Serologic evidence of previous Campylobacter jejuni infection in patients with the Guillain-Barré syndrome

Characteristics of Guillain-Barré syndrome in a Lebanese tertiary care center

Guillain-Barré Syndrome (GBS) is a group of acute inflammatory disorders that share a clinical presentation of progressive polyradiculo-neuropathy. Data on GBS in the Middle East and Lebanon are scarce; hence, we explored the characteristics of patients presenting with GBS to a tertiary care center in Beirut, Lebanon. This was a single-centered retrospective study over a 12-year period. We reviewed the charts of patients presenting with GBS to the American University of Beirut medical center and examined their presentation, management and outcome. 61 patients were included, with the majority being males. 59% of the patients reported an infection prior to admission. 77% had sensory and motor symptoms and 69% were diagnosed with acute inflammatory demyelinating polyneuropathy (AIDP). 57% of patients had initial symptoms in the lower extremities, 25% experienced cranial neuropathies, and 26% complained of pain. 77% were managed by intravenous immunoglobulin with a median hospital stay of 6.5 days. AIDP was noted to be the most prevalent GBS variant in Lebanon. More than 50% had an unfavorable outcome at discharge, which raises the need for better treatment and management approaches.

Association of Hospital-Diagnosed Infections and Antibiotic Use With Risk of Developing Guillain-Barré Syndrome

OBJECTIVE

To determine whether hospital-diagnosed and community-treated infections are important Guillain-Barré syndrome (GBS) risk factors, we investigated the magnitude and duration of associated GBS risk.

METHODS

We conducted a nationwide population-based case-control study of all patients with first-time hospital-diagnosed GBS in Denmark between 1987 and 2016 and 10 matched population controls per case. Hospital-diagnosed infections were determined in the 1987-2016 period and community antibiotic prescriptions in the 2004-2016 period. We used conditional logistic regression to examine the relative risk of GBS associated with having a recent infection.

RESULTS

Hospital-diagnosed infections within 60 days were observed in 4.3% of 2,414 GBS cases vs 0.3% of 23,909 controls, with a matched odds ratio (OR) of 13.7 (95% confidence interval [CI], 10.2-18.5). The strongest association with subsequent GBS was observed for lower respiratory tract infection, gastrointestinal tract infection, and septicemia. Community antibiotic prescriptions within 60 days were observed in 22.4% of 1,086 GBS cases and 7.8% of 10,747 controls, with a matched OR of 3.5 (95% CI, 3.0-4.1). The risk of GBS declined considerably with time since infection, with high ORs of 21.3 (95% CI, 14.5-31.2) and 4.7 (95% CI, 3.9-5.7) observed within the first month after a hospital-diagnosed infection and a community antibiotic prescription, respectively. However, GBS risk remained increased 2.4-fold (95% CI, 1.1-5.5) and 1.5-fold (95% CI, 1.2-2.0) even in the fifth month after infection.

CONCLUSION

There is a strong, temporal association between community antibiotic use and especially infections necessitating hospitalization and risk of subsequent GBS.

Incidence of Campylobacter-Associated Guillain-Barré Syndrome Estimated from Health Insurance Data

Guillain-Barré syndrome (GBS) is sometimes preceded by Campylobacter infection. We estimated the cumulative incidence of Campylobacter-associated GBS in the United States using a retrospective cohort design. We identified a cohort of patients with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code of "intestinal infection due to Campylobacter" (008.43) using MarketScan Research Databases for 2004-2013. Campylobacter patients with an encounter for "acute infective polyneuritis" (AIP; ICD-9-CM 357.0) were identified. Patients with an inpatient encounter having AIP as the principal diagnosis were considered probable GBS cases. Patients with probable GBS ≤8 weeks after the Campylobacter encounter were considered probable Campylobacter-associated GBS cases. For comparison, we repeated this analysis for patients with "other Salmonella infections" (ICD-9-CM: 003). Among 9315 Campylobacter patients, 16 met the case definition for probable GBS. Two were hospitalized with probable GBS ≤8 weeks after the encounter listing a Campylobacter diagnosis (9 and 54 days) and were considered probable cases of Campylobacter-associated GBS; this results in an estimated cumulative incidence of 21.5 per 100,000 Campylobacter patients (95% confidence interval [CI]: 3.7-86.6), or 5% of all estimated GBS cases. The remaining 14 patients were diagnosed with probable GBS on the same encounter (n = 12) or 1-3 days (n = 2), before the encounter listing the Campylobacter diagnosis. Including these cases increased the cumulative incidence to 172 per 100,000 Campylobacter cases (95% CI: 101.7-285.5), 41% of estimated GBS cases. This study, using a method not previously applied to United States data, supports other data that Campylobacter is an important contributor to GBS, accounting for at least 5% and possibly as many as 41% of all GBS cases. These data can be used to inform estimates of the burden of Campylobacter infections, including economic cost.

Serological Markers of Recent Campylobacter jejuni Infection in Patients with Guillain-Barré Syndrome in the State of Piauí, Brazil, 2014-2016

In countries where poliomyelitis has been eradicated, Guillain-Barré syndrome (GBS) is the leading cause of acute flaccid paralysis. The range of infections that precede GBS in Brazil is unknown. Campylobacter jejuni infection is the most frequent trigger of GBS worldwide. Given the lack of systematic surveillance of diarrheal diseases, particularly in adults, the incidence of enteritis caused by C. jejuni in developing countries is unknown. From 2014 to 2016, pretreatment serum samples from 63 GBS patients were tested by immunoglobulin M (IgM) enzyme-linked immunosorbent assay for C. jejuni. Campylobacter jejuni IgM antibodies were detected in 17% (11/63) of the samples. There was no association between serological positivity (IgM) for C. jejuni and the occurrence of diarrhea among the investigated cases (P = 0.36). Hygiene measures, basic sanitation, and precautions during handling and preparation of food of animal origin may help prevent acute flaccid paralysis.

Clinical Evidence for the Microbiome in Inflammatory Diseases

Clinical evidence is accumulating for a role of the microbiome in contributing to or modulating severity of inflammatory diseases. These studies can be organized by various organ systems involved, as well as type of study approach utilized, whether investigators compared the microbiome of cases versus controls, followed patients longitudinally, or intervened with antibiotics, prebiotics, or bacterial introduction. In this review, we summarize the clinical evidence supporting the microbiome as an important mechanism in the onset and maintenance of inflammation.

Review: Molecular mimicry of host structures by lipopolysaccharides of Campylobacter and Helicobacter spp.: implications in pathogenesis

Molecular mimicry of host structures by the saccharide portion of lipopolysaccharide (LPS) contributes to the virulence of certain strains of mucosal pathogens. Mimicry by the low molecular weight (low-Mr) LPSs of Neisseria and Haemophilus spp. have been the most extensively studied. However, studies within the last decade have revealed other types of mimicry within the saccharide moieties of LPSs of the enteric pathogen Campylobacter jejuni and the gastroduodenal pathogen Helicobacter pylori. The core oligosaccharides of low-Mr LPSs of C. jejuni serotypes which are associated with the development of Guillain-Barré syndrome (GBS), a neurological disorder, exhibit mimicry of gangliosides. Cross-reactive antibodies between LPSs and gangliosides which are induced during antecedent C. jejuni infection are considered to play an important role in GBS pathogenesis. The O-polysaccharide chains of high-Mr LPSs of a number of H. pylori strains mimic Lewisx and/or Lewisy blood group antigens. This mimicry may camouflage the bacterium in the gastric mucosa upon initial infection. With the progression of infection, the mimicry may play a role in immune response regulation and the induction of autoantibodies against the gastric proton pump, a glycoprotein that also expresses Lewis antigens.

Unexpected Rapid Improvement and Neurogenic Stunned Myocardium in a Patient With Acute Motor Axonal Neuropathy: A Case Report and Literature Review

Acute Motor Axonal Neuropathy-type Guillain-Barré Syndrome (GBS) is a subset of GBS with either a rapidly improving or protracted course that was first described in China. We describe a 27-year-old previously healthy woman with weakness that progressed to complete tetraplegia and areflexia within 2 weeks after an upper respiratory illness. A lumbar puncture performed 4 days after onset of neurologic symptoms was inconclusive for GBS, and electromyography revealed complete motor axonal neuropathy. The patient had Mycoplasma pneumoniae in her nares and blood, and several antiganglioside antibodies in her blood. She was treated with plasmapheresis, antibiotics, and physical therapy. Her motor function and reflexes improved rapidly with treatment, and she was able to ambulate within 3 weeks. She also experienced cardiomyopathy, which improved with plasmapheresis. We report a rare case of Mycoplasma pneumonia-associated acute motor axonal neuropathy-type GBS presenting with complete tetraplegia, areflexia, and neurogenic stunned myocardium that rapidly improved with plasmapheresis.

Occupational Exposure to Swine, Poultry, and Cattle and Antibody Biomarkers of Campylobacter jejuni Exposure and Autoimmune Peripheral Neuropathy

INTRODUCTION

Foodborne Campylobacter jejuni infection has been associated with an increased risk of autoimmune peripheral neuropathy, but risks of occupational exposure to C. jejuni have received less attention. This study compared anti-C. jejuni IgA, IgG, and IgM antibody levels, as well as the likelihood of testing positive for any of five anti-ganglioside autoantibodies, between animal farmers and non-farmers. Anti-C. jejuni antibody levels were also compared between farmers with different animal herd or flock sizes. The relationship between anti-C. jejuni antibody levels and detection of anti-ganglioside autoantibodies was also assessed.

METHODS

Serum samples from 129 Agricultural Health Study swine farmers (some of whom also worked with other animals) and 46 non-farmers, all from Iowa, were analyzed for anti-C. jejuni antibodies and anti-ganglioside autoantibodies using ELISA. Information on animal exposures was assessed using questionnaire data. Anti-C. jejuni antibody levels were compared using Mann-Whitney tests and linear regression on log-transformed outcomes. Fisher's Exact Tests and logistic regression were used to compare likelihood of positivity for anti-ganglioside autoantibodies.

RESULTS

Farmers had significantly higher levels of anti-C. jejuni IgA (p < 0.0001) and IgG (p = 0.02) antibodies compared to non-farmers. There was no consistent pattern of anti-C. jejuni antibody levels based on animal herd or flock size. A higher percentage of farmers (21%) tested positive for anti-ganglioside autoantibodies compared to non-farmers (9%), but this difference was not statistically significant (p = 0.11). There was no significant association between anti-C. jejuni antibody levels and anti-ganglioside autoantibodies.

CONCLUSIONS

The findings provide evidence that farmers who work with animals may be at increased risk of exposure to C. jejuni. Future research should include longitudinal studies of exposures and outcomes, as well as studies of interventions to reduce exposure. Policies to reduce occupational exposure to C. jejuni should be considered.

Claudin-related intestinal diseases

With up to 200 m(2) the human intestine is the organ with the largest absorptive surface of the body. It is lined by a single layer of epithelial cells that separates the host from the environment. The intestinal epithelium provides both, selective absorption of nutrients, ions, and water but also a highly effective barrier function which includes the first line of defense against environmental antigens. The paracellular part of this barrier function is provided by tight junction (TJ) proteins, especially the large family of claudins. Changes in abundance or molecular structure of claudins can generally result in three typical effects, (i) decreased absorptive passage, (ii) increased secretory passage of small solutes and water causing leak flux diarrhea and (iii) increased absorptive passage of macromolecules which may induce inflammatory processes. Several intestinal diseases are associated with such changes that can result in intestinal inflammation and symptoms like weight loss, abdominal pain or diarrhea. This review summarizes our current knowledge on barrier dysfunction and claudin dysregulation in several intestinal diseases gastroenterologists are often faced with, like inflammatory bowel disease, microscopic colitis, celiac disease, irritable bowel syndrome, gallstones and infectious diseases like HIV enteropathy, Campylobacter jejuni and Clostridium perfringens infection.

Peripheral nervous system manifestations of infectious diseases

Infectious causes of peripheral nervous system (PNS) disease are underrecognized but potentially treatable. Heightened awareness educed by advanced understanding of the presentations and management of these infections can aid diagnosis and facilitate treatment. In this review, we discuss the clinical manifestations, diagnosis, and treatment of common bacterial, viral, and parasitic infections that affect the PNS. We additionally detail PNS side effects of some frequently used antimicrobial agents.

Pathophysiology and diagnosis of Guillain-Barré syndrome - challenges and needs

Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy which presents with acute onset and rapid progression of flaccid, hyporeflexi quadriparesis. Both sensory and autonomic nerve involvement is seen. GBS has various subtypes that vary in their pathophysiology. The pathogenesis involves an immune response triggered by a preceding event which may be an infection, immunisation or surgical procedure. Clinical diagnosis has been largely the primary diagnosing criterion for GBS along with electrodiagnosis, which has several pitfalls and is supported by ancillary testing of cerebrospinal fluid (CSF) analysis and Nerve Conduction Studies. Measurement of anti-ganglioside antibodies is also an effective tool in its diagnosis. Further understanding of pathophysiology and better diagnostic methods are required for better management of GBS.

Is there an unrecognised role for Campylobacter infections in (chronic) inflammatory diseases?

Campylobacter species are one of the major causes of global bacterial-related diarrheal disease worldwide. The disease is most frequently associated with the ingestion of contaminated meat, raw milk, pets, contaminated water, and the organism may be frequently cultured from the faeces of chicken and other domesticated farm animals. Of the 17 established Campylobacter species, the most important pathogens for humans are Campylobacter jejuni (C. jejuni), Campylobacter coli (C. coli) and Campylobacter fetus (C. fetus), which are all associated with diarrheal disease. Further, C. jejuni and C. coli are also associated with the neuroparalytic diseases Guillain-Barré syndrome and Miller Fischer syndrome, respectively, whereas C. fetus is linked with psoriatic arthritis. The discovery of both “molecular mimicry” and translocation-related virulence in the pathogenesis of C. jejuni-induced disease, indicates that Campylobacter-related gastrointestinal infections may not only generate localized, acute intestinal infection in the human host, but may also be involved in the establishment of chronic inflammatory diseases. Indeed, pathogenicity studies on several Campylobacter species now suggest that molecular mimicry and translocation-related virulence is not only related to C. jejuni, but may play a role in human disease caused by other Campylobacter spp. In this review, the authors provide a review based on the current literature describing the potential links between Campylobacter spp. and (chronic) inflammatory diseases, and provide their opinions on the likely role of Campylobacter in such diseases.

Cloning, expression, and antigenicity of 14 proteins from Campylobacter jejuni

Fourteen Campylobacter jejuni genes--porA, cadF, omp18, dnaK, flaC, peb1, peb2, peb3, peb4, ahpC, groEL, tuF, hipO, and Cj0069--were cloned and expressed in Escherichia coli BL21. The recombinant proteins were purified on histidine (His) and glutathione S-transferase (GST) trap columns using the ÄKTA Explorer 100 System. Recombinant proteins were visualized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The antigenicities of these recombinant proteins were assessed by Western blotting and enzyme-linked immunosorbent assays with anti-C. jejuni immune rabbit sera. Four recombinant proteins, including rGST-PorA, rHis-CadF, rGST-GroEL, and rGST-TuF, demonstrated reactions with both anti-serum and preimmune serum, while rHis-DnaK, rGST-FlaC, rGST-PEB2, rGST-PEB3, rGST-PEB4, and rGST-HipO showed variable antigenicity characteristics to the anti-sera derived from different C. jejuni strains. rHis-Omp18, rHis-PEB1, and rGST-AhpC demonstrated universal and specific antigenities with the entire anti-sera panel tested in this present study, while recombinant rGST-Cj0069 and rHis-DnaK did not react with any of the anti-C. jejuni sera tested. In conclusion, rGST-AhpC may be useful as a potential serodiagnostic antigen for C. jejuni infection.

Campylobacter jejuni-mediated induction of CC and CXC chemokines and chemokine receptors in human dendritic cells

Campylobacter jejuni is a leading worldwide bacterial cause of human diarrheal disease. Although the specific molecular mechanisms of C. jejuni pathogenesis have not been characterized in detail, host inflammatory responses are thought to be major contributing factors to the resulting typical acute colitis. The intestinal mucosal chemokine response is particularly important in the initial stages of bacterium-induced gut inflammation. Chemokines attract blood phagocytes and lymphocytes to the site of infection and regulate immune cell maturation and the development of localized lymphoid tissues. The production of chemokines by dendritic cells (DCs) following Campylobacter infection has not yet been analyzed. In the current study, we infected human monocyte-derived DCs with C. jejuni to examine the production of key proinflammatory chemokines and chemokine receptors. The chemokines, including CC families (macrophage inflammatory protein 1α [MIP-1α], MIP-1β, RANTES) and CXC families (growth-related oncogene α [GRO-α], IP-10, and monokine induced by gamma interferon [MIG]), were upregulated in Campylobacter-infected DCs. Chemokine receptors CCR6 and CCR7, with roles in DC trafficking, were also induced in Campylobacter-infected DCs. Further, Campylobacter infection stimulated the phosphorylation of P38, P44/42, and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) mitogen-activated protein kinases (MAPKs) in DCs. NF-κB activation was specifically involved in chemokine induction in DCs infected with C. jejuni. Additionally, STAT3 was significantly increased in Campylobacter-infected DCs compared to that in uninfected DCs. These results suggest that DCs play a significant role in the initiation and modulation of the inflammatory response by enlisting monocytes, neutrophils, and T lymphocytes during human intestinal infection with Campylobacter.

Infectious agents of food- and water-borne illnesses

Food- and water-borne infections have afflicted mankind since the earliest days of human development and preceded the emergence of civilization. Despite current knowledge of microbial pathogenicity, modern methods of food production and rigorous industrial hygiene, these infections are still commonplace and exact significant health and economic tolls on human populations in all parts of the globe. This review uses data derived from new surveillance networks to survey the current epidemiology of bacterial, protozoan and viral pathogens transmitted by food and water. In addition, we will discuss clinical features of human disease caused by pathogens of current and emerging relevance.

A waterborne Campylobacter jejuni outbreak on a Greek island

A case-control and a case-crossover study were performed to investigate a Campylobacter jejuni outbreak in Crete in 2009. Most cases originated from rural areas, served by a different water-supply system from that of the adjacent town. Thirty-seven cases and 79 controls were interviewed; cases were interviewed for two different time periods for the case-crossover study. Stool cultures, PFGE and MLST subtyping were run in human samples. Univariately, consumption of tap water was associated with C. jejuni infection. Stratified analysis revealed that water-supply system was an effect modifier of this association. In the multivariable analysis, the rural areas' water supplier and drinking tap water were risk factors. No risk factors were revealed in the case-crossover study. No Campylobacter were isolated in the tested water samples. There is strong epidemiological evidence that tap water was the vehicle of the outbreak.

Hospitalization and deaths for select enteric illnesses and associated sequelae in Canada, 2001-2004

This paper describes morbidity and mortality parameters for Campylobacter spp., Salmonella spp., enterohaemorrhagic Escherichia coli, Listeria spp., norovirus infections and their primary associated sequelae [Guillain-Barré syndrome (GBS), haemolytic uraemic syndrome, reactive arthropathies and Reiter's syndrome]. Data from a period of 4 years were obtained from three national databases to estimate percentage of reported cases hospitalized, mean annual hospitalization incidence rate, frequency of hospitalization by age and sex, and number of deaths. The length of hospital stay, discharge disposition, hospitalization age, and number of diagnoses per case were also extracted and summarized. In addition, we estimated that each year in Canada, there are between 126 and 251 cases of Campylobacter-associated GBS. This study provides morbidity and mortality estimates for the top enteric pathogens in Canada, including their associated sequelae, which can contribute to the quantification of the burden of illness.

Association of Campylobacter jejuni infection with childhood Guillain-Barré syndrome: a case-control study

A prospective case-control study was conducted to determine the association between Campylobacter jejuni infection and childhood Guillain-Barré syndrome in the Indian population. We found evidence of recent Campylobacter jejuni infection in 27.7% of patients with Guillain-Barré syndrome, as compared with 2.3% in neurological controls (P = .003) and 2.3% in nonneurological controls (P = .003). Of the 15 patients with Campylobacter jejuni infection, 8 (53.3%) reported having had diarrhea within 12 weeks before the onset of the neurologic illness. Our results suggest association between recent Campylobacter jejuni infection and bulbar weakness (P = .043). No statistical difference was observed between the Campylobacter jejuni positive and negative groups with respect to age, other clinical features, albuminocytological dissociation, and residual paralysis at follow-up. It is concluded that subclinical Campylobacter jejuni infection is an important antecedent illness in childhood Guillain-Barré syndrome in the Indian population.

Anti-ganglioside antibody induction by swine (A/NJ/1976/H1N1) and other influenza vaccines: insights into vaccine-associated Guillain-Barré syndrome

BACKGROUND

Receipt of an A/NJ/1976/H1N1 "swine flu" vaccine in 1976, unlike receipt of influenza vaccines used in subsequent years, was strongly associated with the development of the neurologic disorder Guillain-Barré syndrome (GBS). Anti-ganglioside antibodies (e.g., anti-GM(1)) are associated with the development of GBS, and we hypothesized that the swine flu vaccine contained contaminating moieties (such as Campylobacter jejuni antigens that mimic human gangliosides or other vaccine components) that elicited an anti-GM(1) antibody response in susceptible recipients.

METHODS

Surviving samples of monovalent and bivalent 1976 vaccine, comprising those from 3 manufacturers and 11 lot numbers, along with several contemporary vaccines were tested for hemagglutinin (HA) activity, the presence of Campylobacter DNA, and the ability to induce anti-Campylobacter and anti-GM(1) antibodies after inoculation into C3H/HeN mice.

RESULTS

We found that, although C. jejuni was not detected in 1976 swine flu vaccines, these vaccines induced anti-GM(1) antibodies in mice, as did vaccines from 1991-1992 and 2004-2005. Preliminary studies suggest that the influenza HA induces anti-GM(1) antibodies.

CONCLUSIONS

Influenza vaccines contain structures that can induce anti-GM(1) antibodies after inoculation into mice. Further research into influenza vaccine components that elicit anti-ganglioside responses and the role played by these antibodies (if any) in vaccine-associated GBS is warranted.

Epidermal growth factor inhibits Campylobacter jejuni-induced claudin-4 disruption, loss of epithelial barrier function, and Escherichia coli translocation

Campylobacter jejuni is a leading cause of acute bacterial enteritis in humans. Poultry serves as a major reservoir of C. jejuni and is thought to act as a principal vehicle of transmission to humans. Epidermal growth factor (EGF) is a small amino acid peptide that exerts a broad range of activities on the intestinal epithelium. The aims of this study were to determine the effect of EGF on C. jejuni intestinal colonization in newly hatched chicks and to characterize its effects on C. jejuni-induced intestinal epithelial barrier disruption. White Leghorn chicks were treated with EGF daily, starting 1 day prior to C. jejuni infection, and were compared to control and C. jejuni-infected, EGF-treated chicks. Infected chicks shed C. jejuni in their feces throughout the study period. C. jejuni colonized the small intestine and cecum, disseminated to extraintestinal organs, and caused jejunal villus atrophy. EGF reduced jejunal colonization and dissemination of C. jejuni to the liver and spleen. In EGF-treated C. jejuni-infected chicks, villus height was not significantly different from that in untreated C. jejuni-infected chicks or controls. In vitro, C. jejuni attached to and invaded intestinal epithelial cells, disrupted tight junctional claudin-4, and increased transepithelial permeability. C. jejuni also promoted the translocation of noninvasive Escherichia coli C25. These C. jejuni-induced epithelial abnormalities were abolished by pretreatment with EGF, and the effect was dependent upon activation of the EGF receptor. These findings highlight EGF's ability to alter colonization of C. jejuni in the intestinal tract and to protect against pathogen-induced barrier defects.

Immunogenicity and protective efficacy of recombinant Campylobacter jejuni flagellum-secreted proteins in mice

Immunogenicity and protective efficacy of three Campylobacter jejuni flagellum-secreted proteins, FlaC, FspA1, and FspA2, were compared by use of a mouse model. Mice were immunized intranasally with each protein with or without LTR192G as the adjuvant and challenged intranasally with C. jejuni 81-176 or CG8486. All three proteins were immunogenic, although FspA1 induced the highest levels of serum immunoglobulin G (IgG) and fecal IgA. Although immunogenic, FlaC provided only 18% protection against disease from C. jejuni 81-176. Immunization with FspA1 resulted in 57.8% protection without adjuvant or 63.8% protection with adjuvant against homologous challenge with 81-176. Alternatively, immunization with FspA2 provided 38.4% (without adjuvant) or 47.2% (with adjuvant) protection against disease from homologous challenge with CG8486. In contrast to FspA2, FspA1 provided some heterologous protection against C. jejuni CG8486 when delivered with (31.2%) or without (44.8%) LTR192G. These results suggest that FspA1 may be a good subunit vaccine candidate against C. jejuni disease.

A new rat model links two contemporary theories in irritable bowel syndrome

RATIONALE

Two proposed hypotheses for irritable bowel syndrome (IBS) are acute gastroenteritis and bacterial overgrowth. We studied whether acute infection with Campylobacter could precipitate bacterial overgrowth in a rat model in order to link the two hypotheses.

METHODS

Sprague-Dawley outbred rats were randomly administered a vehicle or Campylobacter jejuni strain 81-176 by oral gavage. Three months after clearance of the infectious agent, rats had a stool consistency evaluation. After euthanasia, lumenal bacteria counts were measured via quantitative real-time PCR from self-contained segments of the duodenum, jejunum, ileum, cecum and left colon. Adjacent sections of bowel were fixed in formalin for evaluation of intraepithelial lymphocyte counts.

RESULTS

Three months after clearance of Campylobacter infection, 57% of Campylobacter infected rats had some alteration in stool consistency compared to 7.4% in mock-infected controls (P < 0.001). Among the rats that received Campylobacter, 27% had evidence of bacterial overgrowth by PCR. These rats also had the highest prevalence of altered stool form and had lower body weight. Consistent with post-infectious IBS in humans, bacterial overgrowth rats demonstrated a significant increase in rectal and left colon intraepithelial lymphocytes.

CONCLUSIONS

Acute infection with C. jejuni 81-176 precipitates alterations in stool consistency, bacterial overgrowth and rectal lymphocytosis consistent with findings in IBS patients.

Validation of an ELISA for the diagnosis of recent Campylobacter infections in Guillain–Barré and reactive arthritis patients

Weeks or months following Campylobacter infection, a small proportion of infected individuals develop Guillain-Barré syndrome (GBS) or reactive arthritis (ReA). Stool culture for Campylobacter is often negative in these patients, and serology is therefore the method of choice for diagnosing a recent infection with Campylobacter. This study developed a capture ELISA system to detect anti-Campylobacter IgA and IgM antibodies indicative of a recent infection. The sensitivity of the assay was 82.0% in uncomplicated Campylobacter enteritis patients, 96.2% in GBS patients who were culture-positive for Campylobacter, and 93.1% in culture-positive ReA patients, with a specificity of 93.0%. The assay allows identification of Campylobacter infection in patients with post-infectious neurological and rheumatological complications.

Massive microbiological groundwater contamination associated with a waterborne outbreak in Lake Erie, South Bass Island, Ohio

BACKGROUND

A groundwater-associated outbreak affected approximately 1,450 residents and visitors of South Bass Island, Ohio, between July and September 2004.

OBJECTIVES

To examine the microbiological quality of groundwater wells located on South Bass Island, we sampled 16 wells that provide potable water to public water systems 15-21 September 2004.

METHODS

We tested groundwater wells for fecal indicators, enteric viruses and bacteria, and protozoa (Cryptosporidium and Giardia). The hydrodynamics of Lake Erie were examined to explore the possible surface water-groundwater interactions.

RESULTS

All wells were positive for both total coliform and Escherichia coli. Seven wells tested positive for enterococci and Arcobacter (an emerging bacterial pathogen), and F(+)-specific coliphage was present in four wells. Three wells were positive for all three bacterial indicators, coliphages, and Arcobacter; adenovirus DNA was recovered from two of these wells. We found a cluster of the most contaminated wells at the southeast side of the island.

CONCLUSIONS

Massive groundwater contamination on the island was likely caused by transport of microbiological contaminants from wastewater treatment facilities and septic tanks to the lake and the subsurface, after extreme precipitation events in May-July 2004. This likely raised the water table, saturated the subsurface, and along with very strong Lake Erie currents on 24 July, forced a surge in water levels and rapid surface water-groundwater interchange throughout the island. Landsat images showed massive influx of organic material and turbidity surrounding the island before the peak of the outbreak. These combinations of factors and information can be used to examine vulnerabilities in other coastal systems. Both wastewater and drinking water issues are now being addressed by the Ohio Environmental Protection Agency and the Ohio Department of Health.

Guillain-Barré syndrome and preceding infection with campylobacter, influenza and Epstein-Barr virus in the general practice research database

Background

A number of infectious agents have previously been suggested as risk factors for the development of Guillain-Barré syndrome (GBS), but robust epidemiologic evidence for these associations is lacking.

Methods and Findings

We conducted a nested case-control study using data from the United Kingdom General Practice Research Database between 1991 and 2001. Controls were matched to cases on general practice clinic, sex, year of birth and date of outcome diagnosis in their matched case. We found positive associations between GBS and infection with Campylobacter, Epstein-Barr virus and influenza-like illness in the previous two months, as well as evidence of a protective effect of influenza vaccination. After correction for under-ascertainment of Campylobacter infection, the excess risk of GBS following Campylobacter enteritis was 60-fold and 20% of GBS cases were attributable to this pathogen.

Conclusions

Our findings indicate a far greater excess risk of GBS among Campylobacter enteritis patients than previously reported by retrospective serological studies. In addition, they confirm previously suggested associations between infection due to Epstein-Barr virus infection and influenza-like illness and GBS. Finally, we report evidence of a protective effect of influenza vaccination on GBS risk, which may be mediated through protection against influenza disease, or result from a lower likelihood of vaccination among those with recent infection. Cohort studies of GBS incidence in this population would help to clarify the burden of GBS due to influenza, and any potential protective effect of influenza vaccination.

Infections à Campylobacter jejuni et à cytomégalovirus (CMV) associées au syndrome de Guillain-Barré (SGB)

Guillain-Barre syndrome (GBS) is a rare disease triggered by postinfectious mechanisms. The disease concerns all ages, and is widely distributed around the world. The principal risks are respiratory failure, especially during the initial phase of the disease, and persisting deficit at long term. Among the infectious known agents, Campylobacter jejuni and CMV represent more than 40% of GBS causes. The clinical presentation, and the long-term prognosis of GBS related to these two etiologies are different. The physiopathological mechanisms of the nervous attack are probably also different. There is no proof, at this time, that anti-infectious treatment can improve the prognosis. The treatment is based on the early use of immunomodulatory treatments like intravenous immunoglobulins or plasma exchanges.

Improved serological diagnosis stresses the major role of Campylobacter jejuni in triggering Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is a postinfectious autoimmune polyradiculoneuropathy. The most frequent antecedent pathogen is Campylobacter jejuni, followed by cytomegalovirus. However, more than 40% of GBS cases currently cannot be attributed to triggering events. This might be due to the shortcomings of the serological assays used for diagnosing infections, in particular for C. jejuni. In our study investigating 36 patients with acute GBS, standard serological methods identified the triggering viral or bacterial etiology in only 25% of cases. However, using a highly specific enzyme-linked immunosorbent assay based on two recombinant outer antigens encoded by C. jejuni genes Cj0017 (P39) and Cj0113 (P18), we found serological evidence of a preceding C. jejuni infection in 80.6% of the patients but in only 3.5% of the controls. We conclude that the role of C. jejuni in triggering GBS has been greatly underestimated.

Clinical relevance of virulence genes in Campylobacter jejuni isolates in Bahrain

There are no data describing the genetic make-up of Campylobacter strains (an important aetiological agent of diarrhoea) circulating in the Arabian Gulf region. Here, the molecular characterization of two virulence genes in Campylobacter jejuni from Bahrain and the relationship with clinical infection are reported. Molecular screening for cytolethal distending toxin (cdtB) and invasion-associated marker (iam) genes was carried out on C. jejuni stool isolates collected from January 2002 to January 2004 in Bahrain. The molecular characterization was correlated with the patients' socio-demographic and clinical parameters. Of the 96 C. jejuni strains tested, 50 (52 %) were cdtB+/iam+, 30 (31 %) were cdtB+/iam- and 16 (17 %) were cdtB-/iam-. Sixty-nine per cent (66/96) of patients were less than 3 years old, with significantly higher detection of cdtB+/iam+ and cdtB+/iam- strains (P < 0.001 and P < 0.01, respectively) in this age group. Seventy patients (73 %) were symptomatic. In the group that were less than 3 years old, 62 and 85 % of those with cdtB+/iam+ and cdtB+/iam- strains, respectively, were symptomatic compared with 100 % for those over 3 years of age. However, the presence of cdtB-/iam- strains still resulted in clinical infection in the children under 3 years but not in the older patients. This is the first report describing the molecular characterization of virulence genes in Campylobacter isolates from this region. The findings indicate that strains of different virulence genetic make-up are circulating in the population, with children under the age of 3 years being most vulnerable. Further work on the molecular characterization, gene expression and determination of the invasive phenotypes of C. jejuni strains circulating in different regions is needed.

Amplified fragment length polymorphism, serotyping, and quinolone resistance of Campylobacter jejuni and Campylobacter coli strains from chicken-related samples and humans in Taiwan

The high-resolution genotyping method of amplified fragment length polymorphism (AFLP) analysis was used to study the genetic relationships between Campylobacter jejuni isolates from chicken-related samples (n = 32) and humans (n = 27) as well as between Campylobacter coli isolates from chicken-related samples (n = 27) and humans (n = 5). These isolates were collected between 1994 and 2003 in Taiwan. All C. jejuni and C. coli isolates showed highly heterogeneous fingerprints. C. jejuni isolates were separated in two distinct genetic clusters (A and B) at 40% genetic similarity and 42 different AFLP types at 90% similarity. However, three clusters at 40% genetic similarity and 33 different AFLP types at 90% similarity were observed in C. coli isolates. These results showed that AFLP analysis could be used to identify individual isolates of two Campylobacter species. Among C. jejuni isolates, the predominant AFLP type 1 was observed in five (7.9%) isolates, and types 5 and 12 in four (6.3%) isolates each. Cluster B consisted of 10 isolates, while the majority of isolates (n = 53) belonged to cluster A. In some AFLP types (1, 5, 12, 14 and 31), AFLP fingerprints of chicken-related isolates were closely related genetically to those of isolates from humans with gastroenteritis. The predominant serotypes in C. jejuni isolates were B:2 and Y:37. All isolates belonging to serotype O:19 grouped into one single AFLP type. Some chicken samples yielded multiple isolates of Campylobacter harboring simultaneously quinolone-resistant and quinolone-sensitive isolates attributed to the same species, or harboring C. jejuni and C. coli that have the characteristics of quinolone resistance.

Cytomegalovirus-Associated Periodontitis and Guillain-Barré Syndrome

BACKGROUND

Guillain-Barré syndrome (GBS), an autoimmune disorder of the peripheral nervous system, is characterized by rapidly ascending neural paralysis, hyporeflexia, and areflexia. The polyneuropathy of the GBS affects one to four humans per 100,000 of the population annually throughout the world (adults and children). The pathogenesis of GBS remains unclear. However, there are increasing indications that the disease is triggered by a preceding well-established febrile infection by cytomegalovirus (CMV). The present report describes active CMV within the periodontium of a 37-year-old patient affected by GBS.

METHODS

Real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) was performed to detect CMV, Epstein-Barr virus-1 (EBV-1), herpes simplex 1 (HSV-1) and 2 (HSV-2) virus, and enteroviruses (polio-, coxsackie-, echo-, and enteroviruses 68 and 71) from periodontal sites demonstrating advanced attachment loss. Healthy sites and sites with inflamed gingival tissue were not included in the study. Anaerobic bacterial culture determined the occurrence of potential major periodontal pathogens.

RESULTS

Real-time RT-PCR and microbiologic analysis revealed the presence of a dual infection of CMV and specific bacterial plaque. CMV, Porphyromonas gingivalis, Tannerella forsythensis, and Campylobacter species were associated with periodontitis active sites, loss of attachment, and gingival bleeding. Furthermore, periodontal sites infected by active CMV had no visible radiographic crestal lamina dura.

CONCLUSIONS

The periodontium may serve as a reservoir for CMV and a source of viral replication. However, further research is needed to test whether viral replication in the periodontium precedes the GBS symptoms.

Establishment of a non-human primate Campylobacter disease model for the pre-clinical evaluation of Campylobacter vaccine formulations

Campylobacter jejuni is a common cause of enteritis worldwide. The mechanisms by which C. jejuni causes disease are unclear. Challenge studies in humans are currently considered unethical due to the possibility of severe complications, such as Guillain-Barré syndrome. Campylobacter infection in non-human primates closely mimics the disease and immune response, seen in humans. In this study, we attempted to determine the minimal dose of a pathogenic C. jejuni 81-176 strain required for clinical signs and symptoms of disease (> or = 80% attack rate) in Macaca mulatta monkeys using an escalating dosage (three doses for three monkey groups: 10(7), 10(9) and 10(11) cfu). Eighty percent of the monkeys challenged with highest dose (10(11) cfu) had mild disease, but the 80% attack rate (moderate diarrhea in 80% of the monkeys) was not achieved. However, 100% of monkeys showed IgA seroconversions (three-fold over pre-challenge titers). The elicited immune response was challenge dose-dependent. Campylobacter antigen specific fecal s-IgA responses were observed in all challenged groups but the response was not dose-dependent. Only IgM antibody secreting cells response was observed against Campylobacter antigens. The elicited immune response in three groups of rhesus monkeys was dose-dependent, indicating this monkey model can be used for pre-clinical evaluation of Campylobacter candidate vaccines, however these adult rhesus monkeys are less prone to Campylobacter infection.

Diagnosis and management of acute myelopathies

BACKGROUND

Acute myelopathies represent a heterogeneous group of disorders with distinct etiologies, clinical and radiologic features, and prognoses. Transverse myelitis (TM) is a prototype member of this group in which an immune-mediated process causes neural injury to the spinal cord, resulting in varying degrees of weakness, sensory alterations, and autonomic dysfunction. TM may exist as part of a multifocal CNS disease (eg, MS), multisystemic disease (eg, systemic lupus erythematosus), or as an isolated, idiopathic entity.

REVIEW SUMMARY

In this article, we summarize recent classification and diagnostic schemes, which provide a framework for the diagnosis and management of patients with acute myelopathy. Additionally, we review the state of current knowledge about the epidemiology, natural history, immunopathogenesis, and treatment strategies for patients with TM.

CONCLUSIONS

Our understanding of the classification, diagnosis, pathogenesis, and treatment of TM has recently begun to expand dramatically. With more rigorous criteria applied to distinguish acute myelopathies and with an emerging understanding of immunopathogenic events that underlie TM, it may now be possible to effectively initiate treatments in many of these disorders. Through the investigation of TM, we are also gaining a broader appreciation of the mechanisms that lead to autoimmune neurologic diseases in general.

Campylobacter vaccine development:a key to controlling enteric diseases

Worldwide, Campylobacter jejuni is a major cause of diarrhoea and dysentery, with approximately 400 million cases occurring annually. Control of the disease through public health and antibiotic measures is insufficient, and vaccination offers the most promising solution. Infection produces immunity from disease, suggesting that vaccination may produce similar protection. Epidemiological data suggest that there are conserved antigens among serotypes; immunity against which protects against disease. Therefore a monovalent serotype vaccine seems practical. Several antigens on Campylobacter have been found to be immunogenic and, in some cases, associated with virulence. However, none of these proteins have been produced recombinantly in the proper conformation, nor have they been protective in preclinical models. For this reason, live attenuated or inactivated Campylobacter whole cell (CWC) vaccines may be the best approach. Development of an attenuated strain of Campylobacter has been complicated by the fact that the organism is highly transformable. Rec A mutants of Campylobacter have recently been constructed in an attempt to avoid this trait. Such mutants have been made defective in various virulence properties and are being evaluated for safety in preclinical models. Antex Biologics has made an inactivated CWC vaccine using the Company's patented NST (nutriment signal transduction) technology, whereby the cells are grown using physiologically logical conditions to maximise the expression of antigens associated with in vivo virulence. This vaccine has been shown to be safe, immunogenic, and protective in preclinical models of infection. Inclusion of a mucosal adjuvant in the vaccine increases the immunological response to the antigen. Recent Phase I and Phase II clinical trials, using the CWC vaccine formulated with an adjuvant and orally administered, show that the vaccine is safe and immunogenic in human volunteers. The approach used to develop this inactivated whole cell Campylobacter vaccine is also applicable for the rapid development of new vaccines against a variety of mucosal pathogens.

Sensitivity and specificity of serology in determining recent acute Campylobacter infection

BACKGROUND

The measurement of serum antibodies to Campylobacter spp. has been used to investigate links between prior Campylobacter infections and the development of Guillain-Barre syndrome and its variants. Little is known of the serum antibody response to acute infections in the short- or long-term.

AIMS

The aims of the present study were to investigate the normal serum response to an acute Campylobacter infection and the sensitivity and specificity of anti-Campylobacter antibodies in determining recent Campylobacter infection.

METHODS

An enzyme-linked immunosorbent assay (ELISA) method was used to measure serum anti-Campylobacter immunoglobulin G (IgG), IgA and IgM antibodies. Controls consisted of 420 blood donors without recent gastroenteritis, 25 patients with other gastrointestinal infections, 24 patients with neurological conditions not affecting the peripheral nerves and 19 patients with autoimmune disorders. Three patient groups were assessed: 99 patients with acute Campylobacter infections, all of whom were tested 3 weeks post-infection; 69 of these patients tested 3-6 months later; and 74 additional patients tested >20 months post-infection. Western blot analysis was performed on controls and patients with high titre anti-Campylobacter antibodies to assess for cross-reactivity and specificity.

RESULTS

Following acute infections, all antibody classes rose in the majority of but not in all patients, followed by decreasing titres that did not return to baseline levels. Sixteen per cent of enteritis cases did not demonstrate a rise in titres and 9% of cases had significant levels of antibodies >20 months post-infection. The ELISA used was shown to be highly specific for the detection of Campylobacter antibodies.

CONCLUSION

The use of Campylobacter-specific antibody levels as the sole marker of prior infection is an unreliable method of determining the association between Campylobacter infection and neurological disease.

Detection of preceding Campylobacter jejuni infection by polymerase chain reaction in patients with Guillain-Barré syndrome

Based on culture and serological evidence, a strong association between Campylobacter jejuni infection and Gullain-Barré syndrome (GBS) has been established. However, culture underestimates C. jejuni infection in GBS and the specificity of serology remains uncertain. Thus, a direct sensitive detection method for recent C. jejuni infection is required. We used the PCR technique in GBS patients to assess its role in the diagnosis of C. jejuni infection. From June 2001 to March 2003, stool specimens from 42 patients with GBS and an equal number of age- and gender-matched healthy controls were analysed for C. jejuni infection by culture and PCR. Gullain-Barré syndrome subtypes were classified by clinical and electrophysiological studies. Of the GBS patients, two (4.8%) and eight (19%) were positive by culture and PCR, respectively, and the difference was significant (P < 0.05). None of the controls were positive for C. jejuni by culture or PCR. All C. jejuni-positive GBS patients had axonal degeneration with or without sensory involvement. The incidence of C. jejuni-associated GBS cases was more frequent during summer than winter (7/19, 36.8% vs. 1/23, 4.3%, P < 0.01). Polymerase chain reaction appears to be a sensitive tool to detect preceding C. jejuni infection in GBS patients.

Blood ?? T cells,Campylobacter jejuni, and GM1 titers in Guillain-Barr� syndrome

The gammadelta T cells participate in microbial defense, are prevalent in intestinal epithelia, and are activated in autoimmune diseases. We studied whether peripheral blood gammadelta cells and gammadelta subsets are increased in Guillain-Barré syndrome (GBS) and whether elevations are associated with Campylobacter jejuni infection or GM1 elevations. In 20 GBS patients, we performed serial flow cytometry studies of blood gammadelta, Vdelta1, and Vdelta2 cells (+/- CD8+), C jejuni, and ganglioside titers. There was no significant difference in median gammadelta T-cell percentages between GBS patients and controls at onset and at convalescence. However, 5 patients had marked Vdelta1/CD8+ elevations. Elevated Vdelta1 or Vdelta1/CD8+ cells occurred in 3 of 6 patients with C jejuni or GM1 titer elevations. A minority of GBS patients have elevations of Vdelta1/CD8+ cells, possibly associated with elevated C jejuni or GM1 titers. The gammadelta T cells may have a cytotoxic (or suppressor) role in the disease.

Enteric campylobacter: purging its secrets?

Campylobacterial infections are the most common cause of bacterial enterocolitis in humans. Among children, especially in developing countries, Campylobacter infections can cause severe life-threatening diarrheal disease. Although usually associated with a benign outcome in the developed world, the burden of illness posed by Campylobacter infections is enormous, and serious neurologic sequelae also can occur. For a variety of reasons our understanding of the molecular and cellular pathogenesis of Campylobacter infection has lagged far behind that of other enteric pathogens. However, recent completion of the genome sequence of Campylobacter jejuni promises to open up the Campylobacter research field with the prospect of developing novel therapeutic and preventive strategies.

Severe acute diarrhea

Acute diarrhea is commonly caused by an infection. Severe acute diarrhea warrants immediate medical evaluation and hospitalization. Indications for stool studies include fever; bloody diarrhea; recent travel to an endemic area; recent antibiotics; immunosuppression; and occupational risks, such as food handlers. Noninfectious causes include inflammatory bowel disease, radiation enteritis, and intestinal ischemia. Management of severe acute diarrhea includes intravenous fluid rehydration and empiric antibiotics. Use of antidiarrheal agents is controversial when invasive pathogens are suspected.

Quantitative risk assessment of human campylobacteriosis associated with thermophilic Campylobacter species in chickens

A quantitative risk assessment comprising the elements hazard identification, hazard characterization, exposure assessment, and risk characterization has been prepared to assess the effect of different mitigation strategies on the number of human cases in Denmark associated with thermophilic Campylobacter spp. in chickens. To estimate the human exposure to Campylobacter from a chicken meal and the number of human cases associated with this exposure, a mathematical risk model was developed. The model details the spread and transfer of Campylobacter in chickens from slaughter to consumption and the relationship between ingested dose and the probability of developing campylobacteriosis. Human exposure was estimated in two successive mathematical modules. Module 1 addresses changes in prevalence and numbers of Campylobacter on chicken carcasses throughout the processing steps of a slaughterhouse. Module 2 covers the transfer of Campylobacter during food handling in private kitchens. The age and sex of consumers were included in this module to introduce variable hygiene levels during food preparation and variable sizes and compositions of meals. Finally, the outcome of the exposure assessment modules was integrated with a Beta-Poisson dose-response model to provide a risk estimate. Simulations designed to predict the effect of different mitigation strategies showed that the incidence of campylobacteriosis associated with consumption of chicken meals could be reduced 30 times by introducing a 2 log reduction of the number of Campylobacter on the chicken carcasses. To obtain a similar reduction of the incidence, the flock prevalence should be reduced approximately 30 times or the kitchen hygiene improved approximately 30 times. Cross-contamination from positive to negative flocks during slaughter had almost no effect on the human Campylobacter incidence, which indicates that implementation of logistic slaughter will only have a minor influence on the risk. Finally, the simulations showed that people in the age of 18-29 years had the highest risk of developing campylobacteriosis.

Immunopathogenesis of acute transverse myelitis

Acute transverse myelitis is a group of disorders characterized by focal inflammation of the spinal cord and resultant neural injury. Acute transverse myelitis may be an isolated entity or may occur in the context of multifocal or even multisystemic disease. It is clear that the pathological substrate--injury and dysfunction of neural cells within the spinal cord--may be caused by a variety of immunological mechanisms. For example, in acute transverse myelitis associated with systemic disease (i.e. systemic lupus erythematosus or sarcoidosis), a vasculitic or granulomatous process can often be identified. In idiopathic acute transverse myelitis, there is an intraparenchymal or perivascular cellular influx into the spinal cord, resulting in the breakdown of the blood-brain barrier and variable demyelination and neuronal injury. There are several critical questions that must be answered before we truly understand acute transverse myelitis: (1) What are the various triggers for the inflammatory process that induces neural injury in the spinal cord? (2) What are the cellular and humoral factors that induce this neural injury? and (3) Is there a way to modulate the inflammatory response in order to improve patient outcome? Although much remains to be elucidated about the causes of acute transverse myelitis, tantalizing clues as to the potential immunopathogenic mechanisms in acute transverse myelitis and related inflammatory disorders of the spinal cord have recently emerged. It is the purpose of this review to illustrate recent discoveries that shed light on this topic, relying when necessary on data from related diseases such as acute disseminated encephalomyelitis, Guillain-Barré syndrome and neuromyelitis optica. Developing a further understanding of how the immune system induces neural injury will depend upon confirmation and extension of these findings and will require multicenter collaborative efforts.

Sialosyl-galactose: a common denominator of Guillain-Barré and related disorders?

The immune reactivity implicated in the pathogenesis of Guillain-Barré syndrome (GBS) and related diseases, which occur following infection with specific strains of Campylobacter jejuni bearing sialylated lipopolysaccharide structures that cross-react with specific gangliosides, is consistent with provocation of inflammation via molecular mimicry. In this review, we have focused upon microbial characteristics and structures, the fine structure of the essential carbohydrate determinants, and the application of our proposed criteria, modified from those of Koch for causation of infectious and of Witebsky for autoimmune diseases, to the circumstance of infectious induction of autoimmune disorder.

Identification of motility and autoagglutination Campylobacter jejuni mutants by random transposon mutagenesis

Campylobacter jejuni has been identified as the leading cause of acute bacterial diarrhea in the United States, yet compared with other enteric pathogens, considerably less is understood concerning the virulence factors of this human pathogen. A random in vivo transposon mutagenesis system was recently developed for the purpose of creating a library of C. jejuni transformants. A total of 1,065 C. jejuni transposon mutants were screened for their ability to swarm on motility agar plates and autoagglutinate in liquid cultures; 28 mutants were subsequently identified. The transposon insertion sites were obtained by using random-primed PCR, and the putative genes responsible for these phenotypes were identified. Of these mutants, all 28 were found to have diminished motility (0 to 86% that of the control). Seventeen motility mutants had insertions in genes with strong homology to functionally known motility and chemotaxis genes; however, 11 insertions were in genes of unknown function. Twenty motility mutants were unable to autoagglutinate, suggesting that the expression of flagella is correlated with autoagglutination (AAG). However, four mutants expressed wild-type levels of surface FlaA, as indicated by Western blot analysis, yet were unable to autoagglutinate (Cj1318, Cj1333, Cj1340c, and Cj1062). These results suggest that FlaA is necessary but not sufficient to mediate the AAG phenotype. Furthermore, two of the four AAG mutants (Cj1333 and Cj1062) were unable to invade INT-407 intestinal epithelial cells, as determined by a gentamicin treatment assay. These data identify novel genes important for motility, chemotaxis, and AAG and demonstrate their potential role in virulence.

An unusual case of anti-Borrelia burgdorferi immunoglobulin G seroconversion caused by administration of intravenous gammaglobulins

Administration of gammaglobulins to individuals without specific anti-Borrelia burgdorferi antibodies may lead to immunoglobulin G (IgG) conversion as detected by enzyme-linked immunosorbent assay (ELISA). In some cases however, complementary techniques such as Western blot or avidity will be of prime importance in distinguishing the start of an infection from the passive immunization induced by the gammaglobulins. In all cases, the key element before reaching conclusions in relation to any of these investigations remains the confrontation between the clinical context and the biological findings. This is the scenario that has been followed in our observation.

Polygenic control of autoimmune peripheral nerve inflammation in rat

Experimental autoimmune neuritis (EAN) is the principal animal model for Guillain-Barré syndrome (GBS), an inflammatory disease of the peripheral nervous system. Little is known on the genetic regulation of these diseases. We provide the first genetic linkage analysis of EAN. Susceptibility to EAN in a rat F2 population segregated with high levels of anti-PNM IgG, as well as IgG2b and IgG2c isotype levels, which support that disease genes regulate preferential Th1/Th2 differentiation. Linkage analysis demonstrated co-localization of EAN loci with reported susceptibility loci for experimental arthritis and/or encephalomyelitis and a new region on chromosome 17. Further dissection of these loci may disclose disease pathways in GBS.