Structural determination of the complement inhibitory domain of Borrelia burgdorferi BBK32 provides insight into classical pathway complement evasion by Lyme disease spirochetes.

The carboxy-terminal domain of the BBK32 protein from Borrelia burgdorferi sensu stricto, termed BBK32-C, binds and inhibits the initiating serine protease of the human classical complement pathway, C1r. In this study we investigated the function of BBK32 orthologues of the Lyme-associated Borrelia burgdorferi sensu lato complex, designated BAD16 from B. afzelii strain PGau and BGD19 from B. garinii strain IP90. Our data show that B. afzelii BAD16-C exhibits BBK32-C-like activities in all assays tested, including high-affinity binding to purified C1r protease and C1 complex, and potent inhibition of the classical complement pathway. Recombinant B. garinii BGD19-C also bound C1 and C1r with high-affinity yet exhibited significantly reduced in vitro complement inhibitory activities relative to BBK32-C or BAD16-C. Interestingly, natively produced BGD19 weakly recognized C1r relative to BBK32 and BAD16 and, unlike these proteins, BGD19 did not confer significant protection from serum killing. Site-directed mutagenesis was performed to convert BBK32-C to resemble BGD19-C at three residue positions that are identical between BBK32 and BAD16 but different in BGD19. The resulting chimeric protein was designated BXK32-C and this BBK32-C variant mimicked the properties observed for BGD19-C. To query the disparate complement inhibitory activities of BBK32 orthologues, the crystal structure of BBK32-C was solved to 1.7Å limiting resolution. BBK32-C adopts an anti-parallel four-helix bundle fold with a fifth alpha-helix protruding from the helical core. The structure revealed that the three residues targeted in the BXK32-C chimera are surface-exposed, further supporting their potential relevance in C1r binding and inhibition. Additional binding assays showed that BBK32-C only recognized C1r fragments containing the serine protease domain. The structure-function studies reported here improve our understanding of how BBK32 recognizes and inhibits C1r and provide new insight into complement evasion mechanisms of Lyme-associated spirochetes of the B. burgdorferi sensu lato complex.

Epidemiology of Lyme Disease in a Highly Endemic European Zone.

Background and objective: Lyme disease, also known as Lyme borreliosis (LB), is a tick-borne infectious disease caused by the spirochete bacteria Borrelia. The risk of infection depends on the geographical area, ecological factors, and human behavior. Clinical manifestations of Lyme borreliosis have a wide range, but the most frequent clinical symptom, which is also a diagnostic symptom, is a skin rash called erythema migrans (EM). The disease is very common worldwide. In Lithuania, the disease frequency is 99.9 cases per 100,000 population (Centre for Communicable Diseases and AIDS, Lithuania, 2017). The main aim of this study was to obtain the baseline characteristics of the disease regarding the infected Lithuanian population. Materials and Methods: We analyzed data from the Centre for Communicable Diseases and AIDS about all Lyme disease (A69.2) diagnosed patients over a three-year period (from 2014 to 2016) in Lithuania. Results: In 2014-2016, 7424 (crude incidence rate 85.4) cases with LB were diagnosed in Lithuania. Most of them (4633 (62.4%)) were identified in women. Older people were more likely to suffer from LB. Urban residents were 2.6 times more often affected that those living in villages. Tick bites were primarily observed in high season months, from May to September (90%), with the highest peak in July. There was a higher number of observed tick bites (p = 0.003) in the urban residents. Erythema migrans occurred in 75.6% LB cases, while other symptoms did not exceed a quarter of all LB cases. There were 7353 (99.6%) cases where LB was confirmed via clinical symptoms and/or laboratory tests. Also, 1720 (23.2%) patients were tested for LB immunoglobulins. Conclusions: This study found a high incidence of Lyme disease in Lithuania. We elucidated the baseline characteristics regarding the infected Lithuanian population which may ease medical clinicians' work on new Lyme diagnoses.

Clinical spectrum of Lyme disease.

Lyme disease (borreliosis) is one of the most common vector-borne diseases worldwide. Its incidence and geographic expansion has been steadily increasing in the last decades. Lyme disease is caused by Borrelia burgdorferi sensu lato, a heterogeneous group of which three genospecies have been systematically associated to Lyme disease: B. burgdorferi sensu stricto Borrelia afzelii and Borrelia garinii. Geographical distribution and clinical manifestations vary according to the species involved. Lyme disease clinical manifestations may be divided into three stages. Early localized stage is characterized by erythema migrans in the tick bite site. Early disseminated stage may present multiple erythema migrans lesions, borrelial lymphocytoma, lyme neuroborreliosis, carditis, or arthritis. The late disseminated stage manifests with acordermatitis chronica atrophicans, lyme arthritis, and neurological symptoms. Diagnosis is challenging due to the varied clinical manifestations it may present and usually involves a two-step serological approach. In the current review, we present a thorough revision of the clinical manifestations Lyme disease may present. Additionally, history, microbiology, diagnosis, post-treatment Lyme disease syndrome, treatment, and prognosis are discussed.

A tick beat in the electrocardiogram: Persistent third degree block as only manifestation of Lyme disease.

Lyme disease is the most common tick-borne illness in North America. A 23-year-old female presented to our emergency department with a chief complaint of sudden dyspnea and chest pain. An electrocardiogram revealed a third degree heart block. She was a resident of the Northeast region of Mexico and referred a recent travel to an endemic area for Borrelia burgdorferi in the center of Mexico in the past weeks. Lyme carditis was diagnosed after enzyme linked immunosorbent assay for IgM antibodies against B. burgdorferi was reported positive and corroborated by a confirmatory immunoblot analysis. Persistent AV block was the only manifestation in our patient, a presentation scarcely reported in literature.

Analysis of cases of Lyme arthritis in patients hospitalized in Infectious Diseases Department, University Hospital in Cracow.

Lyme disease is an emerging problem in Poland. Analysis has been undertaken of the medical documentation of 86 patients hospitalized in the Infectious Diseases Department, University Hospital in Cracow in 2013-2016, suspected of Lyme arthritis. It has especially considered medical history including potential exposure to the infection, detailed characteristics of the symptoms, diagnostic challenges and results of the treatment. Only some patients had a history of erythema migrans and not all of them recalled tick-bite. The majority of the patients had affected large joints, especially knee joints, and polyarthritis was rarely observed. Symptoms were resolved completely or partially after antibiotic treatment in most patients. The diagnosis of Lyme arthritis in areas endemic for Lyme disease is still a diagnostic challenge in patients with other rheumatic diseases, including osteoarthritis.

Borrelia Host Adaptation Protein (BadP) Is Required for the Colonization of a Mammalian Host by the Agent of Lyme Disease.

Borrelia burgdorferi, the agent of Lyme disease (LD), uses host-derived signals to modulate gene expression during the vector and mammalian phases of infection. Microarray analysis of mutants lacking the Borrelia host adaptation regulator (BadR) revealed the downregulation of genes encoding enzymes whose role in the pathophysiology of B. burgdorferi is unknown. Immunoblot analysis of the badR mutants confirmed reduced levels of these enzymes, and one of these enzymes, encoded by bb0086, shares homology to prokaryotic magnesium chelatase and Lon-type proteases. The BB0086 levels in B. burgdorferi were higher under conditions mimicking those in fed ticks. Mutants lacking bb0086 had no apparent in vitro growth defect but were incapable of colonizing immunocompetent C3H/HeN or immunodeficient SCID mice. Immunoblot analysis revealed reduced levels of proteins critical for the adaptation of B. burgdorferi to the mammalian host, such as OspC, DbpA, and BBK32. Both RpoS and BosR, key regulators of gene expression in B. burgdorferi, were downregulated in the bb0086 mutants. Therefore, we designated BB0086 the Borrelia host adaptation protein (BadP). Unlike badP mutants, the control strains established infection in C3H/HeN mice at 4 days postinfection, indicating an early colonization defect in mutants due to reduced levels of the lipoproteins/regulators critical for initial stages of infection. However, badP mutants survived within dialysis membrane chambers (DMCs) implanted within the rat peritoneal cavity but, unlike the control strains, did not display complete switching of OspA to OspC, suggesting incomplete adaptation to the mammalian phase of infection. These findings have opened a novel regulatory mechanism which impacts the virulence potential of Bburgdorferi.

Chronic Inflammatory Response Syndrome and the Lyme Patient.

No Abstract Available.

Lyme Disease: Emergency Department Considerations.

BACKGROUND: Lyme disease (LD) is the most common vector-borne illness in North America. Reported cases of LD have increased from approximately 10,000 cases annually in 1991 to >25,000 cases in 2014. Greater recognition, enhanced surveillance, and public education have contributed to the increased prevalence, as have geographic expansion and the number of infected ticks. Cases are reported primarily in the Northeastern United States, Wisconsin, and Minnesota, with children having the highest incidence of LD among all age groups. The increased incidence and prevalence of LD in the United States makes it increasingly more common for patients to present to the emergency department (ED) for tick bites and LD-related chief complaints, such as the characteristic erythema migrans skin manifestation. OBJECTIVE: We sought to review the etiology of LD, describe its clinical presentations and sequela, and provide a practical classification and approach to ED management of patients with LD-related presentations. DISCUSSION: In this review, ED considerations for LD are presented and clinical presentations and management of the disease at different stages is discussed. Delayed sequelae that have significant morbidity, including Lyme carditis and Lyme neuroborreliosis, are discussed. Diagnostic tests and management are described in detail. CONCLUSION: The increasing prevalence and growing geographic reach of Lyme disease makes it critically important for emergency physicians to consider the diagnosis in patients presenting with symptoms suggestive of LD and to initiate appropriate treatment to minimize the potential of delayed sequelae. Special consideration should be made for the epidemiology of LD and a high clinical suspicion should be present for patients in endemic areas or with known exposures to ticks. Emergency physicians can play a critical role in the recognition, diagnosis, and treatment of LD.

[Clinical presentation of Ixodes tick-borne borreliosis caused by Borrelia miyamotoi in the context of an immune response to the pathogen]. / Klinicheskie proiavleniia iksodovogo kleshchevogo borrelioza, vyzvannogo Borrelia miyamotoi, v kontekste immunnogo otveta na vozbuditel'.

Ixodes tick-borne borreliosis caused by Borrelia miyamotoi (ITBB-BM) is a previously unknown infectious disease discovered in Russia. AIM: The present study continues the investigation of the clinical features of ITBB-BM in the context of an immune system-pathogen interaction. SUBJECTS AND METHODS: The study enrolled 117 patients with ITBB-BM and a comparison group of 71 patients with Lyme disease (LD) that is ITBB with erythema migrans. All the patients were treated at the New Hospital, Yekateringburg. More than 100 clinical, epidemiological and laboratory parameters were obtained from each patient's medical history and included in the general database. A subset of patients hospitalized in 2015 and 2016 underwent additional laboratory examinations. Namely, the levels of B. miyamotoi-specific IgM and IgG antibodies were measured by the protein microarray containing GlpQ protein and four variable major proteins (VMPs): Vlp15/16, Vlp18, Vsp1, and Vlp5. The blood concentration of Borrelia was estimated by quantitative real-time PCR. RESULTS: In contrast to LD, first of all (p<0.001) the following clinical features were typical for ITBB-BM: the absence of erythema migrans (in 95% of patients), fever (93%), fatigue (96%), headache (82%), chill (41%), nausea (28%), lymphopenia (56%), thrombocytopenia (46%), the abnormal levels of alanine aminotransferase (54%) and C-reactive protein (98%), proteinuria (61%). Given the set of these indicators, the course of ITBB-BM was more severe in approximately 70% of patients. At admission, only 13% and 38% of patients had antibodies to GlpQ and VMPs, respectively; at discharge, antibodies to GlpQ and VMPs were detected in 88% of patients. There was no statistically significant association of the antibody response with individual clinical manifestations and laboratory parameters of the disease. However, patients with more severe ITBB-BM produced less IgM antibodies to VMPs and GlpQ at the time of discharge. CONCLUSION: ITBB-BM is a moderate systemic disease accompanied by the production of specific antibodies in virtually all patients.

Influence of tick and mammalian physiological temperatures on Borrelia burgdorferi biofilms.

The spirochaete bacterium Borrelia burgdorferisensu lato is the aetiologic agent of Lyme disease. Borrelia is transmitted to mammals through tick bite and is adapted to survive at tick and mammalian physiological temperatures. We have previously shown that B. burgdorferi can exist in different morphological forms, including the antibiotic-resistant biofilm form, in vitro and in vivo. B. burgdorferi forms aggregates in ticks as well as in humans, indicating potential of biofilm formation at both 23 and 37 °C. However, the role of various environmental factors that influence Borrelia biofilm formation remains unknown. In this study, we investigated the effect of tick (23 °C), mammalian physiological (37 °C) and standard in vitro culture (33 °C) temperatures with the objective of elucidating the effect of temperature on Borrelia biofilm phenotypes invitro using two B. burgdorferisensu stricto strains (B31 and 297). Our findings show increased biofilm quantity, biofilm size, exopolysaccharide content and enhanced adherence as well as reduced free spirochaetes at 37 °C for both strains, when compared to growth at 23 and 33 °C. There were no significant variations in the biofilm nano-topography and the type of extracellular polymeric substance in Borrelia biofilms formed at all three temperatures. Significant variations in extracellular DNA content were observed in the biofilms of both strains cultured at the three temperatures. Our results indicate that temperature is an important regulator of Borrelia biofilm development, and that the mammalian physiological temperature favours increased biofilm formation in vitro compared to tick physiological temperature and in vitro culture temperature.

5-hydroxytryptamine and Lyme disease. Opportunity for a novel therapy to reduce the cerebellar tremor?

Lyme boreliosis is caused by the spirochete Borrelia burdorferi, which is transmitted by ticks. A 59 year-old woman developed pyrexia, strong headaches, ataxia, dysarthria and tremor of the limbs after a tick bite. She was unable to work and eat on her own. She was hospitalized three times and diagnosed with cerebellar intention tremor, cerebellar ataxia, dysarthria, bilateral horizontal gaze paralysis and a central lesion of the left facial nerve. There were no pyramidal, sensory or psychiatric disturbances. The brain MRI showed multifocal leucoencephalopathy with many hyperintense areas in both hemispheres, as well as in the left superior pedunculus cerebellaris. Diagnosis was confirmed by serologic examination. Treatment with cephtriaxone, doxycycline, methylprednisolone, cephixime and ciprofloxacine was administered without effect on the tremor, ataxia and horizontal gaze paralysis. Treatment was then administered with 5-hydroxytriptamine (5-HT) in increased doses. The result of the three-month treatment with 5-HT was a gradual diminution of the tremor and the ataxia and an increase in the ability to eat, walk and work independently.

[Lyme disease--clinical manifestations and treatment]. / Lyme-Borreliose.

Lyme disease (Lyme borreliosis) is a systemic infectious disease that can present in a variety of clinical manifestations. The disease is caused by a group of spirochaetes--Borrelia burgdorferi sensu lato or Lyme borrelia--that are transmitted to humans by the bite of Ixodes ticks. Lyme disease is the most common arthropode-borne infectious disease in many European countries including Germany. Early localized infection is typically manifested by an erythema migrans skin lesion, in rarer cases as a borrelial lymphocytoma. The most common early disseminated manifestation is (early) neuroborreliosis. In adults, neuroborreliosis appears typically as meningoradiculoneuritis. Neuroborreliosis in children, however, is typically manifested by meningitis. In addition, multiple erythema migrans lesions and Lyme carditis occur relatively frequently. The most common manifestation oflate Lyme disease is Lyme arthritis. Early manifestations (and usually also late manifestations) of Lyme disease can be treated successfully by application of suitable antibacterial agents. For the treatment of Lyme disease, doxycycline, certain penicillins such as amoxicillin and some cephalosporins (ceftriaxone, cefotaxime, cefuroxime axetil) are recommended in current guidelines. A major challenge is the treatment of chronic, non-specific disorders, i. e., posttreatment Lyme disease syndrome and "chronic Lyme disease". Prevention of Lyme disease is mainly accomplished by protecting against tick bites. Prophylactic administration of doxycycline after tick bites is generally not recommended in Germany. There is no vaccine available for human beings.

Association of immune response to endothelial cell growth factor with early disseminated and late manifestations of Lyme disease but not posttreatment Lyme disease syndrome.

Endothelial cell growth factor has been recently proposed as a potential autoantigen in manifestations of Lyme disease that are thought to involve immune-mediated mechanisms. Our findings indicate that a humoral immune response to this protein is not associated with posttreatment Lyme disease syndrome.

Variability in results from negative binomial models for Lyme disease measured at different spatial scales.

Lyme disease has been the subject of many studies due to increasing incidence rates year after year and the severe complications that can arise in later stages of the disease. Negative binomial models have been used to model Lyme disease in the past with some success. However, there has been little focus on the reliability and consistency of these models when they are used to study Lyme disease at multiple spatial scales. This study seeks to explore how sensitive/consistent negative binomial models are when they are used to study Lyme disease at different spatial scales (at the regional and sub-regional levels). The study area includes the thirteen states in the Northeastern United States with the highest Lyme disease incidence during the 2002-2006 period. Lyme disease incidence at county level for the period of 2002-2006 was linked with several previously identified key landscape and climatic variables in a negative binomial regression model for the Northeastern region and two smaller sub-regions (the New England sub-region and the Mid-Atlantic sub-region). This study found that negative binomial models, indeed, were sensitive/inconsistent when used at different spatial scales. We discuss various plausible explanations for such behavior of negative binomial models. Further investigation of the inconsistency and sensitivity of negative binomial models when used at different spatial scales is important for not only future Lyme disease studies and Lyme disease risk assessment/management but any study that requires use of this model type in a spatial context.

The burden of Lyme borreliosis expressed in disability-adjusted life years.

BACKGROUND: Lyme borreliosis (LB) is the most commonly reported tick-borne infection in Europe and North America. In the last 15 years a 3-fold increase was observed in general practitioner consultations for LB in the Netherlands. To support prioritization of prevention and control efforts for LB, we estimated its burden expressed in Disability-Adjusted Life Years (DALYs). METHODS: We used available incidence estimates for three LB outcomes: (i) erythema migrans (EM), (ii) disseminated LB and (iii) Lyme-related persisting symptoms. To generate DALYs, disability weights and duration per outcome were derived using a patient questionnaire including health-related quality of life as measured by the EQ-5D. RESULTS: We estimated the total LB burden for the Netherlands in 2010 at 10.55 DALYs per 100,000 population (95% CI: 8.80-12.43); i.e. 0.60 DALYs for EM, 0.86 DALYs for disseminated LB and 9.09 DALYs for Lyme-related persisting symptoms. Per patient this was 0.005 DALYs for EM, 0.113 for disseminated LB and 1.661 DALYs for a patient with Lyme-related persisting symptoms. In a sensitivity analysis the total LB burden ranged from 7.58 to 16.93 DALYs per 100,000 population. CONCLUSIONS: LB causes a substantial disease burden in the Netherlands. The vast majority of this burden is caused by patients with Lyme-related persisting symptoms. EM and disseminated Lyme have a more modest impact. Further research should focus on the mechanisms that trigger development of these persisting symptoms that patients and their physicians attribute to LB.

Provider knowledge, attitudes, and practices regarding Lyme disease in Arkansas.

Lyme disease (LD), a vector-borne disease, causes illness for many individuals in the United States. All of the conditions for the promulgation of LD are present in one Southern state in the United States; yet this state reports lower numbers of LD than adjacent states. The purpose of this study was to determine associations between this Southern state's primary care providers' knowledge and attitudes regarding the diagnosis and reporting of LD. A quantitative, cross-sectional study was conducted via a mailed questionnaire by the Arkansas Department of Health to 2,693 primary care providers. Respondents were 660 primary care providers from all regions of this state. Secondary data were analyzed using descriptive, Chi square, and logistic regression techniques. Analysis results included the following: a correct response rate of 59.1 % for symptom recognition, of 46.2 % for knowledge of recommended testing processes, and of 78.9 % for knowing LD is a reportable disease. These results compared to the expected norm were significant in every area with p values of .000. Specialty, region, and years of practice were found to be confounding influences in a number of assessment areas.

Elucidation of Lyme arthritis.

Before the first description of Lyme arthritis in 1976, patients with this disease were often thought to have juvenile or adult rheumatoid arthritis. It is now known that Lyme arthritis is caused by a tick-borne spirochete that disseminates to joints, where it induces marked pro-inflammatory responses. In most patients, the arthritis resolves with antibiotic treatment. However, in the United States, about 10% of patients with Lyme arthritis develop persistent synovitis, which lasts for months or even several years after the apparent eradication of the spirochete from the joint with antibiotic therapy. The elucidation of Lyme arthritis, from acute infection to chronic synovitis, might help in our understanding not only of this entity, but also of other forms of chronic inflammatory arthritis, including rheumatoid arthritis.

Lyme disease presenting as multiple ischaemic strokes.

A 46-year-old man presented with recurrent left hemiparesis and headache. MRI of brain showed an acute right pontine and subacute right thalamic infarcts and MR angiogram showed multiple intracranial arterial stenoses, suggesting cerebral vasculopathy. There was a cerebrospinal fluid lymphocytic pleocytosis with Borrelia burgdorferi antibodies. Central nervous system Lyme disease occasionally presents with ischaemic strokes; this case is unusual in showing vasculopathy on brain imaging, supporting meningovasculitis as the likely mechanism.

Presence of Arp specifically contributes to joint tissue edema associated with early-onset Lyme arthritis.

Antiserum to the Borrelia burgdorferi arthritis-related protein, Arp, has been shown to prevent or reduce arthritis in immunodeficient mice. To directly investigate the requirement for this lipoprotein in the generation of Lyme arthritis, we utilized targeted deletion to generate a B. burgdorferi clone that lacked only the arp gene locus. Infection of Lyme disease-susceptible C3H/HeN mice with the arp deletion mutant demonstrated significantly reduced tibiotarsal joint swelling during the first 6 weeks of infection compared to a wild-type control. The severity of joint swelling was restored to wild-type levels in mice infected with an arp mutant clone complemented in cis. Interestingly, the reduced swelling of joint tissues exhibited by mice infected with the arp deletion mutant did not directly correspond to reduced underlying arthritis. Histopathology data at 2 weeks postinfection showed some reduction in arthritis severity caused by the arp mutant clone; however, by 8 weeks, no significant difference was observed between joint tissues infected by the wild-type or arp mutant clones. The spirochete load in the joint tissues of mice infected with the arp mutant was found to be greater than that exhibited by the wild-type control. Our findings demonstrate that this lipoprotein contributes to the generation of early-onset joint swelling and suggests that arp expression has a negative secondary effect on total spirochete numbers in joint tissues.