Comparison of growth of Borrelia afzelii, B. garinii, and B. burgdorferi sensu stricto in MKP and BSK-II medium

Lyme borreliosis is a tick-borne disease caused by genetically diverse Borrelia strains including B. afzelii, B. garinii, and B. burgdorferi sensu stricto (s.s.). The aim of the present study was to assess and compare the growth of one strain per species of B. afzelii, B. garinii, and B. burgdorferi s.s. in modified Kelly-Pettenkofer (MKP) and Barbour-Stonner-Kelly-II (BSK-II) medium, and to check for the presence of the overgrowth after inoculating the media with a mixture of two different Borrelia species. All three Borrelia strains grew well in both media. In the majority of the experiments the number of B. afzelii cells was higher in MKP than in BSK-II medium while for B. garinii and B. burgdorferi s.s. a tendency for better growth in BSK-II than MKP was established. In a mixture of equivalent amounts of two species, B. burgdorferi s.s. as a rule overgrew the other two species while in the mixture of B. afzelii and B. garinii the latter was a "dominant" strain. Comparing the performance of the two media, B. burgdorferi s.s. usually overgrew either B. afzelii or B. garinii in MKP as well as in BSK-II medium, however, the results were found to be statistically significant only for MKP medium. In the mixture of B. afzelii and B. garinii the latter was the predominant species but significant differences were established only for BSK-II medium. It seems that the overgrowth is predominantly the result of the characteristics of the individual Borrelia species and most probably not a consequence of growth differences in the two culture media. Further work with a larger number of strains is needed to confirm these findings.     

Serodiagnosis of Lyme borreliosis by Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii western blots (immunoblots).

The performance of Western blots (immunoblots) prepared with eight strains of Borrelia burgdorferi representing B. burgdorferi sensu stricto, B. garinii, and B. afzelii genospecies was tested with a panel of sera with various clinical presentations collected from eight geographic regions. European sera were generally more reactive to blots prepared with B. garinii or B. afzelii strain antigens, in particular B. garinii 20047 and B. afzelii VS461. North American sera were more reactive with B. burgdorferi sensu stricto strains. Our observation of significant differences in the levels of reactivity of some sera on Western blots of certain strains is potentially important for the development and implementation of generic interpretive criteria. Preferential reactivity of sera from patients with nerve and/or palsy symptoms to B. garinii strains and with cutaneous disease to B. afzelii strains was observed. On the basis of our results, we have concluded that strain 20047 is the best strain to use for the development of a generic Lyme borreliosis Western blot for Europe.     

Recombinant OspC from Borrelia burgdorferi sensu stricto,B. afzelii and B. garinii in the serodiagnosis of Lyme borreliosis

Genes for the outer-surface protein C (OspC) from three north European human isolates of Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii were cloned and sequenced. Polyhistidine-tagged recombinant OspC (rOspC) proteins were produced in Escherichia coli and used, after biotinylation, as antigens on streptavidin-coated plates in enzyme-linked immunosorbent assays (ELISA). In IgM ELISA, 30% (5/17) and 35% (6/17) of patients with erythema migrans (EM) in the acute or convalescent phase, respectively, reacted with one to three rOspCs. Of the patients, 53% (8/15) with neuroborreliosis (NB) and 53% (8/15) with Lyme arthritis (LA) had IgM antibodies to OspC. The immunoreactivity was stronger against rOspC from B. afzelii and B. garinii than against rOspC from B. burgdorferi sensu stricto. In early Lyme borreliosis (LB), rOspC and flagella performed equally well in detecting IgM antibodies. Cross-reactive antibodies to rOspC were observed in serum samples from patients with rheumatoid factor positivity and with syphilis or Epstein-Barr virus (EBV) infection. In IgM ELISA, thiocyanate in the serum dilution buffer reduced EBV-associated non-specific positive reactions. Of the patient sera examined in IgG ELISA, 30% (5/17) with EM in the acute phase, 35% (6/17) with EM in the convalescent phase, 33% (5/15) with NB and 60% (9/15) with LA were positive. Because of the heterogeneity of OspC, a polyvalent antigen with several OspC variants from at least B. afzelii and B. garinii is needed to improve the sensitivity of OspC ELISA in the serodiagnosis of LB in Europe.     

Infection rate ofIxodes ricinus ticks withBorrelia afzelii,Borrelia garinii,andBorrelia burgdorferi sensu stricto in Slovenia

In spring 1993,Ixodes ricinus ticks were collected from six regions of Slovenia to determine their overall rate of infection withBorrelia burgdorferi sensu lato and to assess the frequency of individual species in these tick populations. Ticks were dissected and midgut tissue inoculated into modified Barbour-Stoenner-Kelly (BSK II) medium.Borrelia isolates were differentiated into separate species using species-specific polymerase chain reaction (PCR) primers and by large restriction fragment pattern (LRFP) analysis. Infected ticks were found in all six regions surveyed. Spirochaetes were isolated from 69 of 363 ticks (19 %): the isolation rate from adult female ticks was 35 % (23/66 ticks cultured), from adult male ticks 22 % (20/91), and from nymphal ticks 13 % (26/206). Determination of the species of 60 isolates revealed that 32 wereBorrelia afzelii (53 %), 20 wereBorrelia garinii (33 %), and 8 wereBorrelia burgdorferi sensu stricto (13 %). In the Ljubljana regionBorrelia afzelii andBorrelia garinii predominated (43 % and 40 %, respectively), whereasBorrelia burgdorferi sensu stricto constituted only 17 % of isolates. In three other regions of the countryBorrelia afzeliiwas isolated exclusively, although the number of isolates investigated was small. This study demonstrates the presence of all three European species ofBorrelia burgdorferi sensu lato within the Slovenian tick population and also within a geographic area of less than 100 m².     

Sequence analysis of ospA genes shows homogeneity within Borrelia burgdorferi sensu stricto and Borrelia afzelii strains but reveals major subgroups within the Borrelia garinii species

The genes coding for the outer surface protein A (OspA) of 19 different Borrelia burgdorferi strains belonging to the seven OspA-serotypes 1–7, previously described [Wilske et al. (1993) J Clin Microbiol, 31: 340–350], have been investigated. B. burgdorferi sensu lato strains were chosen from various biological sources (ticks, human skin and cerebrospinal fluid) as well as different geographical origins (Germany, Slovenia, Austria, United States). The open reading frames of all ospA genes consist of 819–825 nucleotides corresponding to proteins of approximately 30 kDa. The ospA sequences obtained in this study and previous published studies were compared with the results from OspA serotyping with monoclonal antibodies. The classification into the seven OspA serotypes could be confirmed on a genetic basis (ospA genotypes 1–7) for all strains analyzed so far (n=29). In addition, one strain without OspA expression could be assigned to ospA genotype 2. Genetic stability could be proven for the ospA gene of B. burgdorferi strain PWudI after inocculation and reisolation from a gerbil. However, we found evidence for intragenic recombination by cluster analysis of ospA sequence data. Accordance of ospA genotype 1 strains with B. burgdorferi sensu stricto and ospA genotype 2 strains with B. afzelii, as well as the ospA genotype strains 3–7 with B. garinii was confirmed by pulsed-field gel electrophoresis of MluI-digested genomic DNA. B. garinii is not only more heterogenous in respect to the OspA-encoding genes, but shows moreover major subgroups formed by genotypes 4, 5 and 6 and genotypes 3 and 7, respectively. The latter group has not been described previously and is specifically recognized by an OspA-specific monoclonal antibody L32 1F7.     

Analysis of the human antibody response to outer surface protein C (OspC) of Borrelia burgdorferi sensu stricto,B. garinii,and B. afzelii

The aim of this study was to determine by Western blotting (WB) the prevalence of anti-outer surface protein C (OspC) IgM and IgG antibodies in patients with Lyme borreliosis according to each of the three genospecies of Borrelia burgdorferi sensu lato. Strains of B. burgdorferi sensu stricto (MUL), B. garinii (DK 6), and B. afzelii (DK 26) served as antigen, all of which expressed abundant OspC. We examined sera from 117 patients with untreated early and late Lyme borreliosis, as well as from 100 blood donors and 29 patients with syphilis. WB results were compared with the B. burgdorferi flagellum enzyme-linked immunosorbent assay (ELISA) data. OspC from B. burgdorferi sensu stricto showed the lowest diagnostic sensitivity. OspC from B. garinii and B. afzelii performed almost identically in erythema migrans, with an IgM positive rate of 36% versus 34%, whereas OspC from B. garinii performed best in neuroborreliosis (60% versus 44%). The anti-OspC IgG response was less prominent than the IgM response and was infrequent in the late stages of the disease (0 – 20%). The benefit of combining the evaluation of anti-OspC responses with all three species was limited. The overall diagnostic sensitivity of WB anti-B. garinii OspC evaluation was, in the early stages of the disease, comparable to the results obtained using the flagellum ELISA. In erythema migrans and neuroborreliosis, the addition of anti-OspC IgM to the flagellum ELISA increased the sensitivity by 15% and 10%, respectively. It can, therefore, be concluded that OspC from B. garinii is a suitable OspC test antigen, and that supplementary use of OspC from other species adds little to the overall diagnostic sensitivity. An ELISA based on B. garinii OspC and native flagella seems currently the most promising concept for a future antibody test in early Lyme borreliosis. Received: 6 September 1996     

Influence of MKP medium stored for prolonged periods on growth and morphology of Borrelia afzelii,Borrelia garinii,and Borrelia burgdorferi sensu stricto

Modified Kelly‐Pettenkofer (MKP) medium is one of the several media used for isolation and cultivation of Borrelia. The aim of the study was to assess whether particular Borrelia species (B. afzelii, B. garinii, and B. burgdorferi sensu stricto) have the ability to grow in MKP medium stored at +4 °C for periods for 1 month up to 1 year, and how prolonged storage may influences Borrelia growth and morphology. The growth of Borrelia was evaluated after 5 days of incubation at 33 °C: cell count per mL, morphology, and motility were assessed. The results of this study showed that the duration of storage of MKP medium had statistically significant influence on growth of B. afzelii (p = 0.021) and B. garinii (p = 0.004), but not on growth of B. burgdorferi sensu stricto (p = 0.204), whereas duration of storage of the medium had no impact on Borrelia morphology and motility. The results of the study indicate that medium stored for more than 1 and up to 12 months supports Borrelia growth.     

Species-specific serodiagnosis of Lyme arthritis and neuroborreliosis due to Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii by using decorin binding protein A

The antigenic potential of decorin binding protein A (DbpA) was evaluated in serodiagnosis of human Lyme borreliosis (LB). The dbpA was cloned and sequenced from the three pathogenic Borrelia species common in Europe. Sequence analysis revealed high interspecies heterogeneity. The identity of the predicted amino acid sequences was 43 to 62% among Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii. The respective recombinant DbpAs (rDbpAs) were produced and tested as antigens by Western blotting and enzyme-linked immunosorbent assay (ELISA). One hundred percent of patients with neuroborreliosis (NB) and 93% of patients with Lyme arthritis (LA) reacted positively. Sera from the majority of patients reacted with one rDbpA only and had no or low cross-reactivity to other two variant proteins. In patients with culture-positive erythema migrans (EM), the sensitivity of rDbpA immunoglobulin G (IgG) or IgM ELISA was low. The DbpA seems to be a sensitive and specific antigen for the serodiagnosis of LA or NB, but not of EM, provided that variants from all three pathogenic borrelial species are included in the combined set of antigens.     

In vitro susceptibility testing of four antibiotics against Borrelia burgdorferi: a comparison of results for the three genospecies Borrelia afzelii,Borrelia garinii,and Borrelia burgdorferi sensu stricto

MICs and minimal bactericidal concentrations (MBCs) were evaluated for the four antibiotics azithromycin, amoxicillin, ceftriaxone, and doxycycline against the three main genospecies of Borrelia burgdorferi sensu lato. In MBC testing, statistically significant differences between the genospecies could be found in 7 out of 12 comparative evaluations (P < 0.05).     

Use of polymerase chain reaction and specific monoclonal antibodies as rapid method to recognize Borrelia burgdorferi sensu stricto,B. garinii and B. afzelii among Italian isolates of B. burgdorferi

We previously classified locally isolated strains of Borrelia burgdorferi by a restriction fragment length polymorphism analysis of total DNA, by DNA/DNA Southern Blot hybridization and by a hybridization with rRNA 16 + 23 S from Escherichia coli [Cinco et al. (1993) Microbiologica 16:323–332] into three genetic groups which, according to the reference strains used, should correspond to the three species so far described as B. burgdorferi sensu stricto, B. garinii and B. afzelii. To find a simpler method for strain identification, in this study we analyzed the Italian strains and some strains identification, in this study we analyzed the Italian strains and some strains originating from other European countries, employing the species-specific 16S rRNA primers in the polymerase chain reaction technique (PCR) and some phenotypic markers like the B. afzelii-specific monoclonal antibodies and the battery of OspA-specific monoclonal antibodies which were reported to give a reactivity pattern correlated to the species [Wilske et al. (1993) J Clin Microbiol 31:340–350]. The PCR results confirmed those obtained previously by identifying the three groups as B. burgdorferi sensu stricto, B. garinii and B. afzelii; the reactivity patterns obtained with the monoclonal antibodies (mAb) also corresponded to those described as typical of the three species. We standardized the PCR technique to amplify a sample of crude template DNA obtained from a culture of 10⁵ spirochetes.     

Detection of Borrelia afzelii, Borrelia burgdorferi sensu stricto, Borrelia garinii and group VS116 by PCR in skin biopsies of patients with erythema migrans and acrodermatitis chronica atrophicans

Objective: To evaluate the diagnostic performance of two polymerase chain reaction (PCR) procedures using skin biopsies of 20 erythema migrans (EM) and 24 acrodermatitis chronica atrophicans (ACA) patients.
Method: One assay amplified a fragment of the outer surface protein (Osp) A gene. The second method amplified the spacer region between the 5S and 23S rRNA genes; hybridization of this fragment allowed identification of Borrelia burgdorferi sensu lato species.
Results: Among EM patients, both assays detected Borrelia DNA in 15 samples. Among ACA patients, the ospA PCR detected 15 positives and 10 samples were positive by 5S–23S PCR. In 19 samples one species was detected, 15 skin biopsies contained Borrelia afzelii , and Borrelia garinii was found in two patients. Group VS116 was detected in two EM patients, and therefore this group has pathogenic potential. Mixed infections of B. afzelii and B. garinii , group VS116 or B. burgdorferi sensu stricto were found in three EM and three ACA patients.
Conclusions: Diagnosis of EM and ACA by PCR is useful and knowledge of the presence of species may be used to predict the course of disease or the need for further antibiotics.     

Rapid differentiation of Borrelia garinii from Borrelia afzelii and Borrelia burgdorferi sensu stricto by LightCycler fluorescence melting curve analysis of a PCR product of the recA gene

To differentiate the Borrelia burgdorferi sensu lato genospecies, LightCycler real-time PCR was used for the fluorescence (SYBR Green I) melting curve analysis of borrelial recA gene PCR products. The specific melting temperature analyzed is a function of the GC/AT ratio, length, and nucleotide sequence of the amplified product. A total of 32 DNA samples were tested. Of them three were isolated from B. burgdorferi reference strains and 16 were isolated from B. burgdorferi strains cultured from Ixodes ricinus ticks; 13 were directly isolated from nine human biopsy specimens and four I. ricinus tick midguts. The melting temperature of B. garinii was 2 degrees C lower than that of B. burgdorferi sensu stricto and B. afzelii. Melting curve analysis offers a rapid alternative for identification and detection of B. burgdorferi sensu lato genospecies.     

Rate of infection ofIxodes ricinus ticks withBorrelia burgdorferi sensu stricto,Borrelia garinii,Borrelia afzelii and group VS116 in an endemic focus of Lyme disease in Italy

A study to evaluate the natural rate of infection ofIxodes ricinus withBorrelia burgdorferi sensu lato was carried out in an endemic focus of Lyme disease in the Trieste area in northern Italy. Two-hundred and twenty-seven ticks collected in ten different stations were tested individually for the presence of the spirochetes using polymerase chain reaction techniques able to identify bothBorrelia burgdorferi sensu lato and the four genospecies (Borrelia burgdorferi sensu stricto,Borrelia garinii, Borrelia afzelii and group VS116). Multiple infection of individual ticks was found. The infection rate ranged from 0–70%. Infection ofIxodes ricinus withBorrelia burgdorferi group VS116 was found for the first time in Italy in both a high and a low endemic focus of Lyme disease.     

Strain typing of Borrelia burgdorferi,Borrelia afzelii,and Borrelia garinii by using multiple-locus variable-number tandem repeat analysis

Human Lyme borreliosis (LB) is the most prevalent arthropod-borne infection in temperate climate zones around the world and is caused by Borrelia spirochetes. We have identified 10 variable-number tandem repeat (VNTR) loci present within the genome of Borrelia burgdorferi and subsequently developed a multiple-locus VNTR analysis (MLVA) typing system for this disease agent. We report here the successful application of MLVA for strain discrimination among a group of 41 globally diverse Borrelia isolates including B. burgdorferi, B. afzelii, and B. garinii. PCR assays displayed diversity at these loci, with total allele numbers ranging from two to nine and Nei's diversity (D) values ranging from 0.10 to 0.87. The average D value was 0.53 across all VNTR loci. A clear correlation exists between the repeat copy number and the D value (r = 0.62) or the number of alleles (r = 0.93) observed across diverse strains. Cluster analysis by the unweighted pair-group method with arithmetic means resolved the 30 observed unique Borrelia genotypes into five distinct groups. B. burgdorferi, B. afzelii, and B. garinii clustered into distinct affiliations, consistent with current 16S rRNA phylogeny studies. Genetic similarity and diversity suggest that B. afzelii and B. garinii are close relatives and were perhaps recently derived from B. burgdorferi. MLVA provides both phylogenetic relationships and additional resolution to discriminate among strains of Borrelia species. This new level of strain identification and discrimination will allow more detailed epidemiological and phylogenetic analysis in future studies.     

Recombinant Flagellin A Proteins from Borrelia burgdorferi Sensu Stricto, B. afzelii, and B. garinii in Serodiagnosis of Lyme Borreliosis

Genes for flagellin A (FlaA) proteins from European borrelial strains of Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii were cloned and sequenced. An identity of 92 to 93% was observed in the flaA sequences of the different species. Polyhistidine-tagged recombinant FlaA (rFlaA) proteins were produced in Escherichia coli and used as antigens in Western blotting (WB) and enzyme-linked immunosorbent assay (ELISA). In immunoglobulin G (IgG) WB, 71% (10 of 14) of the sera from neuroborreliosis and 86% (12 of 14) of those from Lyme arthritis patients reacted with one to three rFlaAs. In IgG ELISA, 74% (14 of 19) and 79% (15 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive. The immunoreactivity in local European patient sera was stronger against rFlaA from B. garinii and B. afzelii than against rFlaA from B. burgdorferi sensu stricto. Neither IgG nor IgM ELISA was sensitive in the serodiagnosis of erythema migrans. Serum samples from patients with syphilis and systemic lupus erythematosus showed mild cross-reactivity in IgG tests. Sera from Yersinia enterocolitica or beta-hemolytic Streptococcus infections showed only occasional responses. With IgM ELISA, 58% (11 of 19) and 37% (7 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive. Cross-reactive antibodies to FlaA, especially in serum samples from patients with rheumatoid factor positivity and Epstein-Barr virus infection, reduced the specificity of IgM serodiagnosis. Therefore, rFlaA seems to have a limited role for IgM serodiagnosis, yet rFlaA might be useful in the IgG serodiagnosis of disseminated Lyme borreliosis.     

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.     

Comparison of disseminated and nondisseminated strains of Borrelia burgdorferi sensu stricto in mice naturally infected by tick bite

Clinical isolates of Borrelia burgdorferi sensu stricto have been categorized into disseminated and nondisseminated groups based on distinct ribosomal spacer restriction fragment length polymorphism genotypes (RSTs). In order to determine whether transmission by tick bite would alter the dissemination dynamics and disease produced by distinct genotypes, disseminated isolates (RST1), nondisseminated isolates (RST3), and a standard laboratory strain (B-31) were established in a murine cycle utilizing infections transmitted by ticks. B-31 spirochetes circulated in the blood of inbred C3H/HeJ mice longer than in the blood of outbred mice. The majority of C3H mice exposed to RST1-infected ticks contained cultivable spirochetes in their blood for up to 17 days; in contrast, mice exposed to RST3 isolates demonstrated a precipitous decline in infection after day 7 postexposure. A quantitative PCR (q-PCR) assay demonstrated that the densities of spirochetes in blood were similar for the RST1 and RST3 isolates, except during the 2nd week postexposure, when the RST1 isolates displayed a markedly higher density in blood. Spirochete load in the heart and bladder of infected mice was measured by q-PCR at 8 weeks postexposure; the numbers of spirochetes in these tissues were similar for mice infected with either disseminated or nondisseminated strains. Similarly, histopathology samples of heart, bladder, and joint tissue obtained at 8 weeks postexposure did not reveal greater pathology in mice infected with the disseminated isolates. We conclude that although the spirochetemia induced by tick-transmitted disseminated isolates was more intense and of longer duration than that induced by nondisseminated isolates, the resultant pathologies produced by these strains were ultimately similar.     

Detection of genetic diversity in linear plasmids 28-3 and 36 in Borrelia burgdorferi sensu stricto isolates by subtractive hybridization

Recent studies based on sequence divergence in the ospC gene have identified limited subpopulations of B. burgdorferi associated with invasive human disease. Spirochetes with certain OspC types never cause human disease, while some others cause local infection at the primary skin site but do not hematogenously disseminate. Only four OspC genotypes (A, B, I and K) are responsible for disseminated disease and are found in the blood and cerebrospinal fluid, and hence are termed invasive strains. Subtractive hybridization was carried out between a prototype of a low passage invasive type, strain B31, and a strain associated only with local infection, group E, to identify genes associated with hematogenous dissemination. Two clones isolated from the subtraction library were unique to the B31 genome and mapped to locus BBH26 located on linear plasmid 28-3 (lp28-3) and to locus BBK48 located on linear plasmid 36 (lp36). Sequence analysis of the BBH26 locus revealed an amino acid repeat motif in the group E DNA that was absent in the B31 genome. This in-frame repeat motif was present yet variable in DNA isolated from several major OspC groups. However, no consistent sequence diversity was noted when other invasive and non-invasive strains were compared. In contrast, analysis of the BBK48 locus revealed a striking distinction between invasive and non-invasive spirochetes. PCR and Southern blot analysis indicated this locus was only present in invasive groups A, B, I, and K. BBK48 is a member of a gene family clustered on lp36. Therefore, these findings indicate that this genetic loci may participate in differentiating pathogens from non-pathogens and that its presence, which is correlated with ospC type, may play a role determining infectivity in humans.     

Identification and characterization of Lyme disease spirochetes, Borrelia burgdorferi sensu lato, isolated in Korea.

Lyme disease spirochetes, Borrelia burgdorferi sensu lato, were identified and characterized for the first time in Korea. Four isolates, designated Konkuk-1, Konkuk-2, Kangwon-3, and KM-4, were made from midgut suspensions of three Ixodes ticks and heart tissue from one mouse, Apodemus agrarius, collected from Chungbuk and Kangwon provinces. The four Korean isolates and B. burgdorferi sensu lato from other geographic areas and biological sources were compared by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis for protein profiles, Western blot (immunoblot) analysis for reactivities with monoclonal and polyclonal antibodies, and agarose gel electrophoresis for plasmid profiles. Two typing schemes using polymerase chain reaction identified three of the isolates as members of group VS461 and one, Kangwon-3, as Borrelia garinii. These results demonstrate the potential for human Lyme disease to occur in some provinces of Korea.