Tick-borne diseases under the radar in the North Sea Region.

The impact of tick-borne diseases caused by pathogens such as Anaplasma phagocytophilum, Neoehrlichia mikurensis, Borrelia miyamotoi, Rickettsia helvetica and Babesia species on public health is largely unknown. Data on the prevalence of these pathogens in Ixodes ricinus ticks from seven countries within the North Sea Region in Europe as well as the types and availability of diagnostic tests and the main clinical features of their corresponding diseases is reported and discussed. Raised awareness is needed to discover cases of these under-recognized types of tick-borne disease, which should provide valuable insights into these diseases and their clinical significance.

Emerging Tickborne Bacteria in Cattle from Colombia.

Ehrlichia minasensis is a new pathogenic bacterial species that infects cattle, and Borrelia theileri causes bovine borreliosis. We detected E. minasensis and B. theileri DNA in cattle from southwestern Colombia by using PCR. E. minasensis and B. theileri should be considered potential etiologies of febrile syndrome in cattle from Colombia.

Serological Evidence of Borrelia burgdorferi in Patients with Morphea from West-Central Poland: An Original Paper and Review of Literature.

Morphea (localized scleroderma) is an inflammatory connective tissue disease. Borrelia burgdorferi, as a causative factor, has been discussed controversially. The aim of this original study was to evaluate the frequency of IgM and IgG classes of anti-Borrelia antibodies in groups of morphea and psoriasis patients using the traditional ELISA method. Blood samples of 82 patients with morphea and 112 patients with psoriasis vulgaris were examined for the presence of IgM and IgG classes of anti-Borrelia antibodies (ELISA). IgM and IgG classes of anti-Borrelia antibodies were detected in 4% of blood samples taken from morphea patients, while 4.5% of blood samples from patients with psoriasis vulgaris. There is one major limitation in this study that could be addressed in future research. First, the study focused on the determination of IgM and IgG classes of anti-Borrelia antibodies as a risk factor for morphea, but other infectious agents also require further testing, such as Hepatitis B, Hepatitis C, and other viral or bacterial infections. The results of this study showed no significant relationship between Borrelia infection and morphea. Detection of IgM and IgG classes of anti-Borrelia antibodies is not recommended for routine diagnostics of patients with morphea at this time.

Borreliosis Transmission from Ticks Associated with Desert Tortoise Burrows: Examples of Tick-Borne Relapsing Fever in the Mojave Desert.

Ticks transmit pathogens and parasitize wildlife in turn causing zoonotic diseases in many ecosystems. Argasid ticks, such as Ornithodoros spp., harbor and transmit Borrelia spp., resulting in tick-borne relapsing fever (TBRF) in people. In the western United States, TBRF is typically associated with the bite of an infected Ornithodoros hermsi tick found in habitats at high elevations (>1500 ft). This report describes the first TBRF cases in people in the Mojave Desert (Clark County, NV). Individuals documented in these case studies were exposed to Ornithodoros ticks during excavation of soil burrows associated with Mojave Desert tortoises (Gopherus agassizii), with bacteria from one of the human case's blood sample genetically matching to Borrelia turicatae as determined by quantitative PCR and sequencing. Our findings should serve as a precaution to individuals working with tortoises or animal burrows, or those in contact with Ornithodoros ticks in this region.

High Prevalence of Borrelia mayonii (Spirochaetales: Spirochaetaceae) in Field-Caught Tamias striatus (Rodentia: Sciuridae) From Northern Wisconsin.

Borrelia mayonii is a recently discovered bacterial spirochete that causes Lyme disease and is transmitted by the blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae). To date, B. mayonii has been isolated from two vertebrate host species in Minnesota: field-caught white-footed mice (Peromyscus leucopus Rafinesque; Rodentia: Cricetidae) and American red squirrel (Tamiasciurus hudsonicus Erxleben). Here, we describe the first detection of B. mayonii in field-caught eastern chipmunks (Tamias striatus L. (Rodentia: Cricetidae)) from northern Wisconsin. During our study, we captured 530 unique small mammals and found an infection prevalence of 23.50% in field-caught eastern chipmunks (4/17) and 1.19% in Peromyscus spp. (5/420). Mean larval and nymphal burdens were determined for captured Blarina brevicauda (0, 0), Glaucomys volans (0.29, 0.14), Myodes gapperi (0.27, 0), Napaeozapus insignis (0, 0.25), Peromyscus spp. (1.88, 0.11), T. striatus (1.06, 0.65), and Sorex cinereus (0.09, 0). The high B. mayonii infection prevalence in eastern chipmunks suggests that the species may be an important reservoir for B. mayonii in the Upper Midwest.

Retrospective Survey of Borrelia spp. From Rodents and Ticks in Thailand.

Borrelia is a genus of spirochetal bacteria with several species known to cause disease in humans. The distribution of Borrelia has rarely been studied in Thailand. In this study, a retrospective survey of Borrelia was conducted in ticks and wild rodents to better characterize the prevalence, diversity, and distribution of Borrelia across Thailand. Several pools of DNA from tick samples were positive for Borrelia spp. (36/258, 13.9%). Borrelia theileri/B. lonestari was found in 17 tick samples (16 pools of Haemaphysalis bandicota and 1 pool of Rhipicephalus sp.), and Borrelia yangtzensis was found in 8 tick samples (2 pools of H. bandicota and 6 pools of Ixodes granulatus). Borrelia spp. were detected at low prevalence levels in rodent tissue samples (24/2001, 1.2%), with 19 identified as B. theileri or B. lonestari and 5 identified as B. miyamotoi. Several geographic and species-specific infection trends were apparent, with Ixodes ticks infected with B. yangtzensis and Haemaphysalis and Rhipicephalus ticks infected with both B. yangtzensis and B. theileri/B. lonestari. Notably, B. yangtzensis showed a similar geographic distribution to B. miyamotoi, which was identified in new areas of Thailand in this study. The flagellin gene sequence from B. miyamotoi was more similar to European (99.3-99.9%) than Japanese (96.9-97.6%) genotypes. This study greatly expands the knowledge of Borrelia in Thailand and identified several Borrelia species for the first time. It also found several ticks and rodents infected with the pathogen that were not previously known to carry Borrelia.

Ticks, fleas and rodent-hosts analyzed for the presence of Borrelia miyamotoi in Slovakia: the first record of Borrelia miyamotoi in a Haemaphysalis inermis tick.

In Slovakia, little knowledge is available on the occurrence, hosts and vectors of Borrelia miyamotoi of the relapsing fever group. In the current study, 2160 questing and rodent-attached ticks of six species (Ixodes ricinus, Ixodes trianguliceps, Dermacentor marginatus, Dermacentor reticulatus, Haemaphysalis concinna and Haemaphysalis inermis), 279 fleas belonging to 9 species (Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus assimilis, Megabothris turbidus, Amalareus penicilliger, Hystrichopsylla orientalis, Ctenophthalmus uncinatus, Doratopsylla dasycnema and Nosopsyllus fasciatus) and skin biopsies from 245 small mammals belonging to eight species (Apodemus agrarius, Apodemus flavicollis, Apodemus uralensis, Myodes glareolus, Crocidura leucodon, Micromys minutus, Microtus arvalis, Microtus subterraneus) were screened for the presence of B. miyamotoi DNA. The overall prevalence of B. miyamotoi found in questing and rodent-attached ticks was 1.8% (23 positive/1260 examined) and 3.4% (31 positive/900 examined), respectively. Borrelia miyamotoi was detected in questing I. ricinus, rodent-attached I. ricinus and H. inermis ticks, and in one male of the common vole (M. arvalis) in different habitats (mainly rural) in eastern Slovakia. However, B. miyamotoi was not found in any of the tested fleas. Our findings indicate that rural habitats with different species of tick vectors and hosts are appropriate for the occurrence of B. miyamotoi.

Combining genome-wide association study and FST -based approaches to identify targets of Borrelia-mediated selection in natural rodent hosts.

Recent advances in high-throughput sequencing technologies provide opportunities to gain novel insights into the genetic basis of phenotypic trait variation. Yet to date, progress in our understanding of genotype-phenotype associations in nonmodel organisms in general and natural vertebrate populations in particular has been hampered by small sample sizes typically available for wildlife populations and a resulting lack of statistical power, as well as a limited ability to control for false-positive signals. Here we propose to combine a genome-wide association study (GWAS) and FST -based approach with population-level replication to partly overcome these limitations. We present a case study in which we used this approach in combination with genotyping-by-sequencing (GBS) single nucleotide polymorphism (SNP) data to identify genomic regions associated with Borrelia afzelii resistance or susceptibility in the natural rodent host of this Lyme disease-causing spirochete, the bank vole (Myodes glareolus). Using this combined approach we identified four consensus SNPs located in exonic regions of the genes Slc26a4, Tns3, Wscd1 and Espnl, which were significantly associated with the voles' Borrelia infectious status within and across populations. Functional links between host responses to bacterial infections and most of these genes have previously been demonstrated in other rodent systems, making them promising new candidates for the study of evolutionary host responses to Borrelia emergence. Our approach is applicable to other systems and may facilitate the identification of genetic variants underlying disease resistance or susceptibility, as well as other ecologically relevant traits, in wildlife populations.

Molecular detection of reptile-associated Borrelia in Boa constrictor (Squamata: Boidae) from Veracruz, Mexico.

The reptile-associated Borrelia represent a monophyletic group of bacteria transmitted by several species of hard ticks, which has been reported to only infect amphibians and reptiles in Eurasia and Middle East, however, this bacterial group has not been studied in North America. The aim of this study was to assess the presence of Borrelia spirochetes in blood samples of native reptiles of Mexico. Blood samples were directly obtained from individuals, DNA extractions were performed using Chelex-100. The Borrelia detection was performed by conventional PCR. From 102 reptiles tested, only five individuals of Boa constrictor were positive for the presence of DNA of the reptile-associated Borrelia group. Supported by phylogenetic analysis, this study presents the first record of these spirochetes group in Mexico, and initial evidence of B. constrictor as a host of this group.

Molecular detection of avian spirochete Borrelia anserina in Argas persicus ticks in Algeria.

Argasid ticks are one of the most important poultry ectoparasites. They affect poultry directly through blood meal and indirectly through the transmission of pathogens essentially Borrelia anserina, agent of avian borreliosis, one of the most widespread poultry diseases in the world, and is of great economic importance. This study was conducted between April 2014 and March 2015 in the region of Ksar El Boukhari, Algeria, in order to investigate the presence of soft ticks in laying hen farms and to detect B. anserina bacteria using molecular tools. DNA was extracted and screened for the presence of Borrelia spp. DNA by real-time polymerase chain reaction (qPCR). Borrelia spp. screening was performed using primers and probe targeting the 16S rRNA gene. A total of 83 traditional laying hen farms were visited, of which 39 (46.98 %) were found infested with A. persicus tick. Molecular analysis revealed that 2/34 (5.88 %) of ticks were infected by B. anserina. None of the ticks tested were positive for Rickettsia spp., and Coxiella burnetii. These results constitute the first report in Algeria of A. persicus harboring B. anserina.

Borrelia spp. in small mammals in Romania.

BACKGROUND: Small mammals play an important role in the life-cycle of ticks and are reservoirs for several zoonotic pathogens. The aim of this study was to provide epidemiological data regarding the presence of Borrelia spp. in tissues of small mammals from Romania. METHODS: We examined 401 individuals belonging to 11 small mammal species collected in Romania. Collections cover the largest effort to survey these reservoirs in the country. Tissue samples were analyzed by multiplex qPCR targeting the ospA gene of Borrelia burgdorferi (s.l.) and a part of the flaB gene of B. miyamotoi. Positive samples were further analysed by conventional PCR and sequenced. RESULTS: The overall prevalence of infection with Borrelia spp. in small mammal tissues was 4.9%. The most commonly detected species were B. afzelii, followed by B. garinii/B. bavariensis, B. miyamotoi and B. burgdorferi (s.s.). To our knowledge, we report for the first time the detection of Borrelia spp. in Crocidura leucodon and C. suaveolens, and B. miyamotoi in the liver of Myodes glareolus. CONCLUSIONS: To our knowledge, our study evaluates for the first time the occurrence of Borrelia spp. in small mammals in Romania, contributing to a better knowledge of the distribution of these bacteria. This survey upgrades previous data on the spatial distribution of the pathogens and reveals the importance of animal surveillance regarding Lyme borreliosis and relapsing fever caused by B. miyamotoi.

Borrelia spp. in ticks and birds from a protected urban area in Buenos Aires city, Argentina.

This study was aimed to know epidemiological aspects of Borrelia spp. in a protected urban area of Buenos Aires city, Argentina, where thousands of people visit this area for recreational purposes. Ticks were collected from vegetation, birds and dogs. Three hundred and forty birds belonging to 43 species, 41 genera, 18 families and six orders were captured (90.3% corresponded to the order Passeriformes). One hundred and twenty ticks were collected from 47 birds (13.8%) belonging to 10 species (23.2%), all of them from to the order Passeriformes (Emberizidae, Furnariidae, Parulidae, Thraupidae, Troglodytidae, Turdidae). Ticks were identified as Ixodes auritulus (56 larvae, 44 nymphs and 8 females) and Amblyomma aureolatum (1 larva and 11 nymphs). One thousand and ninety-one ticks collected from vegetation, 100 ticks collected from birds, and 89 ticks from dogs were tested for Borrelia infection by PCR trials targeting the flagellin (fla) and 16S rRNA genes. In addition, 101 blood and 168 tissue samples from birds were analyzed. Nine nymphs of A. aureolatum (2.1%) and four nymphs of I. auritulus (0.7%) collected from vegetation were positive. Five nymphs of A. aureolatum (45.4%), and five pools of larvae (minimum infection rate 13.5%), 18 nymphs (40.9%) and one female (14.3%) of I. auritulus collected on birds were also positive. The remaining samples were negative. The phylogenetic tree generated with fla sequences shows that seven of the eight different haplotypes of Borrelia detected in I. auritulus conform an independent lineage within the Borrelia burgdorferi sensu lato complex together with sequences of Borrelia sp. detected in I. auritulus from Canada and Uruguay. The fla sequences of Borrelia obtained from A. aureolatum and one sequence of a single specimen of I. auritulus conform a phylogenetic group with Borrelia turcica, Borrelia sp. isolated from a tortoise in Zambia, Borrelia spp. detected in Amblyomma maculatum from USA and Amblyomma longirostre from Brazil. The epidemiological risk that implies the infection with Borrelia genospecies associated with I. auritulus seems to be low because this tick is not aggressive to humans, but it helps to maintain borrelial spirochetes in the enzootic transmission cycles. The pathogenicity to humans of the Borrelia found in A. aureolatum is unknown; however, adults of this tick species are known to bite humans. This is the first report of the presence of Borrelia in A. aureolatum. Further investigations are necessary to know the risk of transmission of borreliosis by hard ticks in the study area.

The presence of Borrelia theileri in Argentina.

The presence of Borrelia theileri in Argentina is confirmed after recording the spirochete from a bovine in northern Argentina. The analysis of sequences of the flagellin gene (fla) and length of Borrelia spp. specimens on thick blood films shows that the local isolate clusters within a well-supported clade with B. theileri isolates from different geographical origins, confirming the presence of B. theileri in Argentina. The mean length of 30 specimens of B. theileri was 12.89 µm (standard deviation 2.88 µm, range 9.35-20.16 µm). The only known vector of Borrelia theileri in northern Argentina is the cattle tick Rhipicephalus microplus, therefore Borrelia infection should be regarded as a potential complication of other cattle tick-borne diseases such as babesiosis, especially on cattle introduced from areas free of R. microplus. The possibility of serologic cross-reaction with B. theileri must not be minimized in studies of other spirochaetes in the R. microplus infested region of Argentina.

Vertical transmission rates of Borrelia miyamotoi in Ixodes scapularis collected from white-tailed deer.

Borrelia miyamotoi is a relapsing fever spirochete transmitted by ticks in the Ixodes ricinus complex. In the eastern United States, B. miyamotoi is transmitted by I. scapularis, which also vectors several other pathogens including B. burgdorferi sensu stricto. In contrast to Lyme borreliae, B. miyamotoi can be transmitted vertically from infected female ticks to their progeny. Therefore, in addition to nymphs and adults, larvae can vector B. miyamotoi to wildlife and human hosts. Two widely varying filial infection prevalence (FIP) estimates - 6% and 73% - have been reported previously from two vertically infected larval clutches; to our knowledge, no other estimates of FIP or transovarial transmission (TOT) rates for B. miyamotoi have been described in the literature. Thus, we investigated TOT and FIP of larval clutches derived from engorged females collected from hunter-harvested white-tailed deer in 2015 (n = 664) and 2016 (n = 599) from Maine, New Hampshire, Tennessee, and Wisconsin. After engorged females oviposited in the lab, they (n = 492) were tested for B. miyamotoi infection by PCR. Subsequently, from each clutch produced by an infected female, larval pools, as well as 100 individual eggs or larvae, were tested. The TOT rate of the 11 infected females was 90.9% (95% CI; 57.1-99.5%) and the mean FIP of the resulting larval clutches was 84.4% (95% CI; 68.1-100%). Even though the overall observed vertical transmission rate (the product of TOT and FIP; 76.7%, 95% CI; 44.6-93.3%) was high, additional horizontal transmission may be required for enzootic maintenance of B. miyamotoi based on the results of a previously published deterministic model. Further investigation of TOT and FIP variability and the underlying mechanisms, both in nature and the laboratory, will be needed to resolve this question. Meanwhile, studies quantifying the acarological risk of Borrelia miyamotoi disease need to consider not only nymphs and adults, but larval I. scapularis as well.

Borrelia miyamotoi Infections in Small Mammals, California, USA.

Surveillance to investigate the wildlife-vector transmission cycle of the human pathogen Borrelia miyamotoi in California, USA, revealed infections in dusky-footed woodrats, brush mice, and California mice. Phylogenetic analyses suggest a single, well-supported clade of B. miyamotoi is circulating in California.

Role of mustelids in the life-cycle of ixodid ticks and transmission cycles of four tick-borne pathogens.

BACKGROUND: Elucidating which wildlife species significantly contribute to the maintenance of Ixodes ricinus populations and the enzootic cycles of the pathogens they transmit is imperative in understanding the driving forces behind the emergence of tick-borne diseases. Here, we aimed to quantify the relative contribution of four mustelid species in the life-cycles of I. ricinus and Borrelia burgdorferi (sensu lato) in forested areas and to investigate their role in the transmission of other tick-borne pathogens. Road-killed badgers, pine martens, stone martens and polecats were collected in Belgium and the Netherlands. Their organs and feeding ticks were tested for the presence of tick-borne pathogens. RESULTS: Ixodes hexagonus and I. ricinus were found on half of the screened animals (n = 637). Pine martens had the highest I. ricinus burden, whereas polecats had the highest I. hexagonus burden. We detected DNA from B. burgdorferi (s.l.) and Anaplasma phagocytophilum in organs of all four mustelid species (n = 789), and Neoehrlichia mikurensis DNA was detected in all species, except badgers. DNA from B. miyamotoi was not detected in any of the investigated mustelids. From the 15 larvae of I. ricinus feeding on pine martens (n = 44), only one was positive for B. miyamotoi DNA, and all tested negative for B. burgdorferi (s.l.), N. mikurensis and A. phagocytophilum. The two feeding larvae from the investigated polecats (n = 364) and stone martens (n = 39) were negative for all four pathogens. The infection rate of N. mikurensis was higher in feeding nymphs collected from mustelids compared to questing nymphs, but not for B. burgdorferi (s.l.), B. miyamotoi or A. phagocytophilum. CONCLUSIONS: Although all stages of I. ricinus can be found on badgers, polecats, pine and stone martens, their relative contribution to the life-cycle of I. ricinus in forested areas is less than 1%. Consequently, the relative contribution of mustelids to the enzootic cycles of I. ricinus-borne pathogens is negligible, despite the presence of these pathogens in organs and feeding ticks. Interestingly, all four mustelid species carried all stages of I. hexagonus, potentially maintaining enzootic cycles of this tick species apart from the cycle involving hedgehogs as main host species.

Evidence for Clinical Anaplasmosis and Borreliosis in Cats in Maine.

The objectives of this study were to use data from client-owned cats in an Ixodes scapularis endemic area to evaluate for clinical associations with diagnostic test results for Anaplasma phagocytophilum and Borrelia burgdorferi and to provide information from a group of cats with possible borreliosis as the cause of clinical manifestations of disease. All cases were evaluated at one clinic, medical records were evaluated, and sera from all cats were tested using one of two commercially available assays labeled for the use with dog sera (SNAP 4Dx or SNAP 4Dx Plus; IDEXX Laboratories, Westbrook, ME). Of the 159 cats evaluated, 42 cats (26.4%) had clinical signs consistent with A. phagocytophilum or B. burgdorferi infection and 117 cats (73.6%) were apparently healthy. Antibodies against B. burgdorferi or A. phagocytophilum were detected in sera of 18.2% and 6.3% of the 159 cats, respectively. Cats with clinical signs of disease were 4 times more likely to have antibodies against one or both agents than healthy cats (95% confidence interval [CI] 1.7928-8.9246; P = .0007), cats allowed outdoors were 5 times more likely to have antibodies against one or both agents than cats housed exclusively indoors (95% CI 2.0196-12.4497; P = .0005), and cats of owners who purchased acaricides were more likely (odds ratio = .3977) to have antibodies against one or both agents than cats of owners who did not purchase acaricides (95% CI .1659-.9534; P = .0387). The cats in the case series were believed to have B. burgdorferi infection as the most likely cause of illness based on serological testing, select clinical information, and apparent response to administration of doxycycline. The results suggest that both A. phagocytophilum and B. burgdorferi are associated with clinical illness in cats. Owners of cats allowed outdoors should be diligent in the use of acaricides.

Small-scale spatial variation in infection risk shapes the evolution of a Borrelia resistance gene in wild rodents.

Spatial variation in pathogen-mediated selection is predicted to influence the evolutionary trajectory of host populations and lead to spatial variation in their immunogenetic composition. However, to date few studies have been able to directly link small-scale spatial variation in infection risk to host immune gene evolution in natural, nonhuman populations. Here, we use a natural rodent-Borrelia system to test for associations between landscape-level spatial variation in Borrelia infection risk along replicated elevational gradients in the Swiss Alps and Toll-like receptor 2 (TLR2) evolution, a candidate gene for Borrelia resistance, across bank vole (Myodes glareolus) populations. We found that Borrelia infection risk (i.e., the product of Borrelia prevalence in questing ticks and the average tick load of voles at a sampling site) was spatially variable and significantly negatively associated with elevation. Across sampling sites, Borrelia prevalence in bank voles was significantly positively associated with Borrelia infection risk along the elevational clines. We observed a significant association between naturally occurring TLR2 polymorphisms in hosts and their Borrelia infection status. The TLR2 variant associated with a reduced likelihood of Borrelia infection was most common in rodent populations at lower elevations that face a high Borrelia infection risk, and its frequency changed in accordance with the change in Borrelia infection risk along the elevational clines. These results suggest that small-scale spatial variation in parasite-mediated selection affects the immunogenetic composition of natural host populations, providing a striking example that the microbial environment shapes the evolution of the host's immune system in the wild.

First detection and molecular identification of Borrelia species in Bactrian camel (Camelus bactrianus) from Northwest China.

Comprehensive epidemiological surveys for Lyme disease have not been conducted for the Bactrian camel in China. In this study, a total of 138 blood specimens collected from Bactrian camels from Zhangye City in Gansu Province and Yili and Aksu in Xinjiang Province, China, were examined for the presence of Borrelia spp. Species-specificity nested PCR based on the 5S-23S rRNA, OspA, flaB and 16S rRNA genes revealed that the total positive rate of Borrelia spp. was 3.6% (5/138, 95% CI = 0.2-17.9). These results were confirmed by sequence analysis of the positive PCR products or positive colonies. This is the first report of Borrelia pathogens in camels in China. Two Borrelia species that cause Lyme disease and one that causes relapsing fever were identified in the camel blood samples by sequencing. The findings of this study indicate that the Bactrian camel may serve as a potential natural host of Lyme disease and/or relapsing fever in China.

Borrelia miyamotoi sensu lato in Père David Deer and Haemaphysalis longicornis Ticks.

By sequence analysis of 16S rRNA, flaB, p66, and glpQ, we identified Borrelia miyamotoi in 1 of 4 Père David deer (n = 43) seropositive for Borrelia spp. and 1.2% (3/244) of Haemaphysalis longicornis ticks from Dafeng Elk National Natural Reserve, China. Future studies should assess Borrelia pathogenesis in deer.