Epidemiological aspects and molecular characterization of Borrelia burgdorferi s.l. from southern Germany with special respect to the new species Borrelia spielmanii sp. nov

Molecular diagnosis of Borrelia bacteria for the diagnosis of Lyme disease

INTRODUCTION

Lyme borreliosis is the most common vector-borne disease in the temperate climate zone of Europe and the US, and its frequency is increasing. Serology is often negative in the early stage of Lyme borreliosis and cannot distinguish between active and past infection. Culture is cumbersome and not very sensitive, and polymerase chain reaction (PCR) for the diagnosis of Lyme borreliosis has been described over the last 20 years, with varying results.

AREAS COVERED

In this article, all of the major studies in which PCR has been used to diagnose Lyme borreliosis in humans are critically reviewed. However, this article does not include studies that consisted of fewer than 10 patients, nor does it include studies that have inadequate descriptions of the patient population.

EXPERT OPINION

There is a lack of standardized protocols, and preamplification procedures have not been standardized. Nested PCRs seem to perform best, but are prone to contamination. PCR on skin biopsies can be used to diagnose early Lyme borreliosis in patients with atypical forms of erythema migrans. PCR also has diagnostic potential in Lyme arthritis and early neuroborreliosis. Blood and urine should not used for PCR. For future development, preamplification procedures should be optimized using materials from experimentally infected animals. Multi-center studies should follow to evaluate these optimized tests.

Lyme borreliosis in dogs and cats: background, diagnosis, treatment and prevention of infections with Borrelia burgdorferi sensu stricto

Lyme borreliosis (LB), synonymous with the often-used term Lyme disease, is an infectious disease caused by the spirochetal bacterium Borrelia burgdorferi. LB is the most frequent vector-borne disease in humans in the Northern Hemisphere. In animals, clinically apparent disease is found primarily in dogs. Severe polyarthritis, fever and lameness in dogs are reported from the main endemic areas of North America: the New England States, and eastern parts of the United States; several cases of LB are also seen in California and the Midwest. Because of the difficulties in finding sufficient indicative clinical signs, additional information (detailed case history, laboratory testing for antibodies) is especially important to make the clinical diagnosis of Lyme borreliosis. This article reviews the etiology, diagnosis, therapy, and prevention of LB.

Whole genome sequence of an unusual Borrelia burgdorferi sensu lato isolate

Human Lyme disease is caused by a number of related Borrelia burgdorferi sensu lato species. We report here the complete genome sequence of Borrelia sp. isolate SV1 from Finland. This isolate is to date the closest known relative of B. burgdorferi sensu stricto, but it is sufficiently genetically distinct from that species that it and its close relatives warrant its candidacy for new-species status. We suggest that this isolate should be named "Borrelia finlandensis."

Entzündliche Erkrankungen

Unter einer Meningitis versteht man eine Entzündung von Pia mater und Arachnoidea. Das Erregerspektrum ist weit und reicht von Bakterien, die hämatogen-metastatisch, fortgeleitet oder durch offene Hirnverletzung zur eitrigen Meningitis führen, über Viren zu Pilzen und Parasiten. Insbesondere bei den unbehandelt häufig letal verlaufenden eitrigen Meningitiden ist eine rasche Diagnose mit Erregernachweis notwendig. Unverzüglich ist daraufhin eine spezifische, der regionalen Resistenzentwicklung angepasste Therapie einzuleiten. Die meningeale Affektion im Rahmen einer Listeriose oder Tuberkulose verdient aufgrund des klinischen Bildes, des Verlaufs und der spezifischen Therapie besondere Beachtung. Die fungalen Infektionen werden, da klinisch häufig als Meningoenzephalitis imponierend, in Abschn. 33.3 abgehandelt.

Complement factor H-related proteins CFHR2 and CFHR5 represent novel ligands for the infection-associated CRASP proteins of Borrelia burgdorferi

BACKGROUND

One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP) which interact with complement regulator factor H (CFH) and factor H-like protein 1 (FHL1) or factor H-related protein 1 (CFHR1). In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi.

METHODOLOGY/PRINCIPAL FINDINGS

To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement.

CONCLUSIONS/SIGNIFICANCE

In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi.

Prevalence and diversity of Borrelia species in ticks that have bitten humans in Sweden

Members of the genus Borrelia are among the most common infectious agents causing tick-borne disease in humans worldwide. Here, we developed a Light Upon eXtension (LUX) real-time PCR assay that can detect and quantify Borrelia species in ticks that have fed on humans, and we applied the assay to 399 such ticks. Borrelia PCR-positive ticks were identified to species level by sequencing the products of conventional PCR performed using Borrelia group-specific primers. There was a 19% prevalence of Borrelia spp. in the detached ticks, and the number of spirochetes per Borrelia PCR-positive tick ranged from 2.0 × 10(2) to 4.9 × 10(5), with a median of 7.8 × 10(3) spirochetes. Adult ticks had a significantly larger number of spirochetes, with a median of 8.4 × 10(3) compared to the median of nymphs of 4.4 × 10(3). [corrected] Adult ticks also exhibited a higher prevalence of Borrelia (33%) than nymphs (14%). Among the identified species, Borrelia afzelii was found to predominate (61%) and was followed by B. garinii (23%), B. valaisiana (13%), B. burgdorferi sensu stricto (1%), B. lusitaniae (1%), and B. miyamotoi-like (1%). Also, 3% of the ticks were coinfected with multiple strains of B. afzelii. Notably, this is the first report of B. lusitaniae being detected in ticks in Sweden. Our LUX real-time PCR assay proved to be more sensitive than a corresponding TaqMan assay. In conclusion, the novel LUX real-time PCR method is a rapid and sensitive tool for detection and quantification of Borrelia spp. in ticks.

Establishment of a minor groove binder-probe based quantitative real time PCR to detect Borrelia burgdorferi sensu lato and differentiation of Borrelia spielmanii by ospA-specific conventional PCR

BACKGROUND

Borrelia burgdorferi sensu lato (sl), the causative agent of Lyme borreliosis, is transmitted by ticks of the genus Ixodes as vector. For identification of Borrelia infections in ticks a TaqMan minor groove binder (MGB) probe-based quantitative real time PCR (qPCR) was established targeting the 5S-23S intergenic spacer. Extension to a duplex qPCR included an Ixodes spp. positive control to verify successful DNA isolation. Besides qPCR, an ospA-specific conventional PCR for species-specific identification of B. spielmanii was established. Afterwards 1000 I. ricinus flagged in the city of Hanover, Germany, were investigated for B. burgdorferi sl infections followed by species identification. Furthermore, I. hexagonus ticks were investigated to proof applicability of the PCRs.

RESULTS

Quantitative real time PCR (qPCR) identifying B. burgdorferi sl in ticks was able to detect 1-10 copies per reaction. B. spielmanii ospA-specific conventional PCR was also highly specific and showed no cross reactions with the other tested Borrelia species. From 1000 hanoveranian ticks 24.3% were positive compared to only 7.4% positives by dark-field microscopy. Related to tick stage 1.7% larvae, 18.1% nymphs, and 34.6% adults were positive. The most frequent species was B. garinii, followed by B. afzelii, B. spielmanii, B. valaisiana and B. burgdorferi sensu stricto (ss). 70.6% of I. ricinus were mono-infected, whereas 28.0% and 1.4% were infected with two and three Borrelia species, respectively. From 232 I. hexagonus collected from hedgehogs in different sites of Germany, qPCR detected 5.7% to be infected with B. burgdorferi sl, which were identified as B. afzelii, B. garinii and B. spielmanii.

CONCLUSIONS

The evaluated qPCR to detect B. burgdorferi sl in Ixodes spp. is highly specific and sensitive. As a duplex qPCR including detection of Ixodes spp. DNA it is the first DNA based technique incorporating a control for successful DNA isolation from the vector tick. Establishment of a B. spielmanii specific conventional PCR filled the gap in PCR identification of principal European Borrelia genospecies. Practical application showed that all European pathogenic Borrelia spp. were present in I. ricinus flagged in recreational areas of the city of Hanover and confirmed I. hexagonus as reservoir for pathogenic Borrelia spp.

Expression and sequence diversity of the complement regulating outer surface protein E in Borrelia afzelii vs. Borrelia garinii in patients with erythema migrans or neuroborreliosis

Outer surface protein E (OspE) is a complement factor H-binding virulence factor of borrelial subspecies. It is usually absent from in vitro grown Borrelia garinii, although in vivo B. garinii causes neuroborreliosis (NB). We analyzed the presence and sequence spectrum of the ospE genes in vivo in Borrelia spirochetes. DNA samples from the skin, serum and cerebrospinal fluid (CSF) of patients with infections caused by Borrelia afzelii or B. garinii were studied, and anti-OspE antibodies in the corresponding patient sera were detected by IgG ELISA using recombinant OspE as an antigen. ospE genes were found in 20 of 23 erythema migrans (EM) skin biopsies with B. afzelii, in 2 EM skin biopsies with unknown underlying subspecies, in 5 of 9 EM biopsies with B. garinii, and in 1 of 4 CSF samples of NB patients with B. garinii infection. All OspE sequences from B. garinii samples were identical. In contrast, OspE of B. afzelii origin showed more variation. Anti-OspE antibodies were found in 8/21 (38.0%) sera from patients with B. afzelii-associated EM. In conclusion, our results indicate that all borrelial subspecies, but not necessarily all strains, causing human infections can carry ospE genes to protect themselves against complement attack in vivo.

A clear and present danger: tick-borne diseases in Europe

Ticks can transmit a variety of viruses, bacteria or parasites that can cause serious infections or conditions in humans and animals. While tick-borne diseases are becoming an increasing and serious problem in Europe, tick-borne diseases are also responsible for major depressions in livestock production and mortality in sub-Saharan Africa, Latin America and Asia. This review will focus on the most important circulating tick-transmitted pathogens in Europe (Borrelia spp., Anaplasma phagocytophilum, Babesia spp., tick-borne encephalitis virus, Rickettsia spp. and Crimean-Congo hemorrhagic fever virus).

Coexistence of Borrelia spp. and Babesia spp. in Ixodes ricinus ticks in Middle Germany

Altogether, 430 nymphs and 570 adult Ixodes ricinus ticks were collected in 2006 (n = 506) and 2007 (n = 494) from a forest area in Middle Germany (Thuringia). Single ticks were investigated by polymerase chain reaction and restriction fragment length polymorphism or sequencing for Borrelia spp. (ospA gene) and Babesia spp. (18S rRNA gene). Overall, 27.0% (270/1000) were infected with Borrelia species. Out of these, Borrelia garinii was detected most frequently (133/270)-especially, OspA serotype 6 (51/270), followed by Bo. burgdorferi (70/270), Bo. afzelii (42/270), Bo. valaisiana subgroup I (28/270), not typable Borrelia spp. (5/270), Bo. spielmanii (3/270), Bo. valaisiana subgroup II (2/270), and Bo. lusitaniae (1/270). In 1.4% of investigated ticks mixed infections with several Borrelia spp. occurred. Babesia spp.-specific DNA was detected in 5.0% of ticks. Babesia microti was slightly more prevalent (28/50) than Babesia divergens (20/50). Moreover, 5.9% (16/270) of Borrelia spp.-infected ticks were coinfected with Babesia spp. Knowledge on the degree of heterogeneity of Borrelia species and OspA types is prerequisite not only for local risk assessment, but also for diagnostic test and vaccine development.

Prevalence and seasonality of tick-borne pathogens in questing Ixodes ricinus ticks from Luxembourg

In Europe, ixodid ticks are important arthropod vectors of human and animal pathogens, but comprehensive studies of the prevalence of all relevant pathogens in Central Europe are scarce. As a result of ecological changes, the incidences of tick-borne infections are expected to increase. In this study, 1,394 nymphal and adult Ixodes ricinus ticks sampled monthly during the active season from 33 ecologically distinct collection sites throughout Luxembourg were screened for all human tick-borne pathogens relevant in Central Europe. Species were identified by sequence analysis of detection PCR amplicons. Mean infection rates of ticks were 11.3% for Borrelia burgdorferi sensu lato, 5.1% for Rickettsia sp., 2.7% for Babesia sp., and 1.9% for Anaplasma phagocytophilum. No tick was found to be infected with Coxiella sp., Francisella tularensis subsp., or Tick-borne encephalitis virus (TBEV). A total of 3.2% of ticks were infected with more than one pathogen species, including mixed Borrelia infections (1.5%). Seasonal variations of tick infection rates were observed for Borrelia, Babesia, and Anaplasma, possibly reflecting a behavioral adaptation strategy of questing ticks. A positive correlation between the grade of urbanization and Borrelia infection rate of ticks was observed, suggesting an established urban zoonotic cycle. We also found Hepatozoon canis (0.1%) and Bartonella henselae (0.3%), which so far have not been found in questing Ixodes ricinus ticks in Central Europe.

[Pandora's Box: pathogens in Ixodes ricinus ticks in Central Europe]

Among the various species of hard ticks, Ixodes ricinus is the most frequently found tick throughout Europe. As with other ixodid ticks, the developmental cycle runs through three stages. In each stage a blood meal is required in order to develop to the next stage. Ixodes ricinus has been found to feed on more than 300 different vertebrate species. Usually, larval ticks feed on small mammals such as mice and become infected with various microorganisms and viruses, of which some are substantial pathogens to humans. The pathogens remain in the tick during molting and are thus transstadially transmitted to the next developmental stage. Pathogens transmitted to humans are the agents of Lyme borreliosis, the tick-borne encephalitis virus, Rickettsia species, Anaplasma phagocytophilum, occasionally Francisella tularensis, and protozoal Babesia species. Within the scope of an EU project Ixodes ricinus ticks from all federal states of Austria were searched by means of PCR methods for bacterial pathogens such as Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Coxiella burnetii, Ehrlichia spp., Francisella tularensis, Rickettsia spp., and protozoal Babesia. Additionally, the prevalence of Bartonella spp. in this tick species was also determined. Besides the singular detection of Coxiella burnetii and Francisella tularensis in one tick collection site the overall prevalence of Anaplasma phagocytophilum, borreliae, rickettsae and babesiae in Ixodes ricinus amounted to 15%, 14%, 6% and surprising 36% and 51%, respectively. Bartonellae were detected in about 7%.

The borrelial fibronectin-binding protein RevA is an early antigen of human Lyme disease

Previous studies using small numbers of serum samples from human patients and experimentally infected animals identified the frequent presence of antibodies recognizing RevA, a borrelial fibronectin-binding outer surface protein. We now demonstrate that most examined Lyme disease spirochetes from North America and Europe contain genes encoding RevA proteins, some with extensive regions of conservation and others with moderate diversity. Line blot analyses using recombinant RevA from two diverse Lyme disease spirochetes of RevA and serum samples from culture-confirmed human Lyme disease patients from the United States (n = 46, mainly with early Lyme disease) and Germany (>500, with early and late manifestations of Lyme disease) were performed. The results indicated that a sizable proportion of patients produced antibodies that recognized recombinant RevA. Overall, RevA-based serological studies were less sensitive and less specific than other assay types, such as the VlsE-based C6 peptide assay. However, sera from patients in the initial stages of Lyme disease contained antibodies against RevA, demonstrating that this protein is expressed early in human infection. Thus, RevA may be a useful target for preventative or curative therapies.

[Neuroborreliosis]

Neuroborreliosis is easily diagnosed by means of clinical symptoms and laboratory findings. Guiding symptoms are radicular pain and pareses of the extremities and the facial nerve. There is a great number of further less frequently occurring neurological symptoms, which can be attributed to a borrelial infection only by appropriate investigations of the CSF. Radiculitis is cured adequately by oral doxycycline while symptoms of the central nervous system are probably better treated intravenously by ceftriaxone, cefotaxime or penicillin G. Post-Lyme syndrome is a diffuse description of non-specific complaints, which are not the explicit result of a former infection with B. burgdorferi. As further antibiotics do not help and the CSF is unremarkable in most patients, a persistent infection with B. burgdorferi s.l. in all probability can be excluded.

Lyme borreliosis: a European perspective on diagnosis and clinical management

PURPOSE OF REVIEW

Lyme borreliosis has been widely recognized in Europe, but diagnostic and therapy concepts are still a matter for discussion. False-positive microbiologic results can lead to unnecessary antibiotic treatment, which even in genuine cases is sometimes unnecessarily prolonged. This review addresses new research on diagnosis, treatment, and eco-epidemiology.

RECENT FINDINGS

Recent research work in Europe since the last annual review has mostly dealt with diagnostic concepts. Improvement of serology has been achieved by use of multiple recombinant or peptide antigens, or of just the most frequently targeted antigen for detection of specific immunoglobulin G or immunoglobulin M antibodies to Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis. Concerning management of the disease, early work on the efficacy of oral treatment of Lyme neuroborreliosis has been confirmed. Studies on the ecology of the vectors and pathogens have elucidated aspects of epidemiology.

SUMMARY

Widespread awareness of Lyme borreliosis in Europe continues to grow due to increasing numbers of medical publications, information on the Internet, and from the media and patient support groups. The emphasis in scientific and medical publications has been on improvements in laboratory diagnostics, confirmation of therapeutic protocols, and the ecology of the vectors and pathogens.

Diversity of Borrelia genospecies in Ixodes ricinus ticks in a Lyme borreliosis endemic area in Switzerland identified by using new probes for reverse line blotting

In Europe, 7 Borrelia species belonging to the Borrelia burgdorferi sensu lato complex have been reported in Ixodes ricinus ticks. In addition, another Borrelia, related to the relapsing fever spirochaetes, has also been described. In the present study, we designed probes for reverse line blotting allowing detection and identification of all these Borrelia species after amplification of the variable spacer region between the 23S and 5S ribosomal genes. These new probes allowed us investigate the diversity of Borrelia in 915 I. ricinus collected on the south-facing slope of Chaumont (Switzerland). Among the 159 infected ticks, 7 Borrelia species were identified, and B. spielmanii and relapsing fever-like (RFL) spirochaetes were identified in this area for the first time. B. valaisiana and B. spielmanii were significantly less present in male than in female or nymphal ticks. Mixed infection with RFL spirochaetes and Lyme borreliosis spirochaetes were detected in 4 ticks. In addition, the set of probes could identify the recently described species, B. bavariensis.

Destruction of spirochete Borrelia burgdorferi round-body propagules (RBs) by the antibiotic tigecycline

Persistence of tissue spirochetes of Borrelia burgdorferi as helices and round bodies (RBs) explains many erythema-Lyme disease symptoms. Spirochete RBs (reproductive propagules also called coccoid bodies, globular bodies, spherical bodies, granules, cysts, L-forms, sphaeroplasts, or vesicles) are induced by environmental conditions unfavorable for growth. Viable, they grow, move and reversibly convert into motile helices. Reversible pleiomorphy was recorded in at least six spirochete genera (>12 species). Penicillin solution is one unfavorable condition that induces RBs. This antibiotic that inhibits bacterial cell wall synthesis cures neither the second "Great Imitator" (Lyme borreliosis) nor the first: syphilis. Molecular-microscopic techniques, in principle, can detect in animals (insects, ticks, and mammals, including patients) helices and RBs of live spirochetes. Genome sequences of B. burgdorferi and Treponema pallidum spirochetes show absence of >75% of genes in comparison with their free-living relatives. Irreversible integration of spirochetes at behavioral, metabolic, gene product and genetic levels into animal tissue has been documented. Irreversible integration of spirochetes may severely impair immunological response such that they persist undetected in tissue. We report in vitro inhibition and destruction of B. burgdorferi (helices, RBs = "cysts") by the antibiotic Tigecycline (TG; Wyeth), a glycylcycline protein-synthesis inhibitor (of both 30S and 70S ribosome subunits). Studies of the pleiomorphic life history stages in response to TG of both B. burgdorferi and Treponema pallidum in vivo and in vitro are strongly encouraged.

Borrelia burgdorferi sensu lato species in Europe induce diverse immune responses against C6 peptides in infected mice

The diversity of Lyme-borreliosis-inducing Borrelia species in Europe set high standards for the use of serodiagnostic test systems in terms of specificity and sensitivity. In the United States, the one-step C6 antibody test system based on the invariable domain IR6 of the VlsE molecule has been established as a successful diagnostic tool for testing canine samples. However, only a limited set of data are available regarding the antigenicity of the C6 peptides in an experimental murine model and sensitivity of the test regarding European Borrelia species. In order to investigate antibody reactions induced by these spirochetes, a total of 142 C3H/HeN mice were inoculated with Borrelia burgdorferi sensu stricto N40, B. garinii PBi, two isolates of B. afzelii, B. spielmanii A14S, B. valaisiana Rio6, B. valaisiana VS116, or B. lusitaniae. Infection of the mice was documented utilizing tissue culture and PCR. The IR6 sequences of B. burgdorferi sensu stricto B31, B. garinii IP90, and two B. afzelii ACAI strains have been used to synthesize and test additional C6 peptides. Compared to the well-established two-tiered test system, the results indicate that single C6 peptides derived from B. burgdorferi sensu stricto and B. garinii can be used in an enzyme-linked immunosorbent assay-based technique to detect murine antibodies induced by either agent. Little is known about the prevalence or pathogenicity of the B. afzelii strains in mammalian hosts, but our experimental data indicate differences in the C6 peptide test sensitivity for the detection of antibodies induced by different strains or isolates of B. afzelii.

A new Borrelia species defined by multilocus sequence analysis of housekeeping genes

Analysis of Lyme borreliosis (LB) spirochetes, using a novel multilocus sequence analysis scheme, revealed that OspA serotype 4 strains (a rodent-associated ecotype) of Borrelia garinii were sufficiently genetically distinct from bird-associated B. garinii strains to deserve species status. We suggest that OspA serotype 4 strains be raised to species status and named Borrelia bavariensis sp. nov. The rooted phylogenetic trees provide novel insights into the evolutionary history of LB spirochetes.

Acylated cholesteryl galactosides are specific antigens of borrelia causing lyme disease and frequently induce antibodies in late stages of disease

Borrelia burgdorferi sensu lato is the causative agent of Lyme disease (LD), an infectious disease occurring in North America, Europe, and Asia in different clinical stages. B. burgdorferi sensu lato encompasses at least 12 species, with B. burgdorferi sensu stricto, B. garinii, and B. afzelii being of highest clinical importance. Immunologic testing for LD as well as recent vaccination strategies exclusively refer to proteinaceous antigens. However, B. burgdorferi sensu stricto exhibits glycolipid antigens, including 6-O-acylated cholesteryl beta-D-galactopyranoside (ACGal), and first the data indicated that this compound may act as an immunogen. Here we investigated whether B. garinii and B. afzelii also possess this antigen, and whether antibodies directed against these compounds are abundant among patients suffering from different stages of LD. Gas-liquid chromatography/mass spectroscopy and NMR spectroscopy showed that both B. garinii and B. afzelii exhibit ACGal in high quantities. In contrast, B. hermsii causing relapsing fever features 6-O-acylated cholesteryl beta-D-glucopyranoside (ACGlc). Sera derived from patients diagnosed for LD contained antibodies against ACGal, with 80% of patients suffering from late stage disease exhibiting this feature. Antibodies reacted with ACGal from all three B. burgdorferi species tested, but not with ACGlc from B. hermsii. These data show that ACGal is present in all clinically important B. burgdorferi species, and that specific antibodies against this compound are frequently found during LD. ACGal may thus be an interesting tool for improving diagnostics as well as for novel vaccination strategies.

[Lyme borreliosis]

Lyme borreliosis is a multi-system infectious disease that primarily affects the skin, nervous system, heart, and joints. It is caused by the tick-borne spirochete Borrelia burgdorferi sensu lato. Diagnosis is made on the basis of clinical symptoms and supported by a positive serology. Antibiotic therapy should be started immediately after the diagnosis has been established and is administered according to stage and symptoms of the disease. Doxycycline, amoxicillin, and ceftriaxone are the antibiotics of choice. Early Lyme disease is almost always cured by one antibiotic course that also prevents subsequent disease manifestations. After antibiotic therapy of late disease manifestations, symptoms resolve only slowly and remission is usually achieved after weeks or even months. Chronic or therapy-resistant disease courses and residual symptoms after therapy are rare.

In vitro susceptibility of Borrelia spielmanii to antimicrobial agents commonly used for treatment of Lyme disease

Ten isolates of the recently delineated genospecies Borrelia spielmanii were tested against antimicrobial agents used to treat Lyme disease and compared to eight isolates of the other three human-pathogenic borrelial genospecies. Despite some small but significant differences in four out of eight antibiotic agents, the susceptibility pattern of B. spielmanii mainly parallels that of the other known human-pathogenic members of the B. burgdorferi sensu lato complex.

Borrelia bissettii isolates induce pathology in a murine model of disease

The spirochete Borrelia burgdorferi is a tick-borne pathogen that causes Lyme disease. Although B. burgdorferi sensu lato is a diverse group of bacteria, only three genospecies, B. burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii, are known to be pathogenic and commonly recognized to cause human disease. To assess the potential of another common genospecies, Borrelia bissettii, to induce disease, a mouse model was employed. Two Colorado isolates of B. bissettii (CO-Bb) induced lesions of the bladder, heart, and femorotibial joint 8 weeks after inoculation into mice. In contrast, two British Columbia (BC-Bb) isolates, could not be cultured or amplified by PCR from target organs, and did not induce lesions. Consistent with pathology and culture results, the antibody response in mice to BC-Bb was minimal compared to CO-Bb, indicating either transient localized infection or rapid immune clearance of BC-Bb. Although sequence analysis of the rrf (5S)-rrl (23S) intergenic spacer region indicated 99% homology between CO-Bb and BC-Bb, polyacrylamide gel electrophoresis (PAGE) analysis indicated five distinct protein differences between these low-passage isolates. These studies support the prospect that B. bissettii may indeed be the causative agent of Lyme borreliosis cases in Eastern Europe, associated with the atypical Borrelia strain 25015, and in other regions. To our knowledge, this is the first evidence that B. bissettii can induce pathology in a vertebrate host.

Human pathogenic Borrelia spielmanii sp. nov. resists complement-mediated killing by direct binding of immune regulators factor H and factor H-like protein 1

Borrelia spielmanii sp. nov. has recently been shown to be a novel human pathogenic genospecies that causes Lyme disease in Europe. In order to elucidate the immune evasion mechanisms of B. spielmanii, we compared the abilities of isolates obtained from Lyme disease patients and tick isolate PC-Eq17 to escape from complement-mediated bacteriolysis. Using a growth inhibition assay, we show that four B. spielmanii isolates, including PC-Eq17, are serum resistant, whereas a single isolate, PMew, was more sensitive to complement-mediated lysis. All isolates activated complement in vitro, as demonstrated by covalent attachment of C3 fragments; however, deposition of the later activation products C6 and C5b-9 was restricted to the moderately serum-resistant isolate PMew and the serum-sensitive B. garinii isolate G1. Furthermore, serum adsorption experiments revealed that all B. spielmanii isolates acquired the host alternative pathway regulators factor H and factor H-like protein (FHL-1) from human serum. Both complement regulators retained their factor I-mediated C3b inactivation activities when bound to spirochetes. In addition, two distinct factor H and FHL-1 binding proteins, BsCRASP-1 and BsCRASP-2, were identified, which we estimated to be approximately 23 to 25 kDa in mass. A further factor H binding protein, BsCRASP-3, was found exclusively in the tick isolate, PC-Eq17. This is the first report describing an immune evasion mechanism utilized by B. spielmanii sp. nov., and it demonstrates the capture of human immune regulators to resist complement-mediated killing.