Polymerase chain reaction confirmation of Babesia canis canis and Anaplasma phagocytophilum in dogs suspected of babesiosis in Slovakia

Canine babesiosis was considered an imported tick transmitted disease until the first case of autochthonous canine babesiosis in Slovakia was described in 2002. Since then, the number of cases kept increasing every year. The causative agent of babesiosis in dogs is not yet characterized; therefore, the aim of our study was to determine the agent and the rate of infection in the vector tick D. reticulatus in Slovakia. Babesia canis canis was detected in 80 out of 87 blood samples from dogs with clinical manifestations of babesiosis. Six dogs suspected of babesiosis tested positive for presence of Anaplasma phagocytophilum, and one mixed infection of B. c. canis and A. phagocytophilum was detected. B. c. canis was detected in 35.6% questing adults of D. reticulatus. The obtained sequences from blood samples showed 99.7% and from D. reticulatus, 99.4% similarity with the B. c. canis (AY072926) from dogs infected in Croatia. In our study, we characterized the agent of canine babesiosis from blood samples of naturally infected dogs and D. reticulatus, the vector tick. Further, the presence of A. phagocytophilum, bacterium responsible for the canine granulocytic anaplasmosis, was recorded in dogs for the first time in Slovakia.     

Ticks and associated pathogens collected from domestic animals in the Netherlands

Following an outbreak of autochthonous canine babesiosis in the Netherlands, a request made to veterinarians and the public to collect ticks from companion animals resulted in 4298 ticks submitted between July 2005 and October 2006 to our center. Ticks were identified as Ixodes ricinus adults (2907/4298, 67.6%), Ixodes sp. nymphs (529/4298, 12.3%) and Ixodes sp. larvae (385/4298, 9.0%), I. hexagonus adults (328/4298, 7.6%), Dermacentor reticulatus (72/4298, 1.7%), and several other exotic tick species such as Amblyomma flavomaculatum (formerly Aponomma flavomaculatum), Hyalomma marginatum rufipes, Rhipicephalus sanguineus, and R. turanicus (55/4298, 1.3%). Eight localities were surveyed for the presence of local D. reticulatus, a tick not indigenous to the Netherlands, based on multiple submissions of D. reticulatus ticks from these areas. D. reticulatus was collected from the vegetation in six of these localities, confirming the presence of populations of this tick in the Netherlands. Adult I. ricinus (n=251), I. hexagonus (n=237), and D. reticulatus (n=344) ticks were selected at random and subsequently screened by polymerase chain reaction (PCR) and reverse line blot (RLB) hybridization for the presence of Borrelia, Babesia, Theileria, Anaplasma, Ehrlichia, and Rickettsia species. I. ricinus ticks were infected with Rickettsia helvetica (24.7%), spirochetes belonging to the Borrelia burgdorferi sensu lato group (7.2%), the Ehrlichia-like "Schotii" variant (2.4%), Anaplasma phagocytophilum (1.6%), Babesia sp. (EU1) (1.2%), Babesia divergens (0.4%), and Babesia microti (0.4%). A. phagocytophilum (5.9%) and R. helvetica (0.8%) were also detected in adult I. hexagonus ticks. Spotted fever group Rickettsiae, previously reported as Rickettsia sp. DnS14/RpA4 (14.0%), and Borrelia burgdorferi sensu lato (0.3%) were detected in the D. reticulatus ticks, which appeared to be free from B. canis infection. We concluded that a much broader spectrum of ticks and tick-borne pathogens is present in the Netherlands than previously thought, including several potential zoonotic pathogens.     

Anaplasma phagocytophila and protozoans of Babesia genus in dogs from endemic areas of Lyme disease in north-western Poland

Infections caused by the spirochete Borrelia burgdorferi sensu lato may be accompanied by other microorganisms, such as Anaplasma, Ehrlichia and Babesia. These pathogens are transmitted by the ticks and are a risk to humans and animals. Ixodes ricinus ticks collected from recreational areas of Szczecin and northwestern Poland contained DNA of the pathogens mentioned above and cases of double and triple coinfection have been documented. The aim of this paper was to determine if dogs suspect to tick infestation in the area of study are a reservoir for these pathogens and to examine the possibility of coinfection. Canine blood was sampled, part of the material originated from dogs exhibiting symptoms of borreliosis. In an earlier study, the samples were screened for DNA from B. burgdorferi sensu lato. In order to screen for A. phagocytophila and Babesia sp. DNA, a PCR-based method was used with the following primers: EHR521/EHR747 for Anaplasma and FOR1/REV1 for Babesia. In 192 samples only two contained A. phagocytophila DNA. One of these samples originated from a healthy canine, the other from an individual with symptoms of borreliosis. The examined samples were not positive for Babesia sp. DNA. Coinfection was not discovered. The low level of A. phagocytophila infection may indicate that the domestic dog is not a reservoir for Anaplasma and Babesia in Szczecin and northwestern Poland. Moreover, this area does not have populations of the brown dog tick (Rhipicephalus sanguineus) or Dermacentor reticulates--both of which are vectors of E. canis and B. canis and commonly induce ehrlichiosis and babesiosis in canines.     

Detection and characterization of Babesia species in Ixodes ticks in Estonia

The presence of Babesia spp. was studied in 2603 Ixodes ricinus and Ixodes persulcatus ticks collected at seven sites in Estonia. By reverse line blot screening, Babesia spp. was detected in 36 (1.4%) ticks, among them 18 (0.7%) were further recognized by a Babesia microti probe, 3 (0.1%) by a Babesia divergens probe, and the other 15 (0.6%) were recognized only by the universal Babesia spp. "catch all" probe. Sequence analyses of 6 of these 15 samples revealed that all of them belonged to Babesia sp. EU1. B. microti was detected in both tick species I. ricinus and I. persulcatus at the seven sites, whereas B. divergens-like and Babesia sp. EU1 were found only in I. persulcatus and I. ricinus, respectively. Genetic characterization based on partial 18S rRNA showed that the Estonian sequences of B. microti, B. divergens-like, and Babesia sp. EU1 share a high rate of similarity and are closely related to sequences from other European countries, Siberia, and United States. The present study demonstrated for the first time the existence and distribution of Babesia spp. in I. persulcatus and I. ricinus ticks in Estonia.     

Wild cervids are host for tick vectors of babesia species with zoonotic capability in Belgium

Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babesia spp. with zoonotic capability is suspected. To investigate the range and infection rate of Babesia species, ticks were collected from wild cervids in southern Belgium during 2008. DNA extraction was performed for individual ticks, and each sample was evaluated for the absence of PCR inhibition using a PCR test. A Babesia spp. genus-specific PCR based on the 18S rRNA gene was applied to validated tick DNA extracts. A total of 1044 Ixodes ricinus ticks were collected and 1023 validated samples were subsequently screened for the presence of Babesia spp. DNA. Twenty-eight tick samples were found to be positive and identified after sequencing as containing DNA representing: Babesia divergens (3), B. divergens-like (5), Babesia sp. EU1 (11), Babesia sp. EU1-like (3), B. capreoli (2), or unknown Babesia sp. (4). This study confirms the presence of potentially zoonotic species and Babesia capreoli in Belgium, with a tick infection rate of 2.7% (95% CI 1.8,3.9%). Knowledge of the most common reservoir source for transmission of zoonotic Babesia spp. will be useful for models assessing the risk potential of this infection to humans.     

广西壮族自治区犬巴贝虫感染现状调查

目的 分析广西壮族自治区犬巴贝虫病的流行情况. 方法 在广西的玉林、北海、南宁、百色和河池等地区的17个采样点,用FTA试纸卡采集犬血.巢式PCR特异性扩增巴贝虫18s rDNA基因,纯化阳性样本的PCR产物、测序,与GenBank中的巴贝虫序列进行比对.应用Mega5.1软件构建系统发育树,分析系统发生关系. 结果 共采获87份犬血,其中阳性血样11份,感染率为12.64％ （11/87）.11份阳性血样的巴贝虫序列相同,与GenBank中的佛氏巴贝虫（Babesia canis vo-geli的同源性为98.1％.在邻接法构建的系统进化树上,犬血样中检测到的巴贝虫与佛氏巴贝虫同属一个分枝,系统发生关系近. 结论 广西犬血中检测到的巴贝虫与GenBank中的佛氏巴贝虫同源性高,为佛氏巴贝虫.     

Genetic variability of Anaplasma phagocytophilum in Ixodes persulcatus ticks and small mammals in the Asian part of Russia

The specimens of 3552 questing adult Ixodes persulcatus and 1698 blood/tissue samples of small mammals collected in Ural, Siberia, and Far East of Russia were assayed for the presence of Anaplasma phagocytophilum by nested PCR based on the 16S rRNA gene. Totally, A. phagocytophilum was detected in 112 tick and 88 mammalian samples. The nucleotide sequences of the 16S rRNA gene and groESL operon (1244-1295?bp) were determined for A. phagocytophilum samples from 65 ticks and 25 small mammals. Six different 16S rRNA gene variants differing by 1-5 nucleotide substitutions were detected, and only one variant matched the sequences deposited in GenBank. Analysis of groESL sequences allowed the A. phagocytophilum samples to be divided into three groups; moreover, the samples from different groups also differed in the 16S rRNA gene sequences. The A. phagocytophilum sequences from group I were detected in 11 Myodes spp. samples from West Siberia and Far East and in 19 I. persulcatus samples from all examined regions; from group II, in 10 samples of Myodes spp. and common shrews (Sorex araneus) from Ural; and from group III, in four samples of Asian chipmunks (Tamias sibiricus) from West Siberia and Far East; and in 46 I. persulcatus samples from all examined regions. The nucleotide sequences of A. phagocytophilum groESL operon from groups I and II were strictly conserved and formed with A. phagocytophilum groESL sequence from a Swiss bank vole (Myodes glareolus) (GenBank accession no. AF192796), a separate cluster on the phylogenetic tree with a strong bootstrap support. The A. phagocytophilum groESL operon sequences from group III differed from one another by 1-4 nucleotides and formed a separate branch in the cluster generated by European A. phagocytophilum strains from roe deer (Capreolus capreolus) and Ixodes ricinus ticks.     

Hepatozoon canis infection in Slovakia: imported or autochthonous?

Tissue samples from nine red foxes (four samples of striated muscle tissue and five samples of heart tissue) that originated from the Michalovce district (Slovakia), an area with endemic occurrence of canine babesiosis were examined by PCR method using primers amplifying a fragment of the 18S rRNA spanning the V4 region of Babesia and Theileria. An unexpected determination of 450 bp DNA fragment of Hepatozoon canis was found in four samples. Partial sequences of the 18S rRNA gene from the H. canis showed 100% similarity with the sequence from Brasil isolate of H. canis from a pampas fox (Pseudalopex gymnocercus) (AY471615) as well as from a fox in Spain (AY150067) and from a dog in Brazil (AY864677). In the present study, we report the first PCR detection of Hepatozoon canis in a naturally infected red fox from Slovakia, a Rhipicephalus sanguineus-free region. We assume that the infection was spread by infected R. sanguineus that might have been brought to Slovakia by travelers, by golden jackals, or by foxes migrating because of expansion of golden jackals and environmental and climate changes.     

First evidence of Babesia gibsoni (Asian genotype) in dogs in Western Europe

Canine babesiosis in Europe is generally caused by Babesia canis canis and Babesia canis rossi. Here we describe the first two autochthonous cases of Babesia gibsoni (Asian genotype) infection in Germany. Two American pit bull terriers showed clinical and hematologic signs consistent with babesiosis. Polymerase chain reaction (PCR) analysis of the 18S rDNA of blood samples revealed 486 bp fragments. The sequences were 100% identical to each other and 100% identical to Babesia gibsoni (Asian genotype). These results represent the first genetic evidence of Babesia gibsoni (Asian genotype) parasites in dogs in Western Europe.     

Differentiation of medically important Euro-Asian tick species Ixodes ricinus, Ixodes persulcatus, Ixodes hexagonus, and Dermacentor reticulatus by polymerase chain reaction

Understanding epidemiology of the tick-borne pathogens requires the accurate identification of the vector ticks. Morphological analysis of ticks is difficult and often leads to misidentification. Molecular techniques offer an alternative approach of tick identification. To date, no practical and reliable molecular assays for discrimination of Euro-Asian ticks are available. Our aim was to develop such an assay for discrimination between four Euro-Asian tick species of high medical importance such as Ixodes ricinus, Ixodes persulcatus, Ixodes hexagonus, and Dermacentor reticulatus. As a basis, we have chosen conventional species-specific polymerase chain reaction (PCR), a technique providing a good combination of simplicity and reliability. The DNA information available on ticks was searched for orthologous loci containing stretches of sequence dissimilarity sufficient for designing species-specific primers. ITS2 locus (second internal transcribed region of the rRNA gene cluster) was found to be the most favorable for primer design. Finally, for each of the three Ixodes species a PCR was developed amplifying only for the targeted species. One PCR amplified the entire ITS2 locus of the four species and allowed discrimination of D. reticulatus from the Ixodes species on the basis of the size difference of the respective PCR products. This PCR system was successfully tested for discrimination of the ticks at different maturation stages (larva, nymph, and adult) in engorged and unfed conditions, and therefore it may be useful for large-scale epidemiological studies. Differentiation between the closely related I. ricinus and I. persulcatus, the two species most often occurring in the tick-borne diseases in Eurasia, is of special importance.     

Identification of Ehrlichia chaffeensis,Anaplasma phagocytophilum,and A. bovis in Haemaphysalis longicornis and Ixodes persulcatus ticks from Korea

A total of 1,467 tick (1,463 of Haemaphysalis longicornis, three of Ixodes persulcatus and one of I. turdus) collected from nine provinces of Korea were examined by TaqMan real-time PCR for the presence of Ehrlichia and Anaplasma species. One set of primers and a probe were designed for detection of all of the Ehrlichia and Anaplasma species. Template DNAs (total 803) were prepared either from pools of larvae, nymphs, adult males and females, or from the salivary gland and midgut of adult ticks. Only DNAs positive in TaqMan PCR were examined for A. phagocytophilum with nested PCR and for E. chaffeensis with PCR. Four A. phagocytophilum 16S rRNA gene PCR products were sequenced for comparison with sequences previously reported. Amplification of a 16S rRNA gene fragment of Ehrlichia and Anaplasma species was observed in 364 tick DNAs (45.3% of the total). Of these 364 positive ticks, species-specific PCRs confirmed that 35 H. longicornis and one I. persulcatus were positive for A. phagocytophilum and one I. persulcatus was positive in E. chaffeensis. Except for one (AB-GGHL, GenBank accession number [GAN] AF470698), three of the four 16S rRNA gene fragment sequences of the A. phagocytophilum-positive samples were similar or identical to the sequences of variants of A. phagocytophilum deposited in GenBank. The 16S rRNA gene fragment sequence of AB-GGHL was similar to that of Anaplasma (Ehrlichia) bovis 16S rRNA (GAN U03775). The identities of the Anaplasmataceae genus and species DNA in the 327 ticks that could not be confirmed infected with either E. chaffeensis, A. phagocytophilum, or A. bovis are not known. This study is the first to demonstrate the presence of E. chaffeensis, A. phagocytophilum and A. bovis in Korean ticks.     

Persistent detection of Babesia EU1 and Babesia microti in Ixodes ricinus in the Netherlands during a 5-year surveillance: 2003-2007

We report the finding of Babesia EU1 and Babesia microti in Ixodes ricinus ticks in the Netherlands. During 5 years of surveillance between 2003 and 2007, 1488 ticks were collected in a dune forest area near the North Sea and were screened for Babesia infections. In 17 ticks, DNA of the protozoan parasite genus Babesia was detected using a Babesia-specific 18S rRNA polymerase chain reaction. Further, reverse line blot analysis and DNA sequence analysis showed that 13 of these ticks carried Babesia EU1, two ticks carried B. microti, and one tick carried B. divergens. This study shows that the human pathogenic species Babesia EU1 and B. microti can complete their life cycle in the Netherlands.     

Ehrlichia species in Rhipicephalus sanguineus ticks in Cameroon

Ehrlichia and Anaplasma species are tick-transmitted obligately intracellular bacteria that commonly cause disease in dogs worldwide. In addition to causing disease in canines, Ehrlichia chaffeensis, Ehrlichia ewingii, and Anaplasma phagocytophilum are responsible for emerging and life-threatening human zoonoses in the United States. We previously reported a high prevalence of E. canis infection in Cameroonian dogs based on serologic and molecular evidence. This study was undertaken to determine the Ehrlichia species (E. canis, E. chaffeensis, E. ewingii) present in Rhipicephalus sanguineus ticks (n = 92) collected from those dogs (n = 51). Ehrlichial DNA was detected by real-time polymerase chain reaction (PCR) in 28 (30%) unengorged R. sanguineus ticks attached to dogs. E. canis, the causative agent of canine monocytic ehrlichiosis, was detected in 19 (21%) ticks from 15 dogs, E. ewingii was detected in six (6%) ticks from 6 dogs, and E. chaffeensis, the etiologic agent of human monocytotropic ehrlichiosis, was detected in 4 (4%) ticks. Notably, 2 ticks were coinfected with E. chaffeensis and E. canis, one tick with E. canis and E. ewingii, and one tick with E. chaffeensis and E. ewingii. These findings further support our previous conclusion that multiple Ehrlichia species are present in Cameroon and identify R. sanguineus ticks primarily infected with E. canis, but suggest that they may be infected with and transmit other ehrlichial agents in Cameroon, potentially to humans.     

吉林省林区蜱粒细胞无形体感染的调查

目的调查吉林省蜱粒细胞无形体感染。方法运用聚合酶链反应方法对吉林延边地区采集的蜱标本粒细胞无形体16S rRNA和gltA基因片段进行扩增及序列分析,将扩增序列与GenBank注册的基因序列进行比较,构建粒细胞无形体gltA基因进化树。结果共检测游离蜱427只,其中全沟硬蜱100只,森林革蜱327只,粒细胞无形体感染阳性率分别为4.00%和0.00%。寄生蜱感染阳性率2.9%。寄生蜱与游离蜱感染率差别无显著性。16S rRNA序列与我国已在GenBank注册的AF205140序列一致,与国外粒细胞无形体16S rRNA序列存在不同程度的差异,相似性为97%～99%;gltA基因与GenBank的粒细胞无形体gltA基因片段比较,相似性为87%～97%,推导的氨基酸序列相似性为84%～99%。结论我国吉林省林区存在蜱粒细胞无形体感染。     

Babesiosis of human and domestic dog; ethiology, pathogenesis, diagnostics

This article presents the current state of our knowledge on babesiosis (piroplasmosis), one of the dangerous, invasive disease of humans and animals, transmitted by ticks. It is included among emerging diseases because its spread and significance have increased in recent years. This sickness is caused by intraerythrocytic parasites belonging to the Babesia species and it is a well-known zoonosis occurring in animals; as a human disease it was unknown almost till the first half of the last century. The intensified migration of human population and human interference in a forest biotope caused that number of recognized cases has grown considerably in recent years. Piroplasmosis in dogs is widely spread all over the world and it is caused by several Babesia species. The principal etiological factor of babesiosis in dogs is B. canis, which turned out to be a collective species represented by three subspecies for which the vectors are three different species of ticks. Their geographical extent indicates the endemic areas for this often fatal disease. A technique, the most often applied in the detection of Babesia is a full blood smear stained with Giemsa or Wright method. However, the estimation of the specimen depends to a large extent on the experience of the diagnostician. The immunological and serological methods are characterized with a high specificity and sensitivity but there are patients in which the false negative results have been obtained. Therefore, the traditional methods have been complemented or even ousted by the molecular methods, in which polymerase chain reaction (PCR) brings the biggest profits. However, the standardization of this technique still remains under elaboration. The usefulness of the PCR protocol has been tested with different molecular destinations from which sequences of genes encoding rRNA for small ribosomal subunit are taken into consideration. Within ribosome, the evolutionally conservative areas can be distinguished, i.e. having the nucleotide sequences similar to the majority or all Babesia species and to others closely related to them. Such construction of gene enables designing of starters complementary to conservative sites to PCR, detecting a large group of related organisms. Another molecular marker allowing on the accurate identification of Babesia is gene encoding the beta-tubuline protein. There are two introns within this gene, from which the first one shows a big variability with regard to the length as well as to the nucleotide sequence, therefore, the PCR products show a diverse length depending on the Babesia species. But these differences are too small for some species and, confirming methods that extend time of diagnostics are essential. The other genes which sequences can be used as molecular aim to the detection of DNA and Babesia species diversification are genes encoding the Heat Shock Proteins HSP 70. However, the gene hsp 70 shows a big conservatism of the nucleotide sequence even between the non related organisms; therefore, this method, based on the amplification of whole genome or its fragments, applies mainly in analysis of molecular phylogenetic.     

Survey for Tick-Borne Zoonoses in the State of Espirito Santo,Southeastern Brazil

Blood samples collected from 201 humans, 92 dogs, and 27 horses in the state of Espirito Santo, Brazil, were tested by polymerase chain reaction, indirect immunofluorescence assays, and indirect enzyme-linked immunosorbent assay for tick-borne diseases (rickettsiosis, ehrlichiosis, anaplasmosis, borreliosis, babesiosis). Our results indicated that the surveyed counties are endemic for spotted fever group rickettsiosis because sera from 70 (34.8%) humans, 7 (7.6%) dogs, and 7 (25.9%) horses were reactive to at least one of the six Rickettsia species tested. Although there was evidence of ehrlichiosis (Ehrlichia canis) and babesiosis (Babesia canis vogeli, Theileria equi) in domestic animals, no human was positive for babesiosis and only four individuals were serologically positive for E. canis. Borrelia burgdorferi-serologic reactive sera were rare among humans and horses, but encompassed 51% of the canine samples, suggesting that dogs and their ticks can be part of the epidemiological cycle of the causative agent of the Brazilian zoonosis, named Baggio-Yoshinari Syndrome.     

Enzootic transmission of Babesia divergens among cottontail rabbits on Nantucket Island, Massachusetts

Specific ticks seem to locally serve as vector for characteristic microbial assemblages (guilds) comprising spirochetes, piroplasms, ehrlichiae, and arboviruses. Borrelia andersoni and Anaplasma phagocytophilum are intensely transmitted between cottontail rabbits. To test the hypothesis that a piroplasm may also be maintained in rabbits, we sampled these hosts from Nantucket Island, Massachusetts and tested their blood and tissues by a polymerase chain reaction for evidence of infection. Surprisingly, the agent of bovine redwater and of European human babesiosis, Babesia divergens, was detected in 16% of the rabbits sampled during 1998-2002 (> 99% sequence similarity in the 18S ribosomal DNA). The vector of B. divergens on Nantucket appears to be Ixodes dentatus, a rabbit- and bird-feeding tick that may feed on humans. Although the risk of human infection appears to be minimal, an autochthonously acquired Kentucky case due to this rabbit agent was recently reported. Physicians should entertain the diagnosis of babesiosis due to B. divergens for severe hemolytic febrile syndromes in American patients exposed to sites where rabbits are common.     

人巴贝虫病研究进展

巴贝虫病是巴贝虫在红细胞内寄生导致的一种人畜共患寄生虫病.人巴贝虫病主要由田鼠巴贝虫（Babesia microti）、B.duncani、分歧巴贝虫（B.divergens）、B.venatorum等引起,病例呈世界性分布.其传播方式有蜱虫叮咬、输血及母婴传播等.患病症状与疟疾相似,典型的临床症状表现为发热、肌痛、贫血、血红蛋白尿、黄疸等,其严重程度主要取决于自身免疫状况和感染巴贝虫的种类.巴贝虫病常见的诊断方法为涂片染色法、动物接种法、血清学检测法以及分子生物学检测法.     

Detection of a novel Francisella in Dermacentor reticulatus: a need for careful evaluation of PCR-based identification of Francisella tularensis in Eurasian ticks

Francisella tularensis, the causative agent of tularemia, has been detected in ixodid ticks in some regions of North America, Europe, and Asia. In the present study, 245 Dermacentor reticulatus, 211 Ixodes ricinus, and 194 Haemaphysalis concinna adults from Hungary were tested for the presence of F. tularensis by polymerase chain reaction (PCR) assays based on 16S ribosomal RNA (16S rDNA) and T-cell epitope of a Francisella membrane protein (TUL4). No Francisella-specific amplification products were detected in I. ricinus and H. concinna ticks. Francisella DNA was identified using PCR assays based on 16S rDNA and TUL4 gene in D. reticulatus with similar prevalence (minimum 1.2%) as demonstrated in earlier European and Asian studies detecting F. tularensis in D. reticulatus. However, the 16S rDNA and TUL4 gene sequences of the Francisella-like agent occurring in D. reticulatus differed from the homologous sequences of Francisella spp. deposited in GenBank. Phylogenetic reconstructions showed that the new genotype detected in D. reticulatus was closely related to Francisella-like endosymbionts of North American Dermacentor ticks. Although further studies are needed on the relationship of this bacterium with ticks, the results highlight the need for careful evaluation of PCR-based identification in European and Asian laboratories that screen ixodid ticks for F. tularensis.     

PCR detection of the causative agents of infections transmitted by ticks on the Kamchatka Peninsula

There has been recently a rise in referrals for Ixodes tick bites in the spring and summer periods in the Kamchatka Territory. Among the dominant tick species, there has been the taiga tick Ixodes persulcatus habiting the extensive areas of the southern and central parts of the peninsula. Examination of 84 I. persulcatus females collected from human beings and domestic animals in 2003 to 2007 detected DNA of the pathogens of tick-borne borreliosis (B. burgdorferi sensu lato), rickettsiasis (R. tarasevichiae and R. helvetica), and Ehrlichiosis/anaplasmosis (A. phagocytophilum). Tick-borne encephalitis RNA and antigens and babesiasis DNA were not found in the study samples. Despite the small number of taiga ticks in Kamchatka, the detection of the pathogens of various infectious diseases in the ticks suggests that there may be a risk for contamination of the peninsula's population with these pathogens.