Laboratory aspects of Lyme borreliosis

Laboratory Diagnosis of Lyme Borreliosis

Lyme borreliosis is caused by a growing list of related, yet distinct, spirochetes with complex biology and sophisticated immune evasion mechanisms. It may result in a range of clinical manifestations involving different organ systems, and can lead to persistent sequelae in a subset of cases. The pathogenesis of Lyme borreliosis is incompletely understood, and laboratory diagnosis, the focus of this review, requires considerable understanding to interpret the results correctly. Direct detection of the infectious agent is usually not possible or practical, necessitating a continued reliance on serologic testing. Still, some important advances have been made in the area of diagnostics, and there are many promising ideas for future assay development. This review summarizes the state of the art in laboratory diagnostics for Lyme borreliosis, provides guidance in test selection and interpretation, and highlights future directions.

Pathogenesis of Relapsing Fever

Relapsing fever (RF) is caused by several species of Borrelia; all, except two species, are transmitted to humans by soft (argasid) ticks. The species B. recurrentis is transmitted from one human to another by the body louse, while B. miyamotoi is vectored by hard-bodied ixodid tick species. RF Borrelia have several pathogenic features that facilitate invasion and dissemination in the infected host. In this article we discuss the dynamics of vector acquisition and subsequent transmission of RF Borrelia to their vertebrate hosts. We also review taxonomic challenges for RF Borrelia as new species have been isolated throughout the globe. Moreover, aspects of pathogenesis including symptomology, neurotropism, erythrocyte and platelet adhesion are discussed. We expound on RF Borrelia evasion strategies for innate and adaptive immunity, focusing on the most fundamental pathogenetic attributes, multiphasic antigenic variation. Lastly, we review new and emerging species of RF Borrelia and discuss future directions for this global disease.

Lyme borreliosis-from tick bite to diagnosis and treatment

Lyme borreliosis is caused by certain genospecies of the Borrelia burgdorferi sensu lato complex, which are transmitted by hard ticks of the genus Ixodes. The most common clinical manifestation is erythema migrans, an expanding skin redness that usually develops at the site of a tick bite and eventually resolves even without antibiotic treatment. The infecting pathogens can spread to other tissues and organs, resulting in manifestations that can involve the nervous system, joints, heart and skin. Fatal outcome is extremely rare and is due to severe heart involvement; fetal involvement is not reliably ascertained. Laboratory support-mainly by serology-is essential for diagnosis, except in the case of typical erythema migrans. Treatment is usually with antibiotics for 2 to 4 weeks; most patients recover uneventfully. There is no convincing evidence for antibiotic treatment longer than 4 weeks and there is no reliable evidence for survival of borreliae in adequately treated patients. European Lyme borreliosis is a frequent disease with increasing incidence. However, numerous scientifically questionable ideas on its clinical presentation, diagnosis and treatment may confuse physicians and lay people. Since diagnosis of Lyme borreliosis should be based on appropriate clinical signs, solid knowledge of clinical manifestations is essential.

The Significance of Serum Anti-Borrelia Antibodies in the Diagnostic Work-Up of Uveitis

Purpose.

To assess the utility of testing uveitis patients for anti-Borrelia antibodies in an area endemic for Lyme borreliosis.

Methods.

We examined 161 uveitis patients for serum antibodies to Borrelia burgdorferi by Lyme ELISA. Antibodies were determined in patients with uveitis of unknown etiology and non-selectively from patients with an established diagnosis.

Results.

Concentrations of antibodies to B. burgdorferi were elevated in 26 uveitis patients (16.1%), with elevated IgG in 11 of them (6.8%). In four of these patients Lyme borreliosis was a highly suggestive cause of uveitis because of a history of tick bites, systemic symptoms, response to antibiotic therapy, and/or a positive polymerase chain reaction result. Other causes of uveitis were ruled out. All these patients had vitritis.

Conclusions.

Non-selective testing of uveitis patients for Lyme antibodies is not reasonable even in endemic areas. We recommend using the Borrelia antibody test only in cases of uveitis of unknown cause, especially in patients with vitritis or other symptoms of Lyme borreliosis.

Genotyping Strains of Lyme Disease Agents Directly From Ticks, Blood, or Tissue

The tick-borne spirochetes that cause Lyme disease in North America and Eurasia display strong linkage disequilibrium between certain chromosomal and plasmid loci within each three major geographic areas of their distribution. For strain typing for epidemiologic and ecologic purposes, the commonly used genotypes based on a single locus are the spacer between the 16S-23S ribosomal RNA and the ospC gene of a plasmid. A simple genotyping scheme based on the two loci allows for discrimination between strains representing all the areas of distribution. The methods presented here are meant for genotyping directly from ticks and from blood and tissue samples from vertebrates.

Association between body size and reservoir competence of mammals bearing Borrelia burgdorferi at an endemic site in the northeastern United States

Background

The reservoirs for the Lyme disease agent, Borrelia burgdorferi, are dominated by several different small to medium sized mammals in eastern North America.

Findings

To experimentally assess the competence of different mammalian species to transmit this pathogen to ticks, we carried out quantitative species-specific PCR of individual nymphal Ixodes scapularis ticks, which had been collected as replete larvae from animals captured at a field site in eastern Connecticut and then allowed to molt in the laboratory. The mammals, in order of increasing body mass, were the white-footed mouse, pine vole, eastern chipmunk, gray squirrel, Virginia opossum, striped skunk, and common raccoon. The prevalence of infection in the nymphs and the counts of spirochetes in infected ticks allometrically scaled with body mass with exponents of −0.28 and −0.29, respectively. By species, the captured animals from the site differed significantly in the mean counts of spirochetes in the ticks recovered from them, but these associations could not be distinguished from an effect of body size per se.

Conclusions

These empirical findings as well as inferences from modeling suggest that small mammals on the basis of their sizes are more competent as reservoirs of B. burgdorferi in this environment than medium-to large-sized mammals.

Laboratory confirmation of Lyme disease

Lyme disease can be confirmed in the laboratory by isolation or detection of its causative agent, a tick-borne spirochete Borrelia burgdorferi, or by a diagnostic change in the titre of antibodies specific to the agent. B burgdorferi can be isolated and cultivated in Barbour-Stoenner-Kelly II medium. It can be detected by light microscopy in tissue sections or, rarely, in blood smears using various staining methods. There is interest in the development of alternative detection methods, including identification of specific antigens of B burgdorferi in the urine of suspected cases and demonstration of the presence of species-specific DNA using polymerase chain reaction assays. Currently, serological tests (indirect immunofluorescence assay, enzyme-linked immunosorbent assay and Western immunoblot) are the most practical and available methods for confirming Lyme disease. The quest to improve the specificity and sensitivity of serological tests - for example, through the use of specific recombinant antigens - continues.

Application of medical and analytical methods in Lyme borreliosis monitoring

Lyme borreliosis (LB) is one of the most common tick-borne diseases in the northern hemisphere. It is a chronic inflammatory disease caused by the spirochaete Borrelia burgdorferi. In its early stages, pathological skin lesions, namely erythema chronicum migrans, appear. The lesions, usually localised at the site of the bite, may become visible from a few weeks up to 3 months after the infection. Predominant clinical symptoms of the disease also involve joint malfunctions and neurological or cardiac disorders. Lyme disease, in all its stages, may be successfully treated with antibiotics. The best results, however, are obtained in its early stages. In order to diagnose the disease, numerous medical or laboratory techniques have been developed. They are applied to confirm the presence of intact spirochaetes or spirochaete components such as DNA or proteins in tick vectors, reservoir hosts or patients. The methods used for the determination of LB biomarkers have also been reviewed. These biomarkers are formed during the lipid peroxidation process. The formation of peroxidation products generated by human organisms is directly associated with oxidative stress. Apart from aldehydes (malondialdehyde and 4-hydroxy-2-nonenal), many other unsaturated components such as isoprostenes and neuroprostane are obtained. The fast determination of these compounds in encephalic fluid, urine or plasma, especially in early stages of the disease, enables its treatment. Various analytical techniques which allow the determination of the aforementioned biomarkers have been reported. These include spectrophotometry as well as liquid and gas chromatography. The analytical procedure also requires the application of a derivatization step by the use of selected reagents.

Antibiotic treatment of the tick vector Amblyomma americanum reduced reproductive fitness

Background

The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present.

Methodology/Principal Findings

We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline) or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp.

Conclusion/Significance

The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other tick vectors of disease.

Phylogenetic analysis of the spirochetes Borrelia parkeri and Borrelia turicatae and the potential for tick-borne relapsing fever in Florida

Isolates of Borrelia turicatae, Borrelia parkeri, and the Florida canine borrelia (FCB) were examined to further phylogenetically characterize the identities of these spirochetes in the United States. DNA sequences of four chromosomal loci (the 16S rRNA gene, flaB, gyrB, and glpQ) were determined for eight isolates of B. turicatae and six isolates of B. parkeri, which grouped the spirochetes into two distinct but closely related taxa (>98% sequence identity) separate from Borrelia hermsii. The FCB was clearly separated with the group identified as B. turicatae, confirming this bacterium as a relapsing fever spirochete. Therefore, the potential for tick-borne relapsing fever in humans and other animals exists in Florida and future efforts are needed to determine the enzootic hosts and distribution of this spirochete in the southeastern United States. Analysis of plasmids demonstrated both linear and circular forms in B. turicatae but only linear plasmids in B. parkeri, which should be of interest to investigators concerned with plasmid diversity and evolution within this group of spirochetes.

Diagnosis of lyme borreliosis

A large amount of knowledge has been acquired since the original descriptions of Lyme borreliosis (LB) and of its causative agent, Borrelia burgdorferi sensu stricto. The complexity of the organism and the variations in the clinical manifestations of LB caused by the different B. burgdorferi sensu lato species were not then anticipated. Considerable improvement has been achieved in detection of B. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of disease. Culturing plasma and increasing the volume of material cultured have accomplished this. Further improvements might be obtained if molecular methods are used for detection of growth in culture and if culture methods are automated. Unfortunately, culture is insensitive in extracutaneous manifestations of LB. PCR and culture have high sensitivity on skin samples of patients with EM whose diagnosis is based mostly on clinical recognition of the lesion. PCR on material obtained from extracutaneous sites is in general of low sensitivity, with the exception of synovial fluid. PCR on synovial fluid has shown a sensitivity of up to >90% (when using four different primer sets) in patients with untreated or partially treated Lyme arthritis, making it a helpful confirmatory test in these patients. Currently, the best use of PCR is for confirmation of the clinical diagnosis of suspected Lyme arthritis in patients who are IgG immunoblot positive. PCR should not be used as the sole laboratory modality to support a clinical diagnosis of extracutaneous LB. PCR positivity in seronegative patients suspected of having late manifestations of LB most likely represents a false-positive result. Because of difficulties in direct methods of detection, laboratory tests currently in use are mainly those detecting antibodies to B. burgdorferi sensu lato. Tests used to detect antibodies to B. burgdorferi sensu lato have evolved from the initial formats as more knowledge on the immunodominant antigens has been collected. The recommendation for two-tier testing was an attempt to standardize testing and improve specificity in the United States. First-tier assays using whole-cell sonicates of B. burgdorferi sensu lato need to be standardized in terms of antigen composition and detection threshold of specific immunoglobulin classes. The search for improved serologic tests has stimulated the development of recombinant protein antigens and the synthesis of specific peptides from immunodominant antigens. The use of these materials alone or in combination as the source of antigen in a single-tier immunoassay may someday replace the currently recommended two-tier testing strategy. Evaluation of these assays is currently being done, and there is evidence that certain of these antigens may be broadly cross-reactive with the B. burgdorferi sensu lato species causing LB in Europe.

First culture isolation of Borrelia lonestari, putative agent of southern tick-associated rash illness

Southern tick-associated rash illness (STARI) is a Lyme disease-like infection described in patients in the southeastern and south-central United States, where classic Lyme disease is relatively rare. STARI develops following the bite of a lone star tick (Amblyomma americanum) and is thought to be caused by infection with an "uncultivable" spirochete tentatively named Borrelia lonestari. In this study, wild lone star ticks collected from an area where B. lonestari is endemic were cocultured in an established embryonic tick cell line (ISE6). The cultures were examined by dark-field microscopy for evidence of infection, and spirochete identity and morphology were evaluated by flagellin B and 16S rRNA gene sequence, by reaction to Borrelia-wide and B. burgdorferi-specific monoclonal antibodies, and by electron microscopy. Live spirochetes were first visualized in primary culture of A. americanum ticks by dark-field microscopy 14 days after the cell culture was inoculated. The sequences of the flagellin B and 16S rRNA genes of cultured spirochetes were consistent with previously reported sequences of B. lonestari. The cultured spirochetes reacted with a Borrelia-wide flagellin antibody, but did not react with an OspA antibody specific to B. burgdorferi, by indirect fluorescent antibody testing. Electron microscopy demonstrated organisms that were free and associated with ISE6 cells, with characteristic Borrelia sp. morphology. This study describes the first successful isolation of B. lonestari in culture, providing a much needed source of organisms for the development of diagnostic assays and forming a basis for future studies investigating the role of the organism as a human disease agent.

Complement inhibitor factor H binding to Lyme disease spirochetes is mediated by inducible expression of multiple plasmid-encoded outer surface protein E paralogs

Borrelia burgdorferi spirochetes can circumvent the vertebrate host's immune system for long periods of time. B. burgdorferi sensu stricto and B. afzelii, but not B. garinii, bind the complement inhibitor factor H to protect themselves against complement-mediated opsonophagocytosis and killing. We found that factor H binding and complement resistance are due to inducible expression of a wide repertoire of outer surface protein E (OspE) lipoproteins variably called OspE, p21, ErpA, and ErpP. Individual Borrelia strains carry multiple plasmid-encoded OspE paralogs. Together the OspE homologs were found to constitute an array of proteins that bind factor H via multiple C-terminal domains that are exposed outwards from the Borrelial surface. Charged residue substitutions in the key binding regions account for variations between OspE family members in the optimal binding pH, temperature, and ionic strength. This may help the spirochetes to adapt into various host environments. Our finding that multiple plasmid-encoded OspE proteins act as virulence factors of Borrelia can provide new tools for the prevention and treatment of borreliosis.

Laboratory testing for suspected Lyme disease

Laboratory testing for B. burgdorferi infection is intended to substantiate a physician's clinical judgment of whether a patient has Lyme disease or not. Cultivation of B. burgdorferi from a patient's skin or blood is the gold standard for demonstration of active infection, but it is expensive and lacks clinical sensitivity. Detection of spirochetal DNA in clinical samples by PCR has better sensitivity, but PCR for B. burgdorferi has not yet been standardized for more routine diagnostic testing. Detection of antibodies to B. burgdorferi is the most practical and common approach for laboratory work-up of a case of suspected Lyme disease. Serologic assays fall short of 100% sensitivity and specificity, however, and examination of a single specimen in time does not discriminate between previous and ongoing infection. Because of a background false positivity even among healthy populations of nonendemic regions, serologic testing is recommended only when there is at least a one in five chance, in the physician's estimation, that the patient has active Lyme disease. The pretest likelihood of the disease is determined by the physician in the context of epidemiologic and clinical facts of the case. This estimate can serve to reassure patients who are at low risk of B. burgdorferi infection but are seeking a Lyme test for complaints of a more nonspecific nature. Although new subunit serologic assays based on recombinant proteins are becoming available commercially, the longstanding two-test approach, in which a positive or indeterminate result with a standardized, sensitive ELISA test is followed by verification with a more specific Western blot assay, still provides the physician with a reasonably accurate and reliable assessment of the presence of antibodies to B. burgdorferi. More recent challenges for serologic testing are seropositivity in the population as the result of immunization with the Lyme disease vaccine and the emergence of new Borrelia species that cause Lyme disease-like illnesses.

Serodiagnosis of Louse-Borne relapsing fever with glycerophosphodiester phosphodiesterase (GlpQ) from Borrelia recurrentis

Human louse-borne relapsing fever occurs in sporadic outbreaks in central and eastern Africa that are characterized by significant morbidity and mortality. Isolates of the causative agent, Borrelia recurrentis, were obtained from the blood of four patients during a recent epidemic of the disease in southern Sudan. The glpQ gene, encoding glycerophosphodiester phosphodiesterase, from these isolates was sequenced and compared with the glpQ sequences obtained from other relapsing-fever spirochetes. Previously we showed that GlpQ of Borrelia hermsii is an immunogenic protein with utility as a serological test antigen for discriminating tick-borne relapsing fever from Lyme disease. In the present work, we cloned and expressed the glpQ gene from B. recurrentis and used recombinant GlpQ in serological tests. Acute- and convalescent-phase serum samples obtained from 42 patients with louse-borne relapsing fever were tested with an indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) that used whole cells of B. recurrentis and with immunoblotting to whole-cell lysates of the spirochete and Escherichia coli producing recombinant GlpQ. The geometric mean titers of the acute- and convalescent-phase serum samples measured by IFA were 1:83 and 1:575, respectively. The immunoblot analysis identified a high level of reactivity and seroconversion to GlpQ, and the assay was more sensitive than the whole-cell IFA and ELISA using purified, recombinant histidine-tagged GlpQ. Serum antibodies to GlpQ and other antigens persisted for 27 years in one patient. We conclude that assessment of anti-GlpQ antibodies will allow serological confirmation of louse-borne relapsing fever and determination of disease prevalence.

Detection of selected fastidious bacteria

The intent of this article is to describe the optimal methods for culture recovery of 7 fastidious bacteria: Legionella species, Brucella species, Francisella tularensis, Leptospira species, Borrelia burgdorferi, Bartonella species, and Bordetella species. These organisms share much in common beyond the fact that their genus names all end in the letter "a." Culture recovery of these organisms, even from adequate clinical specimens, is logistically demanding, often costly, and lacking in both timeliness and sensitivity. In addition, there is generally no need to recover culture isolates on which to perform antimicrobial susceptibility tests because these 7 bacteria are nearly uniformly susceptible to specific, clinically useful antimicrobial agents and because, for some of them, susceptibility tests of proven reliability have not yet been devised. Perhaps for these reasons, alternative, more rapid, direct diagnostic approaches have been developed that are based on either immunochemical or nucleic-acid detection methods. These methods have generally served to supplant culture as a primary diagnostic modality. Situations exist, however, in which culture may be desirable, if not necessary, to establish a definitive diagnosis of infection with these 7 organisms. This review attempts to summarize how best to proceed in those cases.

Overdiagnosis and overtreatment of Lyme neuroborreliosis are preventable

The problems of diagnosis and treatment of Lyme neuroborreliosis can be minimised by strictly following the clinical diagnostic criteria, and understanding the pitfalls of laboratory tests. The diagnosis is based solely on objective clinical findings, with serologic test results used only to confirm the diagnosis. It must be underscored that serologic testing, when ordered without regard for clinical presentation (i.e., used as a screen), may be misleading due to its extremely low positive predictive value. Enzyme-linked immunosorbent assay should always be confirmed by Western blot. The cerebrospinal fluid Borrelia burgdorferi antibody index is more meaningful than simple titres of specific antibody. Polymerase chain reaction is still a research tool and should not be utilised without clinical correlation. All serologic tests and polymerase chain reaction may remain positive long after successful treatment. Overdiagnosis and overtreatment can be minimised by following these guidelines.

Enzyme-linked immunosorbent assay using recombinant OspC and the internal 14-kDa flagellin fragment for serodiagnosis of early Lyme disease

The outer surface protein C (OspC) and the internal 14-kDa flagellin fragment of strain GeHo of Borrelia burgdorferi sensu stricto were expressed as recombinant proteins in Escherichia coli and were purified for use in an immunoglobulin M (IgM) enzyme-linked immunosorbent assay (OspC-14-kDa antigen ELISA). No hint at disturbing protein-protein interferences, which might influence the availability of immunoreactive epitopes, was found when the recombinant antigens were combined in the ELISA. The recombinant OspC-14-kDa antigen ELISA was compared to a commercial IgM ELISA that used a detergent cell extract from Borrelia afzelii PKo as the antigen. According to the manufacturer's information, the cell extract contains, in addition to other antigens, the following diagnostically relevant antigens: the 100-kDa (synonyms, 93- and 83-kDa antigens), 41-kDa, OspA, OspC, and 17-kDa antigens. The specificity was adjusted to 95% on the basis of data for 154 healthy controls. On testing of 104 serum samples from patients with erythema migrans (EM), the sensitivity of the recombinant ELISA (46%) for IgM antibodies was similar to that of the commercial ELISA (45%). However, when 42 serum samples from patients with polyclonal B-cell stimulation due to an Epstein-Barr virus infection were tested, false-positive reactions were significantly less frequent in the recombinant ELISA (10%) than in the whole-cell-extract ELISA (23%). OspC displays sequence heterogeneity of up to 40% according to the genomospecies. However, when the reactions of serum specimens from controls and EM patients with OspC from representative strains of B. burgdorferi sensu stricto (strain GeHo) and B. afzelii (strain PKo) were compared in an ELISA, almost no differences in specificity and sensitivity were seen. This demonstrates that the sera predominantly recognize the common epitopes of OspC tested in this study. In conclusion, we suggest that the OspC-14-kDa antigens ELISA is a suitable test for the detection of an IgM response in early Lyme disease.

Analysis of the intrathecal immune response in neuroborreliosis to a sonicate antigen and three recombinant antigens of Borrelia burgdorferi sensu stricto

The intrathecal synthesis of borrelial-specific IgM- and IgG-antibodies was studied in 67 patients with neuroborreliosis and in 14 patients with neurosyphilis (controls). Antibody concentrations in serum and in the cerebrospinal fluid were determined by an enzyme immunoassay (EIA) using, as antigens, a sonicate of Borrelia burgdorferi, the recombinant 14 kDa flagellin fragment, the outer surface protein C (22 kDa), and the high molecular mass protein p83 (83 kDa). In the sonicate EIA, IgG- and/or IgM-antibodies to Borrelia burgdorferi in serum were detected in all patients with neuroborreliosis and in 71% of patients with neurosyphilis. Intrathecal synthesis of borrelial-specific IgG- and/or IgM-antibodies was demonstrated in 82% of patients with neuroborreliosis and in 71% of patients with neurosyphilis. Immunoglobulin G- and/or IgM-antibodies in serum against any of the recombinant antigens were detected in 92% of patients with neuroborreliosis and in none of those with neurosyphilis. Intrathecal synthesis of IgG- and/or IgM-antibodies to individual recombinant antigens was demonstrated in 67% of patients with neuroborreliosis and in none of those with neurosyphilis. The sensitivity of the recombinant antigens in serum was almost equal to that of the sonicate EIA, whereas the recombinant antigens were clearly less sensitive in the estimation of the intrathecal specific immune response. It was concluded that in suspected cases of neuroborreliosis, the estimation of high specific antibodies in the recombinant EIA will be helpful in confirming the diagnosis.

Borrelia burgdorferi induces the production and release of proinflammatory cytokines in canine synovial explant cultures

Canine synovial membrane explants were exposed to high- or low-passage Borrelia burgdorferi for 3, 6, 12, and 24 h. Spirochetes received no treatment, were UV light irradiated for 16 h, or were sonicated prior to addition to synovial explant cultures. In explant tissues, mRNA levels for the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-1alpha (IL-1alpha), IL-1beta, and IL-8 were surveyed semiquantitatively by reverse transcription-PCR. Culture supernatants were examined for numbers of total and motile (i.e., viable) spirochetes, TNF-like and IL-1-like activities, polymorphonuclear neutrophil (PMN) chemotaxis-inducing activities, and IL-8. During exposure to synovial explant tissues, the total number of spirochetes in the supernatants decreased gradually by approximately 30%, and the viability also declined. mRNAs for TNF-alpha, IL-1alpha, IL-1beta, and IL-8 were up-regulated in synovial explant tissues within 3 h after infection with untreated or UV light-irradiated B. burgdorferi, and mRNA levels corresponded to the results obtained with bioassays. During 24 h of coincubation, cultures challenged with untreated or UV light-irradiated spirochetes produced similar levels of TNF-like and IL-1-like activities. In contrast, explant tissues exposed to untreated B. burgdorferi generated significantly higher levels of chemotactic factors after 24 h of incubation than did explant tissues exposed to UV light-treated spirochetes. In identical samples, a specific signal for IL-8 was identified by Western blot analysis. High- and low-passage borreliae did not differ in their abilities to induce proinflammatory cytokines. No difference in cytokine induction between untreated and sonicated high-passage spirochetes was observed, suggesting that fractions of the organism can trigger the production and release of inflammatory mediators. The titration of spirochetes revealed a dose-independent cytokine response, where 10(3) to 10(7) B. burgdorferi organisms induced similar TNF-like activities but only 10(7) spirochetes induced measurable IL-1-like activities. The release of chemotactic factors was dose dependent and was initiated when tissues were infected with at least 10(5) organisms. We conclude that intact B. burgdorferi or fractions of the bacterium can induce the local up-regulation of TNF-alpha, IL-1alpha, and IL-1beta in the synovium but that the interaction of viable spirochetes with synovial cells leads to the release of IL-8, which probably is a prime initiator of PMN migration during acute Lyme arthritis.

Borrelia burgdorferi induces chemokines in human monocytes

Lyme disease is clinically and histologically characterized by strong inflammatory reactions that contrast the paucity of spirochetes at lesional sites, indicating that borreliae induce mechanisms that amplify the inflammatory response. To reveal the underlying mechanisms of chemoattraction and activation of responding leukocytes, we investigated the induction of chemokines in human monocytes exposed to Borrelia burgdorferi by a dose-response and kinetic analysis. Lipopolysaccharide (LPS) derived from Escherichia coli was used as a positive control stimulus. The release of the CXC chemokines interleukin-8 (IL-8) and GRO-alpha and the CC chemokines MIP-1alpha, MCP-1, and RANTES was determined by specific enzyme-linked immunosorbent assays, and the corresponding gene expression patterns were determined by Northern blot analysis. The results showed a rapid and strong borrelia-inducible gene expression which was followed by the release of chemokines with peak levels after 12 to 16 h. Spirochetes and LPS were comparably effective in stimulating IL-8, GRO-alpha, MCP-1, and RANTES expression, whereas MIP-1alpha production preceded and exceeded chemokine levels induced by LPS. Unlike other bacteria, the spirochetes themselves did not bear or release factors with intrinsic chemotactic activity for monocytes or neutrophils. Thus, B. burgdorferi appears to be a strong inducer of chemokines which may, by the attraction and activation of phagocytic leukocytes, significantly contribute to inflammation and tissue damage observed in Lyme disease.

Sudeck's atrophy in Lyme borreliosis

A patient with disseminated Lyme borreliosis is reported. The patient suffered from erythema migrans and radicular pain. Serologic tests routinely performed (IFT, ELISA, Western blots with different strains and Borrelia-LTT) were negative. However, Borrelia burgdorferi (genotype Borrelia afzelii) was cultivated from a skin biopsy. Western blot with the patient's isolate and sera showed strong reactivity only with the 60 kDa protein. In spite of immediate diagnosis and intravenous antibiotic treatment according to current recommendations he developed pain in the right ankle, which was resistant to further antibiotic and anti-inflammatory therapy. Sudeck's atrophy was diagnosed by X-ray. Treatment with calcitonin brought immediate relief from pain and led to radiographically demonstrable recalcification.

Rickettsioses as paradigms of new or emerging infectious diseases

Rickettsioses are caused by species of Rickettsia, a genus comprising organisms characterized by their strictly intracellular location and their association with arthropods. Rickettsia species are difficult to cultivate in vitro and exhibit strong serological cross-reactions with each other. These technical difficulties long prohibited a detailed study of the rickettsiae, and it is only following the recent introduction of novel laboratory methods that progress in this field has been possible. In this review, we discuss the impact that these practical innovations have had on the study of rickettsiae. Prior to 1986, only eight rickettsioses were clinically recognized; however, in the last 10 years, an additional six have been discovered. We describe the different steps that resulted in the description of each new rickettsiosis and discuss the influence of factors as diverse as physicians' curiosity and the adoption of molecular biology-based identification in helping to recognize these new infections. We also assess the pathogenic potential of rickettsial strains that to date have been associated only with arthropods, and we discuss diseases of unknown etiology that may be rickettsioses.

GlpQ: an antigen for serological discrimination between relapsing fever and Lyme borreliosis

Tick-borne relapsing fever is caused by numerous Borrelia species maintained in nature by Ornithodoros tick-mammal cycles. Serological confirmation is based on either an immunofluorescence assay or an enzyme-linked immunosorbent assay using whole cells or sonicated Borrelia hermsii as the antigen. However, antigenic variability of this bacterium's outer surface proteins and antigens shared with the Lyme disease spirochete (B. burgdorferi), may cause both false-negative and false-positive results when testing sera of patients suspected to have either relapsing fever or Lyme disease. To develop a specific serological test for relapsing fever, we created a genomic DNA library of B. hermsii, screened transformed Escherichia coli cells for immunoreactivity with high-titered (> or = 1:2,048) human anti-B. hermsii antiserum, and selected an immunoreactive clone (pSPR75) expressing a 39-kDa protein. DNA sequencing, subcloning, and serum adsorption experiments identified the immunoreactive protein as a homolog of GlpQ, a glycerophosphodiester phosphodiesterase identified previously in E. coli, Haemophilus influenzae, and Bacillus subtilis. Serum samples from humans and mice infected with B. hermsii or other species of relapsing fever spirochetes contained antibodies recognizing GlpQ, whereas serum samples from Lyme disease and syphilis patients were nonreactive. Serologic tests based on this antigen will identify people exposed previously to relapsing fever spirochetes and help clarify the distribution of relapsing fever and Lyme disease in situations in which the occurrence of their causative agents is uncertain.

Does Lyme disease occur in the south?: a survey of emerging tick-borne infections in the region

Lyme disease is the most common arthropod-borne infection in the United States. However, the risk of infection varies widely by geographic region. In the South, Borrelia burgdorferi has been identified in ticks and small mammals, but transmission of the agent to humans has not been documented. The Lyme disease-like disorder reported from the region may have another etiology.

Establishment of enzyme-linked immunosorbent assay using purified recombinant 83-kilodalton antigen of Borrelia burgdorferi sensu stricto and Borrelia afzelii for serodiagnosis of Lyme disease

The 83-kDa antigen of Borrelia burgdorferi was expressed as a recombinant protein in Escherichia coli and purified for use in an enzyme-linked immunosorbent assay (p83-ELISA). Antibodies to the 83-kDa antigen of both the immunoglobulin G (IgG) and IgM isotypes could be detected in all stages of Lyme disease. Sensitivity varied, depending on the clinical stage of illness. In early stages, as defined for 118 patients with erythema migrans, it was found to be 20% (24 of 118 patients: 7 with IgM, 16 with IgG, and 1 with IgM and IgG). Of the patients with late-stage Lyme arthritis and acrodermatitis chronica atrophicans, 94% (16 of 17:2 with IgM and IgG and 14 with IgG) and 86% (36 of 42:2 with IgG and IgM and 34 with IgG) revealed positive results in the p83-ELISA, respectively. p83 displays sequence heterogeneity according to the genomospecies, but when the reactions of serum specimens from acrodermatitis chronica atrophicans patients and arthritis patients with p83 derived from representative strains of B. burgdorferi sensu stricto and Borrelia afzelii in ELISAs were compared, no differences in specificity and sensitivity were seen. When 82 serum specimens from healthy controls were tested, none had IgG and only 3 (4%) had IgM antibodies, indicating a high specificity. Positive reactions with antibodies against Treponema pallidum (1 of 37 patients; IgG) and Epstein-Barr virus (1 of 44 patients; IgM) and with autoantibodies of various specificities (1 of 53 patients; IgG) were seen with < 3% of the serum samples te11111111111111111111 high speficicity for B. burgdorferi.2+ 13% for IgM antibodies, the IgM p83-ELISA provided little diagnostic information for Lyme disease, whereas the IgG p83-ELISA appears to be a suita ;e test for serodiagnosis of advanced-stage Lyme disease.

Antibodies against whole sonicated Borrelia burgdorferi spirochetes, 41-kilodalton flagellin, and P39 protein in patients with PCR- or culture-proven late Lyme borreliosis

The sensitivities and specificities of three enzyme-linked immunosorbent assays (ELISAs) for Borrelia burgdorferi antibodies were compared for 41 patients presenting with symptoms compatible with late Lyme borreliosis (LB) and 37 healthy controls. All subjects were living in southwestern Finland, where LB is endemic. Only patients with culture- or PCR-proven disease were enrolled in the study. The antigens of the ELISAs consisted of sonicated spirochetes, 41-kDa flagellin, and recombinant P39 protein of B. burgdorferi. Fifteen patients had strongly or moderately positive results in the serological assay(s), 19 patients had only weakly positive or borderline antibody levels, and the remaining 7 patients were seronegative by ELISA. The sensitivities of the ELISAs were 78.0% with sonicate antigen, 41.5% with 41-kDa flagellin, and 14.6% with P39 protein. The specificities of the tests were 89.2, 86.5, and 94.6%, respectively. The sonicate antigen ELISA seems to be an effective screening method. These results show that antibodies to B. burgdorferi may be present in low levels or even absent in patients with culture- or PCR-proven late LB. Therefore, in addition to serological testing, the use of PCR and cultivation is recommended in the diagnosis of LB.

Lyme Disease: A Review for the Otolaryngologist

Lyme disease is an important consideration in the differential diagnosis of patients seen by the otolaryngologist. Facial paralysis is the most common sign. The otolaryngologist may also see patients with temporal mandibular joint pain, cervical lymphadenopathy, facial pain, headache, tinnitis, vertigo, decreased hearing, otalgia and sore throat. The incidence is increasing and known to be endemic to certain areas of the United States and abroad. This paper reviews the various ways Lyme disease appears to the otolaryngologist. Three cases along with a discussion including epidemiology, vector, animal host relationship, clinical manifestations and pathophysiology are included. The literature is reviewed and the treatment discussed.

Lyme arthritis

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Impact of the saponin adjuvant QS-21 and aluminium hydroxide on the immunogenicity of recombinant OspA and OspB of Borrelia burgdorferi

The impact of the adjuvants QS-21 and aluminium hydroxide (alum) on the immunogenicity of recombinant outer surface proteins A (OspA) and B (OspB) of Borrelia burgdorferi was investigated. Both non-acylated OspA and OspB derived from strain B31 were expressed in Escherichia coli and purified by reversible citraconylation and anion-exchange chromatography. Antisera to OspA or OspB were prepared in mice with antigens formulated with QS-21 or alum, and evaluated for specific immunoglobulin G isotypes, agglutination and borreliacidal activity. QS-21 significantly enhanced IgG2a and IgG2b antibody responses to OspA and OspB, and IgG1 response to OspA when compared with the formulation containing antigen alone. In contrast, alum significantly inhibited the induction of IgG2a and IgG2b responses to OspA. Alum had no significant effect on IgG1 response to OspA, or IgG2a and IgG2b responses to OspB, but significantly enhanced IgG1 antibody response to OspB. Antisera to OspA or OspB formulated by QS-21 possessed higher titres of agglutinating antibody than antisera to OspA or OspB alone. Borreliacidal activity was eight- to 64-fold higher in antisera to OspA formulated with QS-21 than in antisera to OspA formulated with or without alum. These antisera were highly borreliacidal to New York strain B31, a California isolate CA-2-87, German isolate Fr, and Swedish isolate G25. Antisera to OspB formulated with QS-21 were highly borreliacidal to strains B31 and Fr, but not to CA-2-87 and G25. Antisera to OspB formulated with alum were borreliacidal only to B31. Thus, OspA was superior to OspB and QS-21 superior to alum at eliciting functional antibody responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of four immunoserologic assays for detection of antibodies to Borrelia burgdorferi in patients with culture-positive erythema migrans

In view of the significant sequelae associated with Lyme borreliosis, there is a need for timely and accurate diagnosis of erythema migrans (EM). Although Borrelia burgdorferi can be cultured from biopsies of EM lesions, immunodiagnostic testing is more widely available. Four immunoserologic methods were studied by using the sera of 51 patients with EM lesions that were culture positive for B. burgdorferi. Nineteen patients had single primary lesions, and thirty-two had multiple secondary lesions. At the time of biopsy, 40 patients, 8 with primary lesions and all patients with secondary lesions, were seropositive by an immunoglobulin M (IgM) indirect fluorescent-antibody (IgM IFA) test (Bion Enterprises). Twenty-three patients were seropositive by a whole-cell fluorescence enzyme immunoassay (EIA) (BioWhittaker, Inc.), twenty-two were positive by immunoblotting (ViroStat, Inc.), and one was positive by a P39 recombinant EIA (P39 EIA) (General Biometrics, Inc.). Sera from various patient control groups were tested: rheumatoid arthritis (n = 19), infectious mononucleosis (n = 20), systemic lupus (n = 22), syphilis (n = 13), streptococcal sequelae (n = 20), and healthy subjects (n = 16). None of these sera reacted with the IgM IFA test or P39 EIA. Fifteen reacted with the fluorescence EIA. We conclude that the IgM IFA test is an effective and reliable assay for the diagnosis of EM, particularly for patients with secondary lesions. Immunoblot, fluorescence EIA, and P39 EIA lack the sensitivity to reliably diagnose EM.

Lyme disease in northwestern coastal California

To determine the incidence of physician-diagnosed Lyme disease in an endemic area of California, an active surveillance program was implemented in Lake, Mendocino, Sonoma, and southern Humboldt counties. More than 200 medical care providers were called monthly for their list of suspected cases of Lyme disease. Pertinent information was abstracted from the medical record of each patient. Of 153 cases of possible early Lyme disease ascertained from July 1991 to December 1992, 37% consisted of physician-diagnosed erythema migrans. Only 58% of erythema migrans rashes were at least 5 cm in diameter. An additional 43 patients had suspicious rashes not classified as erythema migrans. Of 166 patients with possible late-stage Lyme disease, 31% had specific clinical symptoms and 75% had a positive serologic test. With an incident case defined as physician-diagnosed erythema migrans of at least 5 cm in diameter, the annual incidence of Lyme disease in northwestern coastal California according to active surveillance only was 5.5 per 100,000. The rate of Lyme disease in California is substantially lower than that in the Atlantic northeastern United States. Many suspected cases of Lyme disease in this endemic area do not meet surveillance criteria, which are intentionally restrictive. Although some of the illnesses not meeting surveillance criteria may be due to infection with Borrelia burgdorferi, it appears that Lyme disease is being overdiagnosed in this area.

A bactericidal antibody to Borrelia burgdorferi is directed against a variable region of the OspB protein

Borrelia burgdorferi, an agent of Lyme disease, is killed by some monoclonal antibodies in the absence of complement or phagocytes. In the present study, the bactericidal action of monoclonal antibodies against B. burgdorferi and B. hermsii, a cause of relapsing fever, was further characterized. H6831, an antibody recognizing the OspB proteins of some B. burgdorferi strains, and H4825, an antibody specific for one serotype of B. hermsii, were purified, and Fab fragments of the antibodies were prepared. In time-kill studies, more than 99.9% of strain B31 B. burgdorferi cells were killed after 30 min of exposure to H6831 Fab fragments. The MBC of the Fab fragments was 10 micrograms/ml. Electron microscopy revealed that the bactericidal Fab fragments produced numerous blebs and cell lysis of the borrelias for which they were specific. To identify the epitope for H6831, the OspB sequences of H6831-susceptible and -resistant strains and mutants were determined. The deduced OspB proteins of all H6831-resistant strains and mutants differed from the strain B31 OspB at residue 253. Murine antisera raised against a 21-mer synthetic peptide representing the region around residue 253 were specific for strain B31 by Western blot (immunoblot) and growth inhibition assays. Furthermore, the antipeptide serum inhibited the binding of H6831 to whole borrelias. These findings indicated that the linear component of the bactericidal antibody's epitope was located at or near residue 253.

Fatty acids of Treponema pallidum and Borrelia burgdorferi lipoproteins

A fundamental ultrastructural feature shared by the spirochetal pathogens Treponema pallidum subsp. pallidum (T. pallidum) and Borrelia burgdorferi, the etiological agents of venereal syphilis and Lyme disease, respectively, is that their most abundant membrane proteins contain covalently attached fatty acids. In this study, we identified the fatty acids covalently bound to lipoproteins of B. burgdorferi and T. pallidum and examined potential acyl donors to these molecules. Palmitate was the predominant fatty acid of both B. burgdorferi and T. pallidum lipoproteins. T. pallidum lipoproteins also contained substantial amounts of stearate, a fatty acid not typically prevalent in prokaryotic lipoproteins. In both spirochetes, the fatty acids of cellular lipids differed from those of their respective lipoproteins. To characterize phospholipids in these organisms, spirochetes were metabolically labeled with [3H]palmitate or [3H]oleate; B. burgdorferi contained only phosphatidylglycerol and phosphatidylcholine, while T. pallidum contained phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and cardiolipin. Although palmitate predominated in the lipoproteins, there were no apparent differences in the incorporation of these two fatty acids into phospholipids (putative acyl donors). Phospholipase A1 and A2 digestion of phosphatidylcholine from B. burgdorferi and T. pallidum labeled with either [3H]palmitate or [3H]oleate also revealed that neither fatty acid was incorporated preferentially into the 1 and 2 positions (potential acyl donor sites) of the glycerol backbone. The combined findings suggest that fatty acid utilization during lipoprotein synthesis is determined largely by the fatty acid specificities of the lipoprotein acyl transferases. These findings also provide the basis for ongoing efforts to elucidate the relationship between lipoprotein acylation and the physiological functions and inflammatory activities of these molecules.

Serologic surveillance for the Lyme disease spirochete, Borrelia burgdorferi, in Minnesota by using white-tailed deer as sentinel animals

To determine the effectiveness of white-tailed deer as sentinel animals in serologic surveillance programs for Borrelia burgdorferi, we performed enzyme-linked immunosorbent assay (ELISA) and Western immunoblotting analyses on 467 deer serum samples. The seropositivity rate in the ELISA was 5% for the 150 samples collected at the three sites in which the tick Ixodes scapularis was absent. The three sites with established I. scapularis populations had a seropositivity rate of 80% for 317 samples. Results were similar for two closely situated sites, one with an established I. scapularis population and one without; these sites were only 15 km apart. Rates of seropositivity were significantly higher in yearling and adult deer than in fawns. The mean numbers of bands seen on Western immunoblots were 3.0 for samples negative in the ELISA and 13.8 for samples positive in the ELISA; all of these samples were collected from sites in which I. scapularis was established. At sites in which I. scapularis was absent, the mean numbers of bands seen were 1.6 for samples negative in the ELISA and 8.2 for samples positive in the ELISA. There were 14 different B. burgdorferi antigens that reacted with more than 50% of the ELISA-positive samples from areas with I. scapularis. A 19.5-kDa antigen reacted with 94% of the ELISA-positive samples. Reactivity against OspA and OspB was weak a infrequent (2%). Serologic analysis of white-tailed deer sera appears to be an accurate and sensitive surveillance method for determining whether B. burgdorferi is present in specific geographic locations.

Prevalence of Borrelia burgdorferi in selected tick populations in Finland

The purpose of the studies was to determine the prevalence of Borrelia burgdorferi sensu lato in selected populations of Ixodes ricinus in Finland and to secure strains of the spirochete for further characterization. 1,210 Ixodes ricinus ticks (399 females, 419 males and 392 nymphs) were collected during June to August 1992 by flagging from 8 sites in 3 regions. The frequency of B. burgdorferi infection was determined by isolation in BSK II medium. The species identity of most of the isolates was confirmed with the immunofluorescence method. 67 B. burgdorferi strains were isolated from 8 sites; the prevalence ranged from 2.8% to 7.9%. The overall isolation percentage for adult male ticks was 6.4% (7.5% for females, 5.3% for males); for nymphs, 3.8%. No statistically significant association of the prevalence was observed with either pasture or off-pasture habitats nor with specific geographic region/regions. Prevalence figures were roughly of the same magnitude in areas and parts of the country known to differ in their incidence of human borreliosis. An additional 294 ticks, mainly engorged females, were collected from places outside the main study sites. Of the 7 positive ticks 3 were engorged females, originating from a cow, a dog and a cat, respectively. The results in general demonstrate that tick populations in various parts of Finland quite commonly harbour B. burgdorferi.

Optimization of polymerase chain reaction for the detection of Borrelia burgdorferi in biologic specimens

This study describes the use of a newly constructed set of primers that amplifies an 85-base pair (bp) segment of Borrelia burgdorferi chromosomal DNA. This 85-bp product is not produced when other Borrelia species, Leptospira, or other bacteria are subjected to polymerase chain reaction (PCR). We also describe a rapid method of optimizing the amplification of B. burgdorferi DNA from canine ethylenediaminetetraacetic acid-treated blood and urine samples that circumvents some of the problems encountered due to low number of spirochetes in clinical specimens and that removes inhibiting substances, which improves the PCR diagnosis of canine Lyme borreliosis.

Specific adherence of Borrelia burgdorferi extracellular vesicles to human endothelial cells in culture

Borrelia burgdorferi produces extracellular vesicles which contain some of the outer surface proteins of the bacterium (e.g., OspA and OspB). Borrelial vesicles, isolated by differential centrifugation and filtration, were tested for the ability to bind to cultured human umbilical vein endothelial (HUVE) cells in culture. The recently described lipoprotein OspD was expressed on vesicles. Vesicles exhibited differential expression of OspB and OspD in a relationship with passage number and medium serum supplement type, respectively. Qualitative immunoblotting analyses demonstrated dose-dependent, passage number-dependent adsorption of vesicles by HUVE cells. This adsorption was demonstrated to be dependent upon a borrelial component of the vesicle and not due to the presence of minor contamination with intact spirochetes. Quantitative experiments examining inhibition of B. burgdorferi-HUVE association as a function of prior vesicle-HUVE association demonstrated dependence upon (i) a borrelial component(s) in the vesicle, (ii) low passage number, and (iii) vesicle protein concentration. However, vesicle pretreatment of the HUVE cell monolayer was not requisite for this inhibition. Vesicles from highly passaged borrelias were noninhibitory for B. burgdorferi-HUVE cell association, regardless of the serum used to supplement the medium. The use of vesicles as a tool for studying B. burgdorferi pathogenesis and/or physiology is proposed.

Western blot as a tool in the diagnosis of Lyme borreliosis

Borrelia burgdorferi is the causative agent of Lyme borreliosis, a multisystem disorder, which can mimic numerous immune disorders and inflammatory diseases. Laboratory diagnosis of Borrelia infection relies on immunodiagnostic assays, which, however, are hampered by unsatisfactory specificity. The Western blot technique has been employed to analyze the humoral immune response in Lyme borreliosis and is used as a serodiagnostic confirmation test. The most important immunodominant proteins of Borrelia burgdorferi are the 94 kDa, 60 kDa, 41 kDa (flagellin), 34 kDa (Osp B), 31 kDa (Osp A), 30 kDa, 21 kDa (Osp C), and 17/18 kDa proteins. Whereas the 60 kDa, 41 kDa, and 34 kDa constituents reveal a marked cross-antigenicity with other spirochetes and even more distantly related bacteria, antibodies against the 94 kDa, 31 kDa and 21 kDa proteins are largely species-specific. The early immune response in Lyme borreliosis is triggered mainly by the flagellin. In the later stage a wide range of immunogenic proteins is involved, with the 94 kDa antigen being the best marker for late immune response. If the Western blot is used for diagnostic purposes the differences between early and late-stage immunogenicity of Borrelia proteins must be taken into account. Interpretation criteria for blot positivity in early-stage borreliosis are primarily based on the presence of the 21 kDa band and the semiquantitatively recorded intensity of the 41 kDa band. In the diagnosis of late-stage infection, blot positivity relies on the presence of the 94 kDa, 39 kDa, 31 kDa, 30 kDa and 21 kDa bands.

Evaluation of agents for use in medium for selective isolation of Lyme disease and relapsing fever Borrelia species

Barbour-Stoenner-Kelly (BSK) II medium containing fosfomycin, 5-fluorouracil, trimethoprim and sulfamethoxazole was evaluated for the selective isolation of the Borrelia species responsible for Lyme disease and relapsing fever. The maximum non-inhibitory concentrations of fosfomycin, 5-fluorouracil, trimethoprim and sulfamethoxazole for six strains of borreliae were 500 to > 1000 micrograms/ml, 250 to > 500 micrograms/ml, 125 to 500 micrograms/ml and 125 to 500 micrograms/ml, respectively. The combination of four agents (fosfomycin 400 micrograms/ml, 5-fluorouracil 100 micrograms/ml, trimethoprim 10 micrograms/ml, sulfamethoxazole 50 micrograms/ml) did not inhibit the growth of borreliae, allowing growth in cultures inoculated with a few organisms (theoretically a single organism). In contrast, the four-agent combination completely inhibited the growth of 12 of 13 other bacterial strains tested as possible contaminants. This combination also allowed the selective growth of borreliae in experimentally contaminated specimens. The four-agent combination in BSK II medium may be useful for selective isolation of Borrelia species responsible for Lyme disease and relapsing fever from clinical and environmental samples.

Comparison of seven commercial kits for detection of antibodies to Borrelia burgdorferi

Five enzyme immunoassay (EIA) and two Western blot (WB) commercial kits were compared for their ability to detect antibodies to Borrelia burgdorferi. The panel of 53 test sera consisted of 25 sera positive for antibodies to Borrelia burgdorferi, 15 sera negative for such antibodies, 5 sera reactive in serologic tests for syphilis, and 8 sera containing antinuclear antibodies and/or rheumatoid factor. The rate of agreement with reference results was 93%, 90%, 90% and 88% for EIA kits from Diamedix, Cambridge Biotech, Mardx and Sigma respectively. The sensitivity and specificity was 84% and 100% respectively for Cambridge Biotech, 76% and 94% for Diamedix, 68% and 83% for Mardx, and 68% and 83% for Sigma. The three confirmatory tests, Cambridge Biotech WB, General Biometrics P39 EIA and Mardx WB, demonstrated 75%, 60% and 63% agreement respectively. The sensitivity and specificity was 52% and 100% respectively for Cambridge Biotech WB, 24% and 100% for General Biometrics P39 EIA, and 44% and 100% for Mardx WB. The results demonstrate the variable performance of commercial serologic kits for detection of antibodies to Borrelia burgdorferi. WB appears to be a better confirmatory test than the single protein EIA.

Rapid dissemination by the agent of Lyme disease in hosts that permit fulminating infection

We determined whether the agent of Lyme disease (Borrelia burgdorferi) disseminates more rapidly following deposition in hosts that permit fulminating infection than in hosts in which infection is relatively benign. Thus, individual infected nymphal deer ticks (Ixodes dammini) were permitted to engorge on the ears of C3H mice, and the site of attachment was excised at intervals thereafter. Infection in each mouse was determined by serology and by examining previously noninfected ticks that had engorged on these mice. These results were compared with data obtained similarly by using the CD-1 strain of mice in which the agent is relatively nonpathogenic. When the site of inoculation was ablated within 2 days after the infected tick became replete, dissemination was aborted. Spirochetemia could not be demonstrated in any of these mice. We conclude that Lyme disease spirochetes disseminate from the feeding lesion of an infecting tick more rapidly in certain highly spirochete-susceptible mice than in others in which pathogenesis is less severe.

Cross-reactive antigenic domains of the flagellin protein of Borrelia burgdorferi

The p41 flagellin of Borrelia burgdorferi is the most common antigen recognized by serum of patients with Lyme borreliosis. This antigen shares amino acid homology, particularly in the amino and carboxy termini, with periflagellar antigens found in other microorganisms including Treponema pallidum. We cloned and expressed the p41 open reading frame in Escherichia coli and expressed it both as TrpE fusion and full-length unfused proteins. Also, we generated deletion constructs of various portions of the gene. Sera from patients with late Lyme borreliosis and secondary syphilis were used to identify the recombinant proteins by immunoblot analysis. Sera from 26 patients with Lyme borreliosis, 20 with secondary syphilis and 10 controls were used to identify cross-reactive domains of the B. burgdorferi flagellin. The variable region (amino acids 131-234) of the protein was recognized by 59% (15/26) of patients with late Lyme borreliosis compared to 30% (6/20) of patients with secondary syphilis and no (0/10) control patients. It appears that cross-reactive epitopes between B. burgdorferi and T. pallidum extend to the variable region of the flagellin.

Analysis of the humoral response to the flagellin protein of Borrelia burgdorferi: cloning of regions capable of differentiating Lyme disease from syphilis

Selected regions of the Borrelia burgdorferi flagellin gene (fla) that exhibit high or low homology with related genes from other bacterial species were amplified by the polymerase chain reaction and expressed as fusion proteins in Escherichia coli. Purified fusion proteins were assayed for antibody reactivity in a microtiter plate enzyme-linked immunosorbent assay with sera from Lyme disease patients as well as syphilitic and normal sera. Immunoglobulin G antibody from Lyme disease patient sera reacted predominantly with the central portion of the protein. The region of the flagellin protein encompassing amino acids 64 to 311 detected nearly all of the immunoglobulin G-positive Lyme sera and only reacted with 1 of 26 syphilis patient serum samples. In contrast, 12 of 26 syphilis patient serum samples and 2 of 47 normal serum samples reacted with the amino terminus of the flagellin protein, whereas 4 of 26 syphilis patient serum samples and 7 of 47 normal serum samples reacted with the carboxyl terminus. The central region containing amino acids 64 to 311 may be employed diagnostically to differentiate antibodies to B. burgdorferi from antibodies to Treponema pallidum. In addition, this region also was recognized by immunoglobulin M in the Lyme patient sera, indicating its potential usefulness as a marker for early Lyme disease.

Serologic analysis of white-tailed deer sera for antibodies to Borrelia burgdorferi by enzyme-linked immunosorbent assay and western immunoblotting

White-tailed deer serum samples were collected in the Minneapolis-St. Paul, Minn., metropolitan area during the fall and winter months from 1989 to 1992 and analyzed for antibodies to Borrelia burgdorferi, the etiologic agent of Lyme borreliosis. Ninety-eight percent of the serum samples were collected from regions where currently the vector tick, Ixodes dammini, is nonexistent. Antibodies to B. burgdorferi were detected in 2.2% of 508 samples by enzyme-linked immunosorbent assay, and their presence was confirmed by Western immunoblot analysis. Western immunoblotting yielded mean numbers of reactive bands of 0.1 and 6.0 for samples that were negative and positive for antibodies by enzyme-linked immunosorbent assay, respectively. The molecular weights of the antigens in many of the reactive bands from positive samples were similar to the molecular weights of antigens reactive with samples from humans with Lyme borreliosis. An antibody response to the major outer surface proteins A and B was not detected. Serologic analysis of deer sera may provide a valuable method for surveillance programs designed to monitor the spread of B. burgdorferi in nature.