoring of ticks and tick-borne pathogens through a nationwide research station network in Finland

In 2015 a long-term, nationwide tick and tick-borne pathogen (TBP) monitoring project was started by the Finnish Tick Project and the Finnish Research Station network (RESTAT), with the goal of producing temporally and geographically extensive data regarding exophilic ticks in Finland. In the current study, we present results from the first four years of this collaboration. Ticks were collected by cloth dragging from 11 research stations across Finland in May-September 2015-2018 (2012-2018 in Seili). Collected ticks were screened for twelve different pathogens by qPCR: Borrelia afzelii, Borrelia garinii, Borrelia valaisiana, Borrelia burgdorferi sensu stricto, Borrelia miyamotoi, Babesia spp., Anaplasma phagocytophilum, Rickettsia spp., Candidatus Neoehrlichia mikurensis, Francisella tularensis, Bartonella spp. and tick-borne encephalitis virus (TBEV). Altogether 15 067 Ixodes ricinus and 46 Ixodes persulcatus were collected during 68 km of dragging. Field collections revealed different seasonal activity patterns for the two species. The activity of I. persulcatus adults (only one nymph detected) was unimodal, with activity only in May-July, whereas Ixodes ricinus was active from May to September, with activity peaks in September (nymphs) or July-August (adults). Overall, tick densities were higher during the latter years of the study. Borrelia burgdorferi sensu lato were the most common pathogens detected, with 48.9 ± 8.4% (95% Cl) of adults and 25.3 ± 4.4% of nymphs carrying the bacteria. No samples positive for F. tularensis, Bartonella or TBEV were detected. This collaboration project involving the extensive Finnish Research Station network has ensured enduring and spatially extensive, long-term tick data collection to the foreseeable future.

"Tekenscanner": a novel smartphone application for companion animal owners and veterinarians to engage in tick and tick-borne pathogen surveillance in the Netherlands

Background

The engagement of companion animal owners into the process of collecting epidemiological data can be facilitated through smartphone applications. In April 2018, the “tekenscanner“ (Dutch for tick scanner) app was launched with the aim of engaging pet owners and veterinarians to record ticks removed from their pets and submit these ticks for identification and pathogen testing. Tick-borne pathogens identified in ticks removed from dogs and cats during the first 6 months after the app was launched in the Netherlands are reported.

Methods

The tekenscanner app was used to record the geographical coordinates of ticks removed from dogs or cats onto a map of the Netherlands. A barcode was assigned to each tick for the easy tracking of each submission to our laboratory for taxonomic identification. Thereafter, DNA extracted from the ticks was PCR amplified, subjected to reverse line blot hybridization (RLB) and screened for a broad range of tick-borne pathogens. Results were added to the same app, usually within 2 weeks after the submission of each tick.

Results

The app was downloaded 5591 times and resulted in the collection of 1273 georeferenced and barcoded ticks, with a peak submission in May and June of 2018. There were 1005 ticks collected from 406 dogs and 268 ticks collected from 111 cats. Ixodes ricinus was the predominant species (90.0%), with all stages found on dogs as well as on cats. Ixodes hexagonus (7.3%) female and nymphal ticks were also identified on both hosts, whereas adults of Dermacentor reticulatus (2.4%) and Rhipicephalus sanguineus (0.2%) were exclusively found on dogs. Nearly 15% of the ticks recovered from dogs carried one or more pathogens, whereas 13.8% of the ticks removed from cats were infected. Ixodes ricinus collected from dogs contained Borrelia spp. (1.9%), Babesia spp. (0.7%), Anaplasma phagocytophilum (1.3%), “Candidatus Neoehrlichia mikurensis” (2.9%) and Rickettsia helvetica (7.3%). Ixodes ricinus recovered from cats were infected with Borrelia spp. (1.9%), Babesia spp. (0.4%), A. phagocytophilum (1.9%), “Ca. Neoehrlichia mikurensis” (2.6%) and R. helvetica (6.7%). Ixodes hexagonus ticks (n = 93) were not infected. Dermacentor reticulatus ticks, found only in autumn, were infected with Rickettsia raoultii (16 %) and A. phagocytophilum. Three R. sanguineus, on dogs from France and the USA imported into the Netherlands, were all negative.

Conclusions

The tekenscanner app is a versatile tool to use for submission of ticks and facilitated the fast feedback of test results. Community engagement through the app is suitable for identifying hotspots for ticks and tick-borne pathogens and provided an early warning system for exotic ticks invading the Netherlands.

Detection of pathogens in Dermacentor reticulatus in northwestern Europe: evaluation of a high-throughput array

Background

The geographic distribution of Dermacentor reticulatus is expanding in Europe. Surveillance of this tick species and its pathogens is desirable, as it transmits pathogens of public and veterinary importance. A high-throughput real-time PCR-based array was used to screen 1.741 D. reticulatus ticks from Belgium, Germany, The Netherlands, and Great Britain for the presence of 28 tick-borne bacteria and twelve protozoan parasites. The presence of pathogen DNA was confirmed by conventional PCR followed by sequencing.

Results

The array detected the presence of DNA from Borrelia spp. (7%), B. afzelii (0.1%), B. garinii (0.1%), B. spielmanii (0.1%), B. miyamotoi (0.2%), Anaplasma marginale (0.1%), A. phagocytophilum (0.1%), Ehrlichia canis (2%), Rickettsia helvetica (0.2%), spotted fever group Rickettsia (9.6%), Francisella tularensis or Francisella-like endosymbionts (95%), Coxiella burnettii (0.1%), Babesia divergens (0.2%), B. canis (0.9%) B. vogeli (5.6%), and Theileria equi (0.1%). Only the presence of B. canis and spotted fever group Rickettsia could be confirmed by conventional PCR and sequencing. The spotted fever Rickettsia-positive samples were all identified as R. raoultii.

Conclusions

We successfully detected and determined the prevalence of B. canis and R. raoultii in D. reticulatus. An high-throughput array that allows fast and comprehensive testing of tick-borne pathogens is advantageous for surveillance and future epidemiological studies. The importance of thorough validation of real-time PCR-based assays and careful interpretation is evident.

The importance of study duration and spatial scale in pathogen detection-evidence from a tick-infested island

Ticks (Acari: Ixodoidea) are among the most common vectors of zoonotic pathogens worldwide. While research on tick-borne pathogens is abundant, few studies have thoroughly investigated small-scale spatial differences in their occurrence. Here, we used long-term cloth-dragging data of Ixodes ricinus and its associated, known and putative pathogens (Borrelia burgdorferi s.l., Borrelia miyamotoi, Anaplasma phagocytophilum, Rickettsia spp., Candidatus Neoehrlichia mikurensis, Bartonella spp., Babesia spp., and tick-borne encephalitis virus, TBEV) from a small, well-studied island in southwestern Finland to analyze potential temporal and spatial differences in pathogen prevalence and diversity between and within different biotopes. We found robust evidence indicating significant dissimilarities in B. burgdorferi s.l., A. phagocytophilum, Rickettsia, and Ca. N. mikurensis prevalence, even between proximal study areas on the island. Moreover, during the 6 years of the ongoing study, we witnessed the possible emergence of TBEV and Ca. N. mikurensis on the island. Finally, the stable occurrence of a protozoan pathogen that has not been previously reported in Finland, Babesia venatorum, was observed on the island. Our study underlines the importance of detailed, long-term tick surveys for public health. We propose that by more precisely identifying different environmental factors associated with the emergence and upkeep of enzootic pathogen populations through rigorous longitudinal surveys, we may be able to create more accurate models for both current and future pathogen distributions.

Transmission of Rickettsia raoultii and Rickettsia massiliae DNA by Dermacentor reticulatus and Rhipicephalus sanguineus (s.l.) ticks during artificial feeding

Background

Tick-borne rickettsial pathogens are emerging worldwide and pose an increased health risk to both humans and animals. A plethora of rickettsial species has been identified in ticks recovered from human and animal patients. However, the detection of rickettsial DNA in ticks does not necessarily mean that these ticks can act as vectors for these pathogens. Here, we used artificial feeding of ticks to confirm transmission of Rickettsia massiliae and Rickettsia raoultii by Rhipicephalus sanguineus (sensu lato) and Dermacentor reticulatus ticks, respectively. The speed of transmission was also determined.

Methods

An artificial feeding system based on silicone membranes were used to feed adult R. sanguineus (s.l.) and D. reticulatus ticks. Blood samples from in vitro feeding units were analysed for the presence of rickettsial DNA using PCR and reverse line blot hybridisation.

Results

The attachment rate of R. sanguineus (s.l.) ticks were 40.4% at 8 h post-application, increasing to 70.2% at 72 h. Rickettsia massiliae was detected in blood samples collected 8 h after the R. sanguineus (s.l.) ticks were placed into the in vitro feeding units. D. reticulatus ticks were pre-fed on sheep and subsequently transferred to the in vitro feeding system. The attachment rate was 29.1 % at 24 h post-application, increasing to 43.6 % at 96 h. Rickettsia raoultii was detected in blood collected 24 h after D. reticulatus was placed into the feeding units.

Conclusions

Rhipicephalus sanguineus (s.l.) and D. reticulatus ticks are vectors of R. massiliae and R. raoultii, respectively. The transmission of R. massiliae as early as 8 h after tick attachment emphasises the importance of removing ticks as soon as possible to minimise transmission. This study highlights the relevance of in vitro feeding systems to provide insight into the vectorial capacity of ticks and the dynamics of tick-borne pathogen transmission.

Murine Typhus with Marked Thrombocytopenia in a Child in Northern Greece and Literature Review

We report a case of murine typhus in a 4-year-old boy living in northern Greece. Although the illness started with mild symptoms, a maculopapular rash appeared by the end of the first week of illness followed by marked thrombocytopenia. The detection of IgM antibodies against Rickettsia typhi in the patient's blood and a positive polymerase chain reaction result combined with sequencing confirmed the diagnosis of infection by Rickettsia typhi. Clinicians in northern Greece should be aware of the disease, even in cases presenting with no specific initial symptoms.

Equine Granulocytic Anaplasmosis 28 years later

Equine granulocytic anaplasmosis (EGA) is an important tick borne disease of equines that is caused by Anaplasma phagocytophilum (A. phagocytophilum). The etiological agent has veterinary as well as public health importance because of its zoonotic nature. A. phagocytophilum causes an acute illness in equines with loss of appetite, lethargy, hemorrhages and lameness. Clinically, EGA is diagnosed upon examination of morulae within neutrophils especially granulocytes in the blood. The best diagnostic tool for the detection of EGA is Polymerase chain reaction (PCR). Previous studies suggested that EGA is a self-limiting disease and tetracycline therapy is considered as a best treatment regimen. There is no comprehensive summary on the occurrence and distribution of the infection at global level. Therefore, we intended to provide a comprehensive summary on the prevalence and epidemiology of EGA in different areas of the world. It includes mapping the global distribution of EGA in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. For this purpose, the published data from 1990 to 2018 on EGA was reviewed and collected by electronic literature search of five databases including Google, Google Scholar, Science Direct, PubMed and Web of Science.

The diversity of tick-borne bacteria and parasites in ticks collected from the Strandja Nature Park in south-eastern Bulgaria

Background

Ticks are important carriers of many different zoonotic pathogens. To date, there are many studies about ticks and tick-borne pathogens (TBP), but only a few were carried out in Bulgaria. The present study intends to detect the prevalence of tick-borne bacteria and parasites occurring at the Black Sea in Bulgaria to evaluate the zoonotic potential of the tick-borne pathogens transmitted by ticks in this area.

Methods

In total, cDNA from 1541 ticks (Dermacentor spp., Haemaphysalis spp., Hyalomma spp., Ixodes spp. and Rhipicephalus spp.) collected in Bulgaria by flagging method or from hosts was tested in pools of ten individuals each for Anaplasma phagocytophilum, Babesia spp., Borrelia burgdorferi (s.l.), Rickettsia spp. and “Candidatus Neoehrlichia mikurensis” via conventional and quantitative real-time PCR. Subsequently, samples from positive pools were tested individually and a randomized selection of positive PCR samples was purified, sequenced, and analyzed.

Results

Altogether, 23.2% of ticks were infected with at least one of the tested pathogens. The highest infection levels were noted in nymphs (32.3%) and females (27.5%). Very high prevalence was detected for Rickettsia spp. (48.3%), followed by A. phagocytophilum (6.2%), Borrelia burgdorferi (s.l.) (1.7%), Babesia spp. (0.4%) and “Ca. Neoehrlichia mikurensis” (0.1%). Co-infections were found in 2.5% of the tested ticks (mainly Ixodes spp.). Sequencing revealed the presence of Rickettsia monacensis, R. helvetica, and R. aeschlimannii, Babesia microti and B. caballi, and Theileria buffeli and Borrelia afzelli.

Conclusion

This study shows very high prevalence of zoonotic Rickettsia spp. in ticks from Bulgaria and moderate to low prevalence for all other pathogens tested. One should take into account that tick bites from this area could lead to Rickettsia infection in humans and mammals.

Crimean-Congo Hemorrhagic Fever Virus and Borrelia burgdorferi sensu lato in Ticks from Kosovo and Albania

Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218), Dermacentor marginatus (n = 98), and Haemaphysalis spp. (n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma marginatum (n = 199 from Kosovo, all from Kosovo) and Rhipicephalus bursa (n = 130, 126 from Albania) could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean–Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle) from the Prishtina region (Kosovo). B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus, two I. ricinus one female and one male) from the Mitrovica region (Kosovo). Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus, but also in D. marginatus, in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established.

Approaches for Reverse Line Blot-Based Detection of Microbial Pathogens in Ixodes ricinus Ticks Collected in Austria and Impact of the Chosen Method

Ticks transmit a large number of pathogens capable of causing human disease. In this study, the PCR-reverse line blot (RLB) method was used to screen for pathogens in a total of 554 Ixodes ricinus ticks collected from all provinces of Austria. These pathogens belong to the genera Borrelia, Rickettsiae, Anaplasma/Ehrlichia (including "Candidatus Neoehrlichia"), Babesia, and Coxiella The pathogens with the highest detected prevalence were spirochetes of the Borrelia burgdorferisensu lato complex, in 142 ticks (25.6%). Borrelia afzelii (80/142) was the most frequently detected species, followed by Borrelia burgdorferisensu stricto (38/142) and Borrelia valaisiana (36/142). Borrelia garinii/Borrelia bavariensis, Borrelia lusitaniae, and Borrelia spielmanii were found in 28 ticks, 5 ticks, and 1 tick, respectively. Rickettsia spp. were detected in 93 ticks (16.8%): R. helvetica (39/93), R. raoultii (38/93), R. monacensis (2/93), and R. slovaca (1/93). Thirteen Rickettsia samples remain uncharacterized. "Candidatus Neoehrlichia mikurensis," Babesia spp. (B. venatorum, B. divergens, B. microti), and Anaplasma phagocytophilum were found in 4.5%, 2.7%, and 0.7%, respectively. Coxiella burnetii was not detected. Multiple microorganisms were detected in 40 ticks (7.2%), and the cooccurrence of Babesia spp. and "Candidatus Neoehrlichia mikurensis" showed a significant positive correlation. We also compared different PCR-RLBs for detection of Borrelia burgdorferisensu lato and Rickettsia spp. and showed that different detection approaches provide highly diverse results, indicating that analysis of environmental samples remains challenging.IMPORTANCE This study determined the wide spectrum of tick-borne bacterial and protozoal pathogens that can be encountered in Austria. Surveillance of (putative) pathogenic microorganisms occurring in the environment is of medical importance, especially when those agents can be transmitted by ticks and cause disease. The observation of significant coinfections of certain microorganisms in field-collected ticks is an initial step to an improved understanding of microbial interactions in ticks. In addition, we show that variations in molecular detection methods, such as in primer pairs and target genes, can considerably influence the final results. For instance, detection of certain genospecies of borreliae may be better or worse by one method or the other, a fact of great importance for future screening studies.

Seroprevalence of Ehrlichia Canis Infection in Stray Dogs from Serbia

Canine Monocytic Ehrlichiosis is a zoonotic bacterial disease with worldwide distribution. With regards to the population of stray dogs, the disease is facilitated due to their lifestyle and the lack of anti-parasitic protection. The aim of this study was to provide serological data on the presence of a specific Ehrlichia canis IgG antibodies in stray dogs, originating from 7 municipalities in Serbia. During the period from April 2013 to June 2014, 217 canine sera were submitted to the laboratory of the Department of Infectious Diseases of Animals and Bees, Faculty of Veterinary Medicine in Belgrade. An immunofluorescent antibody test (IFAT) was performed to detect antibodies to Ehrlichia canis (cut off, 1:50). Seropositive dogs were found in 5 out of 7 counties with a seroprevalence varying from 3.57% to 20% and an overall seroprevalence of 11.06% (24/217). There was no statistically significant difference between the prevalence of infection and the host age or gender. Results showed that stray dogs contribute to maintaining and spreading of Ehrlichia canis in Serbia. Due to the close relationship between people and dogs, it is of great importance to constantly monitor and improve prevention of this disease.

Molecular detection of Rickettsia species in ticks collected from the southwestern provinces of the Republic of Korea

Background

Rickettsiae constitute a group of arthropod-borne, Gram-negative, obligate intracellular bacteria that are the causative agents of diseases ranging from mild to life threatening that impact on medical and veterinary health worldwide.

Methods

A total of 6,484 ticks were collected by tick drag from June-October 2013 in the southwestern provinces of the Republic of Korea (ROK) (Jeollanam, n = 3,995; Jeollabuk, n = 680; Chungcheongnam, n = 1,478; and Chungcheongbuk, n = 331). Ticks were sorted into 311 pools according to species, collection site, and stage of development. DNA preparations of tick pools were assayed for rickettsiae by 17 kDa antigen gene and ompA nested PCR (nPCR) assays and the resulting amplicons sequenced to determine the identity and prevalence of spotted fever group rickettsiae (SFGR).

Results

Haemaphysalis longicornis (4,471; 52 adults, 123 nymphs and 4,296 larvae) were the most commonly collected ticks, followed by Haemaphysalis flava (1,582; 28 adults, 263 nymphs and 1,291 larvae), and Ixodes nipponensis (431; 25 adults, 5 nymphs and 401 larvae). The minimum field infection rate/100 ticks (assuming 1 positive tick/pool) was 0.93% for the 17 kDa antigen gene and 0.82% for the ompA nPCR assays. The partial 17 kDa antigen and ompA gene sequences from positive pools of H. longicornis were similar to: Rickettsia sp. HI550 (99.4–100%), Rickettsia sp. FUJ98 (99.3–100%), Rickettsia sp. HIR/D91 (99.3–100%), and R. japonica (99.7%). One sequence of the partial 17 kDa antigen gene for H. flava was similar to Rickettsia sp. 17kd-005 (99.7%), while seven sequences of the 17 kDa antigen gene obtained from I. nipponensis ticks were similar to R. monacensis IrR/Munich (98.7–100%) and Rickettsia sp. IRS3 (98.9%).

Conclusions

SFG rickettsiae were detected in three species of ixodid ticks collected in the southwestern provinces of the ROK during 2013. A number of rickettsiae have been recently reported from ticks in Korea, some of which were identified as medically important. Results from this study and previous reports demonstrate the need to conduct longitudinal investigations to identify tick-borne rickettsiae and better understand their geographical distributions and potential impact on medical and veterinary health, in addition to risk communication and development of rickettsial disease prevention strategies.

Novel Rickettsia raoultii strain isolated and propagated from Austrian Dermacentor reticulatus ticks

Background

Continuous culture of tick cell lines has proven a valuable asset in isolating and propagating several different vector-borne pathogens, making it possible to study these microorganisms under laboratory conditions and develop serological tests to benefit public health. We describe a method for effective, cost- and labor-efficient isolation and propagation of Rickettsia raoultii using generally available laboratory equipment and Rhipicephalus microplus cells, further demonstrating the usefulness of continuous tick cell lines. R. raoultii is one of the causative agents of tick-borne lymphadenopathy (TIBOLA) and is, together with its vector Dermacentor reticulatus, emerging in novel regions of Europe, giving rise to an increased threat to general public health.

Methods

Dermacentor reticulatus ticks were collected in the Donau-Auen (Lobau) national park in Vienna, Austria. The hemolymph of ten collected ticks was screened by PCR-reverse line blot for the presence of rickettsial DNA. A single tick tested positive for R. raoultii DNA and was used to infect Rhipicephalus microplus BME/CTVM2 cells.

Results

Sixty-five days after infection of the tick-cell line with an extract from a R. raoultii-infected tick, we observed intracellular bacteria in the cultured cells. On the basis of microscopy we suspected that the intracellular bacteria were a species of Rickettsia; this was confirmed by several PCRs targeting different genes. Subsequent sequencing showed 99–100 % identity with R. raoultii. Cryopreservation and resuscitation of R. raoultii was successful. After 28 days identical intracellular bacteria were microscopically observed.

Conclusions

R. raoultii was successfully isolated and propagated from D. reticulatus ticks using R. microplus BME/CTVM2 cells. The isolated strain shows significant molecular variation compared to currently known sequences. Furthermore we show for the first time the successful cryopreservation and resuscitation of R. raoultii.

Bacterial pathogens and endosymbionts in ticks

Ticks collected from goats in northern Greece were tested for the presence of tick-borne bacteria. Among adult ticks, 37 (57.8%) were Rhipicephalus bursa, 11 (17.2%) Dermacentor marginatus, 10 (15.6%) Ixodes ricinus, 3 (4.7%) Rhipicephalus sanguineus sensu lato and 2 (3.1%) Haemaphysalis parva; one (1.6%) Rhipicephalus spp. tick was nymph. Rickettsia monacensis, Rickettsia massilae, Anaplasma phagocytophilum and Anaplasma platys were detected in I. ricinus and Rh. bursa ticks. A variety of Coxiella-like endosymbionts were detected in all tick genera tested, forming distinct clades from Coxiella burnetii in the phylogenetic tree based on the 16S rRNA gene. An additional endosymbiont, Candidatus Midichloria mitochondrii, was detected in most of the I. ricinus ticks. Surveillance for human pathogens in ticks provides knowledge helpful for the public health, while further studies are needed to determine the role of endosymbionts in tick physiology, vector competence and probably in public health.

Tick-borne pathogens of zoonotic and veterinary importance in Nigerian cattle

BACKGROUND

Ticks and tick-borne diseases undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. In this West African country, cattle are challenged by numerous tick species, especially during the wet season. Consequently, several TBDs are known to be endemic in Nigerian cattle, including anaplasmosis, babesiosis, cowdriosis and theilerioris (by Theileria mutans and Theileria velifera). To date, all investigations on cattle TBDs in Nigeria have been based on cytological examinations and/or on serological methods. This study aimed to ascertain the occurrence of tick-borne pathogens of veterinary and zoonotic importance in cattle in Nigeria using molecular approaches.

METHODS

In October 2008, 704 whole blood samples were collected from indigenous cattle in the Plateau State, Nigeria. Analysis for tick-borne pathogens was conducted by means of PCR-based reverse line blotting (RLB) and sequencing targeting a panel of five genera of microorganisms (i.e. Babesia, Theileria, Anaplasma, Ehrlichia and Rickettsia spp.).

RESULTS

In total, 561/704 (82.6%) animals were found infected, with 465 (69.6%) of them being infected by two or more microorganisms, with up to 77 possible combinations of pathogens detected. Theileria mutans was the most prevalent microorganism (66.3%), followed by Theileria velifera (52.4%), Theileria taurotragi (39.5%), Anaplasma marginale (39.1%), Anaplasma sp. (Omatjenne) (34.7%), Babesia bigemina (7.9%), Anaplasma centrale (6.3%), Anaplasma platys (3.9%), Rickettsia massiliae (3.5%), Babesia bovis (2.0%) and Ehrlichia ruminantium (1.1%). Calves were found significantly less infected than juvenile and adult cattle.

CONCLUSIONS

This study provides updated, molecular-based information on cattle TBDs in Nigeria. The molecular approach employed allowed the diagnosis of numerous positive cases including carrier statuses, multiple infections and novel pathogen detections within the indigenous cattle population. Moreover, the RLB method here described enabled the detection of veterinary agents not only pertaining to bovine health, including also those of zoonotic importance. The high prevalence recorded for T. mutans, T. velifera, A. marginale, T. taurotragi and Anaplasma sp. (Omatjenne), suggests they may be endemically established in Nigeria, whereas the lower prevalence recorded for other microorganisms (i.e. A. centrale and B. bovis) highlights a less stable epidemiological scenario, requiring further investigations.

Tick-borne bacterial pathogens in southwestern Finland

Background

Ixodes ricinus and Ixodes persulcatus are the main vectors of Lyme borreliosis spirochetes and several other zoonotic bacteria in northern Europe and Russia. However, few studies screening bacterial pathogens in Finnish ticks have been conducted. Therefore, reports on the occurrence and prevalence of several bacterial pathogens detected from ticks elsewhere in Europe and Russia are altogether missing from Finland. The main aim of the current study was to produce novel data on the occurrence and prevalence of several tick-borne bacterial pathogens in ticks collected from southwestern Finland.

Methods

Ticks were collected in 2013–2014 by blanket dragging from 25 localities around southwestern Finland, and additionally from a dog in Lempäälä. Collected ticks were molecularly identified and screened for Borrelia burgdorferi s.l., Borrelia miyamotoi, Rickettsia, Bartonella and Candidatus Neoehrlichia mikurensis using quantitative PCR. Furthermore, detected Rickettsia spp. were sequenced using conventional PCR to determine species.

Results

A total of 3169 ticks in 1174 DNA samples were screened for the listed pathogens. The most common bacteria detected was B. burgdorferi (s.l.) (18.5 % nymphal and 23.5 % adult ticks), followed by Rickettsia spp. (1.1 %; 5.1 %) and B. miyamotoi (0.51 %; 1.02 %). B. miyamotoi and Rickettsia spp. were also detected in larval samples (minimum infection rates 0.31 % and 0.21 %, respectively). Detected Rickettsia spp. were identified by sequencing as R. helvetica and R. monacensis. All screened samples were negative for Bartonella spp. and Ca. N. mikurensis.

Conclusions

In the current study we report for the first time the presence of Rickettsia in Finnish ticks. Furthermore, Rickettsia spp. and B. miyamotoi were found from larval tick samples, emphasizing the importance they may have as vectors of these pathogens. Comparisons of tick density estimates and B. burgdorferi (s.l.) prevalence made between the current study and a previous study conducted in 2000 in ten out of the 25 study localities suggest that an increase in tick abundance and B. burgdorferi (s.l.) prevalence has occurred in at least some of the study localities.

The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum)

The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.

Tick survey for prevalent pathogens in peri-urban recreation sites in Saarland and Rhineland-Palatinate (Germany)

Ixodid ticks are important vectors of human pathogens in Central Europe. Despite this fact, prevalence studies are scarce, especially with regard to much-frequented peri-urban recreation sites. In this pilot study, 4.014 larvae, nymphs and adult ticks sampled monthly during the active seasons in 2011 and 2012 from 14 distinct collection sites in two German states (Saarland and Rhineland-Palatinate) were screened for Borrelia spp., Anaplasma spp. and tick-borne encephalitis virus. Mean prevalence rates were 19.8 % for Borrelia spp., 1.9 % for Anaplasma spp. and 0.1 % for tick-borne encephalitis virus (TBEV), which are in accordance with those reported from other regions in Germany and neighbouring countries. Nevertheless, the detection of TBEV-infected ticks is the first positive result after several unsuccessful efforts over the previous years in official "TBE-risk" zones of Saarland and Rhineland-Palatinate which supports the presumption of the origin of observed local infection. Besides ixodid ticks a non-engorged adult female tick of the invading species Dermacentor reticulatus has been found reflecting the appearance of another vector eventually jeopardising the health of host animals as well as humans.

Borrelia burgdorferi sensu lato and co-infections with Anaplasma phagocytophilum and Rickettsia spp. in Ixodes ricinus in Hamburg, Germany

To obtain initial data on Borrelia burgdorferi sensu lato (Spirochaetales: Spirochaetaceae) in Ixodes ricinus (Ixodida: Ixodidae) ticks in Hamburg, Germany, 1400 questing ticks were collected by flagging at 10 different public recreation areas in 2011 and analysed using probe-based quantitative real-time polymerase chain reaction. The overall rate of infection with B. burgdorferi s.l. was 34.1%; 30.0% of adults were infected (36.7% of females and 26.0% of males), as were 34.5% of nymphs. Significant differences in tick infection rates were observed between the spring and summer/autumn months, as well as among sampling locations. Borrelia genospecies identification by reverse line blotting was successful in 43.6% of positive tick samples. The most frequent genospecies was Borrelia garinii/Borrelia bavariensis, followed by Borrelia afzelii, Borrelia valaisiana, B. burgdorferi sensu stricto, Borrelia spielmanii, Borrelia bissettii and Borrelia lusitaniae. Based on previously published data, co-infection of Borrelia and Rickettsiales spp. was determined in 25.8% of ticks. Overall, 22.9% of ticks were co-infected with Rickettsia spp. (Rickettsiales: Rickettsiaceae), 1.7% with Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae), and 1.2% with both pathogens. Study results show a high prevalence of Borrelia-positive ticks in recreation areas in the northern German city of Hamburg and the potential health risk to humans in these areas should not be underestimated.

Parasites and vector-borne pathogens in client-owned dogs in Albania. Blood pathogens and seroprevalences of parasitic and other infectious agents

Knowledge on the epidemiology of parasitic and vector-borne infections is still very limited for Albania, a country located in the Balkan Peninsula in southeast Europe. Recent publications indicated prevalence rates of up to 52% for vector-borne infections in less-cared dogs in Albania. To provide data on the epidemiological situation in dogs under veterinary care, a total of 602 client-owned dogs presented to four small animal clinics between March 2010 and April 2011 in Tirana, Albania, were screened by examination of Giemsa-stained blood smears, PCR, and serological methods for the presence of arthropod-borne infections, as well as Neospora caninum and Toxoplasma gondii. Eight different pathogens, namely Babesia vogeli, Hepatozoon canis, Leishmania infantum, Dirofilaria immitis, Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, and Mycoplasma haemocanis, were detected by direct methods with prevalence rates ranging from 1 to 9%. Seroprevalence for Babesia spp., L. infantum, Anaplasma spp., and E. canis were 6.6, 5.1, 24.1, and 20.8%, respectively. Dogs >1 year of age were positive for vector-borne infections significantly more often than younger dogs (p = 0.003). More than half (51.7%) of the dogs were seroreactive to T. gondii and 18.3% to N. caninum. This is the first report on the detection of A. phagocytophilum, A. platys, E. canis, and M. haemocanis by PCR as well as the serological confirmation of exposure of dogs to N. caninum and T. gondii in Albania. The spectrum of pathogens and the seroprevalences for N. caninum and T. gondii in client-owned dogs from Tirana, Albania, are comparable to that reported in other countries in the Mediterranean Basin. The prevalence rates of vector-borne pathogens are at the lower range of that reported in studies from this geographical region. This is probably due to increased awareness of the owners of pet dogs, including better husbandry conditions and ectoparasiticidal treatment, thus limiting exposure of dogs to vectors.

Pathogens in ticks collected from dogs in Berlin/Brandenburg, Germany

BACKGROUND

Tick-borne diseases are a major health risk for humans and dogs. In addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases.

METHODS

Ticks were collected from dogs living in the Berlin/Brandenburg area. The three tick species Ixodes ricinus, Ixodes hexagonus and Dermacentor reticulatus were examined for the presence of Babesia spp., Borrelia spp., Rickettsia spp. and Anaplasmataceae. Conventional PCR followed by sequencing was used for pathogen detection and characterization.

RESULTS

Babesia spp. were found in 2.5% and 3% of I. ricinus and I. hexagonus, respectively. Sequencing revealed the presence of Babesia microti, Babesia capreoli and Babesia venatorum. D. reticulatus were free of Babesia canis. Rickettsia spp. were detected in 61% of I. ricinus, 44% of I. hexagonus and 39% of D. reticulatus. Specifically detected were Rickettsia raoulti in D. reticulatus and I. hexagonus, Rickettsia helvetica in I. ricinus and I. hexagonus and Rickettsia monacensis in I. hexagonus. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis have been reported previously in I. ricinus (6.5% and 4.3%, respectively) and I. hexagonus (3.9% and 5.9%). Borrelia spp. were found in 11.6% of I. ricinus and 11.2% of I. hexagonus. Subsequent genospecies analysis revealed Borrelia afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto and Borrelia miyamotoi. Simultanous presence of more than one pathogen was found in 20% of I. ricinus and in 59% of I. hexagonus whereas the total frequency of any pathogen was 65% in I. ricinus, 59% in I. hexagonus and 64% in D. reticulatus. Ticks in which A. phagocytophilum was detected had a significantly increased risk of also containing Rickettsia. Ticks harbouring a pathogen had significantly higher scutal indices than ticks without presence of any pathogen.

CONCLUSIONS

Frequencies of potential human or canine pathogens in ticks were considerable and DNA of all four groups of pathogens was detected. Differences in scutal indices might suggest that pathogens are frequently taken up by ticks when feeding on dogs in Berlin/Brandenburg.

Vector competence of the tick Ixodes sinensis (Acari: Ixodidae) for Rickettsia monacensis

BACKGROUND

Cases of Mediterranean Spotted Fever like rickettsioses, caused by Rickettsia monacensis, have become more common in the last 10 years. In China, natural infection of R. monacensis in various tick species has been confirmed but the vector(s) of R. monacensis have not been recorded.

METHODS

The prevalence of R. monacensis in >1500 Ixodidae ticks from central and southern China was determined using centrifugation-shell vial culture and polymerase chain reaction techniques. The predominant species, Ixodes sinensis, harbored a natural infection of R. monacensis and was assumed to be a vector candidate of R. monacensis. Experimental transmissions were initialized by infecting Rickettsia-free tick colonies with R. monacensis using capillary tube feeding (CTF) or immersion techniques. Transstadial and transovarial transmissions, and transmission from ticks to mice, were conducted under laboratory conditions.

RESULTS

R. monacensis was isolated and identified from hemolymph of Ixodes sinensis using molecular techniques. Transovarial transmission of R. monacensis from infected ♀I. sinensis to offspring was documented and infected offspring successfully passed Rickettsia to mice. Transstadial transmission rates were 58% in larva to nymph and 56% in nymph to adult stages. Infected nymphs and adults were also able to infect mice.

CONCLUSIONS

I. sinensis is a competence vector for R. monacensis as demonstrated by natural infection and transmission studies.

Improved molecular detection of Ehrlichia and Anaplasma species applied to Amblyomma ticks collected from cattle and sheep in Ethiopia

Detection of Ehrlichia and Anaplasma species in animals and tick vectors is crucial for an understanding of the epidemiology of diseases caused by these pathogens. In this study, a pair of primers designated EBR2 and EBR3 was designed from the Anaplasma 16S rDNA sequence and was used along with a previously described primer EHR 16SD for the simultaneous detection of Ehrlichia and Anaplasma species by nested PCR. The primers were used to amplify 925bp of DNA from known species of Ehrlichia and Anaplasma. Restriction with MboII and MspI enzymes allowed Ehrlichia and Anaplasma speciation. Restriction with MboII differentiated between An. marginale, Anaplasma (formerly Ehrlichia) sp. Omatjenne, and An. centrale with An. marginale and Anaplasma (formerly Ehrlichia) sp. Omatjenne yielding 2 distinct fragments each while An. centrale produced 3 distinct bands. Ehrlichia ruminantium and An. phagocytophylum remained undigested. Subsequent restriction with MspI differentiated E. ruminantium from An. phagocytophylum with 2 and 4 fragments, respectively. When used on tick samples from the field, 63 ticks (16.4%) out of 384 collected from cattle and sheep were positive for one or more species of Ehrlichia and Anaplasma. The positivity ranged from 6.3% at Andasa to 36.7% at Habernosa. Higher overall infection rates were found in Amblyomma lepidum than in Amblyomma variegatum ticks (p=0.009). Amblyomma lepidum from Habernosa were more often infected with all detected species of Anaplasma and Ehrlichia than Am. variegatum. At Bako, however, Anaplasma (formerly Ehrlichia) sp. Omatjenne was detected only in Am. variegatum. A significantly higher proportion of ticks collected from cattle (20.6%) was found positive than in those collected from sheep (3.3%) (p=0.003). Simultaneous detection of Ehrlichia and Anaplasma species and correct identification of mixed infections was possible. Since the ticks were collected from animals, the occurrence of the major species of Ehrlichia and Anaplasma in ruminants in the area is confirmed.

Prevalence of Rickettsiales (Anaplasma phagocytophilum and Rickettsia spp.) in hard ticks (Ixodes ricinus) in the city of Hamburg, Germany

To narrow the gap of missing knowledge on Rickettsia spp. and Anaplasma phagocytophilum infections in ticks in northwestern Germany and, at the same time, to provide first prevalence data on these pathogens in the city of Hamburg, a total of 1,400 questing Ixodes ricinus ticks were collected at ten different public green areas from April until October 2011. Ticks were examined using probe-based quantitative real-time PCR. A percentage of 3.6% (51/1,400) ticks were tested positive for A. phagocytophilum infections divided into 2.1% (3/141) adults [1.7% (1/60) females and 2.5% (2/81) males] and 3.8% (48/1,259) nymphs. The percentage of infected ticks per sampling site varied statistically significantly from 0.7% (1/140) to 12.1% (17/140), whereas between sampling months, no statistically significant differences were observed (2.0-6.5%, 4-13/140). The overall Rickettsia spp. infection rate was 52.5% (735/1,400). In adult ticks, Rickettsia spp. infection rate was 56% (79/141) divided into 61.7% (37/60) infected females and 51.9% (42/81) infected males. Nymphs showed an infection rate of 52.1% (656/1,259). In contrast to A. phagocytophilum infections, no statistically significant differences in Rickettsia spp. infection rates among sampling sites (44.3-63.6%, 62-89/140) were observed, whereas seasonal variations were obvious: the percentage of Rickettsia-positive ticks was significantly lower in April (36.5%, 73/200) and May (29.5%, 59/200) compared to the summer and fall months (55.0-64.5%, 110-129/200). Rickettsia species differentiation via real-time pyrosequencing revealed Rickettsia helvetica as the only occurring species. Co-infections with both Rickettsia spp. and A. phagocytophilum were detected in 2.0% (28/1,400) of the ticks. The present study revealed that in the city of Hamburg, the tick infection rate with A. phagocytophilum is comparable with other German data, whereas the Rickettsia spp. infection rate of 52.5% is by far the highest prevalence detected in Germany so far. As the city of Hamburg has 1.8 million inhabitants and attracts millions of tourists every year, the potential health risk should not be underestimated.

High-throughput sequence typing reveals genetic differentiation and host specialization among populations of the Borrelia burgdorferi species complex that infect rodents

Lyme disease is a zoonosis caused by various species belonging to the Borrelia burgdorferi bacterial species complex. These pathogens are transmitted by ticks and infect multiple, taxonomically distinct, host species. From an epidemiological perspective, it is important to determine whether genetic variants within the species complex are able to spread freely through the whole host community or, instead, if certain variants are restricted to particular hosts. To this end, we characterized the genotypes of members of the B. burgdorferi species complex; the bacteria were isolated from more than two hundred individuals captured in the wild and belonging to three different rodent host species. For each individual, we used a high-throughput approach to amplify and sequence rplB, a housekeeping gene, and ospC, which is involved in infection. This approach allowed us to evaluate the genetic diversity both within and among species in the B. burgdorferi species complex. Strong evidence of genetic differentiation among host species was revealed by both genes, even though they are, a priori, not constrained by the same selective pressures. These data are discussed in the context of the advancements made possible by multi-locus high-throughput sequencing and current knowledge of Lyme disease epidemiology.

Co-infection of Borrelia burgdorferi sensu lato and Rickettsia species in ticks and in an erythema migrans patient

Background

Lyme borreliosis is the most prevalent tick-borne disease in Europe. Ixodes ricinus also carries other pathogenic bacteria, but corresponding human diseases are rarely reported. Here, we compared the exposure to Rickettsia helvetica and Rickettsia monacensis with that to Lyme borreliosis spirochetes. We assumed that their exposure corresponds to their infection rate in questing I. ricinus.

Findings

Three Rickettsia species were detected in ticks with a total prevalence of 7.9%, of which the majority was R. helvetica (78%) and R. monacensis (21%). From the same geographic area, skin biopsies of erythema migrans patients were investigated for possible co-infections with Rickettsia spp.. Forty-seven out of 67 skin biopsies were PCR positive for Borrelia burgdorferi s.l. and one sample was positive for R. monacensis. The Borrelia genospecies from the R. monacensis positive patient was identified as Borrelia afzelii. The patient did not show any symptoms associated with rickettsiosis.

Conclusions

Co-infections of I. ricinus with Rickettsia spp. and B. burgdorferi s.l. were as high as expected from the individual prevalence of both pathogens. Co-infection rate in erythema migrans patients corresponded well with tick infection rates. To our knowledge, this is the first reported co-infection of B. afzelii and R. monacensis.

Detection of Rickettsia in Rhipicephalus sanguineus ticks and Ctenocephalides felis fleas from southeastern Tunisia by reverse line blot assay

Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia.

Mediterranean spotted fever in southeastern Romania

Although cases of Mediterranean spotted fever (MSF) have been reported for decades in southeastern Romania, there are few published data. We retrospectively studied 339 patients, diagnosed with MSF at the National Institute of Infectious Diseases “Prof. Dr. Matei Bals” between 2000 and 2011, in order to raise awareness about MSF in certain regions of Romania. According to the Raoult diagnostic criteria 171 (50.4%) had a score >25 points. Mean age was 52.5 years. One hundred and fifty-five (90.6%) patients were from Bucharest and the surrounding region. Almost all patients presented with fever (99.4%) and rash (98.2%), and 57.9% had evidence of a tick bite. There were no recorded deaths. Serologic diagnosis was made by indirect immunofluorescence assay. Of the 171 patients, serology results for R. conorii were available in 147. One hundred and twenty-three (83.7%) of them had a titer IgG ≥1 : 160 or a fourfold increase in titer in paired samples. MSF is endemic in southeastern Romania and should be considered in patients with fever and rash even in the absence of recognized tick exposure. Since the disease is prevalent in areas highly frequented by tourists, travel-associated MSF should be suspected in patients with characteristic symptoms returning from the endemic area.

Spatiotemporal dynamics of emerging pathogens in questing Ixodes ricinus

Ixodes ricinus transmits Borrelia burgdorferi sensu lato, the etiological agent of Lyme disease. Previous studies have also detected Rickettsia helvetica, Anaplasma phagocytophilum, Neoehrlichia mikurensis, and several Babesia species in questing ticks in The Netherlands. In this study, we assessed the acarological risk of exposure to several tick-borne pathogens (TBPs), in The Netherlands. Questing ticks were collected monthly between 2006 and 2010 at 21 sites and between 2000 and 2009 at one other site. Nymphs and adults were analysed individually for the presence of TBPs using an array-approach. Collated data of this and previous studies were used to generate, for each pathogen, a presence/absence map and to further analyse their spatiotemporal variation. R. helvetica (31.1%) and B. burgdorferi sensu lato (11.8%) had the highest overall prevalence and were detected in all areas. N. mikurensis (5.6%), A. phagocytophilum (0.8%), and Babesia spp. (1.7%) were detected in most, but not all areas. The prevalences of pathogens varied among the study areas from 0 to 64%, while the density of questing ticks varied from 1 to 179/100 m². Overall, 37% of the ticks were infected with at least one pathogen and 6.3% with more than one pathogen. One-third of the Borrelia-positive ticks were infected with at least one other pathogen. Coinfection of B. afzelii with N. mikurensis and with Babesia spp. occurred significantly more often than single infections, indicating the existence of mutual reservoir hosts. Alternatively, coinfection of R. helvetica with either B. afzelii or N. mikurensis occurred significantly less frequent. The diversity of TBPs detected in I. ricinus in this study and the frequency of their coinfections with B. burgdorferi s.l., underline the need to consider them when evaluating the risks of infection and subsequently the risk of disease following a tick bite.

Connection of toxin-antitoxin modules to inoculation eschar and arthropod vertical transmission in Rickettsiales

The biological role of toxin-antitoxin systems (TAS) in pathogenicity and cell addiction of Rickettsia was recently reported. We realized a comparative genomic analysis onto 33 rickettsial genomes and correlated the presence of TAS encoding genes with vertical transmission (VT) in arthropod hosts, the presence of inoculation eschar in humans and experimental animals, and the mortality in humans. There is a significant statistical link between TAS and the presence of an eschar (p≤0.0001). The presence of TAS is also significantly inversely correlated with mortality. The toxic effect of TAS may increase the local reaction, thus inhibiting the spread of rickettsiae associated with fatal outcome of the disease. The TAS were also linked to VT (p≤0.0001). Together with our previous findings we speculate that this is the first addiction system evidenced in intracellular bacteria. Thus, the TAS, as selfish genetic elements, might be essential to the evolutionary strategy of intracellular bacteria.

Tick-borne rickettsioses in Europe

Rickettsioses are caused by obligate intracellular bacteria within the genus Rickettsia, mainly transmitted by arthropods. Until recently, Mediterranean spotted fever (MSF) caused by Rickettsia conorii was considered the only tick-borne rickettsiosis in Europe. However, 'new' TBR have been described in Europe during last years. For instance, other subspecies such as R. conorii caspia and R. conorii israelensis have been involved in MSF. Dermacentor-borne necrosis erythema and lymphadenopathy/tick-borne lymphadenopathy (DEBONEL/TIBOLA) cases caused by Rickettsia slovaca, Rickettsia raoultii, and Rickettsia rioja been described in several countries where Dermacentor marginatus ticks (the mainly implicated vector) are present. Rickettsia helvetica has also been involved as a human pathogen in cases of fever with and without rash and in patients with meningitis and carditis. Other TBR such as lymphangitis-associated rickettsioses (LAR), caused by Rickettsia sibirica mongolitimonae, have been diagnosed in different European countries (France, Spain, Portugal and Greece). Rickettsia massiliae is considered an etiological agent of MSF-like illness in the Mediterranean basin. Furthermore, Rickettsia monacensis that is distributed all along Europe has been isolated from patients with MSF-like illness in Spain. Although Rickettsia aeschlimannii has been associated with MSF-like in Africa and is distributed in the Mediterranean area, no autochthonous human cases have been reported for Europe. Other Rickettsia species detected in ticks and unrelated to human disease (Candidatus Rickettsia kotlanii, Candidatus Rickettsia barbariae, Candidatus Rickettsia vini) could be potentially involved in the next years. Climate changes, among other factors, may contribute to the emergence of other rickettsioses or change their distribution. Lastly, African tick-bite fever (ATBF), caused by Rickettsia africae, is frequently diagnosed in Europe in patients returning from endemic areas.

Use of DNA sequences for Rickettsia identification in Ixodes ricinus ticks: the first detection of Rickettsia monacensis in Poland

The cosmopolitan tick Ixodes ricinus inhabiting Europe, including Poland, is a vector for many pathogens, such as various Rickettsia species, which spread to new territories. They are present mainly in the Mediterranean countries, but have also been found in Central Europe at increasing frequency. In the present study, the gltA gene, encoding citrate synthase, and an internal transcribed spacer (ITS) were employed to detect the DNA and identify the species of tick-borne pathogens of the Rickettsia genus. The presence of bacterial DNA was detected in 9.5% of the examined I. ricinus individuals. Based on the nucleotide sequences of the analysed genomic fragments, most pathogens were identified as Rickettsia helvetica, while Rickettsia monacensis was revealed in one case. We have described for the first time, to our knowledge, the occurrence of this species in Poland. Both markers employed in the experiments were successful in species identification of R. helvetica. The newly described species R. monacensis may be identified by the protein-coding gene, but the ITS nucleotide sequences proved insufficient.

Rickettsia species in ticks removed from humans in Istanbul, Turkey

A total of 167 ticks collected from humans in Istanbul (Turkey) in 2006 were screened for Rickettsia species, and nested PCRs targeting gltA and ompA rickettsial fragment genes were carried out. Rickettsia monacensis (51), R. aeschlimannii (8), R. conorii subsp. conorii (3), R. helvetica (2), R. raoultii (1), R. africae (1), R. felis (1), and other Rickettsia spp. (2), were detected. To our knowledge, these Rickettsia species (except R. conorii) had never been reported in ticks removed from humans in Turkey. The presence of R. africae also had not been previously described, either in Hyalomma ticks or in any European tick species. In addition, R. aeschlimannii and R. felis had not been found associated with Rhipicephalus bursa specimens. The presence of human pathogenic Rickettsia in ticks removed from humans provides information about the risk of tick-borne rickettsioses in Turkey.

Study on ticks and tick-borne zoonoses in public parks in Italy

A survey on tick density and on tick-borne zoonoses was carried out in four public parks in the outskirts of Imola (northern Italy) from June to October 2006. All stages of Ixodes ricinus and only larvae of Riphicephalus sanguineus were recovered by dragging, performed on 100-m transects. Almost all ticks (99%) were harvested in one park. I. ricinus density (nymphs/100 m(2) ) ranged from 0 in park L to 6.3 in park F. Nymphs and adults of I. ricinus were subjected to PCR for Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi s. l. and Rickettsia spp. The observed prevalences were 38.3% for Bartonella henselae, 5.2% for Bartonella clarridgeiae, 10.4% for B. burgdorferi s. l., 2.6% for Rickettsia helvetica and 13% for Rickettsia monacensis, respectively. No DNA of A. phagocytophilum was found. Acarological risks (AR) were calculated as probabilities of collecting at least one infected nymph per transect. The AR values calculated for the various zoonotic agents were 11.4% for R. helvetica, 27.7% for B. clarridgeiae, 49.7% for B. burgdorferi s. l., 57.2% for R. monacensis and 90.4% for B. henselae, respectively. In this study, B. clarridgeiae was for the first time identified in I. ricinus ticks.