A newly established real-time PCR for detection of Borrelia miyamotoi in Ixodes ricinus ticks

The Surveillance of Borrelia Species in Camelus dromedarius and Associated Ticks: The First Detection of Borrelia miyamotoi in Egypt

Tick-borne diseases (TBDs) are emerging and re-emerging infections that have a worldwide impact on human and animal health. Lyme borreliosis (LB) is a severe zoonotic disease caused by the spirochete Borrelia burgdorferi sensu lato (s.l.) transmitted to humans by the bite of infected Ixodes ticks. Borrelia miyamotoi is a spirochete that causes relapsing fever (RF) and is genetically related to Borrelia burgdorferi s.l. However, there have been no reports of B. miyamotoi in Egypt, and the data on LB in camels is scarce. Thus, the present study was conducted to screen and genetically identify Borrelia spp. and B. miyamotoi in Egyptian camels and associated ticks using polymerase chain reaction (PCR).

METHODS

A total of 133 blood samples and 1596 adult hard ticks were collected from Camelus dromedaries at Cairo and Giza slaughterhouses in Egypt. Tick species were identified by examining their morphology and sequencing the cytochrome C oxidase subunit 1 (cox1) gene. Borrelia spp. was detected using nested PCR on the IGS (16S-23S) gene, and positive samples were genotyped using 16S rRNA and glpQ spp. genes specific for Borrelia burgdorferi and Borrelia miyamotoi, respectively. The positive PCR products were sequenced and analyzed by phylogenetic tree.

RESULTS

Analysis of the cox1 gene sequence revealed that the adult ticks belonged to three genera; Hyalomma (H), Amblyomma (Am), and Rhipicephalus (R), as well as 12 species, including H. dromedarii, H. marginatum, H. excavatum, H. anatolicum, R. annulatus, R. pulchellus, Am. testudinarium, Am. hebraeum, Am. lipidium, Am. variegatum, Am. cohaerens and Am. gemma. Borrelia spp. was found in 8.3% (11/133) of the camel blood samples and 1.3% (21/1596) of the ticks, respectively. Sequencing of the IGS (16S-23S) gene found that B. afzelii, detected from H. dromedarii and H. marginatum, and B. crocidurae, which belongs to the RF group, was detected from one blood sample. B. burgdorferi and B. miyamotoi were discovered in the blood samples and tick species. Phylogenetic analysis of the glpQ gene showed that the B. miyamotoi in this study was of the Asian and European types.

CONCLUSIONS

These results suggest that the camels can be infected by Lyme borrelia and other Borrelia bacteria species. This study also provides the first insight into the presence of Borrelia miyamotoi and B. afzelii DNA in camels and associated ticks in Egypt.

Tick feeding modulates the human skin immune landscape to facilitate tick-borne pathogen transmission

During cutaneous tick attachment, the feeding cavity becomes a site of transmission for tick salivary compounds and tick-borne pathogens. However, the immunological consequences of tick feeding for human skin remain unclear. Here, we assessed human skin and blood samples upon tick bite and developed a human skin explant model mimicking Ixodes ricinus bites and tick-borne pathogen infection. Following tick attachment, we observed rapidly occurring patterns of immunomodulation, including increases in neutrophils and cutaneous B and T cells. T cells upregulated tissue residency markers, while lymphocytic cytokine production was impaired. In early stages of Borrelia burgdorferi model infections, we detected strain-specific immune responses and close spatial relationships between macrophages and spirochetes. Preincubation of spirochetes with tick salivary gland extracts hampered accumulation of immune cells and increased spirochete loads. Collectively, we showed that tick feeding exerts profound changes on the skin immune network that interfere with the primary response against tick-borne pathogens.

Bacteria and protozoa with pathogenic potential in Ixodes ricinus ticks in Viennese recreational areas

Ixodes ricinus is the most relevant vector for tick-borne diseases in Austria and responsible for the transmission of Borrelia burgdorferi sensu lato (s. l.), which causes Lyme borreliosis in humans; however, also other bacteria and protozoa can be found in ticks and have the potential of infecting people and animals. In this study we collected ticks in popular recreational areas in the city of Vienna in the years 2019 and 2020 and analyzed them for the presence of such putative pathogenic microorganisms. By using reverse line blot (RLB) hybridization we detected DNA of B. burgdorferi s. l., Rickettsia spp., Babesia spp., Candidatus Neoehrlichia mikurensis (CNM) and Anaplasma phagocytophilum. Moreover, we also screened them for the relapsing fever spirochete Borrelia miyamotoi employing real-time PCR. The most frequently detected pathogens were B. burgdorferi s. l. in 28.6% of the ticks in 2019 and 21.3% of the ticks in 2020. The genus Rickettsia was detected in 13.8% of the ticks from 2019 and only in 4.6% from 2020. Babesia spp. were detected in 5.7% in 2019 and 4.2% in 2020. Furthermore, we detected CNM in 4.0% (2019) and 5.6% (2020), A. phagocytophilum in 0.5% (2019) and 1.3% (2020) and finally B. miyamotoi in 3.3% (2019) and 1.7% (2020). Collectively, we show that various microorganisms are prevalent in ticks collected in Vienna and identify hotspots for B. miyamotoi, which we have detected for the first time in the city.

Vector Surveillance and Pathogen Detection in the Working Areas of Military Working Dogs in Eastern Austria

Vector-borne diseases play a major role in human and veterinary medicine worldwide. A previous study detected asymptomatic vector-borne pathogens in military working dogs stationed at a military base in eastern Austria, and a follow-up survey of potential arthropod vectors was conducted in spring 2019 and 2020 in the vicinity of the base to evaluate the presence of vectors and their carrier status for a range of canine and zoonotic pathogens. A total of 1324 ticks (nymphs and adults of Ixodes ricinus, comprising 92.9% of the collected specimens, and adults of Haemaphysalis inermis, a tick previously only rarely described in Austria, Haemaphysalis concinna, and Dermacentor reticulatus) were collected by flagging. In 44.1% (125/284) of all pools (n = 284), one infectious agent was found; in 27.8% (79/284) and in 1.1% (3/284), two and three different agents, respectively, could be identified. Overall, 72.9% of the pools contained at least one pathogen (Borrelia spp., Rickettsia spp., Bartonella spp., and Babesia microti). Borrelia mijamotoi, B. lustinaniae, and B. microti were previously only described in single cases in Austria. Mosquitoes were collected with BG-Sentinel traps monthly during the summer of 2019. A total of 71 individuals from 11 species were collected. No filarioid DNA was detected in the mosquito sample pools, although Dirofilaria repens had been present in the dogs from the military site. In conclusion, vector surveillance should be combined with the surveillance of an exposed population whenever possible to estimate the infection risks for dogs and their handlers.

Maps of ticks (Acari: Argasidae, Ixodidae) for Austria and South Tyrol, Italy

A first compilation of georeferenced tick locations in Austria and South Tyrol, Italy, is presented here. This allows the tick fauna to be examined in the various climatic regions of the European Alps. The dataset comprises 424 tick locations of Austria and 48 tick locations of South Tyrol, which were digitized from literature and visualized in the form of geographical maps. The tick fauna of Austria includes two species of Argasidae in the genera Argas and Carios and 15 species of Ixodidae in the genera Dermacentor, Haemaphysalis, and Ixodes, altogether 17 tick species. In addition, two species of Ixodidae in the genera Hyalomma (each spring imported by migratory birds) and Rhipicephalus (occasionally imported by dogs returning from abroad with their owners) are included in the tick atlas. Of these, the georeferenced locations of 18 tick species are depicted in maps. The occurrence of the one remaining tick species, Ixodes inopinatus, is given at the level of the federal states. The first Austrian distribution map of the long-legged bat tick Ixodes vespertilionis, which was reported from 21 caves, deserves special mention. The most common and widespread tick species is Ixodes ricinus, with records in all nine federal states of Austria, followed by Ixodes canisuga, Ixodes hexagonus, and I. vespertilionis in six federal states each. Haemaphysalis concinna and Dermacentor reticulatus are only endemic in the eastern plains, while Dermacentor marginatus only occurs in the west, in the Tyrolean Alpine valleys. Eight tick species were reported from South Tyrol, Italy. There, the most frequently flagged tick from the vegetation is also I. ricinus, while D. marginatus and Haemaphysalis punctata are often collected from sheep. The locations are shown together with those from North and East Tyrol on a separate Tyrol map. The tick atlas in Austria and South Tyrol as well as the underlying digital dataset in the supplement contribute to the closing of data gaps in global distribution maps of ticks and improve the data basis for new species distribution models.

Infections with Tickborne Pathogens after Tick Bite, Austria, 2015-2018

Knowledge about outcomes of tick bites is crucial because infections with emerging pathogens might be underestimated.

The aim of this prospective study was to assess the risk for tickborne infections after a tick bite. A total of 489 persons bitten by 1,295 ticks were assessed for occurrence of infections with Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia spp., Babesia spp., Candidatus Neoehrlichia mikurensis, and relapsing fever borreliae. B. burgdorferi s.l. infection was found in 25 (5.1%) participants, of whom 15 had erythema migrans. Eleven (2.3%) participants were positive by PCR for Candidatus N. mikurensis. One asymptomatic participant infected with B. miyamotoi was identified. Full engorgement of the tick (odds ratio 9.52) and confirmation of B. burgdorferi s.l. in the tick by PCR (odds ratio 4.39) increased the risk for infection. Rickettsia helvetica was highly abundant in ticks but not pathogenic to humans. Knowledge about the outcome of tick bites is crucial because infections with emerging pathogens might be underestimated because of limited laboratory facilities.

Vector-borne pathogens in clinically healthy military working dogs in eastern Austria

Military working dogs have an increased risk of acquiring an infection with vector-borne pathogens due to kennel housing and regular exposure to wildlife and vectors. To evaluate the level of infections in clinically healthy dogs of the Austrian Armed Forces, 94 individuals of the Military Working Dog Training Centre (MWDTC) Kaisersteinbruch/eastern Austria were examined in August 2016, February 2019 and August 2019. A modified Knott test was used to determine the presence of microfilariae, PCR for DNA detection of filarioid nematodes (incl. Dirofilaria), Leishmania spp., piroplasms, Borrelia spp., Bartonella spp. and Anaplasmataceae, and serological examination for antibodies against Borrelia burgdoferi s. l. and Leishmania infantum in all dogs. Two dogs were positive for Dirofilaria repens in the Knott test, and one of them also by PCR. Six clinically healthy dogs (4.2%) were positive for Babesia canis (PCR). In serology, 10 (10.6%) of the dogs were positive for specific antibodies against Borrelia burgdoferi s. l. The results suggest that the current measures against arthropod vector exposure and the pathogens they can transmit are not fully sufficient for these dogs. Further investigations of the tick and mosquito fauna in this area will shed more light on the risk of exposure for both the dogs and the staff of the MWDTC.

Human Borrelia miyamotoi Infection, Austria

We report a human case of Borrelia miyamotoi infection diagnosed in Austria. Spirochetes were detected in Giemsa-stained blood smears. The presence of B. miyamotoi in the patient’s blood was confirmed by PCR, and phylogenetic analysis identified an infection with a strain from Europe.

Passerine birds as hosts for Ixodes ticks infected with Borrelia burgdorferi sensu stricto in southeastern Virginia

The ecology of vector-borne diseases in a region can be attributed to vector-host interactions. In the United States, tick-borne pathogens are the cause of the highest number of reported vector-borne diseases. In the mid-Atlantic region of the eastern United States, tick-borne diseases such as Lyme disease, have increased in incidence, with tick-host-pathogen interactions considered a contributing factor to this increase. Ticks become infected with pathogens after taking a blood meal from a systemically infected host or through a localized infection while co-feeding on a host with other infected ticks. The host not only plays a role in pathogen acquisition by the tick, but can also facilitate dispersal of the tick locally within a region or over greater distances into new geographical ranges outside of their historical distributional range. In this study conducted in southeastern Virginia (USA), we examined the interaction between both resident and migratory bird species and Ixodes ticks, the primary vectors of Borrelia burgdorferi sensu stricto (s.s.) the main causative agent of Lyme disease on the East coast of the United States. Over a two-year period (2012-2014), 1879 passerine birds were surveyed, with 255 Ixodes ticks tested for the presence of Borrelia spp. Eighty passerine birds (4.3 %) representing 17 bird species were parasitized by at least one Ixodes tick, but only three bird species were parasitized by Ixodes ticks that tested positive for B. burgdorferi s.s. Twenty Ixodes ticks (7.8 %) tested positive for B. burgdorferi s.s. with nearly all collected from resident bird species including the Carolina wren (Thryothorus ludovicianus) and brown thrasher (Toxostoma rufum). Given that millions of birds pass through southeastern Virginia during migration, even with the low number of Ixodes ticks parasitizing passerine birds and the low prevalence of B. burgdorferi s.s. found within Ixodes ticks collected, the sheer volume of passerine birds suggests they may play a role in the maintenance and dispersal of B. burgdorferi s.s. in southeastern Virginia.

Glycerophosphodiester Phosphodiesterase Identified as Non-Reliable Serological Marker for Borrelia miyamotoi Disease

The relapsing fever group Borrelia miyamotoi is an emerging tick-borne pathogen. Diagnosis of infection is currently mainly based on serological methods detecting antibodies against B. miyamotoi glycerophosphodiester phosphodiesterase (GlpQ). Here, we scrutinized the reliability of GlpQ as a diagnostic marker and compared the seroprevalence in different study populations and by applying various immunoblotting methods. Antibodies were detected in the sera of 7/53 hunters and in 1/11 sera of Lyme neuroborreliosis patients. Furthermore, 17/74 sera of persons with high concentrations of anti-Borrelia burgdorferi sensu lato (α-Bbsl) antibodies reacted strongly with B. miyamotoi GlpQ in immunoblots. The B. miyamotoi GlpQ seroprevalence was 7/50 in α-Bbsl negative persons. In healthy blood donors from commercial suppliers and from the Austrian Red Cross, seroprevalences were 5/14 and 10/35, respectively. Strikingly, two B. miyamotoi PCR-positive cases from Austria had negative GlpQ serology, indicating poor sensitivity. Finally, when we analyzed sera of dogs, we found α-B. miyamotoi GlpQ antibody seroprevalence in tick-free dogs (n = 10) and in tick-exposed dogs (n = 19) with 2/10 and 8/19, respectively. Thus, our results indicate that GlpQ-based B. miyamotoi serology holds neither specificity nor sensitivity.

Borrelia miyamotoi: 43 Cases Diagnosed in France by Real-Time PCR in Patients With Persistent Polymorphic Signs and Symptoms

Background:Borrelia species are divided into three groups depending on the induced disease and the tick vector. Borrelia miyamotoi is a relapsing fever Borrelia but can induce symptoms related to Lyme disease. Discovered in 1995, it is found in ticks around the world. In France, this species of Borrelia has been isolated in ticks and rodents, but was not yet observed in humans.

Objective: The aim of the study was to look for B. miyamotoi in symptomatic patients.

Methods: Real-time PCR was performed on 824 blood samples from patients presenting symptoms of persistent polymorphic syndrome possibly due to tick bite, a syndrome recognized by the French Authority for Health, which is close to the post-treatment Lyme disease syndrome. PCR was also performed on 24 healthy control persons. The primers were specifically designed for this particular species of Borrelia. The sequence of interest of 94 bp is located on the glpQ gene. Sequencing of amplification products, randomly chosen, confirmed the amplification specificity. To better investigate cases, a clinical questionnaire was sent to the patients PCR-positive for B. miyamotoi and to their physician.

Results: This search revealed a positive PCR for B. miyamotoi in the blood from 43 patients out of 824 (5.22%). PCR was negative in all control persons. A clinical chart was obtained from 31 of the 43 patients. A history of erythema migrans was reported in five of these 31 patients (16%). All patients complained about fatigue, joint pain and neuro-cognitive disorders. Some patients complained about respiratory problems (chest tightness and/or lack of air in 41.9%). Episodes of relapsing fever were reported by 11 of the 31 patients (35.5%). Chilliness, hot flushes and/or sweats were reported by around half of the patients. B. miyamotoi may not cross-react with B. burgdorferi serology.

Conclusion: This study is the first to detect B. miyamotoi in human blood in France. This series of human B. miyamotoi infection is the largest in patients with long term persistent syndrome. Our data suggest that this infection may be persistent, even on the long term.

Lactoferrin is a natural inhibitor of plasminogen activation

The plasminogen system is essential for dissolution of fibrin clots, and in addition, it is involved in a wide variety of other physiological processes, including proteolytic activation of growth factors, cell migration, and removal of protein aggregates. On the other hand, uncontrolled plasminogen activation contributes to many pathological processes (e.g. tumor cells' invasion in cancer progression). Moreover, some virulent bacterial species (e.g. Streptococci or Borrelia) bind human plasminogen and hijack the host's plasminogen system to penetrate tissue barriers. Thus, the conversion of plasminogen to the active serine protease plasmin must be tightly regulated. Here, we show that human lactoferrin, an iron-binding milk glycoprotein, blocks plasminogen activation on the cell surface by direct binding to human plasminogen. We mapped the mutual binding sites to the N-terminal region of lactoferrin, encompassed also in the bioactive peptide lactoferricin, and kringle 5 of plasminogen. Finally, lactoferrin blocked tumor cell invasion in vitro and also plasminogen activation driven by Borrelia Our results explain many diverse biological properties of lactoferrin and also suggest that lactoferrin may be useful as a potential tool for therapeutic interventions to prevent both invasive malignant cells and virulent bacteria from penetrating host tissues.

Molecular identification of Borrelia spirochetes in questing Ixodes ricinus from northwestern Spain

BACKGROUND

Ixodes ricinus, the predominant tick species in Europe, can transmit the causative agents of important human diseases such as Lyme borreliosis (LB), caused by Borrelia spirochetes. In northern Spain, LB is considered endemic; recently, a significant increase of the annual incidence of LB was reported in the northwestern (NW) region.

METHODS

In order to provide information on the prevalence of Borrelia spp., pooled and individually free-living I. ricinus from NW Spain were molecularly analyzed. Positive samples were characterized at the fla and Glpq genes and the rrfA-rrlB intergenic spacer region to identify Borrelia species/genospecies.

RESULTS

Borrelia burgdorferi (sensu lato) (s.l.) individual prevalence and MIR were significantly higher in adult females (32.3 and 16%) than in nymphs (18.8 and 6.2%) and adult males (15.6 and 8.4%). Five Borrelia genospecies belonging to the B. burgdorferi (s.l.) group were identified: B. garinii was predominant, followed by B. valaisiana, B. lusitaniae, B. afzelii and B. burgdorferi (sensu stricto) (s.s.). One species belonging to the tick-borne relapsing fever group (B. miyamotoi) was also found, showing low individual prevalence (1%), positive pool (0.7%) and MIR (0.1%) values. To our knowledge, this is the first citation of B. miyamotoi in free-living ticks from Spain.

CONCLUSIONS

The significant prevalences of B. burgdorferi (s.l.) genospecies detected in questing ticks from NW Spain are similar to those detected in northern and central European countries and higher to those previously found in Spain. These results together with the high incidence of LB in humans and the high seroprevalence of B. burgdorferi (s.l.) in roe deer shown in other studies reveal that the northwest area is one of the most risky regions for acquiring LB in Spain.

Diagnosing Borreliosis

Borrelia species fall into two groups, the Borrelia burgdorferi sensu lato (Bbsl) complex, the cause of Lyme borreliosis (also known as Lyme disease), and the relapsing fever group. Both groups exhibit inter- and intraspecies diversity and thus have variations in both clinical presentation and diagnostic approaches. A further layer of complexity is derived from the fact that ticks may carry multiple infectious agents and are able to transmit them to the host during blood feeding, with potential overlapping clinical manifestations. Besides this, pathogens like Borrelia have developed strategies to evade the host immune system, which allows them to persist within the host, including humans. Diagnostics can be applied at different times during the clinical course and utilize sample types, each with their own advantages and limitations. These differing methods should always be considered in conjunction with potential exposure and compatible clinical features. Throughout this review, we aim to explore different approaches providing the reader with an overview of methods appropriate for various situations. This review will cover human pathogenic members of Bbsl and relapsing fever borreliae, including newly recognized Borrelia miyamotoi spirochetes.

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.

Borrelia miyamotoi and Co-Infection with Borrelia afzelii in Ixodes ricinus Ticks and Rodents from Slovakia

Borrelia miyamotoi causes relapsing fever in humans. The occurrence of this spirochete has been reported in Ixodes ricinus and wildlife, but there are still gaps in the knowledge of its eco-epidemiology and public health impact. In the current study, questing I. ricinus (nymphs and adults) and skin biopsies from rodents captured in Slovakia were screened for the presence of B. miyamotoi and Borrelia burgdorferi s.l. DNA. The prevalence of B. miyamotoi and B. burgdorferi s.l. in questing ticks was 1.7 and 16.9%, respectively. B. miyamotoi was detected in Apodemus flavicollis (9.3%) and Myodes glareolus (4.4%). In contrast, B. burgdorferi s.l. was identified in 11.9% of rodents, with the highest prevalence in Microtus arvalis (68.4%) and a lower prevalence in Apodemus spp. (8.4%) and M. glareolus (12.4%). Borrelia afzelii was the prevailing genospecies infecting questing I. ricinus (37.9%) and rodents (72.2%). Co-infections of B. miyamotoi and B. burgdorferi s.l. were found in 24.1 and 9.3% of the questing ticks and rodents, respectively, whereas the proportion of ticks and rodents co-infected with B. miyamotoi and B. afzelii was 6.9 and 7.0%, respectively. The results suggest that B. miyamotoi and B. afzelii share amplifying hosts. The sequences of the B. miyamotoi glpQ gene fragment from our study showed a high degree of identity with sequences of the gene amplified from ticks and human patients in Europe. The results seem to suggest that humans in Slovakia are at risk of contracting tick-borne relapsing fever, and in some cases together with Lyme borreliosis.

Host Immune Evasion by Lyme and Relapsing Fever Borreliae: Findings to Lead Future Studies for Borrelia miyamotoi

The emerging pathogen, Borrelia miyamotoi, is a relapsing fever spirochete vectored by the same species of Ixodes ticks that carry the causative agents of Lyme disease in the US, Europe, and Asia. Symptoms caused by infection with B. miyamotoi are similar to a relapsing fever infection. However, B. miyamotoi has adapted to different vectors and reservoirs, which could result in unique physiology, including immune evasion mechanisms. Lyme Borrelia utilize a combination of Ixodes-produced inhibitors and native proteins [i.e., factor H-binding proteins (FHBPs)/complement regulator-acquiring surface proteins, p43, BBK32, BGA66, BGA71, CD59-like protein] to inhibit complement, while some relapsing fever spirochetes use C4b-binding protein and likely Ornithodoros-produced inhibitors. To evade the humoral response, Borrelia utilize antigenic variation of either outer surface proteins (Osps) and the Vmp-like sequences (Vls) system (Lyme borreliae) or variable membrane proteins (Vmps, relapsing fever borreliae). B. miyamotoi possesses putative FHBPs and antigenic variation of Vmps has been demonstrated. This review summarizes and compares the common mechanisms utilized by Lyme and relapsing fever spirochetes, as well as the current state of understanding immune evasion by B. miyamotoi.

Detection of Borrelia miyamotoi and other tick-borne pathogens in human clinical specimens and Ixodes scapularis ticks in New York State, 2012-2015

Borrelia miyamotoi (Bm) is a recently emerging bacterial agent transmitted by several species of ixodid ticks. Diagnosis of Bm infection can be challenging, as the organism is not easily cultivable. We have developed and validated a multiplex real-time PCR to simultaneously identify Bm infection and the agents causing human granulocytic anaplasmosis and human monocytic ehrlichiosis, Anaplasma phagocytophilum and Ehrlichia chaffeensis, respectively. The assay is 100% specific; highly sensitive, detecting 11 gene copies of Bm DNA in both whole blood and cerebral spinal fluid; and provides rapid results in less than two hours. A retrospective study of 796 clinical specimens collected between the years 2012 and 2014 and a prospective study of 366 clinical specimens were performed utilizing this novel assay to evaluate the frequency of Bm infection in New York State (NYS). Eight clinical specimens (1%) were found to be positive for Bm, 216 were positive for A. phagocytophilum, and 10 were positive for E. chaffeensis. Additionally, we tested 411 I. scapularis ticks collected in NYS during 2013 and 2014 in a separate multiplex real-time PCR to determine the prevalence of Bm, A. phagocytophilum, Borrelia burgdorferi s.s., and Borrelia species. Our results indicated rates of 1.5%, 27%, 19.7%, and 8.8% respectively. The ability to monitor both the frequency and geographic distribution of Bm cases and the prevalence and geographic distribution of Bm in ticks will help create a better understanding of this emerging tick-borne pathogen.

The domestic pig as a potential model for Borrelia skin infection

The skin lesion erythema migrans is a characteristic early manifestation of Lyme borreliosis in humans. However, the pathomechanisms leading to development of this erythema are not fully understood. Models that mimic human skin would enhance research in this field. Human and porcine skin structures strongly resemble each other. Therefore, we attempted to induce erythema migrans lesions in experimental Borrelia burgdorferi sensu lato infection in the skin of domestic pigs. The formation of erythema migrans-like lesions was observed after intradermal injection of these spirochetes, with the lesions forming very clearly in 2/6 animals when a strain of B. garinii was used. However, no molecular or clinical proof of systemic infection of the pigs with B. afzelii, B. burgdorferi sensu stricto, or B. garinii could be achieved.

Paired real-time PCR assays for detection of Borrelia miyamotoi in North American Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae)

Borrelia miyamotoi is an emerging, tick-borne human pathogen. In North America, it is primarily associated with Ixodes scapularis and Ixodes pacificus, two species known to bite humans. Here we describe the development and evaluation of a pair of real-time TaqMan PCR assays designed to detect B. miyamotoi in North American ticks. We sought to achieve sensitivity to B. miyamotoi strains associated with ticks throughout North America, the full genetic diversity of which is unknown, by targeting sequences that are largely conserved between B. miyamotoi strains from the eastern United States and genetically distinct B. miyamotoi strains from Japan. The two assays target different loci on the B. miyamotoi chromosome and can be run side by side under identical cycling conditions. One of the assays also includes a tick DNA target that can be used to verify the integrity of tick-derived samples. Using both recombinant plasmid controls and genomic DNA from North American and Japanese strains, we determined that both assays reliably detect as few as 5 copies of the B. miyamotoi genome. We verified that neither detects B. burgdorferi, B. lonestari or B. turicatae. This sensitive and specific pair of assays successfully detected B. miyamotoi in naturally-infected, colony-reared nymphs and in field-collected I. scapularis and I. pacificus from the Northeast and the Pacific Northwest respectively. These assays will be useful in screening field-collected Ixodes spp. from varied regions of North America to assess the risk of human exposure to this emerging pathogen.