Lyme disease

Pathophysiology and Evolving Treatment Options of Septic Arthritis: A Narrative Review

Pyogenic (septic) arthritis is a severe joint infection characterized by the invasion of microorganisms into the synovium, causing inflammation and joint destruction. This review article provides a comprehensive overview of pyogenic arthritis, focusing on etiology, pathogenesis, clinical manifestations, diagnosis, and management strategies. This review explores routes of microbial entry into joints, emphasizing the importance of prompt identification and treatment to prevent irreversible joint damage. Clinical manifestations, such as joint pain, swelling, and limited range of motion, are discussed, along with the challenges in differentiating pyogenic arthritis from other joint disorders. Diagnostic approaches, including joint aspiration and imaging modalities, are critically examined for accuracy in confirming diagnosis. This review also addresses the significance of early intervention through antimicrobial therapy and joint drainage, highlighting the role of multidisciplinary collaboration in optimizing patient outcomes. In summary, the present investigation underscores the complexities of pyogenic arthritis and the need for a comprehensive understanding of pathophysiology for timely and effective management to improve patient prognosis and quality of life.

A chemosensory-like histidine kinase is dispensable for chemotaxis in vitro but regulates the virulence of Borrelia burgdorferi through modulating the stability of RpoS

As an enzootic pathogen, the Lyme disease bacterium Borrelia burgdorferi possesses multiple copies of chemotaxis proteins, including two chemotaxis histidine kinases (CHK), CheA1 and CheA2. Our previous study showed that CheA2 is a genuine CHK that is required for chemotaxis; however, the role of CheA1 remains mysterious. This report first compares the structural features that differentiate CheA1 and CheA2 and then provides evidence to show that CheA1 is an atypical CHK that controls the virulence of B. burgdorferi through modulating the stability of RpoS, a key transcriptional regulator of the spirochete. First, microscopic analyses using green-fluorescence-protein (GFP) tags reveal that CheA1 has a unique and dynamic cellular localization. Second, loss-of-function studies indicate that CheA1 is not required for chemotaxis in vitro despite sharing a high sequence and structural similarity to its counterparts from other bacteria. Third, mouse infection studies using needle inoculations show that a deletion mutant of CheA1 (cheA1mut) is able to establish systemic infection in immune-deficient mice but fails to do so in immune-competent mice albeit the mutant can survive at the inoculation site for up to 28 days. Tick and mouse infection studies further demonstrate that CheA1 is dispensable for tick colonization and acquisition but essential for tick transmission. Lastly, mechanistic studies combining immunoblotting, protein turnover, mutagenesis, and RNA-seq analyses reveal that depletion of CheA1 affects RpoS stability, leading to reduced expression of several RpoS-regulated virulence factors (i.e., OspC, BBK32, and DbpA), likely due to dysregulated clpX and lon protease expression. Bulk RNA-seq analysis of infected mouse skin tissues further show that cheA1mut fails to elicit mouse tnf-α, il-10, il-1β, and ccl2 expression, four important cytokines for Lyme disease development and B. burgdorferi transmigration. Collectively, these results reveal a unique role and regulatory mechanism of CheA1 in modulating virulence factor expression and add new insights into understanding the regulatory network of B. burgdorferi.

Lipid mediators of cerebrospinal fluid in response to TBE and bacterial co-infections

Tick-borne diseases are caused by monoinfection or co-infection with different pathogens, including viruses, bacteria and protozoa. Tick-borne diseases are usually accompanied by oxidative stress which promotes the modifications of the host's lipid metabolism. The aim of the study was to compare total antioxidant status and the level of lipid mediators in the cerebrospinal fluid in response to tick-borne encephalitis (TBE) and bacterial co-infections that cause diseases such as that is Lyme borreliosis (LB) and human granulocytic anaplasmosis (HGA). In our study cerebrospinal fluid samples were obtained from 15 patients with TBE and 6 patients with TBE co-infection with LB and/or HGA at admission and after treatment. Control group consisted of 14 patients in whom meningitis was excluded. Total antioxidant status, levels of lipid peroxidation products, endocannabinoids and eicosanoids (determined by liquid and gas chromatography-mass spectrometry) were compared between the groups. It was found that in TBE patients, total antioxidant status was decreased and accompanied by increased levels of lipid peroxidation products (4-HNE, MDA, isoprostanes and neuroprostanes), major endocannabinoids (AEA and 2AG), and eicosanoids (both anti-inflammatory and pro-inflammatory), which generally declined after treatment. On the other hand, in co-infections, significant changes in the levels of some lipid mediators were observed even after the treatment. TBE alone or along with bacterial co-infections promote redox balance disturbances in the cerebrospinal fluid leading to oxidative stress and increased metabolism of phospholipids in the brain tissue reflected in the level of lipid peroxidation products and lipid mediators. Changes in the level of lipid mediators in patients with co-infections after treatment suggest further intensification of metabolic disturbances rather than their resolution.

Development of an mRNA-lipid nanoparticle vaccine against Lyme disease

Lyme disease is the most common vector-borne infectious disease in the United States, in part because a vaccine against it is not currently available for humans. We propose utilizing the lipid nanoparticle-encapsulated nucleoside-modified mRNA (mRNA-LNP) platform to generate a Lyme disease vaccine like the successful clinical vaccines against SARS-CoV-2. Of the antigens expressed by Borrelia burgdorferi, the causative agent of Lyme disease, outer surface protein A (OspA) is the most promising candidate for vaccine development. We have designed and synthesized an OspA-encoding mRNA-LNP vaccine and compared its immunogenicity and protective efficacy to an alum-adjuvanted OspA protein subunit vaccine. OspA mRNA-LNP induced superior humoral and cell-mediated immune responses in mice after a single immunization. These potent immune responses resulted in protection against bacterial infection. Our study demonstrates that highly efficient mRNA vaccines can be developed against bacterial targets.

A suspected case of Lyme disease causing complete heart block

Carditis is a rare complication of Lyme disease and usually presents in the early dissemination phase, several weeks after exposure to a tick bite. Conduction abnormalities are the most common manifestation of Lyme carditis. The presentation can vary from atrioventricular conduction delay (first-degree atrioventricular conduction block) to life-threatening situations, such as a complete heart block. Although such manifestations occur late, our case report describes an interesting case where the patient developed a complete heart block in the setting of acute Lyme disease. An elevated IgM with negative IgG Lyme serology titer, an unusual finding, initially led us to face a diagnostic dilemma. Our suspicion of a tick bite was affirmed when we detected a positive titer for Babesia microti, an organism carried by the same tick and a common co-infection with Lyme disease. The patient improved with antibiotic therapy and temporary pacemaker support during the initial few days of admission.

Lyme Disease: An Overview

Lyme disease, a tick-borne multisystem disease, is caused by spirochete Borrelia burgdorferi (sensu lato). It is a common illness in temperate countries, especially the United States, but the incidence is increasing across continents due to increasing reforestation, travel and adventure tourism, increased intrusion in the vector habitat, and changing habitat of the vector. Transmission primarily occurs via bite of an infected tick (Ixodes spp.). The appearance of an erythema migrans rash following a tick bite is diagnostic of early Lyme disease even without laboratory evidence. Borrelia lymphocytoma and acrodermatitis chronica atrophicans along with multisystem involvement occur in late disseminated and chronic stages. A two-step serologic testing protocol using an enzyme-linked immunosorbent assay (ELISA) followed by confirmation of positive and equivocal results by Western immunoblot is recommended for the diagnosis. Transplacental transmission to infant occurs in the first trimester with possible congenital Lyme disease making treatment imperative during antenatal period. The treatment is most effective in the early stages of the disease, whereas rheumatological, neurological, or other late manifestations remain difficult to treat with antibiotics alone. Treatment with oral doxycycline is preferred for its additional activity against other tick-borne illnesses which may occur concurrently in 10%-15% of cases. New-generation cephalosporins and azithromycin are alternative options in patients with doxycycline contraindications. No vaccine is available and one episode of the disease will not confer life-long immunity; thus, preventive measures remain a priority. The concept of post-Lyme disease syndrome versus chronic Lyme disease remains contested for want of robust evidence favoring benefits of prolonged antibiotic therapy.

Combining citizen science and molecular diagnostic methods to investigate the prevalence of Borrelia burgdorferi s.l. and Borrelia miyamotoi in tick pools across Great Britain

Lyme disease is the most common tick-borne disease and is caused by a group of bacteria known as Borrelia burgdorferi sensu lato (s.l.) complex. Sharing the same genus as B. burgdorferi, Borrelia miyamotoi is a distinct genotype that causes relapsing fever disease. This emerging tick-borne disease is increasingly becoming a concern in public health. To investigate the prevalence of B. burgdorferi s.l. and B. miyamotoi in ticks first, we developed a PCR (Bmer-qPCR) that targets the phage terminase large subunit (terL) gene carried by B. miyamotoi. A similar approach had been used successfully in developing Ter-qPCR for detecting B. burgdorferi s.l. The terL protein functions as an enzyme in packaging phage DNA. Analytical validation of the Bmer-qPCR confirmed its specificity, efficiency and sensitivity. Second, we designed a citizen science-based approach to detect 838 ticks collected from numerous sites across Great Britain. Finally, we applied Bmer-qPCR and Ter-qPCR to 153 tick pools and revealed that the prevalence of B. burgdorferi s.l. and B. miyamotoi was dependent on their geographical locations, i.e. Scotland showed a higher rate of B. burgdorferi s.l. and lower rate of B. miyamotoi carriage as compared to those of the England data. A pattern of diminishing rate of B. miyamotoi carriage from southern England to northern Scotland was visible. Together, the citizen science-based approach provided an estimation of the carriage rate of B. burgdorferi s.l. and B. miyamotoi in tick pools and a potential spreading pattern of B. miyamotoi from the south to the north of Great Britain. Our findings underscore the power of combining citizen science with the molecular diagnostic method to reveal hidden pattern of pathogen-host-environment interplay. Our approach can provide a powerful tool to elucidate the ecology of tick-borne diseases and may offer guidance for pathogen control initiatives. In an era of limited resources, monitoring pathogens requires both field and laboratory support. Citizen science approaches provide a method to empower the public for sample collection. Coupling citizen science approaches with laboratory diagnostic tests can make real-time monitoring of pathogen distribution and prevalence possible.

Chemotaxis Coupling Protein CheW2 Is Not Required for the Chemotaxis but Contributes to the Full Pathogenicity of Borreliella burgdorferi

The bacterial chemotaxis regulatory circuit mainly consists of coupling protein CheW, sensor histidine kinase CheA, and response regulator CheY. Most bacteria, such as Escherichia coli, have a single gene encoding each of these proteins. Interestingly, the Lyme disease pathogen, Borreliella burgdorferi, has multiple chemotaxis proteins, e.g., two CheA, three CheW, and three CheY proteins. The genes encoding these proteins mainly reside in two operons: cheW2-cheA1-cheB2-cheY2 (A-I) and cheA2-cheW3-cheX-cheY3 (A-II). Previous studies demonstrate that all the genes in A-II are essential for the chemotaxis of B. burgdorferi; however, the role of those genes in A-I remains unknown. This study aimed to fill this gap using the CheW2 gene, the first gene in A-I, as a surrogate. We first mapped the transcription start site of A-I upstream of cheW2 and identified a σ70-like promoter (PW2) and two binding sites (BS1 and BS2) of BosR, an unorthodox Fur/Per homolog. We then demonstrated that BosR binds to PW2 via BS1 and BS2 and that deletion of bosR significantly represses the expression of cheW2 and other genes in A-I, implying that BosR is a positive regulator of A-I. Deletion of cheW2 has no impact on the chemotaxis of B. burgdorferi in vitro but abrogates its ability to evade host adaptive immunity, because the mutant can establish systemic infection only in SCID mice and not in immunocompetent BALB/c mice. This report substantiates the previous proposition that A-I is not implicated in chemotaxis; rather, it may function as a signaling transduction pathway to regulate B. burgdorferi virulence gene expression.

Lyme borreliosis in pregnancy and associations with parent and offspring health outcomes: An international cross-sectional survey

Background

Lyme disease (LD) is a complex tick-borne pathology caused by Borrelia burgdorferi sensu lato bacteria. Currently, there are limited data regarding the health outcomes of people infected during pregnancy, the potential for perinatal transmission to their fetus, and the long-term effects on these children. Therefore, the primary objective of this survey study was to investigate the impact of LD in pregnancy on both the parent and their offspring.

Methods

A seven-section survey was developed and administered in REDCap. Although recruitment was primarily through LD-focused organizations, participation was open to anyone over the age of 18 who had been pregnant. Participant health/symptoms were compared across those with “Diagnosed LD,” “Suspected LD,” or “No LD” at any time in their lives. The timing of LD events in the participants’ histories (tick bite, diagnosis, treatment start, etc.) were then utilized to classify the participants’ pregnancies into one of five groups: “Probable Treated LD,” “Probable Untreated LD,” “Possible Untreated LD,” “No Evidence of LD,” and “Unclear.”

Results

A total of 691 eligible people participated in the survey, of whom 65% had Diagnosed LD, 6% had Suspected LD, and 29% had No LD ever. Both the Diagnosed LD and Suspected LD groups indicated a high symptom burden (p < 0.01). Unfortunately, direct testing of fetal/newborn tissues for Borrelia burgdorferi only occurred following 3% of pregnancies at risk of transmission; positive/equivocal results were obtained in 14% of these cases. Pregnancies with No Evidence of LD experienced the fewest complications (p < 0.01) and were most likely to result in a live birth (p = 0.01) and limited short- and long-term offspring pathologies (p < 0.01). Within the LD-affected pregnancy groups, obtaining treatment did not decrease complications for the parent themselves but did ameliorate neonatal health status, with reduced rates of rashes, hypotonia, and respiratory distress (all p < 0.01). The impact of parent LD treatment on longer-term child outcomes was less clear.

Conclusion

Overall, this pioneering survey represents significant progress toward understanding the effects of LD on pregnancy and child health. A large prospective study of pregnant people with LD, combining consistent diagnostic testing, exhaustive assessment of fetal/newborn samples, and long-term offspring follow-up, is warranted.

Neurological Pain, Psychological Symptoms, and Diagnostic Struggles among Patients with Tick-Borne Diseases

Public health reports contain limited information regarding the psychological and neurological symptoms of tick-borne diseases (TBDs). Employing a mixed-method approach, this analysis triangulates three sources of symptomology and provides a comparison of official public health information, case reports, medical literature, and the self-reported symptoms of patients with Lyme disease and other TBDs. Out of the fifteen neuropsychiatric symptoms reported in the medical literature for common TBDs, headaches and fatigue and/or malaise are the only two symptoms fully recognized by public health officials. Of TBDs, Lyme disease is the least recognized by public health officials for presenting with neuropsychiatric symptoms; only headaches and fatigue are recognized as overlapping symptoms of Lyme disease. Comparisons from a patient symptoms survey indicate that self-reports of TBDs and the associated symptoms align with medical and case reports. Anxiety, depression, panic attacks, hallucinations, delusions, and pain—ranging from headaches to neck stiffness and arthritis—are common among patients who report a TBD diagnosis. Given the multitude of non-specific patient symptoms, and the number and range of neuropsychiatric presentations that do not align with public health guidance, this study indicates the need for a revised approach to TBD diagnosis and for improved communication from official public health sources regarding the wide range of associated symptoms.

A single tick screening for infectious pathogens using targeted mass spectrometry

The black-legged tick, Ixodes scapularis, is a well-known vector for the Lyme disease-causing pathogen (Borrelia burgdorferi) but can also carry other disease-causing pathogens such as Rickettsia, Anaplasma, Bartonella, Ehrlichia, and Theileria. Hence, tick screening using highly specific protein signatures for specific pathogens will help assess the prevalence of infected ticks and understand the pathogen-tick interactions in a specific geographic area. In this study, we used data-dependent acquisition to key pathogen protein signatures in black-legged ticks collected from the Southern Tier New York. Bottom-up proteomic analysis of extract from five combined ticks identified 2,052 tick proteins and 41 pathogen proteins with high confidence (≥ 99% C.I.). Results show high peptide spectral match counts for Rickettsia species and Borrelia species and lower counts for other rarer pathogens such as Anaplasma phagocytophilum. Parallel reaction monitoring performed on protein extracts from individual ticks (n = 10) revealed that 8 out of the 10 screened ticks carried Rickettsia species, 5 carried Borrelia species, 3 carried both pathogens, and only 1 tick carried no detectable bacteria. Mass spectrometry-based proteomics is a highly specific way to define the expression of different types of pathogen proteins in infected ticks. This might bring insights into the tick-pathogen interactions at the molecular level and especially expression pathogen surface proteins in ticks.

Comprehensive Mapping of the Cell Response to Borrelia bavariensis in the Brain Microvascular Endothelial Cells in vitro Using RNA-Seq

Borrelia bavariensis can invade the central nervous system (CNS) by crossing the blood-brain barrier (BBB). It is predicted that B. bavariensis evokes numerous signaling cascades in the human brain microvascular endothelial cells (hBMECs) and exploits them to traverse across the BBB. The complete picture of signaling events in hBMECs induced by B. bavariensis remains uncovered. Using RNA sequencing, we mapped 11,398 genes and identified 295 differentially expressed genes (DEGs, 251 upregulated genes and 44 downregulated genes) in B. bavariensis challenged hBMECs. The results obtained from RNA-seq were validated with qPCR. Gene ontology analysis revealed the participation of DEGs in a number of biological processes like cell communication, organization of the extracellular matrix, vesicle-mediated transport, cell response triggered by pattern recognition receptors, antigen processing via MHC class I, cellular stress, metabolism, signal transduction, etc. The expression of several non-protein coding genes was also evoked. In this manuscript, we discuss in detail the correlation between several signaling cascades elicited and the translocation of BBB by B. bavariensis. The data revealed here may contribute to a better understanding of the mechanisms employed by B. bavariensis to cross the BBB.

Lyme Disease Training and Knowledge Translation Resources Available to Canadian Healthcare Professionals: A Gray Literature Review

Introduction:

Lyme Disease (LD) is the most common tick-borne disease in North America. With the number of cases increasing yearly, Canadian healthcare professionals (HCP) rely on up-to-date and evidence-informed guidelines, instruction, and resources to effectively prevent, diagnose, and treat Lyme disease (LD). This review is the first of its kind to examine gray literature and analyze the diversity of recommendations provided to Canadian HCP about the prevention, diagnosis, and treatment of Lyme disease.

Methods:

A gray literature review consisting of 4 search strategies was conducted to retrieve materials targeted to Canadian HCP. Searches within targeted websites, targeted Google searches, and gray literature databases, and consultation with content experts were done to look for continuing medical education (CME) events, clinical flow charts, webinars, videos, and reference documents that discussed the prevention, diagnosis, and treatment of Lyme disease.

Results:

A total of 115 resources were included in this study. Recommendations surrounding prevention strategies were less varied between materials, whereas diagnosis and treatment recommendations were more varied. Our findings suggest that Canadian HCP are met with varying and sometimes contradictory recommendations for diagnosing and treating LD.

Conclusions:

Due to the increasing incidence of LD in Canada, there is a greater need for resource consistency. Providing this consistency may help mitigate LD burden, standardize approaches to prevention, diagnosis and treatment, and improve patient outcomes.

A Review on Important Zoonotic Bacterial Tick-Borne Diseases in the Eastern Mediterranean Region

Background

Zoonotic diseases as health concerns worldwide account for more than half of the emerging infectious diseases. Arachnids are powerful vectors to transmit several diseases to humans. Additionally, these emerging zoonotic diseases have been a considerable health threat in the Eastern Mediterranean Region of the WHO (EMRO) due to the large population living close to farms and international trade with nearby countries.

Methods

This review study is based on the reported three tick-borne diseases, Lyme disease, Tularemia, and Q fever, from Iran and other EMRO countries. To this end, we searched PubMed central, ISI web of Science, and Google with the related keywords in English at any time. The reported data are then sorted by countries for each disease.

Results

According to the published data, 15 countries in the region have one/more emerging infectious diseases. Q fever has been the most frequent infection in EMRO countries, while Lyme was less recorded. Furthermore, Iran is among the countries with documented history of all three investigated diseases.

Conclusion

Tick-borne disease is popular among EMRO countries, indicating that they have natural conditions for infections in animals and humans. It appears necessary to develop a disease management strategy and control programs against tick-borne diseases (TBDs). Moreover, the disease-resistant animal could be bred instead of susceptible livestock. Therefore, research studies to control TBDs should be regarded as a top priority plan.

Rodent host population dynamics drive zoonotic Lyme Borreliosis and Orthohantavirus infections in humans in Northern Europe

Zoonotic diseases, caused by pathogens transmitted between other vertebrate animals and humans, pose a major risk to human health. Rodents are important reservoir hosts for many zoonotic pathogens, and rodent population dynamics affect the infection dynamics of rodent-borne diseases, such as diseases caused by hantaviruses. However, the role of rodent population dynamics in determining the infection dynamics of rodent-associated tick-borne diseases, such as Lyme borreliosis (LB), caused by Borrelia burgdorferi sensu lato bacteria, have gained limited attention in Northern Europe, despite the multiannual abundance fluctuations, the so-called vole cycles, that characterise rodent population dynamics in the region. Here, we quantify the associations between rodent abundance and LB human cases and Puumala Orthohantavirus (PUUV) infections by using two time series (25-year and 9-year) in Finland. Both bank vole (Myodes glareolus) abundance as well as LB and PUUV infection incidence in humans showed approximately 3-year cycles. Without vector transmitted PUUV infections followed the bank vole host abundance fluctuations with two-month time lag, whereas tick-transmitted LB was associated with bank vole abundance ca. 12 and 24 months earlier. However, the strength of association between LB incidence and bank vole abundance ca. 12 months before varied over the study years. This study highlights that the human risk to acquire rodent-borne pathogens, as well as rodent-associated tick-borne pathogens is associated with the vole cycles in Northern Fennoscandia, yet with complex time lags.

Epidemiological investigation of hemophagocytic lymphohistiocytosis in China

Background

Currently, most research on hemophagocytic lymphohistiocytosis (HLH) have focused on etiology and therapy, leaving few epidemiological reports. The published studies of China are mainly regional investigations. We aimed to present the overall epidemiological status of HLH in China, and provide Chinese data for the international HLH epidemiological investigation.

Methods

The data of HLH cases in China in 2019 were collected and statistically analyzed.

Findings

Epstein-Barr virus accounted for 44.01% of the 1445 cases in 31 regions and was the most common cause. Lymphoma-associated HLH patients were more often male (P < 0.05) while rheumatic and immune-associated HLH were more often female (P < 0.001). Primary HLH and Epstein-Barr Virus-associated HLH were predominant in children (P < 0.001) while tumor-associated HLH was predominant in adults. Lymphoma-associated HLH was positively correlated with the age of onset (P < 0.01). The diagnosis rate of 29 areas had a significant correlation with per capita Gross domestic product (P < 0.05).

Conclusion

The different distribution of HLH etiology by age and gender contributes to the diagnosis of HLH by clinicians; The suboptimal diagnosis rate in regions with a high incidence of HLH in China is a result of the effect of the local economic level indicating the importance of improving the regional medical level.

A curious case of Lyme carditis in an urban hospital

Lyme carditis (LC), a manifestation of early disseminated Lyme disease, most commonly presents with cardiac conduction abnormalities. It is a transient condition with good prognosis but in extremely rare cases may be life-threatening. We describe a 42-year-old man who presented with progressively worsening generalized weakness, presyncope and dyspnea on exertion for 2 weeks after sustaining a tick bite. He subsequently developed a ‘bull’s eye rash’ on his flank 2 days before his presentation. He was found to have symptomatic third-degree AV conduction blockade with a ventricular escape rhythm resulting in a brief cardiac arrest. Intravenous (IV) ceftriaxone was commenced empirically and a temporary transvenous pacemaker was placed. In a few days he showed dramatic, rapid improvement; the pacemaker was removed, and the patient was discharged on oral doxycycline to complete a 24-day course. This case is unique due to its occurrence in an urban hospital where such cases are uncommon. Cardiac arrest, although brief in this case, is a rare occurrence. Lyme carditis was a surprise diagnosis in our hospital due to the patient’s geographical dislocation during the COVID-19 pandemic.

Infectious ophthalmoplegias

Though infections account for a significant proportion of patients with ocular motor palsies, there is surprising paucity of literature on infectious ophthalmoplegias. Almost all types of infectious agents (bacteria, viruses, fungi and parasites) can lead to ocular motor palsies. The causative infectious agent can be diagnosed in most cases using an orderly stepwise approach. In this review we discuss how to approach a patient with ophthalmoplegia with main focus on infectious etiologies.

The Borrelia burgdorferi VlsE Lipoprotein Prevents Antibody Binding to an Arthritis-Related Surface Antigen

Arp is an immunogenic protein of the Lyme disease spirochete Borrelia burgdorferi and contributes to joint inflammation during infection. Despite Arp eliciting a strong humoral response, antibodies fail to clear the infection. Given previous evidence of immune avoidance mediated by the antigenically variable lipoprotein of B. burgdorferi, VlsE, we use passive immunization assays to examine whether VlsE protects the pathogen from anti-Arp antibodies. The results show that spirochetes are only able to successfully infect passively immunized mice when VlsE is expressed. Subsequent immunofluorescence assays reveal that VlsE prevents binding of Arp-specific antibodies, thereby providing an explanation for the failure of Arp antisera to clear the infection. The results also show that the shielding effect of VlsE is not universal for all B. burgdorferi cell-surface antigens. The findings reported here represent a direct demonstration of VlsE-mediated protection of a specific B. burgdorferi surface antigen through a possible epitope-shielding mechanism.

Lone and Bankhead report that the antigenically variable VlsE protein of the Lyme disease agent Borrelia burgdorferi can prevent antibody binding to a surface antigen of the pathogen. They show that protection is likely via an epitope-shielding mechanism, thus expanding the current role of VlsE in immune evasion.

Merging Patches, an Atypical Presentation of Disseminated Cutaneous Lyme Disease: A Case Report

BACKGROUND

Lyme disease, spread by the Ixodes tick, is typically associated with a single "bull's eye rash" that emergency physicians are comfortable recognizing and treating during the summer months when this disease is most prevalent. However, Lyme disease can also present in disseminated forms that are more difficult to diagnose.

CASE REPORT

We describe a phenomenon of disseminated Lyme with multiple rash complexes that is unrecognized by clinicians. A 65-year-old woman with no prior medical history presented with flu-like symptoms including headache, nausea, and arthralgias, as well as a nonpruritic rash on her lower limbs. On physical examination, multiple red, blanching patches with a diameter of up to 20 cm were seen. Although she was initially thought to have a nonsteroidal anti-inflammatory drug reaction as her skin biopsy for Borrelia burgdorferi was negative, an immunoglobulin M test for B. burgdorferi was found to be positive during her emergency department visit. Despite the diverging results, a diagnosis of early-disseminated Lyme was made. She was discharged home on a 3-week course of oral doxycycline, and a complete resolution of her symptoms was noted on a follow-up visit. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: With the incidence of Lyme disease and its atypical presentations on the rise, the emergency physician should be aware of the other rashes that are associated with this disease, particularly those associated with disseminated cutaneous Lyme. Early diagnosis of the disseminated forms of Lyme is critical to prevent the occurrence of life-threatening cardiovascular and neurological complications known to occur with this disease.

Specific composition of polyphenolic compounds with fatty acids as an approach in helping to reduce spirochete burden in Lyme disease: in vivo and human observational study

Background:

Lyme disease (LD) is a tick-borne infection caused by Borrelia burgdorferi sensu lato. The current therapeutic approach to this disease is limited to antibiotics. However, after their administration, about 20% of patients experience delayed onset of this illness manifesting as lingering persistent symptoms.

Methods:

To determine a suitable approach that would help reduce this number, we examined the efficacy of a composition of polyphenolic compounds (baicalein, luteolin, and rosmarinic acid) with fatty acids (monolaurin and cis-2-decenoic acid), and iodine/kelp in a Lyme disease animal model and volunteers.

Results:

The results showed that 4 weeks of dietary intake of this composition reduced the spirochete burden in animal tissues by about 75%. Basic and differential blood parameters did not show significant differences between control animals and the animals fed with this composition. Also, hepatic and renal toxicity markers were not changed and apoptosis was not observed. Relevant inflammatory cytokines such as IL-6, IL-17, TNF-α, and INF-γ, were elevated in infected animals but normalized in infected and treated animals. A small observational study revealed that after administration of this composition to 17 volunteers three times per day for 6 months, 67.4% of the volunteers with late or persistent LD, and not receptive to previous antibiotic application, responded positively, in terms of energy status as well as physical and psychological wellbeing to supplementation with this composition, while 17.7% had slight improvement, and 17.7% were none responsive.

Conclusion:

We concluded that this specific composition revealed feasible benefits in late or persistent LD management, although double-blind controlled clinical trials are warranted.

Lyme Endocarditis as an Emerging Infectious Disease: A Review of the Literature

Lyme endocarditis is extremely rare manifestation of Lyme disease. The clinical manifestations of Lyme endocarditis are non-specific and can be very challenging diagnosis to make when it is the only manifestation of the disease. Until now, only a few cases where reported. Physicians should keep in mind the possibility of borrelial etiology of endocarditis in endemic areas. Appropriate valve tissue sample should be sent for histopathology, culture, and PCR especially in case of endocarditis of unknown origin PCR on heart valve samples is recommended. With more frequent PCR, Borrelia spp. may be increasingly found as a cause of infective endocarditis. Prompt diagnosis and treatment of Lyme carditis may prevent surgical treatment and pacemaker implantations. Due to climate change and global warming Lyme disease is a growing problem. Rising number of Lyme disease cases we can expect and rising number of Lyme endocarditis.

Increasing Burden of Lyme Carditis in United States Children's Hospitals

We sought to characterize the shifting epidemiology and resource utilization of Lyme disease and associated carditis in US children's hospitals. We hypothesized that the Lyme carditis burden has increased and that hospitalizations for Lyme carditis are costlier than those for Lyme disease without carditis. The PHIS database was queried for Lyme disease encounters between January 1, 2007 and December 31, 2013. Additional diagnostic codes consistent with carditis identified Lyme carditis cases. Demographic, clinical, and resource utilization data were analyzed. All costs were adjusted to 2014 US dollars. Lyme disease was identified in 3620 encounters with 189 (5%) associated with carditis. Lyme disease (360 cases in 2007 vs. 672 in 2013, p = 0.01) and Lyme carditis (17 cases in 2007 vs. 40 in 2013, p = 0.03) both significantly increased in frequency. This is primarily accounted for by their increase within the Midwest region. Carditis frequency among cases of Lyme disease was stable (p = 0.15). Encounters for Lyme carditis are dramatically costlier than those for Lyme disease without carditis [median $9104 (3741-19,003) vs. 922 (238-4987), p < 0.001] The increase in Lyme carditis cases in US children's hospitals is associated with an increased Lyme disease incidence, suggesting that there has not been a change in its virulence or cardiac tropism. The increasing number of serious cardiac events and costs associated with Lyme disease emphasize the need for prevention and early detection of disease and control of its spread.

Regulation of macrophage activity by surface receptors contained within Borrelia burgdorferi-enriched phagosomal fractions

Macrophages mediate the elimination of pathogens by phagocytosis resulting in the activation of specific signaling pathways that lead to the production of cytokines, chemokines and other factors. Borrelia burgdorferi, the causative agent of Lyme disease, causes a wide variety of pro-inflammatory symptoms. The proinflammatory capacity of macrophages is intimately related to the internalization of the spirochete. However, most receptors mediating this process are largely unknown. We have applied a multiomic approach, including the proteomic analysis of B. burgdorferi-containing phagosome-enriched fractions, to identify surface receptors that are involved in the phagocytic capacity of macrophages as well as their inflammatory output. Sucrose gradient protein fractions of human monocyte-derived macrophages exposed to B. burgdorferi contained the phagocytic receptor, CR3/CD14 highlighting the major role played by these proteins in spirochetal phagocytosis. Other proteins identified in these fractions include C-type lectins, scavenger receptors or Siglecs, of which some are directly involved in the interaction with the spirochete. We also identified the Fc gamma receptor pathway, including the binding receptor, CD64, as involved both in the phagocytosis of, and TNF induction in response to B. burgdorferi in the absence of antibodies. The common gamma chain, FcγR, mediates the phagocytosis of the spirochete, likely through Fc receptors and C-type lectins, in a process that involves Syk activation. Overall, these findings highlight the complex array of receptors involved in the phagocytic response of macrophages to B. burgdorferi.

Macrophages eliminate infecting microorganisms through the concerted action of surface receptors and signaling molecules. As a consequence, these cells produce a series of soluble factors that participate in the inflammatory response during infections. The composition of the full complement of receptors that participate in the recognition and internalization of the causative agent of Lyme disease, Borrelia burgdorferi, is largely unknown. We have analyzed the protein composition of phagosomes containing B. burgdorferi from human macrophages and identified a series of surface proteins that may be involved in the process. Through the use of gene silencing techniques, we have determined the participation of several of these receptors both in the internalization of the bacterium and the subsequent inflammatory response. Among these, we have identified the Fc gamma receptor pathway as involved in this process in the absence of antibodies. We have also identified receptors that are directly involved in the attachment of B. burgdorferi, while others seem to have an accessory role in the internalization and/or induction of proinflammatory cytokines in response to the spirochete. These data clarify the complex array of interactions between macrophages and B. burgdorferi and shed light on the overall response to this infectious agent.

Structure and Function Relationships in Diseases of the Small Airways

It is well known that particulate matter suspended in the earth's atmosphere generated by tobacco smoke, automobile exhaust, industrial processes, and forest fires has been identified as a major risk factor for chronic lung disease. Particulate matter can be divided into large, intermediate, and fine particulates. When inhaled, large particulates develop sufficient momentum to leave the flowing stream of inhaled air and deposit by impaction in the nose, mouth, nasopharynx, larynx, trachea, and central bronchi. Intermediate-sized particulates that develop less momentum deposit in the smaller bronchi and larger bronchioles, and the finest particulates that develop the least momentum make it to the distal gas-exchanging tissue, where gas moves solely by diffusion. On the basis of Einstein's classic work on Brownian motion that showed particles suspended in a gas diffuse much more slowly than the gas in which they are suspended, we postulate that the small airways that accommodate the shift from bulk airflow to diffusion become the major site for deposition of fine particles, resulting in a host immune response. Much remains to be learned about the interaction between the deposition of fine particulates and the host immune and tissue responses; the purpose of this review is to examine the hypothesis that the smallest conducting airways and proximal gas-exchanging tissue are the primary sites for the deposition of the finest particulates inhaled into the lungs.

Potential Persistent Borrelia Infection and Response to Antibiotic Therapy; a Clinical Case Study and Review of Recent Literature

This report describes the case of an individual who was clinically diagnosed with Lyme borreliosis and initially responded to standard antibiotic therapy. Subsequent to treatment cessation, the patient experienced symptomatic rebound and failed to respond to a second course of the same antibiotic. The patient was eventually diagnosed with both Borrelia and Anaplasma infections by serological testing performed in a private laboratory. Following a two-month course of combination antibiotic therapy, the patient responded clinically, with a return to almost normal functioning. We discuss this case in the context of recent pre-clinical research examining potential Borrelial persistence despite antibiotic therapy.

Evaluation and Management of Septic Arthritis and its Mimics in the Emergency Department

Septic arthritis is a dangerous medical condition associated with significant morbidity and mortality. However, the differential diagnosis can be broad with conditions that mimic this disease and require different evaluation and treatment. This narrative review presents the emergency medicine evaluation and management, as well as important medical conditions that may mimic this disease. Septic arthritis commonly presents with monoarticular joint pain with erythema, warmth, swelling, and pain on palpation and movement. Fever is present in many patients, though most are low grade. Blood testing and imaging may assist with the diagnosis, but the gold standard is joint aspiration. Management includes intravenous antibiotics and orthopedic surgery consult for operative management vs. serial aspirations. Clinicians should consider mimics, such as abscess, avascular necrosis, cellulitis, crystal-induced arthropathies, Lyme disease, malignancy, osteomyelitis, reactive arthritis, rheumatoid arthritis, and transient synovitis. While monoarticular arthritis can be due to septic arthritis, other medical and surgical conditions present similarly and require different management. It is essential for the emergency clinician to be aware how to diagnose and treat these mimics.

Lyme Arthritis: An Update for Clinical Practice

Lyme disease is the most common vector-borne illness in North America, with the majority of cases occurring in the Northeast and upper Midwest. Lyme arthritis is the most prevalent manifestation of late-stage Lyme disease. Lyme arthritis typically presents as a monoarthritis or oligoarthritis in large joints such as the knee. Accompanying positive 2-tier Lyme serologies or polymerase chain reaction from synovial fluid/tissue is considered diagnostic for patients from an endemic area. The mainstay of initial treatment is a prolonged course of oral antibiotics.

Whole genome sequence and comparative analysis of Borrelia burgdorferi MM1

Lyme disease is caused by spirochaetes of the Borrelia burgdorferi sensu lato genospecies. Complete genome assemblies are available for fewer than ten strains of Borrelia burgdorferi sensu stricto, the primary cause of Lyme disease in North America. MM1 is a sensu stricto strain originally isolated in the midwestern United States. Aside from a small number of genes, the complete genome sequence of this strain has not been reported. Here we present the complete genome sequence of MM1 in relation to other sensu stricto strains and in terms of its Multi Locus Sequence Typing. Our results indicate that MM1 is a new sequence type which contains a conserved main chromosome and 15 plasmids. Our results include the first contiguous 28.5 kb assembly of lp28-8, a linear plasmid carrying the vls antigenic variation system, from a Borrelia burgdorferi sensu stricto strain.

A multi-omic analysis reveals the regulatory role of CD180 during the response of macrophages to Borrelia burgdorferi

Macrophages are cells of the innate immune system with the ability to phagocytose and induce a global pattern of responses that depend on several signaling pathways. We have determined the biosignature of murine bone marrow-derived macrophages and human blood monocytes using transcriptomic and proteomic approaches. We identified a common pattern of genes that are transcriptionally regulated and overall indicate that the response to B. burgdorferi involves the interaction of spirochetal antigens with several inflammatory pathways corresponding to primary (triggered by pattern-recognition receptors) and secondary (induced by proinflammatory cytokines) responses. We also show that the Toll-like receptor family member CD180 is downregulated by the stimulation of macrophages, but not monocytes, with the spirochete. Silencing Cd180 results in increased phagocytosis while tempering the production of the proinflammatory cytokine TNF. Cd180-silenced cells produce increased levels of Itgam and surface CD11b, suggesting that the regulation of CD180 by the spirochete initiates a cascade that increases CR3-mediated phagocytosis of the bacterium while repressing the consequent inflammatory response.

Lyme Carditis: A Case Report and Review of Management

Purpose: A case report of a patient who presented with an acute onset, fluctuating atrioventricular (AV) block and was diagnosed with Lyme carditis is presented. Summary: A 55-year-old man with progressively worsening generalized malaise, flu-like symptoms, dyspnea on exertion, and near syncope was admitted with bradycardia (heart rate was between 20 and 30 beats per minute upon admission). He endorsed having several tick bites after which he developed erythema migrans on his arm and abdomen. An electrocardiogram (ECG) revealed a second-degree AV block, fluctuating between Mobitz type I and Mobitz type II heart block, with a P-R interval of 300 ms. A presumptive diagnosis of Lyme carditis was made based on a confirmed history of tick exposure, presence of erythema migrans, and AV block. The patient was started on ceftriaxone. On day 3 of hospitalization, patient's heart rate was between 50 and 60 beats per minute. A diagnosis of Lyme disease was confirmed based on serologic testing. A repeat ECG revealed a first-degree AV block with a P-R interval of 300 ms. On day 5 of hospitalization, a peripherally inserted central catheter line was placed and the patient was discharged to his home on a 28-day course of ceftriaxone. Patient's heart rate was 65 beats per minute on discharge day. Conclusion: Considering Lyme carditis as a differential diagnosis in patients with an AV block of an unknown etiology can result in a timely diagnosis and treatment of Lyme carditis.

An Unusual Cluster of Neuroinvasive Lyme Disease Cases Presenting With Bannwarth Syndrome in the Midwest United States

Bannwarth syndrome (BWS), an infrequent manifestation of neuroinvasive Lyme disease (LD) characterized by radiculopathy, neuropathy, and lymphocytic pleocytosis, is more commonly documented in Europe than North America. Here, we describe a cluster of 5 neuroinvasive LD cases with BWS in the upper Midwest United States between July and August 2017.

Manifestations of Lyme carditis

The first data of Lyme carditis, a relatively rare manifestation of Lyme disease, were published in eighties of the last century. Clinical manifestations include syncope, light-headedness, fainting, shortness of breath, palpitations, and/or chest pain. Atrioventricular (AV) electrical block of varying severity presents the most common conduction disorder in Lyme carditis. Although is usually mild, AV block can fluctuates rapidly and progress from a prolonged P-R interval to a His-Purkinje block within minutes to hours and days. Rarely, Lyme disease may be the cause of endocarditis, while some studies and reports, based on serological and/or molecular investigations, have suggested possible influence of Borrelia burgdorferi on degenerative cardiac valvular disease. Myocarditis, pericarditis, pancarditis, dilated cardiomyopathy, and heart failure have also been described as possible manifestations of Lyme carditis. The clinical course of Lyme carditis is generally mild, short term, and in most cases, completely reversible after adequate antibiotic treatment.

In vitro evaluation of antibacterial activity of phytochemicals and micronutrients against Borrelia burgdorferi and Borrelia garinii

Aims

Little is known about the effects of phytochemicals against Borrelia sp. causing Lyme disease. Current therapeutic approach to this disease is limited to antibiotics. This study examined the anti‐borreliae efficacy of several plant‐derived compounds and micronutrients.

Methods and Results

We tested the efficacy of 15 phytochemicals and micronutrients against three morphological forms of Borrelia burgdoferi and Borrelia garinii: spirochetes, latent rounded forms and biofilm. The results showed that the most potent substances against the spirochete and rounded forms of B. burgdorferi and B. garinii were cis‐2‐decenoic acid, baicalein, monolaurin and kelp (iodine); whereas, only baicalein and monolaurin revealed significant activity against the biofilm. Moreover, cis‐2‐decenoic acid, baicalein and monolaurin did not cause statistically significant cytotoxicity to human HepG2 cells up to 125 μg ml⁻¹ and kelp up to 20 μg ml⁻¹.

Conclusions

The most effective antimicrobial compounds against all morphological forms of the two tested Borrelia sp. were baicalein and monolaurin. This might indicate that the presence of fatty acid and phenyl groups is important for comprehensive antibacterial activity.

Significance and Impact of the Study

This study reveals the potential of phytochemicals as an important tool in the fight against the species of Borrelia causing Lyme disease.

Comparison of synganglion neuropeptides, neuropeptide receptors and neurotransmitter receptors and their gene expression in response to feeding in Ixodes scapularis (Ixodidae) vs. Ornithodoros turicata (Argasidae)

Illumina GAII high-throughput sequencing was used to compare expressed genes for female synganglion neuropeptides, neuropeptide receptors and neurotransmitter receptors of the soft tick Ornithodoros turicata with the hard tick Ixodes scapularis. Gene ontology molecular level three mapping revealed no significant differences amongst the same categories represented in O. turicata and I. scapularis. Transcripts predicting 22 neuropeptides or their receptors in the O. turicata synganglion were similar to annotations for 23 neuropeptides or receptors previously identified from I scapularis, with minor exceptions. A transcript predicting ecdysis triggering hormone receptor was identified in O. turicata; transcripts encoding for proprotein convertase and glycoprotein B were identified in both species. Transcripts predicting the same neurotransmitter receptors were found in the synganglion of both species. Gene expression of the transcripts showed numerous differences in response to feeding. Major differences were observed in expression of genes believed important in regulating slow vs. rapid feeding, blood water elimination, cuticle synthesis plasticity and in signalling reproductive activity. Although the glutamate receptor was strongly upregulated in both species, the gamma aminobutyric acid receptor, which inhibits glutamate, was upregulated significantly only in I. scapularis. These differences are consistent with the slow vs. rapid action of the pharyngeal pump in the two species.

Application of Nanotrap technology for high sensitivity measurement of urinary outer surface protein A carboxyl-terminus domain in early stage Lyme borreliosis

OBJECTIVES

Prompt antibiotic treatment of early stage Lyme borreliosis (LB) prevents progression to severe multisystem disease. There is a clinical need to improve the diagnostic specificity of early stage Lyme assays in the period prior to the mounting of a robust serology response. Using a novel analyte harvesting nanotechnology, Nanotrap particles, we evaluated urinary Borrelia Outer surface protein A (OspA) C-terminus peptide in early stage LB before and after treatment, and in patients suspected of late stage disseminated LB.

METHOD

We employed Nanotrap particles to concentrate urinary OspA and used a highly specific anti-OspA monoclonal antibody (mAb) as a detector of the C-terminus peptides. We mapped the mAb epitope to a narrow specific OspA C-terminal domain OspA236-239 conserved across infectious Borrelia species but with no homology to human proteins and no cross-reactivity with relevant viral and non-Borrelia bacterial proteins. 268 urine samples from patients being evaluated for all categories of LB were collected in a LB endemic area. The urinary OspA assay, blinded to outcome, utilized Nanotrap particle pre-processing, western blotting to evaluate the OspA molecular size, and OspA peptide competition for confirmation.

RESULTS

OspA test characteristics: sensitivity 1.7 pg/mL (lowest limit of detection), % coefficient of variation (CV) = 8 %, dynamic range 1.7-30 pg/mL. Pre-treatment, 24/24 newly diagnosed patients with an erythema migrans (EM) rash were positive for urinary OspA while false positives for asymptomatic patients were 0/117 (Chi squared p < 10(-6)). For 10 patients who exhibited persistence of the EM rash during the course of antibiotic therapy, 10/10 were positive for urinary OspA. Urinary OspA of 8/8 patients switched from detectable to undetectable following symptom resolution post-treatment. Specificity of the urinary OspA test for the clinical symptoms was 40/40. Specificity of the urinary OspA antigen test for later serology outcome was 87.5 % (21 urinary OspA positive/24 serology positive, Chi squared p = 4.072e(-15)). 41 of 100 patients under surveillance for persistent LB in an endemic area were positive for urinary OspA protein.

CONCLUSIONS

OspA urinary shedding was strongly linked to concurrent active symptoms (e.g. EM rash and arthritis), while resolution of these symptoms after therapy correlated with urinary conversion to OspA negative.

Lyme Disease Presenting as a Spontaneous Knee Effusion

Musculoskeletal complaints, which are frequently associated with Lyme disease, often prompt patients to see a physician. In particular, transient episodes of spontaneous knee effusion are common early in the progression of Lyme disease, and, if left untreated, 60% of patients diagnosed with the disease develop Lyme arthritis. This disease is easily treated with antibiotics; therefore, inclusion of Lyme disease in the differential diagnosis as a potential cause of a spontaneous knee effusion can prevent the development of more severe symptoms associated with the disease. However, the time required to receive test results and the inconsistencies between serum and synovial tests can complicate diagnosis of the disease.

Cerebrospinal Fluid Cytology of Lyme Neuroborreliosis: A Report of 3 Cases with Literature Review

Lyme disease can affect the central nervous system causing a B-cell-predominant lymphocytic pleocytosis. Since most reactions to infection in the cerebrospinal fluid (CSF) are typically T-cell predominant, a B-cell-predominant lymphocytosis raises concern for lymphoma. We present 3 Lyme neuroborreliosis cases in order to illustrate the challenging cytomorphological and immunophenotypic features of their CSF specimens. Three male patients who presented with central nervous system manifestations were diagnosed with Lyme disease. The clinical presentation, laboratory tests, CSF cytological examination and flow-cytometric studies were described for each case. CSF cytology showed lymphocytic pleocytosis with increased plasmacytoid cells and/or plasma cells. Flow cytometry showed the presence of polytypic B lymphocytes with evidence of plasmacytic differentiation in 2 cases. In all cases, Lyme disease was confirmed by the Lyme screening test and Western blotting. In such cases of Lyme neuroborreliosis, flow cytometry of CSF samples employing plasmacytic markers and cytoplasmic light-chain analysis is diagnostically helpful to exclude lymphoma.

Longistatin in tick saliva blocks advanced glycation end-product receptor activation

Ticks are notorious hematophagous ectoparasites and vectors of many deadly pathogens. As an effective vector, ticks must break the strong barrier provided by the skin of their host during feeding, and their saliva contains a complex mixture of bioactive molecules that paralyze host defenses. The receptor for advanced glycation end products (RAGE) mediates immune cell activation at inflammatory sites and is constitutively and highly expressed in skin. Here, we demonstrate that longistatin secreted with saliva of the tick Haemaphysalis longicornis binds RAGE and modulates the host immune response. Similar to other RAGE ligands, longistatin specifically bound the RAGE V domain, and stimulated cultured HUVECs adhered to a longistatin-coated surface; this binding was dramatically inhibited by soluble RAGE or RAGE siRNA. Treatment of HUVECs with longistatin prior to stimulation substantially attenuated cellular oxidative stress and prevented NF-κB translocation, thereby reducing adhesion molecule and cytokine production. Recombinant longistatin inhibited RAGE-mediated migration of mouse peritoneal resident cells (mPRCs) and ameliorated inflammation in mouse footpad edema and pneumonia models. Importantly, tick bite upregulated RAGE ligands in skin, and endogenous longistatin attenuated RAGE-mediated inflammation during tick feeding. Our results suggest that longistatin is a RAGE antagonist that suppresses tick bite-associated inflammation, allowing successful blood-meal acquisition from hosts.

Bacterial heterogeneity is a requirement for host superinfection by the Lyme disease spirochete

In nature, mixed Borrelia burgdorferi infections are common and possibly can be acquired by either superinfection or coinfection. Superinfection by heterologous B. burgdorferi strains has been established experimentally, although the ability of homologous B. burgdorferi clones to superinfect a host has not been studied in detail. Information regarding any potential immune barriers to secondary infection also currently is unavailable. In the present study, the ability to superinfect various mouse models by homologous wild-type clones was examined and compared to superinfection by heterologous strains. To assess the ability of homologous B. burgdorferi clones to successfully superinfect a mouse host, primary- and secondary-infecting spirochetes were recovered via in vitro cultivation of collected blood or tissue samples. This was accomplished by generating two different antibiotic-resistant versions of the wild-type B31-A3 clone in order to distinguish superinfecting B. burgdorferi from primary-infecting spirochetes. The data demonstrate an inability of homologous B. burgdorferi to superinfect immunocompetent mice as opposed to heterologous strains. Attempts to superinfect different types of immunodeficient mice with homologous B. burgdorferi indicate that the murine innate immune system represents a major barrier to intrastrain superinfection. Consequently, the possibility of innate immunity as a driving force for B. burgdorferi heterogeneity during the enzootic cycle is discussed.

Transcriptome of the female synganglion of the black-legged tick Ixodes scapularis (Acari: Ixodidae) with comparison between Illumina and 454 systems

Illumina and 454 pyrosequencing were used to characterize genes from the synganglion of female Ixodes scapularis. GO term searching success for biological processes was similar for samples sequenced by both methods. However, for molecular processes, it was more successful for the Illumina samples than for 454 samples. Functional assignments of transcripts predicting neuropeptides, neuropeptide receptors, neurotransmitter receptors and other genes of interest was done, supported by strong e-values (<-6), and high consensus sequence alignments. Transcripts predicting 15 putative neuropeptide prepropeptides ((allatostatin, allatotropin, bursicon α, corticotropin releasing factor (CRF), CRF-binding protein, eclosion hormone, FMRFamide, glycoprotein A, insulin-like peptide, ion transport peptide, myoinhibitory peptide, inotocin ( =  neurophysin-oxytocin), Neuropeptide F, sulfakinin and SIFamide)) and transcripts predicting receptors for 14 neuropeptides (allatostatin, calcitonin, cardioacceleratory peptide, corazonin, CRF, eclosion hormone, gonadotropin-releasing hormone/AKH-like, insulin-like peptide, neuropeptide F, proctolin, pyrokinin, SIFamide, sulfakinin and tachykinin) are reported. Similar to Dermacentor variabilis, we found transcripts matching pro-protein convertase, essential for converting neuropeptide hormones to their mature form. Additionally, transcripts predicting 6 neurotransmitter/neuromodulator receptors (acetylcholine, GABA, dopamine, glutamate, octopamine and serotonin) and 3 neurotransmitter transporters (GABA transporter, noradrenalin-norepinephrine transporter and Na+-neurotransmitter/symporter) are described. Further, we found transcripts predicting genes for pheromone odorant receptor, gustatory receptor, novel GPCR messages, ecdysone nuclear receptor, JH esterase binding protein, steroidogenic activating protein, chitin synthase, chitinase, and other genes of interest. Also found were transcripts predicting genes for spermatogenesis-associated protein, major sperm protein, spermidine oxidase and spermidine synthase, genes not normally expressed in the female CNS of other invertebrates. The diversity of messages predicting important genes identified in this study offers a valuable resource useful for understanding how the tick synganglion regulates important physiological functions.

Geographical and genospecies distribution of Borrelia burgdorferi sensu lato DNA detected in humans in the USA

The present study investigated the cause of illness in human patients primarily in the southern USA with suspected Lyme disease based on erythema migrans-like skin lesions and/or symptoms consistent with early localized or late disseminated Lyme borreliosis. The study also included some patients from other states throughout the USA. Several PCR assays specific for either members of the genus Borrelia or only for Lyme group Borrelia spp. (Borrelia burgdorferi sensu lato), and DNA sequence analysis, were used to identify Borrelia spp. DNA in blood and skin biopsy samples from human patients. B. burgdorferi sensu lato DNA was found in both blood and skin biopsy samples from patients residing in the southern states and elsewhere in the USA, but no evidence of DNA from other Borrelia spp. was detected. Based on phylogenetic analysis of partial flagellin (flaB) gene sequences, strains that clustered separately with B. burgdorferi sensu stricto, Borrelia americana or Borrelia andersonii were associated with Lyme disease-like signs and symptoms in patients from the southern states, as well as from some other areas of the country. Strains most similar to B. burgdorferi sensu stricto and B. americana were found most commonly and appeared to be widely distributed among patients residing throughout the USA. The study findings suggest that human cases of Lyme disease in the southern USA may be more common than previously recognized and may also be caused by more than one species of B. burgdorferi sensu lato. This study provides further evidence that B. burgdorferi sensu stricto is not the only species associated with signs and/or symptoms consistent with Lyme borreliosis in the USA.

The Impact of Three Genospecies of Borrelia on Expression of Genes Associated with Chemokines and Their Receptors in Normal Human Dermal Fibroblasts in Vitro

An important role in pathomechanism of Lyme disease is played by the ability of spirochetes to spread within tissues, and to adhere (to platelets, erythrocytes and vascular epithelium). The principal factors regulating that process are chemokines, cytokines and adhesion particles. The aim of this study was to select genes related to the chemokines and their receptors, differentiating the type of infection in the system model, i.e. a culture of normal human diploid fibroblasts infected with three different spirochete genospecies: B. afzelii, B. garinii and B. burgdorferii sensu stricto, by comparing the infected fibroblast culture with that of the control fibroblast. The differences in the expression of genes selected on the basis of a scientific database Affymetrix were analysed by comparing transcriptomes from the four cultures of fibroblasts, using the oligonucleotide microarrays HG_U133A. In the result of infection of fibroblast cultivation with a specific Borrelia genospecies, a variable expression of the chemokines and their receptors, specific for one genospecies was observed. The fibroblast infected with B. afzelii expressed CCL4, CCL1, CCL2 and CCR10; with B. garinii - CXCL12, IL6, CCR3 and CXCR5; and with B. burgorferii sensu stricto - CCL5, CCR1, CCL3, CCL16, CXCR6, IL8, CXCR7 and CXCR3.

Lyme arthritis in Southern Norway--an endemic area for Lyme borreliosis

Background

Despite Southern Norway is an endemic area for Lyme borreliosis there is a lack of data on Lyme arthritis (LA). In the literature controversies exist if acute LA can develop into chronic arthritis. Our objective was to identify and characterize patients with LA in Southern Norway and explore disease course after antibiotic treatment.

Methods

Patients aged 20 years or older with arthritis and a positive serology for Borrelia burgdorferi infection (IgG and/or IgM) suspected of having LA were consecutively recruited either from general practitioners or from hospital departments.

Results

From January 2007 to December 2010 a total of 27 patients were assessed. Mean (range) age was 56 years (41–80) and mean symptom duration prior to inclusion was 11.2 weeks (1 day – 2 years). Definite LA was diagnosed in 16 patients, probable LA in 5 patients and 6 patients were concluded to have other arthritis disorders. Among the 21 LA patients 20 had mono-arthritis (knee 18, ankle 2) and 1 had polyarthritis.

All LA patients responded favourable to antibiotic treatment and none of the patients developed chronic arthritis after long term follow up, not even in LA patients who had intraarticular glucocorticosteroid (GC) injection prior to antibiotic treatment.

Conclusions

Our data shows that LA in Southern Norway is a benign disease which successfully can be treated with antibiotics even in patients treated with GC prior to antibiotics.