Distribution of the clpX gene in Brachyspira species and reactivity of recombinant Brachyspira pilosicoli ClpX with sera from mice and humans

Previously, aclpXgene encoding a predicted 67 kDa membrane-associated ATPase subunit of the Clp protease (ClpX) was identified in a porcine strain (95/1000) of the intestinal spirochaeteBrachyspira pilosicoli.In the current study, the distribution of this largeclpXgene was investigated in a collection of strains representing all sevenBrachyspiraspp. Using PCR with internal primers, an 878 bp portion of the gene was detected in 29 of 35 strains (83 %) ofB. pilosicoli, 6 of 24 strains (25 %) ofBrachyspira hyodysenteriae, 14 of 16 strains (88 %) ofBrachyspira intermedia, 6 of 17 strains (35 %) ofBrachyspira innocens, 1 of 6 strains (17 %) ofBrachyspira murdochii, 1 of 2 strains (50 %) ofBrachyspira aalborgiand not in the single strain ofBrachyspira alvinipulli. The whole gene was sequenced from 20Brachyspiraspp. strains and compared with theclpXgene fromB. pilosicoli95/1000 (GenBank accession no. AY466377). The genes had 99.3–99.7 % nucleotide sequence similarity and the predicted products had 99.7–100 % amino acid sequence similarity. TheclpXgene from WesB, a human strain ofB. pilosicoli, was cloned and expressed as a histidine-tagged fusion protein inEscherichia coliBL21. The purified protein was used to vaccinate mice and their sera were found to recognize the expected ∼67 kDa protein in whole-cell preparations of WesB. Sera from mice vaccinated with formalin-treated whole-cell proteins of WesB reacted with the recombinant protein. These results indicate that ClpX is both conserved and immunogenic and hence might be useful as a subunit vaccine component forBrachyspiraspp. infections. Sera from humans with no known exposure toB. pilosicolireacted with the recombinant ClpX protein, indicating that it is unlikely to be useful as a reagent for serological detection ofBrachyspiraspp. infections.

The specific antibody to Brachyspira aalborgi in serum obtained from a patient with intestinal spirochetosis

Serum obtained from a patient histopathologically diagnosed as intestinal spirochetosis was investigated serodiagnostically by agglutination test. B. aalborgi which is a human intestinal spirochete reacted strongly with the human serum, while B. pilosicoli which has potential pathogenicity to humans reacted with the serum, but as strongly and its titer was different than the other three species. On the other hand, intestinal spirochetes (Matsumoto isolates) were isolated from the biopsy samples of the patient. The morphological, biochemical, and genetic characteristics of the isolates were very similar to those of B. aalborgi. Furthermore, the protein profiles of the Matsumoto isolates were also similar to those of B. aalborgi but were different than those of B. pilosicoli and B. hyodysenteriae. The reaction profiles of the Matsumoto isolates in immunoblotting were relatively similar to those of B. aalborgi except for a 74 kDa band but were different from those of B. pilosicoli and B. hyodysenteriae. Therefore, we identified the Matsumoto isolates as B. aalborgi and diagnosed the patient with a B. aalborgi infection.

Symptomatic colonic spirochaetosis in an immunocompetent patient

Spirochaetes are organisms that can infect the colon of people with normal or compromised immune systems. Infected patients can present with a variety of gastrointestinal symptoms, including diarrhoea and rectal bleeding. However, some report a lack of association between specific symptoms and the presence of spirochaetes. It is therefore unclear whether the spirochaetes colonising the colon are true pathogens. Diagnosis is typically made by histological examination, with the biopsy specimen showing a band-like growth of spirochaetes adherent to the colonic luminal surface, giving an accentuated brush-border appearance. A course of metronidazole can eliminate the spirochaetes, but treatment might not lead to improvement of symptoms. Owing to the lack of a definite association between symptoms and the presence of spirochaetes, observation without specific antibiotic treatment can be pursued in most patients.

Consecutive pathological and immunological alterations during experimentally induced swine dysentery - a study performed by repeated endoscopy and biopsy samplings through an intestinal cannula

The development of intestinal lesions after inoculation with Brachyspira hyodysenteriae was followed by repeated endoscopy and biopsy sampling through a caecal cannula. Seven eight-week-old pigs were cannulated and inoculated, two were cannulated but not inoculated, and two pigs were inoculated but not cannulated. Endoscopy, biopsy, and blood sampling to determine SAA (serum amyloid A), haptoglobin, cortisol, and WBC counts were performed at scheduled time-points. At the third day of disease, endoscopy showed a hyperaemic, perturbed mucosa and excessive amount of mucus. Histologically, crypt hyperplasia, depletion of goblet cell mucus, and erosions were noted. Simultaneously, elevated acute phase proteins and circulating monocytes, and decreased number of intraepithelial CD3⁺ cells were observed. After five days the pigs recovered. Intestinal lesions were demarcated and interspersed among apparently normal mucosa and blood parameters returned to initial values. Endoscopy through an intestinal cannula made it possible to follow the development of intestinal alterations in vivo and describe the sequential events during the course of swine dysentery. The number of animals used in a study could thus be minimised and the precision of the experiment increased.

Immunological alterations during the clinical and recovery phases of experimental swine dysentery

The aim of this study was to examine changes in the systemic immune response during the incubation period and following the onset of clinical swine dysentery, including the recovery period. Ten healthy conventional pigs were inoculated with Brachyspira hyodysenteriae. Blood was sampled at pre-inoculation, at days 4 and 14 post-inoculation, during the first 4 days with clinical signs of dysentery and at days 1, 3, 7, 11 and 15 of the recovery period. Eight pigs developed haemorrhagic diarrhoea. Flow-cytometric analyses of lymphocyte subpopulations showed that all animals, including the two that remained healthy, had an increase in CD8alpha+ CD4- cells and gammadelta T cells at days 4 and 14 post-inoculation. In addition, an increase in CD4+ CD8alpha+ cells and CD8alpha+ CD8beta+ cells was observed at days 4 and 14 post-inoculation in animals that developed dysentery. During clinical signs of dysentery, the acute-phase protein serum amyloid A was increased. There was a two- to threefold increase in both neutrophils and monocytes during signs of dysentery and at the beginning of the recovery period. The numbers of CD8alpha+ CD8beta- CD4-, CD45RA- lymphocytes also increased during the dysentery period. Circulating CD21+ cells and CD21+ CD45RA- cells decreased at the end of the incubation period, during signs of dysentery and at the beginning of the recovery period. The dysentery-affected animals developed antibodies to B. hyodysenteriae-specific antigens (approximately 16 kDa and approximately 30 kDa) from the first day of recovery, and gammadelta T cells showed an increase during the recovery period. In comparison with pre-inoculation, increased numbers of monocytes, neutrophils, CD8alpha+ CD8beta- CD4- lymphocytes and CD45RA- lymphocytes were observed during clinical dysentery. Increased numbers of neutrophils, gammadelta T cells and specific antibodies were seen during the recovery period.

Induction of differential immune reactivity to members of the flora of gnotobiotic mice following colonization with Helicobacter bilis or Brachyspira hyodysenteriae

Aberrant host immune responses to bacterial components of the resident microflora may initiate and perpetuate gastrointestinal inflammation. To investigate how microbial perturbation promotes host immunological responsiveness to commensal bacteria and contributes to the development of typhlocolitis, we selectively colonized defined (altered Schaedler) flora C3H mice with either Helicobacter bilis or Brachyspira hyodysenteriae. Following selective colonization, tissues were analyzed for gross/histopathologic lesions and bacterial antigen-specific B- and T-cell responses. Gnotobiotic mice colonized with H. bilis or B. hyodysenteriae developed typhlocolitis of varying severity, with the most severe gross and histopathogical lesions observed in B. hyodysenteriae-colonized mice. Antigen-specific IgG1 and IgG2a responses to the resident microflora were increased in both H. bilis-and B. hyodysenteriae-colonized mice. The greater antibody responses were associated with less severe cecal inflammation in H. bilis-colonized mice. Altered Schaedler flora (ASF)-stimulated mesenteric lymphocytes from B. hyodysenteriae-colonized mice produced higher levels of interferon-gamma and interleukin (IL)-4 than did lymphocytes from H. bilis-colonized mice. However, ASF-stimulated mesenteric and splenic lymphocytes from both H. bilis and B. hyodysenteriae-colonized mice secreted higher amounts of IL-10 compared to similarly stimulated lymphocytes recovered from control mice. These results indicate that microbial perturbation may induce differential immune responses to nonpathogenic resident bacteria that can lead to intestinal inflammation.

Lipoprotein-dependent and -independent immune responses to spirochetal infection

In this study, we used the epidermal suction blister technique, in conjunction with multiparameter flow cytometry, to analyze the cellular and cytokine responses elicited by intradermal injection of human volunteers with synthetic analogs for spirochetal lipoproteins and compared the responses to findings previously reported from patients with erythema migrans (EM). Compared with peripheral blood (PB), lipopeptides derived from the N termini of the Borrelia burgdorferi outer surface protein C and the 17-kDa lipoprotein of Treponema pallidum (OspC-L and 17-L, respectively) elicited infiltrates enriched in monocytes/macrophages and dendritic cells (DCs) but also containing substantial percentages of neutrophils and T cells. Monocytoid (CD11c(+)) and plasmacytoid (CD11c(-)) DCs were selectively recruited to the skin in ratios similar to those in PB, but only the former expressed the activation/maturation surface markers CD80, CD83, and DC-SIGN. Monocytes/macrophages and monocytoid DCs, but not plasmacytoid DCs, displayed significant increases in surface expression of Toll-like receptor 1 (TLR1), TLR2, and TLR4. Staining for CD45RO and CD27 revealed that lipopeptides preferentially recruited antigen-experienced T-cell subsets; despite their lack of antigenicity, these agonists induced marked T-cell activation, as evidenced by surface expression of CD69, CD25, and CD71. Lipopeptides also induced significant increases in interleukin 12 (IL-12), IL-10, gamma interferon, and most notably IL-6 without corresponding increases in serum levels of these cytokines. Although lipopeptides and EM lesional infiltrates shared many similarities, differences were noted in a number of immunologic parameters. These studies have provided in situ evidence for a prominent "lipoprotein effect" during human infection while at the same time helping to pinpoint aspects of the cutaneous response that are uniquely driven by spirochetal pathogens.

Proposed mechanisms and preventative options of Jarisch-Herxheimer reactions

OBJECTIVE

To review the aetiologies and preventative methods associated with Jarisch-Herxheimer reactions (JHR).

DATA SOURCES

Ovid Medline (1966-June Week 1 2004) was utilized to assess biomedical literature; a review of the bibliographies of articles was also performed.

DATA SYNTHESIS

JHR often occurs with the treatment of spirochete infections. However, the mechanism by which the reaction takes place is not clearly defined.

CONCLUSION

Studies suggest with conflicting evidence that the JHR is caused by release of endotoxin-like material from the spirochete as well as cytokine elevation in the body. It appears the type of drug and the rate of spirochete clearance from the body have little effect on the incidence of the reaction. Many pretreatment options have been explored with limited efficacy with the exception of anti-tumour necrosis factor antibodies.

Protection of pigs from swine dysentery by vaccination with recombinant BmpB, a 29.7 kDa outer-membrane lipoprotein of Brachyspira hyodysenteriae

Swine dysentery (SD) is an important endemic infection in many piggeries, and control can be problematic. In this study the efficacy of BmpB, a 29.7 kDa outer-membrane lipoprotein of Brachyspira hyodysenteriae, was evaluated as an SD vaccine. Non-lipidated BmpB was expressed in Escherichia coli as a histidine-tagged protein (His6-BmpB), or as an 8 kDa carboxy-terminal portion fused to maltose-binding protein (MBP-BmpB-F604). The purified proteins were emulsified with oil-based adjuvants for intramuscular (im) administrations. In experiment 1, 20 weaner pigs were vaccinated im with 1 mg of His6-BmpB. After 3 weeks, 10 received 1 mg of the protein orally (im/oral), and 10 received 1 mg im (im/im). Ten acted as unvaccinated controls. In experiment 2, 12 pigs were vaccinated im with 1 mg of His6-BmpB, and 12 with 1 mg of MBP-BmpB-F604. Three weeks later, each was given 1 mg of the same protein orally. Twelve pigs acted as unvaccinated controls. All pigs were challenged orally with B. hyodysenteriae 2 weeks after their second vaccination. In both experiments, all pigs vaccinated with His6-BmpB developed serum antibodies to BmpB, and oral administration provided boosting of im-induced serum antibody titres. In experiment 1, seven non-vaccinated control pigs developed dysentery and severe colitis. Three pigs vaccinated im/oral developed diarrhoea; two had severe colitis and one had mild lesions. Four pigs vaccinated im/im developed diarrhoea; one had severe colitis and the others had mild lesions. In experiment 2, six control pigs developed SD with severe colitis. Two His6-BmpB vaccinated pigs developed SD with mild colitis. Nine pigs vaccinated with MBP-BmpB-F604 developed SD and severe colitis. Overall, 50-70% of controls and 17-40% of His6-BmpB vaccinated pigs developed disease. Vaccination with MBP-BmpB-F604 did not induce serum titres against BmpB, nor confer protection. The incidence of disease for the three His6-BmpB vaccinated groups was significantly less (P = 0.047) than for the control groups, with a approximately 50% reduction. BmpB appears to have potential as an SD vaccine component.

Differences in lymphocyte subpopulations and cell counts before and after experimentally induced swine dysentery

The aim of this study was to examine the levels of circulating leukocytes and lymphocyte subpopulations before and immediately after experimentally induced swine dysentery. Twenty-one healthy crossbred pigs (approximately 22 kg) were orally inoculated with Brachyspira hyodysenteriae. Blood was sampled before inoculation and when clinical signs of swine dysentery occurred. Pigs that remained healthy were sampled when killed. Total and differential white blood cell counts were performed, and lymphocyte subpopulations were analysed using flow cytometry. Following a mean incubation period of 13 days, 12 pigs developed swine dysentery, whereas nine remained healthy throughout the study. Before inoculation, pigs that subsequently developed swine dysentery displayed higher levels of circulating gamma delta T cells (mean +/- se; 30.7 +/- 3.5 %) compared with pigs that remained healthy (14.9 +/- 1.4 %). Sick animals also displayed lower levels of CD8 cells (24.6 +/- 1.5 %), cytotoxic/suppressor T cells (10.9 +/- 1.3 %) and CD4 CD8 T cells (8.1 +/- 1.0 %) than the pigs that remained healthy (34.9 +/- 3.1 %; 17.6 +/- 2.0 %; 13.6 +/- 2.3 %). No difference was observed in leukocyte counts before inoculation. At onset of swine dysentery, there was an increase in monocytes (from 1.5 +/- 0.2 x 10 to 3.8 +/- 0.5 x 10 l) and CD4 CD8 T cells (from 5.8 +/- 0.9 to 8.9 +/- 0.7 %). In conclusion, gamma delta T cells and CD8 cells may be associated with susceptibility to experimentally induced swine dysentery, whereas monocytes and CD4 CD8 T cells appear to be the major responding leukocytes during the disease.

Differential requirements for proliferation of CD4+ and γδ+ T cells to spirochetal antigens

Alphabeta+ and gammadelta+ T cells have different mechanisms of epitope recognition and are stimulated by antigens of different chemical nature. An immunization model with antigens from the spirochete Brachyspira hyodysenteriae was used to examine the requirements for proliferation of circulating porcine CD4+ and gammadelta+ T cells in mixed lymphocyte cultures. CD4+ T cells only responded to stimulation with B. hyodysenteriae antigens, whereas gammadelta+ T cells proliferated when cultures were stimulated with either spirochetal antigens or interleukin-2 (IL-2). T cells that had proliferated expressed high levels of IL-2-receptor-alpha (IL-2Ralpha). Furthermore, neutralization of IL-2 at the beginning of the culture period was more efficient in blocking gammadelta+ than CD4+ T cell proliferation. Immunization induced interferon-gamma (IFN-gamma) production by CD4+ T cells, whereas only a small fraction of the antigen-stimulated gammadelta+ T cells produced this cytokine. Our results indicate that, under the same environmental conditions, CD4+ T cell functions are more tightly regulated when compared to gammadelta+ T cells. We conclude that these differences are due, in part, to the enhanced gammadelta+ T cell responsiveness to IL-2.

Serologic detection of Brachyspira (Serpulina) hyodysenteriae infections

Swine dysentery (SD) caused by the intestinal spirochete Brachyspira hyodysenteriae is an economically important disease in pig-producing countries throughout the world. To date, no specific serologic assay is commercially available for the diagnosis of pigs with SD. Several serologic techniques have been identified in the past; however, these tests have all used either whole-cell proteins or lipopolysaccharide (LPS) as the antigen. Whole-cell antigens are plagued with false-positive reactions due to cross-reactivity with common proteins shared with other spirochetes. LPS antigens produce fewer false-positives; however, false-negatives may result due to LPS components being serogroup-specific. Generally, these techniques are useful for detecting infected herds, but are unreliable for the detection of individual infected pigs. In order to develop improved serologic tests it will be necessary to identify suitable diagnostic antigens, in particular immunogenic cell-surface structures which are specific to B. hyodysenteriae but common amongst different strains of the species. Recently, we identified and cloned a 30-kDa outer membrane lipoprotein (BmpB) which is specific to B. hyodysenteriae and is recognized by experimentally and naturally infected pigs. In this review we summarize the available serologic tests for SD, and speculate on the use of recombinant BmpB as an antigen for future development of an improved serologic test for SD diagnosis.

Antigen-specific proliferation of porcine CD8alphaalpha cells to an extracellular bacterial pathogen

A vaccine inducing protective immunity to a spirochaete-induced colitis of pigs predominantly stimulates expansion of CD8+ cells in vivo and in antigen-stimulated lymphocyte cultures. CD8+ cells, however, are rarely considered necessary for protection against extracellular bacterial pathogens. In the present study, pigs recovering from colitis resulting from experimental infection with Brachyspira (Serpulina) hyodysenteriae had increased percentages of peripheral blood CD4- CD8+ (alphaalpha-expressing) cells compared with non-infected pigs. CD8alphaalpha+ cells proliferated in antigen-stimulated cultures of peripheral blood mononuclear cells from B. hyodysenteriae-vaccinated pigs. Proliferating CD8alphaalpha+ cells consisted of CD4-, CD4+ and gammadelta T-cell receptor-positive cells. CD4- CD8alphabeta+ cells from vaccinated or infected pigs did not proliferate upon in vitro antigen stimulation. Of the CD8alphaalpha cells that had proliferated, flow cytometric analysis indicated that the majority of the CD4+ CD8+ cells were large (i.e. lymphoblasts) whereas the CD4- CD8+ cells were predominantly small. Addition of monoclonal antibodies (mAb) specific for either porcine major histocompatibility complex (MHC) class I or class II antigens diminished B. hyodysenteriae-specific proliferative responses whereas addition of mAb to porcine MHC II, but not porcine MHC I, reduced the CD8alphaalpha response. In vitro depletion of CD4+ cells by flow cytometric cell sorting diminished, but did not completely abrogate, the proliferative response of cells from vaccinated pigs to B. hyodysenteriae antigen stimulation. These results suggest that CD8alphaalpha cells are involved in recovery and possibly protection from a spirochaete-induced colitis of pigs; yet, this response appears to be partially dependent upon CD4+ cells.

Reduction in inflammation following blockade of CD18 or CD29 adhesive pathways during the acute phase of a spirochetal-induced colitis in mice

Colitis develops in mice infected with Brachyspira (Serpulina) hyodysenteriae. Numerous granulocytes (PMNs) are evident in cecal tissue sections 24-48 h post-infection. The role of PMNs was assessed by utilizing monoclonal antibodies specific for CD18 or CD29 to block PMN recruitment. Macroscopic lesions were less severe in mice treated with either monoclonal antibody compared to lesions observed in isotype control-treated mice. While these monoclonal antibodies may inhibit extravasation of other leukocytes, the central role of PMNs was further demonstrated in that colitis was reduced following neutrophil depletion. There was less edema and epithelial erosions in ceca of mice receiving anti-Ly6G, -CD18 or -CD29 monoclonal antibody compared to mice receiving the control. Moreover, there was a significant reduction in PMN infiltration in tissues of mice treated with anti-CD18. The reduction in infiltrating PMNs did not result from downregulation of neutrophil chemoattractant MIP-2 expression in anti-CD18-treated mice. In contrast, PMN recruitment into the cecum was apparently CD29-independent. It is noteworthy that the number of PMNs observed in anti-CD18-treated mice was significantly higher than observed in non-infected mice. The data provide evidence for a threshold number of PMNs necessary for lesion development and indicate that CD18, but not CD29, adhesive pathways are crucial for PMN recruitment in bacterial colitis.

Presence of 22-kDa protein reacting with sera in piglets experimentally infected with Brachyspira hyodysenteriae

In order to examine the effect of spectinomycin on outbreaks of swine dysentery, experimental infection of piglets with Brachyspira hyodysenteriae was carried out. Feed with and without spectinomycin (SP) was given to each piglet ad libitum and the susceptibility of the piglets to infection with B. hyodysenteriae was compared between SP-treated and untreated piglets. The results showed that the SP-treated piglets did not display clinical signs of swine dysentery unlike the untreated piglets. The sera obtained from these piglets were examined by the microscopic agglutination test and antibodies to B. hyodysenteriae in both groups of experimentally infected piglets were detected and the reaction was serogroup-specific. The agglutination titers were very high in the untreated piglets with dysentery while the titers in the SP-treated piglets were lower than those in the untreated piglets. In addition, the immunoblotting technique was applied and the results demonstrated that 22- and 17-kDa proteins in strain ATCC 31212 (serogroup B) reacted strongly with the sera from the untreated piglets but not with the sera from the SP-treated piglets. The 22- and 17-kDa proteins also reacted with strain ATCC 27164 (serogroup A) which belongs to a different serogroup. The 22- and 17-kDa proteins were also confirmed in six other strains of B. hyodysenteriae which belong to six different serogroups. These proteins were sensitive to proteinase K. These results indicate that the 22- and 17-kDa proteins are common to eight strains of B. hyodysenteriae which differ serologically from each other.

Recovery from colonic infection elicits serum IgG antibodies to specific Serpulina pilosicoli outer membrane antigens (SPOMA)

Colonic spirochetosis caused by S. pilosicoli is a disease of human and animals characterized by intimate attachment of the spirochete to colonic epithelial cells and colitis. To identify antigens that are potentially involved in recovery from the disease, whole-cell lysate (WC) and various detergent extracts including Sarkosyl-soluble (SS) and insoluble (SI), and Triton X-114 detergent phase (TXD) and aqueous phase (TXA) of the human isolate SP16 were examined by Western blotting with Serpulina spp. periplasmic flagellar protein FlaB-specific monoclonal antibody 7G2 as well as pooled pre-immune serum (PS), hyperimmune serum (HS), and convalescent serum (CS) from swine. The HS reacted with several antigens that were not identified by the CS, including the periplasmic flagellar proteins and some lower molecular weight bands. The CS identified three major immunoreactive double (D) or single (S) bands of approximately: (i) 64-kDa in the WC(S), SS(D), and TXD/A(S), (ii) 54-kDa in the WC(S), SS/I(S), and TXD(S), and (iii) 47-kDa in the SS(S) fraction. The data indicate recovery from colonic infection elicits serum IgG antibodies to specific S. pilosicoli outer membrane antigens (SPOMA).

Cellular immune responses of pigs induced by vaccination with either a whole cell sonicate or pepsin-digested Brachyspira (Serpulina) hyodysenteriae bacterin

Brachyspira (Serpulina) hyodysenteriae infection of pigs (swine dysentery) causes a mucohemorrhagic diarrhea resulting in significant economic losses for producers. A commercial vaccine consisting of a proteinase-digested bacterin has shown efficacy in the reduction of disease due to B. hyodysenteriae. Vaccines consisting of whole cell bacterins, however, generally fail to protect pigs from disease. In the present study, cellular immune responses induced by a proteinase-digested bacterin were compared to responses induced by a whole cell sonicate antigen preparation. In addition, usage of either squalene or Freund's incomplete adjuvants in combination with each antigen preparation was also compared. Both antigen preparations induced significant cellular immune responses as measured by in vitro (IFN-gamma production and T cell proliferation) and in vivo methods (DTH responses). No significant differences were detected in proliferative, interferon-gamma (IFN-gamma), or delayed type hypersensitivity (DTH) responses by pigs receiving either adjuvant or antigen preparation. T cells (CD3(+)) but not B cells from vaccinated animals proliferated in response to in vitro stimulation with B. hyodysenteriae antigen. CD8(+) (single positive and CD4/CD8 double positive) and gammadelta(+) T cells were particularly responsive. In addition, high percentages of both CD8 single positive and CD4/CD8 double positive cells were detected in antigen-stimulated cultures. These findings demonstrate the unique sensitivity of porcine CD8(+) T cells to priming for recall response by vaccination with a proteinase-digested B. hyodysenteriae bacterin.

Presence of 22- and 17-kDa proteins reacting with sera in mice experimentally infected with Brachyspira (Serpulina) hyodysenteriae

The antibodies to B. (S.)hyodysenteriae in experimentally infected mice were detected by microscopic agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA). The reactions in MAT were serotype specific while those in ELISA were common to both strains. A further investigation with immunoblotting technique demonstrated that 22- and 17-kDa proteins reacted strongly with the sera. The proteins in ATCC 27164 strain strongly reacted with the serum from ATCC 31212 strain-infected mouse and vice versa. These proteins were sensitive to proteinase K.

Humoral response of dairy cattle to spirochetes isolated from papillomatous digital dermatitis lesions

OBJECTIVE

To determine whether a humoral response against spirochetes isolated from papillomatous digital dermatitis (PDD) lesions is elicited in dairy cattle affected with PDD.

SAMPLE POPULATION

41 cattle with PDD from 8 dairies (study population) and 30 cattle from 2 dairies free of PDD (control population). Additionally evaluated were 32 cattle from a dairy with a past history of PDD but no current disease, and 52 cattle from a dairy with high prevalence of PDD, 25 with and 27 without detectable lesions.

PROCEDURE

ELISA were used to evaluate the humoral response of all cattle to representative isolates from 2 groups of spirochetes of unknown species isolated from PDD lesions. Specificity of the response was evaluated, using immune sera prepared against each of the spirochetes, and by adsorption studies of immune and field sera. The potential for confounding by an antibody response to other spirochetes associated with diseases of cattle was assessed.

RESULTS

The antibody response (specific) to both PDD spirochete groups of cows with PDD was significantly increased, compared with that of cows from PDD-free dairies. There was no association between antibody response to PDD-associated spirochetes and antibody response to other spirochetal diseases of cattle. None of the cattle from the dairy with previous history of PDD but without current disease were classified as test positive by either PDD ELISA. There was a significant (P < 0.01) difference in classification results for both PDD ELISA for cattle with PDD from the dairy with a high herd prevalence of PDD, compared with cattle without detectable disease from the same dairy.

CONCLUSIONS AND CLINICAL RELEVANCE

The humoral response in cattle with PDD lesions was significantly different from that in cattle without detectable lesions, thus providing additional information regarding the potential role of spirochetes isolated from PDD lesions in the etiopathogenesis of PDD.

Rapid identification of porcine Serpulina species by colony blot assay using a genus-specific monoclonal antibody

An immunoglobulin G monoclonal antibody (mAb C9E8) recognising a genus-specific epitope on the 26 kDa protein of porcine Serpulina species organisms was used in a simple colony blot assay to detect Serpulina in cultures grown directly on blood agar plates from pig faeces and tissues. The mAb detected even a few colonies of the organism in the presence of an abundant growth of non-Serpulina organisms. The whole procedure was completed in less than three hours. A total of 123 strains of S hyodysenteriae and S innocens were correctly identified by the colony blot assay whereas all the 26 non-Serpulina Gram-negative organisms commonly isolated from faecal material or tissues of pigs remained negative. The assay was rapid, highly specific and sufficiently reliable to be used with confidence for identifying porcine Serpulina colonies directly on blood agar plates.

Identification and characterization of genus-specific epitopes of Serpulina species using monoclonal antibodies

Four murine monoclonal antibodies (mAbs) designated as C9E8, A10, G12, and G8 which recognized both Serpulina hyodysenteriae and S. innocens were produced and characterized. The mAbs reacted with whole cell antigens in ELISA, indirect immunofluorescence and immunoblot assays. The mAbs did not show any cross reactivity in rapid dot ELISA or immunoblot assay with Leptospira icterohemorrhagiae, Campylobacter jejuni and Escherichia coli. Treatment of whole cell suspension with proteinase K and sodium periodate indicated that the reacting epitopes of the mAbs were protein in nature. The genus-specific antigens were identified as heat-stable proteins with molecular weight in the range of 26 to 45 kDa. Immunofluorescence and immunogold labelling studies showed that the antibody-binding epitopes were exposed on the outer-surface of the spirochaetal cell wall. The mAbs inhibited growth of reference strains of both S. hyodysenteriae and S. innocens in vitro but failed to cause agglutination. The detection of spirochaetal forms directly in fecal smears or paraffin-embeded tissue sections from experimentally infected pigs indicated that such mAbs were potentially useful for the diagnosis of swine spirochaetosis. This is the first report of mAbs identifying and characterizing common antigens of porcine Serpulina.

Evaluation of different serological tests for detection of antibodies against Serpulina hyodysenteriae in pig sera

Swine dysentery is a mucohemorrhagic diarrheal disease caused by S. hyodysenteriae. The detection of asymptomatic carriers in herds is possible by serological tests. However, cross-reactions between S. hyodysenteriae and S. innocens pose a major problem in serological diagnosis. Several serological tests were evaluated for detection of antibodies to S. hyodysenteriae such as: indirect hemagglutination, passive hemolysis, conglutination and microagglutination tests. Among the tests used, only the microagglutination test was able to detect antibodies to S. hyodysenteriae. 70 to 95% of the pigs were invariably seropositive in a single dilution of 1:10 in actively infected herds whereas the number of seropositives did not exceed 10% in presumably non-infected herds. The test was found to be simple, and reliable to be used with confidence for detection of herd infection using boiled cell suspension as an antigen.

Serpulina hyodysenteriae challenge of fattening pigs vaccinated with anadjuvanted bivalent bacterin against swine dysentery

An experimental fattening period was performed with 36 pigs in order to evaluate the safety and efficacy of a bivalent adjuvanted Serpulina hyodysenteriae bacterin. The pigs originated from three different farms and were split into six groups. Eighteen pigs were vaccinated twice, two weeks apart and the rest served as controls. One unvaccinated pig in each group was inoculated intragastrically with 4 x 10(8) active S. hyodysenteriae spirochaetes, B 78 strain. Weight evolution, clinical symptoms, shedding of S. hyodysenteriae and serum antibody titres were monitored for 12 weeks in all pigs. The severity of clinical symptoms and shedding of spirochaetes in faeces were significantly reduced in vaccinated pigs as compared to controls. Statistically significant differences in weight gain between vaccinates and controls were detected coinciding with the maximum shedding of S. hyodysenteriae in faeces. All vaccinated pigs seroconverted, as measured by indirect ELISA, and had a good anamnestic response after the second vaccine dose. The bacterin proved to be useful for both the reduction of clinical symptoms and the number of infected animals in a fattening unit. Adverse post-vaccinal reactions were not observed in any pig.

Immunoglobulin-containing cells in the colonic mucosa in patients with human intestinal spirochaetosis

The relative proportions of cells containing the various classes of immunoglobulins in the colonic mucosa were determined in eight patients with human intestinal spirochaetosis (HIS) and in eight controls. All specimens were taken from colonic resections performed because of adenocarcinoma. None of the cases with HIS showed an inflammatory reaction in the mucosa as judged subjectively by light microscopy. Cases with HIS had smaller proportions of IgD- and IgE-positive cells and a larger proportion of IgA cells as compared with the controls, whereas the proportions of IgG and IgM cells were similar in the two groups. Taking into account the large individual variations in the proportions of immunoglobulins in both groups, our findings must be interpreted with caution. However, our results do not support the previous demonstration of increased percentages of IgE-positive cells in patients with HIS.

Exacerbated onset of dysentery in swine vaccinated with inactivated adjuvanted Serpulina hyodysenteriae

After oral challenge exposure with Serpulina hyodysenteriae-infected diced colon, fewer swine vaccinated with an experimental vaccine adjuvanted with mineral oil died (8 of 25 [32%]) than did nonvaccinated controls (6 of 15 [40%]), although the difference was not significant. However, onset and exacerbation of dysentery were accelerated in vaccinated swine because: 5 of the 8 dead vaccinated swine died before any of the nonvaccinates, which was significant (P < 0.01); vaccinated swine that died were observed to have more hemorrhage in the feces, colonic mucosa, and colonic lumen than did nonvaccinated swine; and the earlier diarrhea onset in vaccinates, the more days of hemorrhagic diarrhea (P < 0.05). Antibody titer in vaccinated swine immediately before challenge exposure that subsequently died was significantly (P < 0.05) higher than that in vaccinated swine that recovered. Of of the 30 swine vaccinated with the experimental vaccine, 20 had dispersed droplets of mineral oil at the site of vaccination in the neck muscles and 3 swine had purulent abscesses at the injection site. It was concluded that vaccination with the experimental vaccine for controlling swine dysentery was ineffective.

Alzheimer's disease--a spirochetosis?

The aetiology of Alzheimer's disease (AD), which affects a large proportion of the aged population is unknown and the treatment unresolved. The role of beta amyloid protein (beta A4), derived from a larger amyloid precursor protein (APP) in AD is the subject of intense research. Here I report observations that in 14 autopsy cases with histopathologically confirmed AD, spirochetes were found in blood and cerebrospinal fluid and, moreover, could be isolated from brain tissue. Thirteen age-matched control cases were without spirochetes. Reference strains of spirochetes and those isolated from brains of AD patients, showed positive immunoreaction with monoclonal antibody against the beta amyloid precursor protein. These observations suggest that spirochetes may be one of the causes of AD and that they may be the source of the beta amyloid deposited in the AD brain.

Lymphocyte blastogenesis and cellular cytotoxicity in a congenital infection of bovine fetuses related to epizootic bovine abortion

The disease referred to as epizootic bovine abortion (EBA) was experimentally induced in bovine fetuses. Dark-field microscopy was used to detect congenital infection with an unclassified spirochaete-like organism. Some of the fetuses collected at abattoirs were also found to be naturally infected with a morphologically similar microorganism. Blood counts and organ weights were correlated with the presence of the microorganism. Lymphocyte blastogenesis increased, the result of in vivo stimulation among the infected fetuses. Phytomitogens (phytohaemagglutinin, concanavalin A and lipopolysaccharide) also stimulated greater responses in infected fetuses when compared to results in normal fetuses. Cellular cytotoxicity was examined by the single cell assay and results indicated that there were fewer cytotoxic lymphocytes among the diseased fetuses. The infected abattoir-collected specimens were obtained from clinically normal adult cattle, and the immunological changes in these fetuses were closely characterised with those of the EBA diseased fetuses. These naturally infected fetuses showed signs of a mild infectious disease.

[Local immune reaction in human intestinal spirochetosis]

The pathogenetic and clinical importance of intestinal spirochaetes in man is still unresolved. In 12 patients mainly presenting with mild diarrhoea, light and electron microscopy demonstrated massive spirochaetal infestation of the colonic mucosa (spirochaetosis). There were several hitherto unreported features: spirochaetes adhered not only to the surface epithelium of the intestine but were also present within epithelial cells and subepithelial macrophages; many partially degranulated mast cells were noted within the epithelium; there was a marked increase of IgE plasma cells within the lamina propria. In control biopsies intraepithelial mast cells were absent and IgE cells occurred only sporadically. Penetration of the microorganisms into the intestinal mucosa may be responsible for this unusual immune response. Spirochaetes, symptoms and findings disappeared after antibiotic therapy. The authors therefore suggest that intestinal spirochaetosis can cause clinical symptoms in man, and that spirochaetes should not invariably be considered harmless commensals.

Cross-reactivity in serological tests for Lyme disease and other spirochetal infections

Serum specimens from 163 persons with Lyme disease, tick-borne or louse-borne relapsing fever, yaws, syphilis, leptospirosis, or Rocky Mountain spotted fever were analyzed to assess the specificity of indirect fluorescent antibody (IFA) tests, an enzyme-linked immunosorbent assay (ELISA), and microscopic agglutination (MA) procedures. Strong cross-reactivity occurred when sera from individuals with Lyme disease, tick-borne relapsing fever, and louse-borne relapsing fever were tested against heterologous Borrelia antigens. Antibodies to Borrelia burgdorferi bound to Treponema pallidum in immunofluorescence tests for syphilis. Sera from subjects with syphilis cross-reacted in IFA tests and the ELISA for Lyme disease. Immunoglobulin antibodies to Borrelia or Treponema spirochetes, however, did not react with serovars of Leptospira interrogans in MA or IFA tests, and the prevalence of false-positive results in the reciprocal analyses was negligible.

[Etiology of acrodermatitis chronica atrophicans and erythema chronicum migrans]

In Lyme's disease (LD) as well as in the European form of erythema chronicum migrans (ECM), the etiologic agents are spirochetes. As fas as we know by now, these microbes are closely related but not identical. Consequently, LD and ECM should be regarded as closely related but not as identical diseases. The sera of our 21 patients suffering from acrodermatitis chronica atrophicans (ACA) contained elevated antibody titers directed against the etiological agent found in ECM. These findings strongly suggest that ACA is also induced by spirochetes-possibly by the same microbes found in ECM.

Erythema chronicum migrans in Sweden: clinical manifestations and antibodies to Ixodes ricinus spirochete measured by indirect immunofluorescence and enzyme-linked immunosorbent assay

26 Swedish patients with erythema chronicum migrans (ECM) were studied regarding associated clinical symptoms and antibodies to Swedish Ixodes ricinus spirochete. 11/26 (42%) of the patients had associated symptoms, compared to more than 90% of 314 American patients with ECM, as described by Steere et al. Only 2/26 (8%) had multiple skin lesions, compared to 48% of the American patients. Elevated erythrocyte sedimentation rate and circulating immune complexes were demonstrated in 6/25 (24%) and 8/25 patients (32%), respectively, as against in 53% and 84%, respectively, of the American patients. The antibody response to Ixodes ricinus spirochete was measured by indirect immunofluorescence (IFA) and enzyme-linked immunosorbent assay (ELISA). Compared to the 95% percentile of controls, significantly high antibody titers were demonstrated in 3/25 (12%) by IFA, and 7/25 (28%) by ELISA. The ELISA antibody titers differed significantly (p less than 0.05) between ECM-patients and controls. The spirochetal antibody response in ECM was also compared with that in spirochete-associated disease of the central nervous system.

Tick-borne spirochetes as a cause of facial palsy

Twenty consecutive patients visiting an otolaryngological department in Sweden with a facial palsy were investigated for serological signs of tick-borne spirochete infection. Four patients showed serological evidence of and had a medical history compatible with a tick-borne spirochetosis. Spinal fluid analyses were performed in 3 of these patients and showed elevated specific antispirochetal antibody titres and an increase in mononuclear cells. The importance of a correct diagnosis and of antibiotic therapy in patients with spirochete-induced facial palsy is emphasized.

[Meningopolyneuritis (Garin-Bujadoux, Bannwarth) erythema chronicum migrans disease of the nervous system transmitted by ticks]

The clinical spectrum of this remarkable non-syphilitic spirochaetosis (spirochaeta infection) of the nervous system is described in light of 53 further cases with reference to our earlier description of 47 cases. As the etiological diagnosis is not possible in all cases the knowledge of clinical courses is especially important. Males are affected almost twice as often as women. The disease is especially prevalent in the sixth decade. Usually, the syndrome begins in the warm season with exquisite pain and other sensory irritations in combination with marked malaise. Initial signs during the winter as well as painless clinical courses were also noted. About one half of the patients remembered contact with arthropodes or a chronic migrating erythema. In most cases (95%), asymmetrical peripheral signs followed the painful stage. More than two thirds of the patients showed affection of cranial nerves, usually facial palsy. Twenty percent demonstrated paresis of the extremities alone, the combination of involvement of cranial nerves and extremities was noted in one third of the cases. The sensory signs were usually only mild. Occasionally, the neurological impairment was limited to isolated sensory impairment. In contrast to the closely related Lyme disease, central nervous affection as well as cardiac and arthritic involvement is rare: 34 percent demonstrated mild psychopathological impairment; in one case a Babinski-phenomenon was elicited. Knee joint pain and gonarthritis were found in one case each. Even though meningeal signs were usually absent, the CSF showed alterations suggestive of chronic lymphocytic meningitis in all cases. At the same time, local synthesis of all three immune globulins was documented, especially of IgM (85%).

Ixodes ricinus spirochete infection as the cause of postinfectious arthritis in Sweden

Antibodies to Swedish Ixodes ricinus spirochete were determined by an enzyme-linked immunosorbent assay (ELISA) in sera from 298 patients with postinfectious arthritis. Sera from healthy individuals, patients with acute infectious meningitis of proven etiology and patients with multiple sclerosis served as controls. With the upper limit of normal values set at the 95 percentile of controls, 18 of 298 (6%) arthritis patients had positive serum antibody titres. Titres above the 100 percentile of controls were found in 5 of 298 (2%) arthritis patients. Two of the arthritis patients had extremely high titres--higher than any earlier found in Swedish patients with spirochetal meningitis. The clinical manifestations and laboratory findings in the 5 patients with high spirochetal antibody titres are described. It is concluded that a spirochetal etiology should be considered in patients with reactive or postinfectious arthritis of unknown origin.

Human phagocyte interactions with the Lyme disease spirochete

The interaction between human polymorphonuclear leukocytes and monocytes and the Lyme disease spirochete was investigated by incubating phagocytes with microorganisms adherent to plastic or glass surfaces. Both cell populations readily phagocytized and killed spirochetes, and antibodies facilitated but were not essential for phagocytosis.

Experimental Lyme disease in rabbits: spirochetes found in erythema migrans and blood

In attempts to produce experimental Lyme disease, 33 rabbits were inoculated with Lyme spirochetes by tick feeding or from tick organ homogenates or cultures. Two rabbits developed erythema chronicum migrans at the site of inoculation, in one instance 2 days after injection of a tick organ homogenate and in the other instance, 17 days after feeding of infected Ixodes dammini ticks. Spirochetes were seen in skin biopsy specimens of the second lesion with Warthin-Starry and immunoperoxidase stains. Spirochetes were also recovered from blood cultures of two additional rabbits 2 weeks post-inoculation. These findings are characteristic of early Lyme disease in humans and give additional support for the spirochetal etiology of Lyme disease.

Serological diagnosis of erythema migrans disease and related disorders

An indirect immunofluorescence technique for the determination of antibodies against ixodid tick spirochetes is described. Differences in the reactivity between Ixodes ricinus spirochete and Ixodes dammini spirochete antigens were not observed. Cross-reacting antibodies against Treponema pallidum and Treponema phagedenis can be eliminated by quantitative absorption with T. phagedenis. Cross-reactions with leptospira were not observed by immunofluorescence. In the IgM test, false negative reactions caused by high-titered specific IgG antibodies or false positive reactions caused by rheumatoid factor occur. This can be avoided by testing the IgM fraction (19S-IgM-test) or using sera previously treated with anti-IgG serum. Significantly elevated antibody titers against ixodid tick spirochetes were observed in 45% of 44 cases with erythema migrans disease, in 72% of 29 cases of lymphocytic meningoradiculitis, in all of nine patients with acrodermatitis chronica atrophicans and in all of four investigated patients with lymphocytoma (lymphadenosis benigna cutis).

Antibody response in Lyme disease: evaluation of diagnostic tests

The antibody response to the Ixodes dammini spirochete was determined in 41 serial serum samples from 12 patients with Lyme disease. By enzyme-linked immunosorbent assay (ELISA), 11 of the 12 patients had higher titers of specific IgM antibody (greater than 1:200) during early disease than did 40 control subjects. Specific IgM antibody titers, which correlated with total amounts of IgM antibody (P less than .001), sometimes remained elevated throughout the illness. During neuritis, nine of 10 patients had higher specific IgG antibody titers (greater than 1:200) than did controls, and when arthritis was present, all had such titers, which remained elevated after months of remission. In the ELISA, antibody responses determined by single or serial dilutions were similar, but the ELISA was more sensitive and specific than was immunofluorescence. Adsorption of sera with Borrelia hermsii generally resulted in a fourfold decrease in titers of cross-reactive antibodies, but the titers of sera from patients with Lyme disease were also reduced. Currently, the ELISA, without adsorption, is the best diagnostic test for Lyme disease.

[Lyme arthritis (erythema migrans arthritis)]

In the light of an observation of a patient with Lyme arthritis living near the Swiss-German border, the authors describe "Lyme or erythema migrans disease". The clinical findings include erythema chronicum migrans, meningoradiculitis and arthritis, and, occasionally, carditis. Also, it has recently become possible to describe this entity serologically, by detection of antibodies against the etiologically responsible spirochetes, which are usually transmitted by tick bites. This diagnostic procedure can also be expected to provide a better overview of the incidence of Lyme arthritis in our region.

[Spirochete etiology of erythema chronicum migrans disease]

From ticks of the type Ixodes ricinus, 19 strains of a spirochete were isolated at three places of infection of erythema chronicum migrans disease. The spirochete was immunologically related to Borrelia duttoni, Treponema pallidum and Ixodes dammini spirochete, the causative organism of North American erythema chronicum migrans disease (Lyme disease). The isolated spirochete differed from the North American one in its reaction with monoclonal antibodies and possibly in its electronmicroscopic structure. A corresponding spirochete was isolated from the blood of a woman with erythema chronicum migrans. Of 39 patients with erythema chronicum migrans mostly treated with antibiotics 50% had increased IgG antibody titre (1:64 to 1:1024) against the isolated spirochete, while among 51 untreated patients with tick-transmitted meningopolyneuritis 90% had increased IgG antibody titres. Fourfold antibody titres increases or falls were found on 50 occasions. IgG antibody titres up to 1:64 were demonstrated also in CSF, in 22 instances with significant changes. Increased serum IgM antibody titres of 1:32 to 1:256 were observed in 20% and 68%, respectively, of patients. These findings suggest that the isolated spirochete is the causative agent of erythema chronicum migrans disease in Europe. Its antigen structure and arrangement is similar to that of the causative agent of Lyme disease.

Lyme disease spirochetes and ixodid tick spirochetes share a common surface antigenic determinant defined by a monoclonal antibody

Ixodid tick-associated spirochetes have been implicated as the etiological agents of Lyme disease. We raised a murine monoclonal antibody (H5332) against a spirochete, strain B31, isolated from Ixodes dammini ticks. In indirect immunofluorescence assays and western blot analyses, H5332 reacted with whole cells or isolated components of not only strain B31 but also spirochetes isolated from Ixodes ricinus ticks, a field mouse, a raccoon, and patients with Lyme disease. In contrast, H5332 did not bind to representative borreliae, treponemes, and leptospires. Using indirect immunofluorescence assays and immune electron microscopy, we found the H5332 determinant to be diffusely distributed over the surface of prefixed spirochetes but to be aggregated in patches when the organisms were incubated with H5332 and a second ligand before fixation. Radioimmunoprecipitation and western blot studies revealed the H5332 determinant to be either on or tightly associated with an abundant outer membrane protein with an apparent subunit molecular weight of 31,000.

Antibodies of patients with Lyme disease to components of the Ixodes dammini spirochete

Lyme disease is an inflammatory disorder of skin, joints, nervous system, and heart. The disease is associated with a preceding tick bite and is ameliorated by penicillin treatment. A spirochete (IDS) isolated from Ixodes dammini ticks has been implicated as the etiologic agent of Lyme disease. We examined the antibody responses of Lyme disease patients to IDS lysate components in order to further understand the pathogenesis of this disease. The components were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose, reacted with patients' sera, and the bound IgG was detected with 125I-labeled protein A (western blot). We found that (a) Lyme disease patients had antibodies to IDS components (b) most patients studied had antibodies to two components with apparent subunit molecular weights of 41,000 and 60,000, and (c) the patients' antibody responses during illness and remission were specific, for the most part, for the IDS. In contrast to the findings with Lyme disease sera, sera from controls showed little reactivity with IDS components in either the western blots or a derivative solid-phase radioimmunoassay.

Influence of medication on development of serum antibody to swine dysentery as detected with indirect fluorescent antibody method

Serums from 119 swine exposed to swine dysentery inoculum, and medicated with various drugs, were tested for antibodies to the large spirochete, using the indirect fluorescent antibody test, and were compared in tests with known positive serums from 18 nonmedicated swine which had recovered naturally. An inverse relationship existed between the efficacy of the drug and the serum antibody titer (highest dilution of the serum producing immunofluorescence of large spirochetes). The more efficacious drugs or doses resulted in lesser development of serum antibody. Diarrhea usually seemed necessary for the development of serum antibody. With the less efficacious drugs, there were more days of diarrhea. Some swine had diarrhea but did not develop an antibody titer, and a few swine had a titer but did not develop diarrhea. Swine which developed a titer were more immune against reexposure with infective inoculum. The medicaments, especially those given at higher concentrations, seemed to resolve the diarrhea or prevent the development of diarrhea, occurrences which were necessary for the development of immunity.