Enzyme-linked immunosorbent assay and indirect immunofluorescence assay for Lyme disease

The sensitivity and specificity of an indirect immunofluorescence assay (IFA) and ELISA for Lyme disease were estimated. Sera from patients with Lyme disease, patients with other infections, and healthy individuals were examined. Significant cross-reactivity occurred only with sera from patients with syphilis, yaws, and pinta . All tested sera from patients with Lyme disease, however, gave negative results in the rapid reagin screening test and the microhemagglutination assay for antibodies to Treponema pallidum confirmatory for syphilis. When sera from patients with treponemal diseases were excluded from the analysis, the IFA and ELISA were highly specific, having 97% and 100% reliability, respectively. Sensitivity of both tests varied with the stage of disease but was 100% for both tests during complicated Lyme disease. The results indicate that both tests are highly specific and sensitive for complicated Lyme disease but relatively insensitive for patients with erythema chronicum migrans alone.

Interleukin-8 and granulocyte elastase in gingival crevicular fluid in relation to periodontopathogens in untreated adult periodontitis

BACKGROUND

This study aimed to determine the relationships among interleukin (IL)-8 and granulocyte elastase levels in gingival crevicular fluid (GCF) and the concomitant presence of periodontopathogens in untreated adult periodontitis.

METHODS

GCF and subgingival plaque samples were collected from 16 patients with untreated adult periodontitis and 10 healthy control subjects. IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). Granulocyte elastase was analyzed with a neutrophilic granulocyte-specific, low molecular weight and chromogenic substrate, L-pyroglutamyl-L-prolyl-L-valine-p-nitroanilide, and the maximal rate of elastase activity (MR-EA) was calculated. Five DNA probes were used to detect the presence of A. actinomycetemcomitans (A.a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.).

RESULTS

Lower IL-8 concentrations and higher granulocyte elastase activities were found in patients than in healthy controls as well as in diseased conditions co-infected with B.f., P.g., P.i., and T.d. as compared to healthy conditions without the target species (P <0.05). IL-8 concentrations were positively correlated with MR-EA levels in the periodontitis conditions co-infected with B.f., P.g., P.i., and T.d. (P <0.05). A wide range of IL-8 concentrations was found among 15 patients when the periodontitis condition was characterized by co-infection with B.f., P.g., P.i., and T.d. MR-EA levels in the high IL-8 group of subjects were significantly higher than those in the low IL-8 group of subjects (P <0.01).

CONCLUSIONS

The present study shows that the local host-bacteria interactions in untreated periodontitis are diverse in terms of the intensity of inflammatory responses measured by IL-8-related granulocyte elastase activity in GCF. This might reflect different phases of the inflammatory response due to shifts in host-bacteria interactions and therefore be indicative of a range of periodontal disease activity levels.

TprK sequence diversity accumulates during infection of rabbits with Treponema pallidum subsp. pallidum Nichols strain

The tprK gene in Treponema pallidum undergoes antigenic variation. In all T. pallidum isolates examined to date, except the Nichols type strain, heterogeneous tprK sequences have been identified. This heterogeneity is localized to seven variable (V) regions, and tprK sequence diversity accumulates with serial passage in naïve rabbits. The T. pallidum Nichols genome described a single tprK sequence, and after decades of independent passage, only minor tprK sequence diversity is seen among the Nichols strains from different laboratories. We hypothesized that T. pallidum Nichols is capable of only limited tprK diversification. To address this hypothesis, we passaged the T. pallidum Nichols strain in naïve rabbits at the peak of infection (rapid passage) or after the adaptive immune response had cleared most organisms in vivo (slow passage). After 22 rapid passages (9- to 10-day intervals), no tprK V region sequence changes were observed. In contrast, after two slow passages (30- to 35-day intervals), three V regions had sequences that were completely different from that of the original inoculum. New sequences were observed in all seven V regions by the fifth slow passage. In contrast to the rapid-passaged Nichols strain, rapid-passaged Chicago C, a clonal strain isolated from the highly diverse parent Chicago strain, developed significant tprK diversification. These findings suggest that tprK variation can occur, but at a lower rate, in Nichols and that immune pressure may be required for accumulation of bacteria with diverse tprK sequences. Adaptation to growth in rabbits may explain the limited repertoire of V region sequences seen in the Nichols strain.

Characterization of the major outer membrane antigens of Treponema hyodysenteriae

Outer membrane extracts of Treponema hyodysenteriae were used to evaluate the antibody responses in immunized or convalescent pigs. Western blot (immunoblot) analysis identified antibodies in sera reactive with 14- to 19-kilodalton (kDa) antigens. Reactivity against these antigens could be removed only by absorption of sera with butanol-water-extracted endotoxin from the homologous strain of T. hyodysenteriae. Treatment of the outer membrane extracts with 0.1 M sodium meta-periodate, but not with proteinase K, abolished reactivity with both outer membrane and endotoxin antigens (14 and 19 kDa). These results indicate that swine vaccinated with the outer membrane extract of T. hyodysenteriae develop antibody responses to outer membrane antigens qualitatively similar to those of swine convalescing from active infection, especially antibodies against low-molecular-mass antigens. The nature of the 14- to 19-kDa antigens appears consistent with that of treponemal endotoxin and lipopolysaccharide.

Treponemal phospholipids inhibit innate immune responses induced by pathogen-associated molecular patterns

Host innate immune responses to microbial components, known as pathogen-associated molecular patterns (PAMPs), are regulated and modified by cellular receptors and serum proteins, including Toll-like receptors (TLRs), CD14, and LPS-binding protein (LBP). We demonstrated that a treponemal membrane lipid inhibited PAMPs-induced immune responses. The chemical structure of the lipid was elucidated as a phosphatidylglycerol (PG) derivative, which is scarce in most mammalian tissues, but relatively abundant in treponemal membrane lipids. Natural and synthetic PG counterparts as well as related natural anionic phospholipids, phosphatidylinositol, phosphatidylserine, and cardiolipin, also demonstrated an inhibitory effect. Further, we noted that PG inhibited PAMPs-induced immune responses by blocking the binding of PAMPs with LBP and CD14. In addition, PG decreased proinflammatory cytokine production in serum of LPS-injected mice and depressed abscess formation in mice infected with treponemes. These results suggest that treponemal phospholipid interfere the function of LBP/CD14 and act as a modulator of innate immune responses.

Enzyme-linked immunosorbent assay for detection of antibody to Treponema hyodysenteriae antigens

The enzyme-linked immunosorbent assay (ELISA) was evaluated and compared with the microtitration agglutination test for the detection of swine antibody to Treponema hyodysenteriae lipopolysaccharide antigens. Cells of T. hyodysenteriae serotypes 1 and 2 were extracted with hot phenol-water (68 degrees C). The lipopolysaccharide fraction from the aqueous phase was coated on plastic wells at concentrations of 1 micrograms (serotype 1) and 10 micrograms (serotype 2) of carbohydrate per ml. The ELISA was serotype specific when lipopolysaccharide antigens were reacted against sera from convalescent swine. Seroconversion of infected pigs was detectable with the ELISA within 1 to 2 weeks postinoculation and with the microtitration agglutination test 2 to 3 weeks postinoculation. Antibody titers could be detected in convalescent pigs as long as 19 weeks postinoculation by the ELISA and 12 to 13 weeks postinoculation by the microtitration agglutination test. Therefore, the ELISA may be useful for the detection of asymptomatic carriers.

Papillomatous digital dermatitis spirochetes suppress the bovine macrophage innate immune response

Papillomatous digital dermatitis (PDD) is a polymicrobial infection in soft tissue adjacent to the hoof and is the leading cause of lameness in dairy cattle. Treponema phagedenis-like (TPL) spirochetes are a constant feature of PDD lesions and are localized deep in infected tissue. Host-cell response mechanisms to TPL spirochetes are poorly understood. To assess how bovine macrophages respond to cellular constituents of TPL spirochetes, changes in transcription were analyzed using serial analysis of gene expression (SAGE) and real time RT-PCR. This analysis revealed that some proinflammatory cytokines (e.g. GCP-2 and IL-8) are induced in treated macrophages, while receptors and their accessory proteins for IL-1, IL-6 and IL-11 are either down regulated or unchanged. Two genes encoding proteins having negative effects on NFkappaB, IkappaB and SIVA-1, are significantly induced in stimulated cells. Several genes associated with the cytoskeleton and antigen presentation are down regulated after exposure to sonicated TPL spirochetes, as are genes associated with wound repair. Combined, these data suggest that the innate immune and wound repair functions of bovine macrophages exposed to TPL cellular constituents are impaired thereby enabling bacteria to resist clearance and induce lesion formation. Use of this in vitro bovine macrophage model should be useful in elucidating host-spirochete interactions and facilitate identification of potential virulence traits.

Lesion formation and antibody response induced by papillomatous digital dermatitis-associated spirochetes in a murine abscess model

Papillomatous digital dermatitis (PDD), also known as hairy heel wart, is a growing cause of lameness of cows in the U.S. dairy industry. Farms with PDD-afflicted cows experience economic loss due to treatment costs, decreased milk production, lower reproductive efficiency, and premature culling. While the exact cause of PDD is unknown, lesion development is associated with the presence of anaerobic spirochetes. This study was undertaken to investigate the virulence and antigenic relatedness of four previously isolated Treponema phagedenis-like spirochetes (1A, 3A, 4A, and 5B) by using a mouse abscess model with subcutaneous inoculation of 10(9), 10(10), and 10(11) spirochetes. Each of the PDD isolates induced abscess formation, with strain 3A causing cutaneous ulceration. Lesion development and antibody responses were dose dependent and differed significantly from those seen with the nonpathogenic human T. phagedenis strain. Strains 3A, 4A, and 5B showed two-way cross-reactivity with each other and a one-way cross-reaction with T. phagedenis. Strain 5B showed one-way cross-reactivity with 1A. None of the isolates showed cross-reactivity with T. denticola. In addition, distinct differences in immunoglobulin G subclass elicitation occurred between the PDD strains and T. phagedenis. From these data, we conclude that spirochetes isolated from PDD lesions have differential virulence and antigenic traits in vivo. Continuing investigation of these properties is important for the elucidation of virulence mechanisms and antigenic targets for vaccine development.

Identification of the major antigens of Treponema hyodysenteriae and comparison with those of Treponema innocens

Eleven strains of Treponema hyodysenteriae isolated from pigs with swine dysentery were examined by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. T. hyodysenteriae strains formed a homogeneous group with respect to sodium dodecyl sulfate-soluble proteins. However, immunoblotting with antiserum from rabbits immunized with T. hyodysenteriae CN8368 revealed heterogeneity among the lipopolysaccharide complexes of different strains. Polypeptides of molecular weights between 30,000 and 36,000 were the predominant T. hyodysenteriae polypeptides detected by porcine immune serum. In contrast, Treponema innocens did not form a homogeneous group with respect to sodium dodecyl sulfate-soluble proteins. Adsorption studies and immunoblotting identified polypeptide antigens present on cells of T. hyodysenteriae which were not detected on cells of T. innocens. These unique antigens may play a role in the virulence of T. hyodysenteriae.

VDRL antibodies enhance phagocytosis of Treponema pallidum by macrophages

Although reactivity in nontreponemal tests develops in patients with untreated syphilis, no immunologic function has been ascribed to these antibodies. This study demonstrates that rabbit antibodies induced by immunization with VDRL antigen and VDRL antibodies affinity-purified from syphilitic rabbit serum enhance phagocytosis of Treponema pallidum. The proportion of macrophages ingesting treponemes in the presence of these antisera was 45% +/- 5% and 27% +/- 4%, respectively, versus 14% +/- 3% for normal serum (P < .001 and P < .01). Both IgG and IgM fractions contained opsonic activity. Absorption of VDRL antibodies from syphilitic serum diminished but did not eliminate opsonization, suggesting at least two classes of target molecules. Despite opsonic capacity, VDRL antibodies fail to facilitate macrophage-mediated killing of T. pallidum. Nevertheless, VDRL-immunized rabbits are partially protected against T. pallidum infection, developing fewer lesions (delayed and smaller) than do unimmunized controls. These results suggest a heretofore unrecognized functional role for VDRL antibodies in syphilis infection.

Ocular manifestations of endemic syphilis (bejel)

Bejel or nonvenereal syphilis is a treponemal infection that is still endemic in many parts of the world including Saudi Arabia. The authors have examined 17 patients with clinical findings consistent with bejel. All patients had positive serologic tests for bejel. There were 11 male and six female patients, with a mean age of 54 years (range, 37-73 years). Results of clinical examination showed uveitis in nine patients, optic atrophy in six, and chorioretinitis scars in six. In four patients who needed intraocular surgery, two aqueous specimens showed positive antibodies for Treponema pallidum.

Serotype-specific protection against Treponema hyodysenteriae infection in ligated colonic loops of pigs recovered from swine dysentery

Resistance to Treponema hyodysenteriae (serotypes 1, 2, 3, and 4) infection was evaluated in ligated colonic loops in pigs recovered from swine dysentery. Lesions were present in most loops from recovered swine inoculated with heterologous serotypes; however, lesions were not present in loops of recovered swine inoculated with homologous serotypes.

Molecular characterization of proteins from porcine spirochetes

Sonicated preparations of Treponema hyodysenteriae and Treponema innocens were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis. Treponemal proteins were electrophoresed on a 10% polyacrylamide slab gel in a discontinuous Tris-glycine system and either stained with Coomassie blue dye or transferred electrophoretically at 20 mA for 16 h and 30 mA for 3 h to nitrocellulose paper. Staining of the gels revealed at least 42 distinct T. hyodysenteriae and T. innocens proteins, with molecular sizes ranging from greater than 100 to 14 kilodaltons (kDa). Each species contained 12 to 16 major protein bands; five of the proteins were common to both species. Fourteen major antigens were identified in T. hyodysenteriae isolate B204 by using serum specimens from pigs in the acute stage of swine dysentery. Twelve additional antigens were detected in isolate B204 when convalescent-phase serum specimens were reacted to the blot. A wide band at 16 kDa was identified with convalescent-phase serum specimens in T. hyodysenteriae but not in T. innocens. This 16-kDa antigen was also identified in T. hyodysenteriae with colonic secretions from convalescent pigs.

Detection of nonspecific resistance to Listeria monocytogenes in rabbits infected with Treponema pallidum

Several lines of evidence suggest that cell-mediated immunity (CMI) is suppressed in the early stages of infection caused by Treponema pallidum and becomes activated at the time that latency is induced. In the studies reported in this paper, rabbits were infected intravenously with T. pallidum and subsequently challenged with Listeria monocytogenes. Enhanced ability to suppress the growth of Listeria was detected in their livers between 3 and 5 weeks after infection with T. pallidum, corresponding to the onset and regression of the generalized syphilitic eruption. A second infection of T. pallidum 4 weeks after the first, at a time when suppression was beginning to wane, prolonged the listericidal activity. These observations support the hypothesis that infection by T. pallidum stimulates CMI, which, in turn, may play a role in inducing latency.

Automated, quantitative microhemagglutination assay for Treponema pallidum antibodies

An automated, quantitative microhemagglutination assay for antibodies to Treponema pallidum was developed by using T. pallidum-sensitized erythrocytes and an automatic serial-dilution instrument. Reactivity was found in sera from 54 rabbits and 6 chimpanzees infected with T. pallidum. Reactivity was also found in sera from animals infected with T. pertenue, T. carateum, and T. cuniculi. No reactivity was found in sera from 75 normal rabbits or from 129 rabbits immunized with cultivatable treponemes or a variety of other bacteria. In approximately 3 min, 13 twofold serial dilutions of each of 8 preabsorbed sera and the addition of sensitized erythrocytes to each dilution were accomplished automatically. The automated assay can serve as a research tool in quantitating antibodies to pathogenic treponemes, and evaluation of its clinical usefulness seems warranted.

Serological reactions with treponemal antigens in nonhuman primates and the natural history of treponematosis in man

Treponemal reagins were studied in the sera of 125 nonhuman primates belonging to 9 species. Seven sera were reactive, and 13 were weakly reactive. Spinal fluids available from the reactive group yielded negative results. The animals did not show clinical signs of treponemal disease. Most of the species with positive reactions have had little or no contact with man. All primates except one with positive serology came from wet tropical forest areas. If the positive results were actually due to treponemal infection, the causative agent may be related to that of yaws rather than to those of syphilis or pinta. The presence of enzootic treponematosis in apes and monkeys is suspected.

Molecular characterization of Treponema denticola infection-induced bone and soft tissue transcriptional profiles

Treponema denticola is associated with subgingival biofilms in adult periodontitis and with acute necrotizing ulcerative gingivitis. However, the molecular mechanisms by which T. denticola impacts periodontal inflammation and alveolar bone resorption remain unclear. Here, we examined changes in the host transcriptional profiles during a T. denticola infection using a murine calvarial model of inflammation and bone resorption. T. denticola was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and the calvarial bones were excised. RNA was isolated and analysed for transcript profiling using Murine GeneChip arrays. Following T. denticola infection, 2905 and 1234 genes in the infected calvarial bones and soft tissues, respectively, were differentially expressed (P Collapse

Key Words

• calvarial bone
• gene expression
• microarray
• tissue
• treponema denticola

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MESH Headings

• Animals
• Antibodies, Bacterial/blood
• Bone Resorption/genetics
• Bone Resorption/immunology
• Bone Resorption/microbiology
• Cytokines/biosynthesis
• Cytokines/genetics
• Epithelial Cells/microbiology
• Female
• Gene Expression Profiling
• Host-Pathogen Interactions
• Inflammation Mediators/metabolism
• Mice
• Mice, Inbred BALB C
• Oligonucleotide Array Sequence Analysis
• Osteocytes/microbiology
• Reverse Transcriptase Polymerase Chain Reaction
• Skull
• Transcriptional Activation
• Treponema denticola/physiology
• Treponemal Infections/genetics
• Treponemal Infections/immunology

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Grants

• R01 AR043510 NIAMS NIH HHS
• R01 DE015720 NIDCR NIH HHS
• AR43510 NIAMS NIH HHS
• DE015720 NIDCR NIH HHS

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Collaborators Collapse

Experimental infection of man with rabbit-virulent Treponema paraluis-cuniculi

Virulent Treponema paraluis-cuniculi was inoculated intradermally into the arm of a human volunteer and into the shaved backs of 10 rabbits. An identical, but heat-killed, preparation was inoculated into the opposite arm of the volunteer as control. A superficial and transient infection developed in the volunteer, shown by a small zone of erythema that persisted for 24 days. The control preparation caused a smaller zone of erythema that disappeared after five days. A very poor immune response was detected by standard serological tests for syphilis. The inoculated rabbits developed lesions about six days after infection and seroconverted by 84 days. The poor antitreponemal antibody response to T paraluis-cuniculi infection in the volunteer suggests that this naturally attenuated treponeme may not be suitable as a vaccine against infection with t pallidum in humans.

A new look at the serology of treponemal disease

The serology of treponemal disease has become simpler and more rational in recent years, mainly as a result of the widespread adoption of specific antibody tests and the use of monospecific fluorescent antibody procedures which give information about the immunoglobulin class of antibodies. A set of tests which has proved particularly useful in routine diagnosis is the following: quantitative TPHA test, quantitative VDRL test, and monospecific (IgG and IgM) FTA-ABS tests. This combination is especially valuable in the assessment of new patients with positive results to serological tests and in the management of patients with treated syphilis.

Treponema denticola immunoinhibitory protein induces irreversible G1 arrest in activated human lymphocytes

Oral spirochetes may contribute to the pathogenesis of a number of disorders including periodontal and periradicular diseases; however, the mechanism (s) by which these organisms act to cause disease is unknown. We have previously shown that extracts of the oral spirochete, Treponema denticola, contain an immunosuppressive protein (Sip) which impairs human lymphocyte proliferation. The objective of this study was to determine the mechanism by which Sip alters the proliferative response of lymphocytes. Human T-cells were activated by PHA in the presence or absence of Sip and cell cycle progression was assessed by flow cytometry. Cell cycle distribution was based upon DNA, RNA and protein content as well as expression of the activation markers; CD69 and IL-2R. Seventy-two hours following activation with PHA, cells were found in the G0, G1, S and G2/M phases of the cell cycle. In contrast, pretreatment with Sip resulted in a significant reduction of cells in the S and G2/M phases and a concomitant increase in the G1 phase. Sip did not alter the expression of the early activation markers CD69 and CD25R. To determine if G1 arrest resulted in activation of the checkpoint and cell death, we also monitored Sip-treated cells for apoptosis. Indeed, treatment with Sip resulted in both DNA fragmentation and caspase activation after 96 h. Our results indicate that Sip induces G1 arrest in human T-cells and, furthermore, that the arrest is irreversible, culminating in activation of the apoptotic cascade. We propose that if cell cycle arrest occurs in vivo, it may result in local and/or systemic immunosuppression and thereby enhance the pathogenicity of spirochetes and/or that of other opportunistic organisms.

Diagnosis of swine dysentery using an absorbed fluorescent antiserum

The specifity of a direct fluorescent antibody test for the detection of pathogenic Treponema hyodysenteriae associated with swine dysentery was improved by absorbing the original conjugated serum with a non pathogenic treponeme.

Immune T cells sorted by flow cytometry confer protection against infection with Treponema pallidum subsp. pertenue in hamsters

The role of cell-mediated immunity against infection with Treponema pallidum subsp. pertenue in humans or experimental animals is unclear. Hamsters injected subcutaneously in the hind paws with 4 x 10(6) unfractionated lymph node cells or enriched lymph node T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters were resistant to challenge with T. pallidum subsp. pertenue. The popliteal lymph nodes of hamsters that received immune cells weighed less and had significantly fewer treponemes than did lymph nodes from hamsters infused with cells from nonimmune donors. Furthermore, recipients of immune T cells failed to develop antitreponemal antibodies 21 days after challenge. Enriched T cells were obtained by flow cytometric separation by using monoclonal anti-Ia antibody 14-4-4s, which identified hamster B cells. Flow cytometric analysis by two-color immunofluorescent staining with anti-hamster-immunoglobulin and monoclonal anti-Ia antibody 14-4-4s confirmed that monoclonal anti-Ia antibody 14-4-4s recognized B cells. In addition, lymph node cells obtained after treatment with anti-Ia monoclonal antibody 14-4-4s and complement were 97% T cells, as determined by monoclonal antibody 20, a hamster T-cell marker. These results demonstrated that highly enriched T cells (immunoglobulin negative, Ia negative) from T. pallidum subsp. pertenue-immune hamsters conferred partial protection on hamsters against infection with T. pallidum subsp. pertenue.

A study of swine dysentery by immunofluorescence and histology

Twenty-six specific-pathogen-free pigs were fed pure cultures of Treponema hyodysenteriae. Five untreated pigs were controls. Distribution of this large spirochete in pigs with swine dysentery was shown by the indirect fluorescent antibody technique. Findings by this method were compared with those from dark-field examination of colonic mucosal scrapings and from tissue sections. The cultures caused mucohemorrhagic colitis which by 10 days after inoculation was indistinguishable from the colitis of swine dysentery. Control pigs remained normal. Pigs killed when spirochetes were first seen in the feces had normal colonic mucosa with only a few spirochetes. At the first sign of diarrhea, however, the colonic mucosa was thicker than normal and had many spirochetes. T. hyodysenteriae was confined to regions of hypertrophy and exudation of the large intestine mucosa throughout the course of disease.

Application and evaluation of enzyme-linked immunosorbent assay and immunoblotting for detection of antibodies to Treponema hyodysenteriae in swine

An enzyme-linked immunoassay (ELISA) has been developed to detect serum Immunoglobulin antibodies G and M to Treponema hyodysenteriae in vaccinated, experimentally infected and naturally infected swine. Naturally infected swine gave ELISA titres that were similar to experimentally infected swine, but were significantly less than the titres of vaccinated swine. When serum from naturally infected swine was used to probe nitrocellulose blots of sodium dodecyl sulphate-polyacrylamide gel electrophoresed whole cell proteins of T. hyodysenteriae, the immunoblotting patterns showed IgG antibodies were produced against many T. hyodysenteriae protein antigens and against lipopolysaccharide (LPS). The IgG antibodies directed against LPS were serotype-specific for that LPS and could be used to identify the serotype involved in the T. hyodysenteriae infection in that herd. IgM immunoblots also reacted with the many protein antigens but were less specific for LPS antigen, with a substantial degree of cross-reaction between the LPS of all serotypes. The data demonstrate that a microplate enzyme-linked immunosorbent assay, coupled with immunoblotting, is a very specific and sensitive test for detection of antibody to Treponema hyodysenteriae in swine.