Campylobacter jejuni strains from patients with Guillain-Barré syndrome belong mostly to Penner serogroup 19 and contain beta-N-acetylglucosamine residues

Capsular Genotype and Lipooligosaccharide Class Associated Genomic Characterizations of Campylobacter jejuni Isolates From Food Animals in China

Campylobacter jejuni (C. jejuni) is the leading causative agent of gastroenteritis and Guillain–Barré syndrome (GBS). Capsular polysaccharide (CPS) and lipooligosaccharide (LOS) contribute to the susceptibility of campylobacteriosis, which have been concern the major evaluation indicators of C. jejuni isolates from clinical patients. As a foodborne disease, food animal plays a primary role in the infection of campylobacteriosis. To assess the pathogenic characterizations of C. jejuni isolates from various ecological origins, 1609 isolates sampled from 2005 to 2019 in China were analyzed using capsular genotyping. Strains from cattle and poultry were further characterized by LOS classification and multilocus sequence typing (MLST), compared with the isolates from human patients worldwide with enteritis and GBS. Results showed that the disease associated capsular genotypes and LOS classes over-represented in human isolates were also dominant in animal isolates, especially cattle isolates. Based on the same disease associated capsular genotype, more LOS class types were represented by food animal isolates than human disease isolates. Importantly, high-risk lineages CC-22, CC-464, and CC-21 were found dominated in human isolates with GBS worldwide, which were also represented in the food animal isolates with disease associated capsular types, suggesting a possibility of clonal spread of isolates across different regions and hosts. This is the first study providing genetic evidence for food animal isolates of particular capsular genotypes harbor similar pathogenic characteristics to human clinical isolates. Collective efforts for campylobacteriosis hazard control need to be focused on the zoonotic pathogenicity of animal isolates, along the food chain “from farm to table.”

Genomic Relatedness, Antibiotic Resistance and Virulence Traits of Campylobacter jejuni HS19 Isolates From Cattle in China Indicate Pathogenic Potential

Although campylobacteriosis is a zoonotic foodborne illness, high-risk isolates from animal sources are rarely characterized, and the pathogenic potential of zoonotic strains remains an obstacle to effective intervention against human infection. HS19 has been acknowledged as a maker serotype represented by Campylobacter jejuni (C. jejuni) isolates from patients with post-infection Guillain-Barré syndrome (GBS), which is circulation in developed countries. However, a previous serotype epidemiological study of C. jejuni isolates in an animal population revealed that HS19 was also prevalent in isolates from cattle in China. In this study, to investigate the hazardous potential of zoonotic strains, 14 HS19 isolates from cattle were systematically characterized both by genotype and phenotype. The results showed that all of these cattle isolates belonged to the ST-22 complex, a high-risk lineage represented by 77.2% HS19 clinical isolates from patients worldwide in the PubMLST database, indicating that the ST-22 complex is the prominent clonal complex of HS19 isolates, as well as the possibility of clonal spread of HS19 isolates across different regions and hosts. Nevertheless, these cattle strains clustered closely with the HS19 isolates from patients, suggesting a remarkable phylogenetic relatedness and genomic similarity. Importantly, both tetracycline genes tet(O) and gyrA (T86I) reached a higher proportional representation among the cattle isolates than among the human clinical isolates. A worrying level of multidrug resistance (MDR) was observed in all the cattle isolates, and two MDR profiles of the cattle isolates also existed in human clinical isolates. Notably, although shared with the same serotype HS19 and sequence type ST-22, 35.7% of cattle isolates induced severe gastrointestinal pathology in the IL-10^–/– C57BL/6 mice model, indicating that some bacteria could change due to host adaptation to induce a disease epidemic, thus the associated genetic elements deserve further investigation. In this study, HS19 isolates from cattle were first characterized by a systematic evaluation of bacterial genomics and in vitro virulence, which improved our understanding of the potential zoonotic hazard from food animal isolates with high-risk serotypes, and provided critical information for the development of targeted C. jejuni mitigation strategies.

Miller Fisher Syndrome Triggered by Infections: A Review of the Literature and a Case Report

AIM

We reported a case of Miller Fisher syndrome following a breakthrough varicella zoster virus infection in an otherwise healthy 6-year-old male. The objective of this review was to summarize the infectious etiologic agents known to trigger Miller Fisher syndrome.

METHODS

Review of the literature on infections associated with Miller Fisher syndrome.

RESULTS

We identified 762 studies after duplicates were removed. Titles, abstracts, and full texts were screened. Finally, 37 studies were included in qualitative synthesis after citations and reference list were checked. The age range of cases reported was 0-78 years, and male sex was predominant in studies where these parameters were reported. The most common causative agent was Campylobacter jejuni followed by Haemophilus influenzae.

CONCLUSIONS

Our review highlights the importance of recognizing the infections triggering Miller Fisher syndrome. We also present a unique case of Miller Fisher syndrome associated with breakthrough varicella zoster virus infection. Preventive policies may consider population immunization for certain causative agents.

Miller Fisher Syndrome Triggered by Infections: A Review of the Literature and a Case Report

AIM

We reported a case of Miller Fisher syndrome following a breakthrough varicella zoster virus infection in an otherwise healthy 6-year-old male. The objective of this review was to summarize the infectious etiologic agents known to trigger Miller Fisher syndrome.

METHODS

Review of the literature on infections associated with Miller Fisher syndrome.

RESULTS

We identified 762 studies after duplicates were removed. Titles, abstracts, and full texts were screened. Finally, 37 studies were included in qualitative synthesis after citations and reference list were checked. The age range of cases reported was 0-78 years, and male sex was predominant in studies where these parameters were reported. The most common causative agent was Campylobacter jejuni followed by Haemophilus influenzae.

CONCLUSIONS

Our review highlights the importance of recognizing the infections triggering Miller Fisher syndrome. We also present a unique case of Miller Fisher syndrome associated with breakthrough varicella zoster virus infection. Preventive policies may consider population immunization for certain causative agents.

Investigation of the Role of Campylobacter Infection in Suspected Acute Polyradiculoneuritis in Dogs

Background

Acute polyradiculoneuritis (APN) is an immune‐mediated peripheral nerve disorder in dogs that shares many similarities with Guillain‐Barré syndrome (GBS) in humans, in which the bacterial pathogen Campylobacter spp. now is considered to be a major triggering agent. Little information is available concerning the relationship between APN and Campylobacter spp. in dogs.

Hypothesis/Objectives

To estimate the association between Campylobacter spp. infection and APN. Associations with additional potential risk factors also were investigated, particularly consumption of raw chicken.

Animals

Twenty‐seven client‐owned dogs suffering from suspected APN and 47 healthy dogs, client‐owned or owned by staff members.

Methods

Case‐control study with incidence density‐based sampling. Fecal samples were collected from each enrolled animal to perform direct culture, DNA extraction, and polymerase chain reaction (PCR) for detection of Campylobacter spp. In some cases, species identification was performed by sequence analysis of the amplicon. Data were obtained from the medical records and owner questionnaires in both groups.

Results

In cases in which the fecal sample was collected within 7 days from onset of clinical signs, APN cases were 9.4 times more likely to be positive for Campylobacter spp compared to control dogs (P < 0.001). In addition, a significant association was detected between dogs affected by APN and the consumption of raw chicken (96% of APN cases; 26% of control dogs). The most common Campylobacter spp. identified was Campylobacter upsaliensis.

Conclusions and Clinical Importance

Raw chicken consumption is a risk factor in dogs for the development of APN, which potentially is mediated by infection with Campylobacter spp.

Immunoproteomic identification of antigenic candidate Campylobacter jejuni and human peripheral nerve proteins involved in Guillain-Barré syndrome

Immunoproteomics is become a potent methodology used for identifying immunoreactive proteins. In this study, an immunoproteomic approach based on 2-dimensional gel electrophoresis (2D-PAGE) and immunoblotting combined with high resolution mass spectrometry (MS) was used to identify immunoreactive proteins that might be involved in mechanisms of Guillain-Barré syndrome (GBS) development, regardless of their potential reciprocal molecular mimicry. Proteins isolated from C. jejuni and human peripheral nerve tissue (HPN) were separated with 2D SDS-PAGE and subjected to western blotting using serum samples from GBS patients. The peptides generated after proteolysis of the immunoreactive proteins were submitted to nanoflow-high performance liquid chromatography-nano electrospray ionization coupled to high resolution mass spectrometry (nHPLC-nESI-MS and MS/MS) followed by SEQUESTdata analysis for proteins identification. In C. jejuni, immunoreactivity was found for GroEL and DnaK, structural proteins (MOMP), key enzymatic proteins necessary for the microbial proliferation (adenylate kinase, enolase, inorganic pyrophosphatase and aspartate ammonia-lyase), and antioxidant enzymes (alkyl hydroperoxide reductase-AhpC and DNA protection during starvation protein - DNA protection factor against Fe²⁺-mediated oxidative stress). HPN immunoreactive proteins identified were heat shock proteins (HSP), intermediate filaments (vimentin and desmin), and other proteins and enzymes such as troponin/tropomyosin complex and ATP synthase subunit beta and the keratan sulfate proteoglycan lumican. The targeting of vimentin and desmin, suggested that the neuronal autoimmune damage is specifically directed to intermediate neuronal (vimentin) and neuromuscular IF, probably localized nearby cell surface, affording increased accessibility to autoantibodies. These findings suggest that the post-infectious development of GBS may be also associated to additional concomitant immune factors that lead to nerve damage generated by auto-immune trigger(s) different from molecular mimicry.

Capsular genotype and lipooligosaccharide locus class distribution in Campylobacter jejuni from young children with diarrhea and asymptomatic carriers in Bangladesh

Campylobacter jejuni-related diarrheal diseases is one of the major health issues among young children (0-59 months old) in low-income countries. Monitoring of the capsular (capsule polysaccharide, CPS) types of virulent C. jejuni strains in regions where the disease is endemic is of great importance for the development of a customized capsule-based multivalent vaccine. Therefore, we aimed to determine the prevalence of CPS genotypes among C. jejuni strains isolated from young children with enteritis (n = 152) and asymptomatic carriers matched by age, sex, and residence defined as the control group (n = 215) in Bangladesh. CPS genotyping was performed using a newly established multiplex polymerase chain reaction (PCR) method and lipooligosaccharide (LOS) locus classes (A-E) were characterized using PCR as well. We identified 24 different CPS genotypes among the 367 isolates. Four prevalent capsular types, HS5/31 complex (n = 27, 18%), HS3 (n = 26, 17%), HS4A (n = 10, 7%), and HS8/17 (n = 10, 7%) covered almost 50% of the strains from enteritis patients and 43% of the isolates from controls. In combination, the CPS genotype and LOS class was not discriminative between cases and controls. Dominant capsular types previously identified in C. jejuni strains isolated from patients with Guillain-Barré syndrome in Bangladesh were rarely detected in strains isolated from the young children. A similar distribution was evident among enteritis- and control-related strains when comparison was done between CPS types and LOS classes. This is the first systematic study presenting the distribution of CPS genotypes of C. jejuni strains isolated in Bangladesh from children with diarrhea and controls, with capsular genotypes HS5/31 complex, HS3, HS4A, and HS8/17 being prevalent in both. In conclusion, systematic studies are required to develop a multivalent capsule-based vaccine for children in low-income countries.

A Comparative Evaluation Study of Growth Conditions for Culturing the Isolates of Campylobacter spp

Campylobacter is one of the leading causes of foodborne travelers' diarrhea worldwide. Although a large number cases of campylobacteriosis go undiagnosed or unreported, it is considered as the second most common foodborne illness in the USA affecting over 1.3 million individuals every year. Of various Campylobacter species, C. jejuni, C. coli, and C. lari have been accounted for causing more than 99% of human infections. Thus, there is a need to have efficient isolation method to protect public health on food safety and monitoring the burden of campylobacteriosis. Nevertheless, it is a challenging task as the exposure of environmental stress during isolation process makes Campylobacter species less culturable. Sixteen Campylobacter spp. were used to evaluate the current protocols used in Campylobacter isolation. For optimal recovery, a range of growth media (Bolton, Columbia, Muller Hinton, CVA Campy and mCCDA), incubation temperatures, and additional supplements (including antibiotics) were tested. Blood agars without antibiotics were sufficient for the initial recovery. Afterward, the isolates could grow on agars without any supplements, and in some cases growth was observed in the presence of antibiotics. Incubation at 37 °C was found to be the optimal temperature for the recovery and the growth of most species. Additionally, a food adulteration study was also carried out by artificially contaminating three food matrices that included egg, milk, and infant cereal, with two isolates of C. jejuni and C. coli. Results of this study should provide the insight for culturing and isolation of Campylobacter from food and other sources.

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.

Genetic Characteristics and Multiple-PCR Development for Capsular Identification of Specific Serotypes of Campylobacter jejuni

The polysaccharide capsule (CPS) of Campylobacter jejuni is a virulence factor linked to cell surface carbohydrate diversity which mainly determines the serotypes. Thirty-four CPS gene cluster structures have been published and some of them can be distinguished by multiple-PCR. Penner serotypes HS1/44c, HS2, HS4c, HS19, HS23/36c and HS41 are markers for Guillain—Barré syndrome (GBS). The capsules may contribute to GBS susceptibility. Analysis of 18 CPS loci revealed high gene content diversity and a mosaic nature of the capsule loci, which are possibly due to gene gain/loss events, and demonstrated a high degree of conservation of genes within serotypes/serotype complexes. A method of multiple-PCR was developed to distinguish five specific serotypes and three GBS-related serotypes. Primers specific for each capsule type were designed on the basis of paralogs or a unique DNA region of the CPS locus. The multiple-PCR can distinguish the eight serotypes in two PCRs with sensitivity and specificity of 100% using 227 strains of known Penner type. The multiple-PCR method will help to distinguish serotypes simply and rapidly.

Miller Fisher syndrome

A man aged 30 years presented to the emergency department (ED) with ataxia, areflexia, facial weakness, ophthalmoplegia, extremity weakness and back pain for 4 days. 4 days prior to attending the ED, the patient had suffered from diarrhoea for 2 weeks. The diagnosis of Miller Fisher syndrome was performed on the dual basis of clinical features in addition to an investigations report. Nerve conduction studies and anti-GQ1b IgG antibody analysis were requested. Once IgA deficiency was ruled out, the patient was started on intravenous immunoglobulin (400 mg/kg/day).

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.

DNA diversity of the wla gene cluster among serotype HS:19 and non-HS:19 Campylobacter jejuni strains

Campylobacter jejuni infection is an important trigger of Guillain-Barré syndrome (GBS), and serotype HS:19 strains are over-represented among GBS-associated isolates. Structures in C. jejuni lipooligosaccharide (LOS) resemble human gangliosides, suggesting that molecular mimicry could be important in triggering the neural injury. We assessed the genetic diversity among 36 C. jejuni serotype HS:19 and non-HS:19 strains by analysis of PCR-based restriction fragment length polymorphism (RFLP) patterns of 12 LOS biosynthesis-related genes ( wla cluster). PCR amplification revealed that the size, order, and direction of each wla gene was identical among all strains tested. However, an additional ORF, located between wlaI and wlaK, was detected in 28 of the 36 isolates examined, and nucleotide sequence analysis revealed that the gene was identical to orfE in C. jejuni strain NCTC 11168. An inverted repeat motif was found downstream of the wlaI stop codon and upstream of the orfE stop codon, an organization allowing pairing of repeated sequences that could lead to deletion of the internal segment. Digestion of the PCR products with restriction endonuclease DdeI or AluI and cluster analysis of RFLP banding patterns showed that all HS:19 strains were closely related and distinct from non-HS:19 strains, consistent with earlier analyses, suggesting that HS:19 strains represent a highly clonal population. RFLP analysis of wla genes also may be useful for epidemiological studies.

Antibody cross-reactivities between gangliosides and lipopolysaccharides of Campylobacter jejuni serotypes associated with Guillain-Barré syndrome

Ganglioside-antibodies produced subsequent to Campylobacter jejuni infection may play a role in the pathogenesis of the neurological disorder Guillain-Barré syndrome (GBS). Since lipopolysaccharides (LPS) of certain C. jejuni serotypes associated with GBS (O:2, O:4, O:19) exhibit structural mimicry of gangliosides in their core oligosaccharides, we investigated antibody and ligand cross-reactivities between gangliosides and LPS of these C. jejuni serotypes. GM1-antibody reacted with O:19 LPS reflecting GM1 mimicry by the O:19 core oligosaccharide. On the other hand, asialoGM1-antibody bound to O:2 and O:19 LPS indicating a shared epitope not dependent on ganglioside mimicry. Serum IgA from GBS patients after C. jejuni infection reacted with gangliosides, predominantly GM1, and LPS of all three serotypes. Cholera toxin (GM1 ligand) recognized O:4 and O:19 LPS, whereas peanut agglutinin (Galβ1-3GalNAc ligand) recognized LPS of all three serotypes, thereby confirming structural mimicry. These results suggest that LPS from certain C. jejuni strains may function as cross-reactive antigens for anti-ganglioside B cells.

Clinical relevance of infections with zoonotic and human oral species of Campylobacter

Genus Campylobacter has been recognized as a causative bacterial agent of animal and human diseases. Human Campylobacter infections have caused more concern. Campylobacters can be classified into two groups in terms of their original host: zoonotic and human oral species. The major zoonotic species are Campylobacter jejuni and Campylobacter coli, which mostly reside in the intestines of avian species and are transmitted to humans via consumption of contaminated poultry products, thus causing human gastroenteritis and other diseases as sequelae. The other campylobacters, human oral species, include C. concisus, C. showae, C. gracilis, C. ureolyticus, C. curvus, and C. rectus. These species are isolated from the oral cavity, natural colonization site, but have potential clinical relevance in the periodontal region to varying extent. Two species, C. jejuni and C. coli, are believed to be mainly associated with intestinal diseases, but recent studies suggested that oral Campylobacter species also play a significant role in intestinal diseases. This review offers an outline of the two Campylobacter groups (zoonotic and human oral), their virulence traits, and the associated illnesses including gastroenteritis.

Campylobacter jejuni capsular genotypes are related to Guillain-Barré syndrome

In about one in a thousand cases, a Campylobacter jejuni infection results in the severe polyneuropathy Guillain-Barré syndrome (GBS). It is established that sialylated lipo-oligosaccharides (LOS) of C. jejuni are a crucial virulence factor in GBS development. Frequent detection of C. jejuni with sialylated LOS in stools derived from patients with uncomplicated enteritis implies that additional bacterial factors should be involved. To assess whether the polysaccharide capsule is a marker for GBS, the capsular genotypes of two geographically distinct GBS-associated C. jejuni strain collections and an uncomplicated enteritis control collection were determined. Capsular genotyping of C. jejuni strains from the Netherlands revealed that three capsular genotypes, HS1/44c, HS2 and HS4c, were dominant in GBS-associated strains and capsular types HS1/44c and HS4c were significantly associated with GBS (p 0.05 and p 0.01, respectively) when compared with uncomplicated enteritis. In a GBS-associated strain collection from Bangladesh, capsular types HS23/36c, HS19 and HS41 were most prevalent and the capsular types HS19 and HS41 were associated with GBS (p 0.008 and p 0.02, respectively). Next, specific combinations of the LOS class and capsular genotypes were identified that were related to the occurrence of GBS. Multilocus sequence typing revealed restricted genetic diversity for strain populations with the capsular types HS2, HS19 and HS41. We conclude that capsular types HS1/44c, HS2, HS4c, HS19, HS23/36c and HS41 are markers for GBS. Besides a crucial role for sialylated LOS of C. jejuni in GBS pathogenesis, the identified capsules may contribute to GBS susceptibility.

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.

Role of Campylobacter jejuni infection in the pathogenesis of Guillain-Barré syndrome: an update

Our current knowledge on Campylobacter jejuni infections in humans has progressively increased over the past few decades. Infection with C. jejuni is the most common cause of bacterial gastroenteritis, sometimes surpassing other infections due to Salmonella, Shigella, and Escherichia coli. Most infections are acquired due to consumption of raw or undercooked poultry, unpasteurized milk, and contaminated water. After developing the diagnostic methods to detect C. jejuni, the possibility to identify the association of its infection with new diseases has been increased. After the successful isolation of C. jejuni, reports have been published citing the occurrence of GBS following C. jejuni infection. Thus, C. jejuni is now considered as a major triggering agent of GBS. Molecular mimicry between sialylated lipooligosaccharide structures on the cell envelope of these bacteria and ganglioside epitopes on the human nerves that generates cross-reactive immune response results in autoimmune-driven nerve damage. Though C. jejuni is associated with several pathologic forms of GBS, axonal subtypes following C. jejuni infection may be more severe. Ample amount of existing data covers a large spectrum of GBS; however, the studies on C. jejuni-associated GBS are still inconclusive. Therefore, this review provides an update on the C. jejuni infections engaged in the pathogenesis of GBS.

Analysis of Campylobacter jejuni isolates of various sources for loci associated with Guillain-Barré Syndrome

Campylobacter jejuni is a major cause of the Guillain-Barré syndrome (GBS) and related diseases. These autoimmune diseases are caused by antibodies cross-reacting with the peripheral (GBS) and central neural tissue (Miller Fisher syndrome - MFS, Bicker-staff's brainstem encephalitis - BBE), leading to acute polyneuropathy. Recently, specific gene loci in C. jejuni have been distinguished which are associated with the onset of GBS, despite a molecular or phenotypic clustering. In this study, we used PCR to analyse C. jejuni isolates of different origin (i.e. bovine, poultry, human) for these genes. A total of 196 isolates were tested for cst-II and neuA. Of these, 101 isolates harboured the cst-II locus and 102 the neuA locus. Eighty-six isolates (44%) hold both genes. The frequency of cst-II in different sources of isolates of bovine, poultry and human isolates did not vary significantly (52, 50 and 52%, respectively). In contrast, the neuA locus was less often found in poultry isolates. Two human strains - from a family outbreak of campylobacteriosis (in 1989 in Austria) in which one person developed MFS - harboured both genes. Thus, although only one in more than 3000 patients with Campylobacter-associated enteritis develop GBS, about half of Campylobacter jejuni strains found in different environments are possibly able to cause GBS. These strains almost equally distributed in bovine, poultry and human isolates. Our results suggest that isolates associated with GBS are not selected by environmental or host-specific factors. Accordingly, this study indicates that host factors such as humoral and cellular immunity are possibly responsible for the development of these autoimmune diseases.

Miller Fisher syndrome associated with influenza A infection

A 36-year-old, previously healthy man presented with Miller Fisher syndrome (MFS) five days after he was diagnosed with an influenza A infection by a rapid antigen test. He had not received any recent vaccinations. He had no loss of consciousness. Bilateral ophthalmoplegia, blepharoptosis, areflexia, and ataxic gait were noted. One week after treatment with intravenous immunoglobulin, his ophthalmoplegia, blepharoptosis, and ataxic gait had gradually improved, and his deep tendon reflexes returned. Anti-GQ1b IgG antibodies were detected in his serum. There has been no previous report of postinfectious MFS following confirmed an influenza A infection in an adult.

Immunopathology and Th1/Th2 immune response of Campylobacter jejuni-induced paralysis resembling Guillain-Barré syndrome in chicken

Immunopathogenesis of Campylobacter jejuni-associated Guillain-Barré syndrome (GBS) is not yet well established probably due to lack of experimental model. Therefore, we studied the Th1/Th2 immune response and pathological changes in C. jejuni-induced chicken model for GBS. C. jejuni (5 × 10(9) CFU/ml) and placebo were fed to 30 chickens each. Stools of all birds were negative for C. jejuni by culture and PCR before experiment. The birds were regularly assessed for disease symptoms up to 30 days. Sciatic nerves from all chickens were examined at 5 days intervals by histopathology and immunohistochemistry, and also for the expression of Th1/Th2 cytokines. Twenty-two chickens (73.3%) developed diarrhea after C. jejuni infection; 18 (60.0%) experimental chickens developed GBS-like paralytic neuropathy. Pathology in the sciatic nerves of these chickens included perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration, myelin swelling and presence of macrophages within the nerve fibers on 10th-20th post-infection day (PID). Cytokines (IFN-γ, IL-1β, TNF-α, IL-6 and IL-2) were elevated in early phase (5th-15th PID) and TGF-β2, IL-10 and IL-4 in the recovery phase (25th-30th PID) of the disease. The study provides evidence that C. jejuni infection in the chicken can provide an experimental animal model of GBS.

The role of molecular mimicry in the etiology of Guillain Barré Syndrome

Molecular mimicry between host tissue structures and microbial components has been proposed as the pathogenic mechanism for triggering of autoimmune diseases by preceding infection. Recent studies stated that molecular mimicry as the causative mechanism remains unproven for most of the human diseases. Still, in the case of the peripheral neuropathy Guillain-Barré syndrome (GBS) this hypothesis is supported by abundant experimental evidence. GBS is the most frequent cause of acute neuromuscular paralysis and in some cases occurs after infection with Campylobacter jejuni (C. jejuni). Epidemiological studies, showed that more than one third of GBS patients had antecedent C. jejuni infection and that only specific C. jejuni serotypes are associated with development of GBS. The molecular mimicry between the human gangliosides and the core oligosaccharides of bacterial lipopolysaccharides (LPSs) presumably results in production of antiganglioside cross-reactive antibodies which are likely to be a contributory factor in the induction and pathogenesis of GBS. Antiganglioside antibodies were found in the sera from patients with GBS and by sensitization of rabbits with gangliosides and C. jejuni LPSs animal disease models of GBS were established. GBS as prototype of post-infection immune-mediated disease probably will provide the first verification that an autoimmune disease can be triggered by molecular mimicry.

Miller Fisher syndrome in a toddler with influenza A (pH1N1) infection

A 17-month-old previously healthy child presented with a 2-day history of inability to fully open his eyes and slight gait ataxia. In the month preceding admission, he had had low grade, intermittent fevers, followed by a nonproductive cough and sneezing. During hospital admission he lost deep tendon reflexes and was unable to walk. Lumbar puncture revealed abnormally high protein, and a nasopharyngeal specimen was positive for influenza A (pH1N1). He received intravenous immunoglobulin and oseltamivir with clinical improvement. Although it is difficult to ascertain whether pH1N1 or another microorganism was responsible for this toddler's neurologic syndrome, this is the first reported case of Miller Fisher syndrome associated with pH1N1. During pandemics, one may expect to see an increased incidence of uncommon neurologic complications of influenza.

Plasma exchange and intravenous immunoglobulins: mechanism of action in immune-mediated neuropathies

Immune-mediated neuropathies are a heterogeneous group of peripheral nerve disorders, which are classified by time course, clinical pattern, affected nerves and pathological features. Plasma exchange (PE) and intravenous immunoglobulins (IVIg) are mainstays in the treatment of immune-mediated neuropathies. Of all treatments currently used, IVIg has probably the widest application range in immune-mediated neuropathies and efficacy has been well documented in several randomized controlled trials for Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP). Beneficial effects of IVIg have also been proven for multifocal motor neuropathy (MMN). Likewise, PE is an established treatment for GBS and CIDP, whereas it is considered to be ineffective in MMN. Different mechanisms of action are sought to be responsible for the immunemodulatory effect of PE and IVIg in autoimmune disorders. Some of those might be important for immune-mediated neuropathies, while others are probably negligible. The aim of this review is to summarize the recent advances in elucidating disease-specific mechanisms of actions of PE and IVIg in the treatment of immune-mediated neuropathies.

Molecular typing and antimicrobial susceptibility profiles of Campylobacter jejuni isolates from north China

To obtain the genotype and antimicrobial susceptibility profiles of Campylobacter jejuni isolates from north China, 93 C. jejuni isolates (56 isolates from patients with diarrhoea, 7 isolates from Guillain-Barré syndrome patients and 30 isolates from chicken stools) were selected for multilocus sequence typing (MLST), PFGE and drug resistance testing. A total of 49 sequence types (STs) were identified from the entire panel of 93 C. jejuni isolates. Fifty-six isolates belonged to 14 clonal complexes, while 37 isolates could not be assigned to any known clonal complex. The most frequently observed clonal complexes were ST-21 (11 isolates), ST-353 (10 isolates) and ST-443 (6 isolates). Fifty-three PFGE SmaI patterns were identified among 93 isolates. No erythromycin-, gentamicin- or streptomycin-resistant isolates were found among the 44 strains isolated in 2008. Resistance to nalidixic acid, levofloxacin and ciprofloxacin was observed in 100 % (44/44) of the tested isolates. This study has shown the genetic characteristics of C. jejuni isolates in north China. In addition, overlapping clonal groups were defined by both MLST and PFGE for C. jejuni human and chicken isolates.

Guillain-Barré syndrome following H1N1 immunization in a pediatric patient

OBJECTIVE

To report a case of Guillain-Barré syndrome (GBS) following a dose of influenza A (H1N1) vaccine (Arepanrix).

CASE SUMMARY

An 11-year-old boy was admitted to the hospital after presenting with facial diplegia; abdominal, forehead, and thigh pain; and acute cervical pain. He had received the Arepanrix H1N1 subcutaneous vaccine 13 days before symptom onset. The neurologic examination also revealed a symmetric bilateral paralysis of the VIIth cranial nerve and intense pain, proximal weakness of the shoulder girdles and pelvis, and preserved deep tendon reflexes. Cerebrospinal fluid analysis revealed an albuminocytologic dissociation. Therefore, a diagnosis of atypical GBS following vaccination against HINI influenza was made.

DISCUSSION

Based on the clinical evaluation, laboratory test results, neurologic features, and the exclusion of alternative diagnoses, the Naranjo probability scale revealed a probable relationship between the clinical manifestations of GBS and the vaccine against influenza A (H1N1) received by the patient. This is the first published case for the 2009 influenza pandemic in children.

CONCLUSIONS

While recent studies have found inconclusive results on the association between influenza vaccine and GBS, all suspected cases should be published for further evaluation.

Detection of Campylobacter jejuni by culture and real-time PCR in a French cohort of patients with Guillain-Barre syndrome

Bacteriological culture and real-time PCR (RT-PCR) were used to detect Campylobacter jejuni in fecal samples from a French cohort of 237 patients with Guillain-Barré syndrome (GBS). We provide evidence that diverse serotypes and genotypes of C. jejuni are a major trigger of GBS in France.

Campylobacter infection as a trigger for Guillain-Barré syndrome in Egypt

BACKGROUND

Most studies of Campylobacter infection triggering Guillain-Barré Syndrome (GBS) are conducted in western nations were Campylobacter infection and immunity is relatively rare. In this study, we explored Campylobacter infections, Campylobacter serotypes, autoantibodies to gangliosides, and GBS in Egypt, a country where Campylobacter exposure is common.

METHODS

GBS cases (n = 133) were compared to age- and hospital-matched patient controls (n = 374). A nerve conduction study was performed on cases and a clinical history, serum sample, and stool specimen obtained for all subjects.

RESULTS

Most (63.3%) cases were demyelinating type; median age four years. Cases were more likely than controls to have diarrhea (29.5% vs. 22.5%, Adjusted Odds Ratio (ORa) = 1.69, P = 0.03), to have higher geometric mean IgM anti-Campylobacter antibody titers (8.18 vs. 7.25 P<0.001), and to produce antiganglioside antibodies (e.g., anti-Gd1a, 35.3 vs. 11.5, ORa = 4.39, P<0.0001). Of 26 Penner:Lior Campylobacter serotypes isolated, only one (41:27, C. jejuni, P = 0.02) was associated with GBS.

CONCLUSIONS

Unlike results from western nations, data suggested that GBS cases were primarily in the young and cases and many controls had a history of infection to a variety of Campylobacter serotypes. Still, the higher rates of diarrhea and greater antibody production against Campylobacter and gangliosides in GBS patients were consistent with findings from western countries.

Host-pathogen interactions in Campylobacter infections: the host perspective

Campylobacter is a major cause of acute bacterial diarrhea in humans worldwide. This study was aimed at summarizing the current understanding of host mechanisms involved in the defense against Campylobacter by evaluating data available from three sources: (i) epidemiological observations, (ii) observations of patients, and (iii) experimental observations including observations of animal models and human volunteer studies. Analysis of available data clearly indicates that an effective immune system is crucial for the host defense against Campylobacter infection. Innate, cell-mediated, and humoral immune responses are induced during Campylobacter infection, but the relative importance of these mechanisms in conferring protective immunity against reinfection is unclear. Frequent exposure to Campylobacter does lead to the induction of short-term protection against disease but most probably not against colonization. Recent progress in the development of more suitable animal models for studying Campylobacter infection has opened up possibilities to study the importance of innate and adaptive immunity during infection and in protection against reinfection. In addition, advances in genomics and proteomics technologies will enable more detailed molecular studies. Such studies combined with better integration of host and pathogen research driven by epidemiological findings may truly advance our understanding of Campylobacter infection in humans.

Comparative genomic analysis of clinical strains of Campylobacter jejuni from South Africa

BACKGROUND

Campylobacter jejuni is a common cause of acute gastroenteritis and is also associated with the post-infectious neuropathies, Guillain-Barré and Miller Fisher syndromes. In the Cape Town area of South Africa, C. jejuni strains with Penner heat-stable (HS) serotype HS:41 have been observed to be overrepresented among cases of Guillain-Barré syndrome. The present study examined the genetic content of a collection of 32 South African C. jejuni strains with different serotypes, including 13 HS:41 strains, that were recovered from patients with enteritis, Guillain-Barré or Miller Fisher syndromes. The sequence-based typing methods, multilocus sequence typing and DNA microarrays, were employed to potentially identify distinguishing features within the genomes of these C. jejuni strains with various disease outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

Comparative genomic analyses demonstrated that the HS:41 South African strains were clearly distinct from the other South African strains. Further DNA microarray analysis demonstrated that the HS:41 strains from South African patients with the Guillain-Barré syndrome or enteritis were highly similar in gene content. Interestingly, the South African HS:41 strains were distinct in gene content when compared to HS:41 strains from other geographical locations due to the presence of genomic islands, referred to as Campylobacter jejuni integrated elements (CJIEs). Only the integrated element CJIE1, a Campylobacter Mu-like prophage, was present in the South African HS:41 strains whereas this element was absent in two closely-related HS:41 strains from Mexico. A more distantly-related HS:41 strain from Canada possessed both integrated elements CJIE1 and CJIE2.

CONCLUSION/SIGNIFICANCE

These findings demonstrate that CJIEs may contribute to the differentiation of closely-related C. jejuni strains. In addition, the presence of bacteriophage-related genes in CJIE1 may contribute to the genomic diversity of C. jejuni strains. This comparative genomic analysis of C. jejuni provides fundamental information that potentially could lead to improved methods for analyzing the epidemiology of disease outbreaks.

Comparative genomic analysis of Campylobacter jejuni associated with Guillain-Barré and Miller Fisher syndromes: neuropathogenic and enteritis-associated isolates can share high levels of genomic similarity

Background

Campylobacter jejuni infection represents the most frequent antecedent infection triggering the onset of the neuropathic disorders Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS). Although sialylated ganglioside-mimicking lipo-oligosaccharide (LOS) structures are the strongest neuropathogenic determinants in C. jejuni, they do not appear to be the only requirement for a neuropathic outcome since strains capable of their production have been isolated from patients with uncomplicated cases of enteritis. Consequently, other pathogen and/or host-related factors contribute to the onset of neurological complications. We have used comparative genomic hybridization to perform a detailed genomic comparison of strains isolated from GBS/MFS and enteritis-only patients. Our dataset, in which the gene conservation profile for 1712 genes was assayed in 102 strains, including 56 neuropathogenic isolates, represents the largest systematic search for C. jejuni factors associated with GBS/MFS to date and has allowed us to analyze the genetic background of neuropathogenic C. jejuni strains with an unprecedented level of resolution.

Results

The majority of GBS/MFS strains can be assigned to one of six major lineages, suggesting that several genetic backgrounds can result in a neuropathogenic phenotype. A statistical analysis of gene conservation rates revealed that although genes involved in the sialylation of LOS structures were significantly associated with neuropathogenic strains, still many enteritis-control strains both bear these genes and share remarkable levels of genomic similarity with their neuropathogenic counterparts. Two capsule biosynthesis genes (Cj1421c and Cj1428c) showed higher conservation rates among neuropathogenic strains compared to enteritis-control strains. Any potential involvement of these genes in neuropathogenesis must be assessed. A single gene (HS:3 Cj1135) had a higher conservation rate among enteritis-control strains. This gene encodes a glucosyltransferase that is found in some of the LOS classes that do not express ganglioside mimics.

Conclusion

Our findings corroborate that neuropathogenic factors may be transferred between unrelated strains of different genetic background. Our results would also suggest that the failure of some strains isolated from uncomplicated cases of enteritis to elicit a neuropathic clinical outcome may be due to subtle genetic differences that silence their neuropathogenic potential and/or due to host-related factors.

The microarray data has been deposited in NCBI's Gene Expression Omnibus under accession number GSE3579.

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.

Ganglioside mimicry and peripheral nerve disease

Four criteria must be satisfied to conclude that a given microorganism causes Guillain-Barré (GBS) or Fisher (FS) syndrome associated with anti-ganglioside antibodies: (1) an epidemiological association between the infecting microbe and GBS or FS; (2) isolation in the acute progressive phase of illness of that microorganism from GBS or FS patients with associated anti-ganglioside IgG antibodies; (3) identification of a microbial ganglioside mimic; and (4) a GBS or FS with associated anti-ganglioside antibodies model produced by sensitization with the microbe itself or its component, as well as with ganglioside. Campylobacter jejuni is a definitive causative microorganism of acute motor axonal neuropathy and may cause FS and related conditions. Haemophilus influenzae and Mycoplasma pneumoniae are possible causative microorganisms of acute motor axonal neuropathy or FS. Acute and chronic inflammatory demyelinating polyneuropathies may be produced by mechanisms other than ganglioside mimicry.

Utility of serum Campylobacter specific antibodies in determining prior Campylobacter infection in neurological disease

Campylobacter jejuni has been implicated in the pathogenesis of Guillain-Barre syndrome (GBS); however, little information exists on the utility of Campylobacter serology in determining recent infection in the patient population. C. jejuni specific antibodies (CAs) were measured in 420 blood donors (controls), 99 patients with recent C. jejuni infection, 34 patients with central nervous system disorders (neurology controls), and 44 patients with peripheral nervous system (PNS) disorders: 18 with GBS, 12 with MND and 14 with chronic inflammatory neuropathies. Elevated CA titres consistent with recent C. jejuni infection were found in six of the 44 patients with PNS disorders (three with GBS, two with neuropathy, and one with MND, only one of whom had a history of recent C. jejuni infection), compared with two of 454 controls (p = 0.00001). Therefore, we conclude that CAs are often raised in patients with PNS disorders who do not have a history of recent C. jejuni gastroenteritis, so Campylobacter serology may be an unreliable marker of recent infection in this patient group.

PCR-based restriction fragment length polymorphism (RFLP) analysis of Campylobacter jejuni isolates from humans, chickens and dogs in northern Taiwan

Two hundred and twenty strains of Campylobacter jejuni (70 human, 51 canine and 99 chicken strains) were isolated from September 2003 to September 2004 in northern Taiwan. These strains were subtyped by PCR-RFLP analysis of the flagellin (FlaA) gene. On the basis of restrictive digest, six types were identified with AfaI, seven types with MboI and five types with HaeIII. With the combination of these three enzymes, 47 distinct PCR-RFLP patterns were observed-25 each from human and chicken isolates, and 9 from canine isolates. In human strains, the most frequently occurring types were Cj-28 (14.3%), Cj-17 (10%), Cj-16 (8.6%), Cj-37 (7.1%) and Cj-46 (7.1%). In canine strains, the most prevalent types were Cj-1 (33.3%), Cj-26 (19.6%), Cj-3 (15.7%), Cj-2 (9.8%) and Cj-10 (9.8%). In chicken strains, the most frequently occurring types were Cj-46 (40.4%), Cj-29 (9.1%), Cj-45 (7.1%) and Cj-41 (5.1%). The results suggest that poultry is a source, but not the sole source, of C. jejuni infection in humans. Two RFLP types, Cj-17 and Cj-37, frequently occurring in human isolates in this study have also been found to be prevalent in human isolates in Japan, China and the Czech Republic, indicating a possible international clonal spread.

The HS:19 serostrain of Campylobacter jejuni has a hyaluronic acid-type capsular polysaccharide with a nonstoichiometric sorbose branch and O-methyl phosphoramidate group

A recent study that examined multiple strains of Campylobacter jejuni reported that HS:19, a serostrain that has been associated with the onset of Guillain-Barré syndrome, had unidentified labile, capsular polysaccharide (CPS) structures. In this study, we expand on this observation by using current glyco-analytical technologies to characterize these unknown groups. Capillary electrophoresis electrospray ionization MS and NMR analysis with a cryogenically cooled probe (cold probe) of CPS purified using a gentle enzymatic method revealed a hyaluronic acid-type [-4)-beta-D-GlcA6NGro-(1-3)-beta-D-GlcNAc-(1-]n repeating unit, where NGro is 2-aminoglycerol. A labile alpha-sorbofuranose branch located at C2 of GlcA was determined to have the L configuration using a novel pyranose oxidase assay and is the first report of this sugar in a bacterial glycan. A labile O-methyl phosphoramidate group, CH3OP(O)(NH2)(OR) (MeOPN), was found at C4 of GlcNAc. Structural heterogeneity of the CPS was due to nonstoichiometric glycosylation with sorbose at C2 of GlcA and the nonstoichiometric, variably methylated phosphoramidate group. Examination of whole bacterial cells using high-resolution magic angle spinning NMR revealed that the MeOPN group is a prominent feature on the cell surface for this serostrain. These results are reminiscent of those in the 11168 and HS:1 strains and suggest that decoration of CPS with nonstoichiometric elements such as keto sugars and the phosphoramidate is a common mechanism used by this bacterium to produce a structurally complex surface glycan from a limited number of genes. The findings of this work with the HS:19 serostrain now present a means to explore the role of CPS as a virulence factor in C. jejuni.

In vitro antimicrobial susceptibility, genetic diversity and prevalence of UDP-glucose 4-epimerase (galE) gene in Campylobacter coli and Campylobacter jejuni from Turkey production facilities

This study evaluated the genetic diversity of multi-drug resistant Campylobacter jejuni (n=44) and C. coli (n=30) isolated from 18 turkey houses. Antimicrobial resistances to ampicillin, ciprofloxacin and nalidixic acid were higher (P<0.05) in C. coli than in C. jejuni strains. PCR analysis indicated that 82% of total isolates tested, including 91% of C. jejuni and 70% of C. coli tested positive for a 496-bp UDP-glucose 4-epimerase (galE) gene. The diversity of isolates was mapped by antibiogram, SmaI-PFGE and flaA-RFLP typing methods using the discriminatory index (DI). RFLP was more suitable in discriminating C. coli (DI=0.895) than PFGE (DI=0.816) or antibiogram profile (DI=0.552), while either PFGE (DI=0.941) or RFLP (DI=0.942) could be used in discriminating C. jejuni strains. The combined PFGE and antibiogram dendrogram had the highest DI for both C. coli (0.910) and C. jejuni (0.968), suggesting that a combination of typing methods is more useful in examining the diverse Campylobacter population on turkey farms.

The sialic acid residue is a crucial component of C. jejuni lipooligosaccharide ganglioside mimicry in the induction Guillain–Barré syndrome

Guillain-Barré syndrome (GBS) is an autoimmune neuropathy that often follows C. jejuni infection. Sialic acid (N-acetylneuraminic acid, NANA) is a common constituent of lipooligosaccharide (LOS). The molecular mimicry between C. jejuni LOS and human peripheral nerve gangliosides is believed to play an important role in the pathogenesis of GBS. The neuB1 encodes NANA synthetase, required for the synthesis of NANA of C. jejuni LOS. A neuB1 mutant was constructed from a C. jejuni HS:19 wild strain. Mutant LOS could not bind the cholera toxin B subunit, failed to induce anti-GM1 antibodies, and did not cause pathological changes in the peripheral nerves. These data suggest that the NANA residue in LOS is a crucial epitope in realization of ganglioside molecular mimicry.

Identification of DNA sequence variation in Campylobacter jejuni strains associated with the Guillain-Barré syndrome by high-throughput AFLP analysis

BACKGROUND

Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barré (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular.

RESULTS

We compared 6 different isolates of the "genome strain" NCTC 11168 obtained from different laboratories. HtAFLP analysis generated approximately 3000 markers per stain, 19 of which were polymorphic. The DNA polymorphisms could not be confirmed by PCR-RFLP analysis, suggesting a baseline level of 0.6% AFLP artefacts. Comparison of NCTC 11168 with 4 GBS-associated strains revealed 23 potentially GBS-specific markers, 17 of which were identified by DNA sequencing. A collection of 27 GBS/MFS-associated and 17 enteritis control strains was analyzed with PCR-RFLP tests based on 11 of these markers. We identified 3 markers, located in the LOS biosynthesis genes cj1136, cj1138 and cj1139c, that were significantly associated with GBS (P = 0.024, P = 0.047 and P < 0.001, respectively). HtAFLP analysis of 13 highly clonal South African GBS/MFS-associated and enteritis control strains did not reveal GBS-specific markers.

CONCLUSION

This study shows that bacterial GBS markers are limited in number and located in the LOS biosynthesis genes, which corroborates the current consensus that LOS mimicry may be the prime etiologic determinant of GBS. Furthermore, our results demonstrate that htAFLP, with its high reproducibility and resolution, is an effective technique for the detection and subsequent identification of putative bacterial disease markers.

Genomic diversity in Campylobacter jejuni: identification of C. jejuni 81-176-specific genes

Since the publication of the complete genomic sequence of Campylobacter jejuni NCTC 11168 in February 2000, evidence has been compiling that suggests C. jejuni strains exhibit high genomic diversity. In order to investigate this diversity, the unique genomic DNA sequences from a nonsequenced Campylobacter strain, C. jejuni 81-176, were identified by comparison with C. jejuni NCTC 11168 by using a shotgun DNA microarray approach. Up to 63 kb of new chromosomal DNA sequences unique to this pathogen were obtained. Eighty-six open reading frames were identified by the presence of uninterrupted coding regions encoding a minimum of 40 amino acids. In addition, this study shows that the whole-plasmid shotgun microarray approach is effective and provides a comprehensive coverage of DNA regions that differ between two closely related genomes. The two plasmids harbored by this Campylobacter strain, pTet and pVir, were also sequenced, with coverages of 2.5- and 2.9-fold, respectively, representing 72 and 92% of their complete nucleotide sequences. The unique chromosomal genes encode proteins involved in capsule and lipooligosaccharide biosynthesis, restriction and modification systems, and respiratory metabolism. Several of these unique genes are likely associated with C. jejuni 81-176 fitness and virulence. Interestingly, the comparison of C. jejuni 81-176 unique genes with those of C. jejuni ATCC 43431 revealed a single gene which encodes a probable TraG-like protein. The product of this gene might be associated with the mechanism of C. jejuni invasion into epithelial cells. In conclusion, this study extends the repertoire of C. jejuni genes and thus will permit the construction of a composite and more comprehensive microarray of C. jejuni.

Considerations for development of whole cell bacterial vaccines to prevent diarrheal diseases in children in developing countries

Enteric pathogens constitute a major pediatric threat in the developing world through their impact on morbidity and mortality, physical and cognitive development and cause and effect relationship with malnutrition. Although many bacterial pathogens can cause diarrheal diseases, a group of less than 10 including Shigella spp., enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, and possibly, Campylobacter jejuni account for a significant percentage of these diseases in developing countries. Rotavirus is also a major cause of diarrheal diseases. Vaccines against these agents offer a potentially effective control measure against these diseases, but safe, practical, and effective vaccines for many of these agents have yet to be realized. Many vaccine development approaches are under investigation, but the one that is currently most advanced and that has been most widely applied to enteric pathogens is the use of orally administered live or killed whole pathogen preparations. If inactivated, these vaccines will probably be administered as multiple doses with approximately 10(10) to 10(11) total particles per dose, but they are relatively safe for oral administration. Further, they may not require a buffer for delivery and can be stored in liquid formulations. Fewer doses may be required for some live attenuated pathogen vaccines, but a buffer will most likely be required for oral delivery and the product must be stored in a dried formulation. Also, safety becomes more of a concern with live pathogens depending on the degree of attenuation, host immunocompetence, and the total number and kinds of attenuated pathogens which may be present in a combined agent vaccine. Both live and killed whole pathogen vaccines can be immunogenic and have the possibility to serve as vectors for other antigens. Although many organisms and serotypes are clinically important, by exploiting antigenic cross reactivity and using some pathogen components as vectors for cloned antigens of other pathogens, it could be possible to induce immunity against major enteric pathogens/serotypes with <10 whole pathogen components in a multi-agent vaccine. Safe and effective mucosal adjuvants may in the future be useful in whole pathogen vaccines, but they do not seem to be essential for immunization. Further, dietary supplements such as zinc, mixed routes of delivery and new regimens are under study which may in the future enhance further the effectiveness of the whole pathogen vaccines which now seem realizable in the near term. For this to happen, however, a coordinated and committed effort is necessary now to address the immunologic, regulatory, manufacturing, testing and implementation issues which will be involved in the realization of this important product to benefit children's health worldwide.

Epidemiology of Campylobacter jejuni isolated from patients with Guillain-Barré and Fisher syndromes in Japan

Campylobacter jejuni isolation is the standard for the diagnosis of this type of bacterial infection, but there have been no epidemiological studies of a large number of C. jejuni isolates from patients with Guillain-Barre syndrome (GBS) and Fisher syndrome (FS). For 13 years, stool specimens from GBS/FS patients have been sent from 378 hospitals throughout Japan to the Tokyo Metropolitan Institute of Public Health. A total of 113 strains (11%) were isolated from the stool specimens from 1,049 patients. The isolation rate did not differ by region. The rates were 22% for 449 patients with a history of diarrhea and 2% for the others. An additional 18 isolates were provided by various hospitals. There was no noticeable seasonal distribution in the onset of C. jejuni isolated from patients with GBS/FS. The male/female ratios were 1.7:1 for GBS and 2.2:1 for FS. The patient age range showed a peak in 10- to 30-year-old subjects who had GBS and in 10- to 20-year-old subjects who had FS. The predominance of young adults and male patients who had C. jejuni-associated GBS/FS may be related to the preponderance of young adults and male patients who had C. jejuni enteritis. The median interval from diarrhea onset to neurologic symptom onset was 10 days for GBS/FS. Penner's C. jejuni serotype HS:19 was more frequently present in GBS (67%) than in enteritis (6%) patients. HS:2 was more frequent in FS (41%) than in enteritis (14%) patients. These findings suggest that certain C. jejuni strains specifically trigger GBS and that others specifically trigger FS.

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.

Guillain-Barré syndrome: epidemiology, pathophysiology and management

Guillain-Barré syndrome (GBS) is clinically defined as an acute peripheral neuropathy causing limb weakness that progresses over a time period of days or, at the most, up to 4 weeks. GBS occurs throughout the world with a median annual incidence of 1.3 cases per population of 100 000, with men being more frequently affected than women. GBS is considered to be an autoimmune disease triggered by a preceding bacterial or viral infection. Campylobacter jejuni, cytomegalovirus, Epstein-Barr virus and Mycoplasma pneumoniae are commonly identified antecedent pathogens. In the acute motor axonal neuropathy (AMAN) form of GBS, the infecting organisms probably share homologous epitopes to a component of the peripheral nerves (molecular mimicry) and, therefore, the immune responses cross-react with the nerves causing axonal degeneration; the target molecules in AMAN are likely to be gangliosides GM1, GM1b, GD1a and GalNAc-GD1a expressed on the motor axolemma. In the acute inflammatory demyelinating polyneuropathy (AIDP) form, immune system reactions against target epitopes in Schwann cells or myelin result in demyelination; however, the exact target molecules in the case of AIDP have not yet been identified. AIDP is by far the most common form of GBS in Europe and North America, whereas AMAN occurs more frequently in east Asia (China and Japan). The prognosis of GBS is generally favourable, but it is a serious disease with a mortality of approximately 10% and approximately 20% of patients are left with severe disability. Treatment of GBS is subdivided into: (i) the management of severely paralysed patients with intensive care and ventilatory support; and (ii) specific immunomodulating treatments that shorten the progressive course of GBS, presumably by limiting nerve damage. High-dose intravenous immunoglobulin (IVIg) therapy and plasma exchange aid more rapid resolution of the disease. The predominant mechanisms by which IVIg therapy exerts its action appear to be a combined effect of complement inactivation, neutralisation of idiotypic antibodies, cytokine inhibition and saturation of Fc receptors on macrophages. Corticosteroids alone do not alter the outcome of GBS.

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.