A secreted sirtuin from Campylobacter jejuni contributes to neutrophil activation and intestinal inflammation during infection

Histone modifications control numerous processes in eukaryotes, including inflammation. Some bacterial pathogens alter the activity or expression of host-derived factors, including sirtuins, to modify histones and induce responses that promote infection. In this study, we identified a deacetylase encoded by Campylobacter jejuni which has sirtuin activities and contributes to activation of human neutrophils by the pathogen. This sirtuin is secreted from the bacterium into neutrophils, where it associates with and deacetylates host histones to promote neutrophil activation and extracellular trap production. Using the murine model of campylobacteriosis, we found that a mutant of this bacterial sirtuin efficiently colonized the gastrointestinal tract but was unable to induce cytokine production, gastrointestinal inflammation, and tissue pathology. In conclusion, these results suggest that secreted bacterial sirtuins represent a previously unreported class of bacterial effector and that bacterial-mediated modification of host histones is responsible for the inflammation and pathology that occurs during campylobacteriosis.

Placentitis and abortion caused by a multidrug resistant strain of Campylobacter fetus subspecies fetus in a sheep in Uruguay

Campylobacter fetusfetus (Cff) is a major infectious cause of abortion in sheep worldwide, and an opportunistic human pathogen. Information on Cff as an ovine abortifacient in South America is limited. We describe a case of abortion caused by a multidrug resistant strain of Cff in a sheep in Uruguay. In August 2017, 3/57 pregnant ewes (5.3%) aborted whithin one week. Histopathologic examination of the placenta of an aborted ewe revealed severe neutrophilic and fibrinonecrotizing placentitis with vasculitis and thrombosis of the chorionic arterioles. Cff was isolated on microaerobic culture in Skirrow agar, and further confirmed by 16S rDNA PCR amplification and sequencing, and endpoint and real time PCR assays. Antimicrobial sensitivity testing revealed resistance to tetracyclines, nalidixic acid, telithromycin and clindamycin. Other abortifacients were not detected. Further studies are necessary to determine the geographic distribution, ecology, epidemiology, economic impact, and antimicrobial resistance of Cff in sheep flocks in Uruguay.

Analysis of complete Campylobacter concisus genomes identifies genomospecies features, secretion systems and novel plasmids and their association with severe ulcerative colitis

Campylobacter concisus is an emerging enteric pathogen that is associated with several gastrointestinal diseases, such as inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC). Currently, only three complete C. concisus genomes are available and more complete C. concisus genomes are needed in order to better understand the genomic features and pathogenicity of this emerging pathogen. DNA extracted from 22 C. concisus strains were subjected to Oxford Nanopore genome sequencing. Complete genome assembly was performed using Nanopore genome data in combination with previously reported short-read Illumina data. Genome features of complete C. concisus genomes were analysed using bioinformatic tools. The enteric disease associations of C. concisus plasmids were examined using 239 C. concisus strains and confirmed using PCRs. Proteomic analysis was used to examine T6SS secreted proteins. We successfully obtained 13 complete C. concisus genomes in this study. Analysis of 16 complete C. concisus genomes (3 from public databases) identified multiple novel plasmids. pSma1 plasmid was found to be associated with severe UC. Sec-SRP, Tat and T6SS were found to be the main secretion systems in C. concisus and proteomic data showed a functional T6SS despite the lack of ClpV. T4SS was found in 25% of complete C. concisus genomes. This study also found that GS2 strains had larger genomes and higher GC content than GS1 strains and more often had plasmids. In conclusion, this study provides fundamental genomic data for understanding C. concisus plasmids, genomospecies features, evolution, secretion systems and pathogenicity.

Detection of Campylobacter jejuni liver dissemination in experimentally colonized turkey poults

Consumption of contaminated poultry products, including chicken livers, is the main source of human campylobacteriosis and approximately 90% of human cases are caused by Campylobacter jejuni subsp. jejuni (C. jejuni). Recent culinary trends that favor undercooked chicken livers may be responsible for outbreaks. Turkey is an emerging human protein source, and poultry livers are commonly prepared in popular cuisine such as pâté. The mechanism of how Campylobacter disseminates to poultry liver tissue is unknown. We have previously demonstrated that certain strains of C. jejuni persistently colonize turkeys with the highest density in the ceca. Whether C. jejuni disseminates to the liver of turkeys following intestinal colonization is unknown. In this study, 45 D of hatch turkey poults were co-housed for 30 D. Five poults were euthanized to screen for Campylobacter colonization, and were free of detectable Campylobacter. The remaining 40 poults were randomly split into 2 rooms, with 20 poults per room. At 35 D of age, poults were inoculated by oral gavage with 1 × 10⁶ cfu of C. jejuni isolate NCTC 11168 or mock-inoculated with sterile medium. Ten poults from each room were euthanized at 7 and 14 D post-inoculation (dpi), and cecal contents and livers were cultured and/or enriched for Campylobacter. Livers were harvested aseptically. The ceca of C. jejuni-inoculated poults were highly colonized at 7 and 14 dpi with approximately 10⁸ cfu/mL of cecal contents. At 7 and 14 dpi, 3 and 5 of 10 liver samples were positive for C. jejuni culture (8.6 × 10³ cfu/g of liver ± 4.43 × 10³ and 5.10 × 10³ cfu/g of liver ± 1.74 × 10³), respectively. At 14 dpi, liver samples were cultured by enrichment, and 6 of 10 were positive for Campylobacter. Some liver samples may be below the limit of detection for direct plate culturing. These data determined that turkey liver is a potential reservoir of C. jejuni following intestinal colonization, and identified a potential food safety consideration when turkey liver is prepared for human or pet food consumption.

(-)-α-Pinene reduces quorum sensing and Campylobacter jejuni colonization in broiler chickens

Campylobacter jejuni is one of the most prevalent causes of bacterial gastroenteritis worldwide, and it is largely associated with consumption of contaminated poultry. Current Campylobacter control measures at the poultry production level remain insufficient, and hence there is the need for alternative control strategies. We evaluated the potential of the monoterpene (-)-α-pinene for control of C. jejuni in poultry. The antibacterial and resistance-modulatory activities of (-)-α-pinene were also determined against 57 C. jejuni strains. In addition, the anti-quorum-sensing activity of (-)-α-pinene against C. jejuni NCTC 11168 was determined for three subinhibitory concentrations (125, 62.5, 31.25 mg/L) over three incubation times using an autoinducer-2 bioassay based on Vibrio harveyi BB170 bioluminescence measurements. The effects of a subinhibitory concentration of (-)-α-pinene (250 mg/L) on survival of C. jejuni, and in combination with enrofloxacin on fluoroquinolone resistance development in C. jejuni, were determined in a broiler chicken model, by addition of (-)-α-pinene to the broiler water supply. The reduction of C. jejuni numbers by (-)-α-pinene was further determined in broiler chickens that were colonized with either fluoroquinolone-susceptible or -resistant strains, by direct gavage treatment. We observed weak in vitro antimicrobial activity for (-)-α-pinene alone (MIC >500 mg/L), but strong potentiating effects on antibiotics erythromycin and ciprofloxacin against different Campylobacter strains (>512 fold change). After 24 h of treatment of C. jejuni with (-)-α-pinene, its quorum-sensing signaling was reduced by >80% compared to the untreated control. When given in the drinking water, (-)-α-pinene did not show any significant inhibitory effects on the level of C. jejuni in the colonized chickens, and did not reduce fluoroquinolone resistance development in combination with enrofloxacin. Conversely, when (-)-α-pinene was administered by direct gavage, it significantly reduced the number of fluoroquinolone susceptible C. jejuni in the colonized broiler chickens. These results demonstrate that (-)-α-pinene modulates quorum-sensing in Campylobacter, potentiates antibiotics against different Campylobacter strains, and reduces Campylobacter colonization in broiler chickens.

Determinants of Campylobacter infection and association with growth and enteric inflammation in children under 2 years of age in low-resource settings

Campylobacter species infections have been associated with malnutrition and intestinal inflammation among children in low-resource settings. However, it remains unclear whether that association is specific to Campylobacter jejuni/coli. The aim of this study was to assess the association between both all Campylobacter species infections and Campylobacter jejuni/coli infections on growth and enteric inflammation in children aged 1-24 months. We analyzed data from 1715 children followed from birth until 24 months of age in the MAL-ED birth cohort study, including detection of Campylobacter species by enzyme immunoassay and Campylobacter jejuni/coli by quantitative PCR in stool samples. Myeloperoxidase (MPO) concentration in stool, used as a quantitative index of enteric inflammation, was measured. The incidence rate per 100 child-months of infections with Campylobacter jejuni/coli and Campylobacter species during 1-24 month follow up were 17.7 and 29.6 respectively. Female sex of child, shorter duration of exclusive breastfeeding, lower maternal age, mother having less than 3 living children, maternal educational level of <6 years, lack of routine treatment of drinking water, and unimproved sanitation were associated with Campylobacter jejuni/coli infection. The cumulative burden of both Campylobacter jejuni/coli infections and Campylobacter species were associated with poor growth and increased intestinal inflammation.

Associations between animal welfare indicators and Campylobacter spp. in broiler chickens under commercial settings: A case study

Few studies have previously investigated how poor animal welfare might be associated with infection of zoonotic pathogens in humans. This paper assesses the predictive value of the presence of Campylobacter spp. in broiler chicken flocks when animal-based measures related to footpad dermatitis, hock burns, body lesions and arthritis are identified under commercial conditions (high density). The study population included 32 flocks analysed on farm and at slaughter, slaughtered between April and August 2008 in six different slaughter plants in Brittany, France. Welfare and health indicators are those indicated by the European legislation and sampling was carried out in the framework of the European baseline survey on the prevalence of Campylobacter in broiler chicken. Caecal contents, sampled both on farm and at slaughter, and carcass skin samples from the neck and breast at slaughter, were investigated for the presence of Campylobacter spp. Logistic models/classification trees were used to estimate the probability of the presence (or absence) of a specific foodborne pathogen in a flock based on specific animal-based measures (or combinations of measures) in order to study the potential relationship between welfare indicators and foodborne pathogen prevalence/incidence levels. On farm, flocks with more than 25% animals with severe lesions on between 25 and 50% of the footpad are predicted to be Campylobacter-positive whereas flocks where less than 13 individuals have arthritis are predicted to be Campylobacter-negative. The error rate on farm and at slaughter was 10 and 4% respectively indicating good predicting abilities. A poor welfare environment may result in stress, which reduces chicken immunocompetence making them more susceptible to Campylobacter spp. An infection with Campylobacter spp may lead to impaired defence and susceptibility to other pathogens which may result in greater intestinal excretion. Poor welfare and high growing rate lead to digestive troubles that lead to litter humidity. Litter humidity that, among other things, causes footpad dermatitis may also influence the horizontal transmission of the Campylobacter spp. infection due to the normal coprophagic behaviour of poultry. Reducing welfare problems by a better management of rearing conditions would not only improve broiler welfare, but it would also decrease the risks of Campylobacter contamination, of carcass condemnations and of economic loss for the poultry industry.

Matrix metalloproteinases-2 and -9 in Campylobacter jejuni-induced paralytic neuropathy resembling Guillain-Barré syndrome in chickens

Inflammation in Guillain-Barré syndrome (GBS) is manifested by changes in matrix metalloproteinase (MMP) and pro-inflammatory cytokine expression. We investigated the expression of MMP-2, -9 and TNF-α and correlated it with pathological changes in sciatic nerve tissue from Campylobacter jejuni-induced chicken model for GBS. Campylobacter jejuni and placebo were fed to chickens and assessed for disease symptoms. Sciatic nerves were examined by histopathology and immunohistochemistry. Expressions of MMPs and TNF-α, were determined by real-time PCR, and activities of MMPs by zymography. Diarrhea developed in 73.3% chickens after infection and 60.0% of them developed GBS like neuropathy. Pathology in sciatic nerves showed perinodal and/or patchy demyelination, perivascular focal lymphocytic infiltration and myelin swelling on 10th- 20th post infection day (PID). MMP-2, -9 and TNF-α were up-regulated in progressive phase of the disease. Enhanced MMP-2, -9 and TNF-α production in progressive phase correlated with sciatic nerve pathology in C. jejuni-induced GBS chicken model.

Using Galleria mellonella as an Infection Model for Campylobacter jejuni Pathogenesis

Nonmammalian model systems of infection have been employed recently to study bacterial virulence. For instance, Galleria mellonella (the greater wax moth) has been shown to be susceptible to infection by many bacterial pathogens including the enteric pathogen Campylobacter jejuni. In contrast to the traditional animal models for C. jejuni such as the chick colonization model and ferret diarrheal model, the Galleria mellonella infection model has the advantages of lower cost, ease of use and no animal breeding is required. However, injecting the larvae with bacteria requires care to avoid killing of larvae, which could lead to misleading results. Here, we describe the infection of G. mellonella larvae by C. jejuni and how to record/interpret results.

Campylobacter-induced Fetal Death in a Rhesus Monkey

A pregnant 4-year-old rhesus monkey ( Macaca mulatta) was presented with a history of acute vaginal bleeding. Physical examination revealed an open cervix. An ultrasound scan demonstrated a viable early third-trimester fetus, approximately 16 weeks of gestational age. Hematology results showed that the monkey was anemic, with a normal leukogram and Döhle bodies. A subsequent cervical culture was positive for Campylobacter fetus. The fetus died 3 days later, and a necropsy of the fetus and placenta was performed. Microscopic examination of the placenta revealed villitis, perivillitis, and deciduitis with S-shaped and gull wing-shaped bacteria. C. fetus was considered the cause of the placental lesions and fetal death; however, the pathogenesis of the infection (hematogenous vs. ascending from the maternal genital tract) was not clear. This is the first report of a Campylobacter-induced fetal death in the rhesus monkey. Because macaques can be asymptomatic carriers and Campylobacter-induced diarrhea is common, this finding has implications for breeding success in nonhuman primate breeding colonies.

Interleukin-18 Mediates Immune Responses to Campylobacter jejuni Infection in Gnotobiotic Mice

BACKGROUND

Human Campylobacter jejuni infections are progressively rising worldwide. Information about the molecular mechanisms underlying campylobacteriosis, however, are limited. In the present study we investigated whether cytokines such as IL-23, IL-22 and IL-18, which share pivotal functions in host immunity, were involved in mediating intestinal and systemic immunopathological responses upon C. jejuni infection.

METHODOLOGY/PRINCIPAL FINDINGS

To assure stable infection, gnotobiotic (i.e. secondary abiotic) IL-23p19-/-, IL-22-/- and IL-18-/- mice were generated by broad-spectrum antibiotic treatment. Following peroral C. jejuni strain 81-176 infection, mice of all genotypes harbored comparably high pathogenic loads in their intestines. As compared to wildtype controls, however, IL-18-/- mice displayed less distinct C. jejuni induced sequelae as indicated by less pronounced large intestinal shrinkage and lower numbers of apoptotic cells in the colonic epithelial layer at day 8 postinfection (p.i.). Furthermore, lower colonic numbers of adaptive immune cells including regulatory T cells and B lymphocytes were accompanied by less distinct secretion of pro-inflammatory cytokines such as TNF and IFN-γ and lower IL-17A mRNA expression levels in colonic ex vivo biopsies of infected IL-18-/- as compared to wildtype mice. Upon C. jejuni infection, colonic IL-23p19 expression was up-regulated in IL-18-/- mice only, whereas IL-22 mRNA levels were lower in uninfected and infected IL-23p19-/- as well as infected IL-18-/- as compared to respective wildtype control mice. Remarkably, not only intestinal, but also systemic infection-induced immune responses were less pronounced in IL-18-/- mice as indicated by lower TNF, IFN-γ and IL-6 serum levels as compared to wildtype mice.

CONCLUSION/SIGNIFICANCE

We here show for the first time that IL-18 is essentially involved in mediating C. jejuni infection in the gnotobiotic mouse model. Future studies need to further unravel the underlying regulatory mechanisms orchestrating pathogen-host interaction.

Heterogeneity in the Infection Biology of Campylobacter jejuni Isolates in Three Infection Models Reveals an Invasive and Virulent Phenotype in a ST21 Isolate from Poultry

Although Campylobacter is the leading cause of bacterial foodborne gastroenteritis in the world and the importance of poultry as a source of infection is well understood we know relatively little about its infection biology in the broiler chicken. Much of what we know about the biology of Campylobacter jejuni is based on infection of inbred or SPF laboratory lines of chickens with a small number of isolates used in most laboratory studies. Recently we have shown that both the host response and microbial ecology of C. jejuni in the broiler chicken varies with both the host-type and significantly between C. jejuni isolates. Here we describe heterogeneity in infection within a panel of C. jejuni isolates in two broiler chicken breeds, human intestinal epithelial cells and the Galleria insect model of virulence. All C. jejuni isolates colonised the chicken caeca, though colonisation of other parts of the gastrointestinal tract varied between isolates. Extra-intestinal spread to the liver varied between isolates and bird breed but a poultry isolate 13126 (sequence type 21) showed the greatest levels of extra-intestinal spread to the liver in both broiler breeds with over 70% of birds of the fast growing breed and 50% of the slower growing breed having C. jejuni in their livers. Crucially 13126 is significantly more invasive than other isolates in human intestinal epithelial cells and gave the highest mortality in the Galleria infection model. Taken together our findings suggest that not only is there considerable heterogeneity in the infection biology of C. jejuni in avian, mammalian and alternative models, but that some isolates have an invasive and virulent phenotype. Isolates with an invasive phenotype would pose a significant risk and increased difficulty in control in chicken production and coupled with the virulent phenotype seen in 13126 could be an increased risk to public health.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Systematic review and meta-analysis of the proportion of Campylobacter cases that develop chronic sequelae

BACKGROUND

Understanding of chronic sequelae development after Campylobacter infection is limited. The objective of the study was to determine via systematic review and meta-analysis the proportion of Campylobacter cases that develop chronic sequelae.

METHODS

A systematic review of English language articles published prior to July 2011 located using Pubmed, Agricola, CabDirect, and Food Safety and Technology Abstracts. Observational studies reporting the number of Campylobacter cases that developed reactive arthritis (ReA), Reiter's syndrome (RS), haemolytic uraemic syndrome (HUS), irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) ,Guillain Barré syndrome (GBS) or Miller Fisher syndrome (MFS) were included. Data extraction through independent extraction of articles by four reviewers (two per article). Random effects meta-analysis was performed and heterogeneity was assessed using the I(2) value. Meta-regression was used to explore the influence of study level variables on heterogeneity.

RESULTS

A total of 31 studies were identified; 20 reported on ReA, 2 reported on RS, 9 reported on IBS, 3 studies reported on IBD, 8 reported on GBS, 1 reported on MFS and 3 reported on HUS. The proportion of Campylobacter cases that developed ReA was 2.86% (95% CI 1.40% - 5.61%, I(2) = 97.7%), irritable bowel syndrome was 4.01% (95% CI 1.41% - 10.88%, I(2) = 99.2%). Guillain Barré syndrome was 0.07% (95% CI 0.03% - 0.15%, I(2) = 72.7%).

CONCLUSIONS

A significant number of Campylobacter cases develop a chronic sequela. However, results should be interpreted with caution due to the high heterogeneity.

Stress response and virulence of heat-stressed Campylobacter jejuni

Thermotolerant Campylobacter spp. frequently cause bacterial gastroenteritis in humans commonly infected through the consumption of undercooked poultry meat. We examined Campylobacter jejuni heat-stress responses in vitro after exposure to 48°C and 55°C. The in vivo modulation of its pathogenicity was also investigated using BALB/c mice intravenously infected with stressed C. jejuni. Regardless of the bacterial growth phase, the culturability and viability of C. jejuni in vitro was reduced after exposure to 55°C. This correlated with the altered protein profile and decreased virulence properties observed in vivo. Heat stress at 48°C elicited the transition to more resistant bacterial forms, independent of morphological changes or the appearance of shorter spiral and coccoid cells. This treatment did not cause marked changes in bacterial virulence properties in vivo. These results indicated that the characteristics and pathogenicity of C. jejuni in response to heat stress are temperature dependent. Further studies on the responses of C. jejuni to stresses used during food processing, as well as the modulation of its virulence, are important for a better understanding of its contamination and infective cycle, and will, thus, contribute to improved safety in the food production chain.

A novel mouse model of Campylobacter jejuni gastroenteritis reveals key pro-inflammatory and tissue protective roles for Toll-like receptor signaling during infection

Campylobacter jejuni is a major source of foodborne illness in the developed world, and a common cause of clinical gastroenteritis. Exactly how C. jejuni colonizes its host's intestines and causes disease is poorly understood. Although it causes severe diarrhea and gastroenteritis in humans, C. jejuni typically dwells as a commensal microbe within the intestines of most animals, including birds, where its colonization is asymptomatic. Pretreatment of C57BL/6 mice with the antibiotic vancomycin facilitated intestinal C. jejuni colonization, albeit with minimal pathology. In contrast, vancomycin pretreatment of mice deficient in SIGIRR (Sigirr^−/−), a negative regulator of MyD88-dependent signaling led to heavy and widespread C. jejuni colonization, accompanied by severe gastroenteritis involving strongly elevated transcription of Th1/Th17 cytokines. C. jejuni heavily colonized the cecal and colonic crypts of Sigirr^−/− mice, adhering to, as well as invading intestinal epithelial cells. This infectivity was dependent on established C. jejuni pathogenicity factors, capsular polysaccharides (kpsM) and motility/flagella (flaA). We also explored the basis for the inflammatory response elicited by C. jejuni in Sigirr^−/− mice, focusing on the roles played by Toll-like receptors (TLR) 2 and 4, as these innate receptors were strongly stimulated by C. jejuni. Despite heavy colonization, Tlr4^−/−/Sigirr^−/− mice were largely unresponsive to infection by C. jejuni, whereas Tlr2^−/−/Sigirr^−/− mice developed exaggerated inflammation and pathology. This indicates that TLR4 signaling underlies the majority of the enteritis seen in this model, whereas TLR2 signaling had a protective role, acting to promote mucosal integrity. Furthermore, we found that loss of the C. jejuni capsule led to increased TLR4 activation and exaggerated inflammation and gastroenteritis. Together, these results validate the use of Sigirr^−/− mice as an exciting and relevant animal model for studying the pathogenesis and innate immune responses to C. jejuni.

Research into the key virulence strategies of the bacterial pathogen Campylobacter jejuni, as well as the host immune responses that develop against this microbe have, in many ways, been limited by the lack of relevant animal models. Here we describe the use of Sigirr deficient (^−/−) mice as a model for C. jejuni pathogenesis. Not only do Sigirr^−/− mice develop significant intestinal inflammation in response to colonization by C. jejuni, but the ability of this pathogen to trigger gastroenteritis was dependent on key virulence factors. We also found that the induction of the inflammatory and Th1/Th17 immune responses to infection in these mice depended on specific Toll-like receptors, principally TLR4, which we identified as the main driver of inflammation. In contrast, TLR2 signaling was found to protect mucosal integrity, with Tlr2^−/−/Sigirr^−/− mice suffering exaggerated mucosal damage and inflammation. Notably, we found that C. jejuni's capsule helped conceal it from the host's immune system as its loss led to significantly increased activation of host TLRs and exaggerated gastroenteritis. Our research shows that the increased sensitivity of Sigirr^−/− mice can be used to generate a unique and exciting model that facilitates the study of C. jejuni pathogenesis as well as host immunity to this enteric pathogen.

Campylobacter fetus infections in humans: exposure and disease

Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants.

[Campylobacteriosis]

Campylobacteriosis belongs to the most frequent bacterial gastrointestinal infections worldwide. In the past several years, an increasing trend in the prevalence of campylobacteriosis has been observed in many countries. The rapid spread of antibiotic resistance in Campylobacter spp. also poses a major challenge. The authors review current knowledge on the microbiology of Campylobacter spp., complex pathogenetic as well as pathophysiological mechanisms in the development and course of campylobacteriosis and related complications such as Guillain-Barré syndrome.

Foodborne Campylobacter: infections, metabolism, pathogenesis and reservoirs

Campylobacter species are a leading cause of bacterial-derived foodborne illnesses worldwide. The emergence of this bacterial group as a significant causative agent of human disease and their propensity to carry antibiotic resistance elements that allows them to resist antibacterial therapy make them a serious public health threat. Campylobacter jejuni and Campylobacter coli are considered to be the most important enteropathogens of this genus and their ability to colonize and survive in a wide variety of animal species and habitats make them extremely difficult to control. This article reviews the historical and emerging importance of this bacterial group and addresses aspects of the human infections they cause, their metabolism and pathogenesis, and their natural reservoirs in order to address the need for appropriate food safety regulations and interventions.

Capsaicin-sensitive vagal afferent neurons contribute to the detection of pathogenic bacterial colonization in the gut

Vagal activation can reduce inflammation and disease activity in various animal models of intestinal inflammation via the cholinergic anti-inflammatory pathway. In the current model of this pathway, activation of descending vagal efferents is dependent on a signal initiated by stimulation of vagal afferents. However, little is known about how vagal afferents are activated, especially in the context of subclinical or clinical pathogenic bacterial infection. To address this question, we first determined if selective lesions of capsaicin-sensitive vagal afferents altered c-Fos expression in the nucleus of the solitary tract (nTS) after mice were inoculated with either Campylobacter jejuni or Salmonella typhimurium. Our results demonstrate that the activation of nTS neurons by intraluminal pathogenic bacteria is dependent on intact, capsaicin sensitive vagal afferents. We next determined if inflammatory mediators could cause the observed increase in c-Fos expression in the nTS by a direct action on vagal afferents. This was tested by the use of single-cell calcium measurements in cultured vagal afferent neurons. We found that tumor necrosis factor alpha (TNFα) and lipopolysaccharide (LPS) directly activate cultured vagal afferent neurons and that almost all TNFα and LPS responsive neurons were sensitive to capsaicin. We conclude that activation of the afferent arm of the parasympathetic neuroimmune reflex by pathogenic bacteria in the gut is dependent on capsaicin sensitive vagal afferent neurons and that the release of inflammatory mediators into intestinal tissue can be directly sensed by these neurons.

Outcome of infection of C57BL/6 IL-10(-/-) mice with Campylobacter jejuni strains is correlated with genome content of open reading frames up- and down-regulated in vivo

Human Campylobacter jejuni infection can result in an asymptomatic carrier state, watery or bloody diarrhea, bacteremia, meningitis, or autoimmune neurological sequelae. Infection outcomes of C57BL/6 IL-10(-/-) mice orally infected with twenty-two phylogenetically diverse C. jejuni strains were evaluated to correlate colonization and disease phenotypes with genetic composition of the strains. Variation between strains was observed in colonization, timing of development of clinical signs, and occurrence of enteric lesions. Five pathotypes of C. jejuni in C57BL/6 IL-10(-/-) mice were delineated: little or no colonization, colonization without disease, colonization with enteritis, colonization with hemorrhagic enteritis, and colonization with neurological signs with or without enteritis. Virulence gene content of ten sequenced strains was compared in silico; virulence gene content of twelve additional strains was compared using a C. jejuni pan-genome microarray. Neither total nor virulence gene content predicted pathotype; nor was pathotype correlated with multilocus sequence type. Each strain was unique with regard to absences of known virulence-related loci and/or possession of point mutations and indels, including phase variation, in virulence-related genes. An experiment in C. jejuni 11168-infected germ-free mice showed that expression levels of ninety open reading frames (ORFs) were significantly up- or down-regulated in the mouse cecum at least two-fold compared to in vitro growth. Genomic content of these ninety C. jejuni 11168 ORFs was significantly correlated with the capacity to colonize and cause enteritis in C57BL/6 IL-10(-/-) mice. Differences in gene expression levels and patterns are thus an important determinant of pathotype in C. jejuni strains in this mouse model.

Sialylation of Campylobacter jejuni lipo-oligosaccharides: impact on phagocytosis and cytokine production in mice

Background

Guillain-Barré syndrome (GBS) is a post-infectious polyradiculoneuropathy, frequently associated with antecedent Campylobacter jejuni (C. jejuni) infection. The presence of sialic acid on C. jejuni lipo-oligosaccharide (LOS) is considered a risk factor for development of GBS as it crucially determines the structural homology between LOS and gangliosides, explaining the induction of cross-reactive neurotoxic antibodies. Sialylated C. jejuni are recognised by TLR4 and sialoadhesin; however, the functional implications of these interactions in vivo are unknown.

Methodology/Principal Findings

In this study we investigated the effects of bacterial sialylation on phagocytosis and cytokine secretion by mouse myeloid cells in vitro and in vivo. Using fluorescently labelled GM1a/GD1a ganglioside-mimicking C. jejuni strains and corresponding (Cst-II-mutant) control strains lacking sialic acid, we show that sialylated C. jejuni was more efficiently phagocytosed in vitro by BM-MΦ, but not by BM-DC. In addition, LOS sialylation increased the production of IL-10, IL-6 and IFN-β by both BM-MΦ and BM-DC. Subsequent in vivo experiments revealed that sialylation augmented the deposition of fluorescent bacteria in splenic DC, but not macrophages. In addition, sialylation significantly amplified the production of type I interferons, which was independent of pDC.

Conclusions/Significance

These results identify novel immune stimulatory effects of C. jejuni sialylation, which may be important in inducing cross-reactive humoral responses that cause GBS.

The pathogenic potential of Campylobacter concisus strains associated with chronic intestinal diseases

Campylobacter concisus has garnered increasing attention due to its association with intestinal disease, thus, the pathogenic potential of strains isolated from different intestinal diseases was investigated. A method to isolate C. concisus was developed and the ability of eight strains from chronic and acute intestinal diseases to adhere to and invade intestinal epithelial cells was determined. Features associated with bacterial invasion were investigated using comparative genomic analyses and the effect of C. concisus on host protein expression was examined using proteomics. Our isolation method from intestinal biopsies resulted in the isolation of three C. concisus strains from children with Crohn's disease or chronic gastroenteritis. Four C. concisus strains from patients with chronic intestinal diseases can attach to and invade host cells using mechanisms such as chemoattraction to mucin, aggregation, flagellum-mediated attachment, "membrane ruffling", cell penetration and damage. C. concisus strains isolated from patients with chronic intestinal diseases have significantly higher invasive potential than those from acute intestinal diseases. Investigation of the cause of this increased pathogenic potential revealed a plasmid to be responsible. 78 and 47 proteins were upregulated and downregulated in cells infected with C. concisus, respectively. Functional analysis of these proteins showed that C. concisus infection regulated processes related to interleukin-12 production, proteasome activation and NF-κB activation. Infection with all eight C. concisus strains resulted in host cells producing high levels of interleukin-12, however, only strains capable of invading host cells resulted in interferon-γ production as confirmed by ELISA. These findings considerably support the emergence of C. concisus as an intestinal pathogen, but more significantly, provide novel insights into the host immune response and an explanation for the heterogeneity observed in the outcome of C. concisus infection. Moreover, response to infection with invasive strains has substantial similarities to that observed in the inflamed mucosa of Crohn's disease patients.

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.

Immune response to and histopathology of Campylobacter jejuni infection in ferrets (Mustela putorius furo)

Campylobacter jejuni is 1 of the most common enteric bacterial pathogens worldwide. The mechanisms of pathogenesis remain obscure, in part because of limitations of small animal models. Young ferrets develop diarrhea when fed C. jejuni, but their pathology and the immune response after infection have not been examined in detail. In the present study, we examined the pathogenesis of C. jejuni CG8421 and associated immune responses in ferrets. After oral infection with C. jejuni CG8421, 86.7% of the animals developed diarrhea and inflammatory responses that were similar to those seen in human infection. Pronounced histopathologic changes in the colonic mucosa of infected animals were observed during the acute phase (days 1 through 3) of infection. Electron micrographs of colonic epithelium revealed disruption of the villi and internalized bacteria that were not within membrane vacuoles. During the acute phase, C. jejuni was isolated from the livers of 7 of 9 (78%) animals, and bacteria were visualized immunohistochemically in the livers from 5 of the 7 animals (71%) from which C. jejuni was isolated. A vigorous systemic and mucosal immune response to Campylobacter antigens was elicited after infection of ferrets. The data presented contribute to the current knowledge of the pathogenicity of and immunologic response to C. jejuni CG8421 in ferrets and better understanding of this model.

Sialylation of Campylobacter jejuni lipo-oligosaccharides is associated with severe gastro-enteritis and reactive arthritis

We used various genotyping methods to identify bacterial genetic markers for development of arthritic symptoms following Campylobacter enteritis. We genotyped a collection of population derived Campylobacter strains, with detailed information on clinical characteristics, including arthritic symptoms. Besides using whole genome screening methods, we focused on the lipo-oligosaccharide (LOS) gene locus in which marker genes for developing post-Campylobacter neurological disease are present. Patients with arthritic symptoms were more frequently infected with Campylobacter jejuni strains with a class A LOS locus. We also found that patients who were infected with a C. jejuni strain containing sialic acid-positive LOS (class A, B or C) more frequently had bloody diarrhoea and a longer duration of symptoms. Furthermore, the IgM antibody response against Campylobacter was stronger in patients with a sialic acid containing LOS. Ganglioside auto-antibodies were observed in a small number of patients following infection with a class C strain. We conclude that sialylation of C. jejuni LOS is not only a risk factor for development of post-infectious symptoms, but is also associated with increased severity of enteric disease.

Campylobacter spp.--a significant microbiological hazard in food. II. Lesions and infection development, pathogenic mechanisms and complications

Infections with Campylobacter spp. occur as a result of consumption of live cells with food. In developing countries those infections are immensely common, particularly during early childhood and 5 to 10 cases can appear during the initial two years of life. The symptoms appear usually after 1-7 days from infection depending on the number of ingested cells and individual sensitivity. Characteristic symptoms of infections caused by Campylobacter spp. infrequently occurring jointly in the clinical form of the disease include: diarrhea, abdominal pain and increased temperature. In the majority of cases the disease is mild and lasts from 2 to 7 days. Usually Campylobacter are excreted with feces during a period of 7-21 days, sometimes even longer. Occasionally in the increased risk group dangerous complications may occur. They include: bacteremia, meningo-myelitis, neurological disturbances and reactive arthritis.

[Campylobacter-jejuni-associated hepatitis and myocardial injury]

BACKGROUND

Campylobacter-jejuni infection can lead to different extraintestinal manifestations. Myo-/pericarditis and toxic hepatitis have been reported. A combined appearance has not been described yet.

CASE REPORT

A 22-year-old woman presented with sudden left thoracic pain. An increase in troponin T, creatine kinase and myoglobin was noted. In the absence of signs of myocardial ischemia, the diagnosis of myocarditis was made. The patient reported diarrhea persisting for 5 days. Campylobacter-jejuni could be identified in the feces. On account of rising transaminases, a biopsy of the liver was performed. The histological examination revealed lesions caused by Campylobacter-jejuni.

CONCLUSION

Given the increasing incidence of Campylobacter-jejuni infections, the case presented here should draw the attention to extraintestinal manifestations.

Campylobacter jejuni: molecular biology and pathogenesis

Campylobacter jejuni is a foodborne bacterial pathogen that is common in the developed world. However, we know less about its biology and pathogenicity than we do about other less prevalent pathogens. Interest in C. jejuni has increased in recent years as a result of the growing appreciation of its importance as a pathogen and the availability of new model systems and genetic and genomic technologies. C. jejuni establishes persistent, benign infections in chickens and is rapidly cleared by many strains of laboratory mouse, but causes significant inflammation and enteritis in humans. Comparing the different host responses to C. jejuni colonization should increase our understanding of this organism.

MUC1 cell surface mucin is a critical element of the mucosal barrier to infection

Cell surface mucin glycoproteins are highly expressed by all mucosal tissues, yet their physiological role is currently unknown. We hypothesized that cell surface mucins protect mucosal cells from infection. A rapid progressive increase in gastrointestinal expression of mucin 1 (Muc1) cell surface mucin followed infection of mice with the bacterial pathogen Campylobacter jejuni. In the first week following oral infection, C. jejuni was detected in the systemic organs of the vast majority of Muc1(-/-) mice but never in Muc1(+/+) mice. Although C. jejuni entered gastrointestinal epithelial cells of both Muc1(-/-) and Muc1(+/+) mice, small intestinal damage as manifested by increased apoptosis and enucleated and shed villous epithelium was more common in Muc1(-/-) mice. Using radiation chimeras, we determined that prevention of systemic infection in wild-type mice was due exclusively to epithelial Muc1 rather than Muc1 on hematopoietic cells. Expression of MUC1-enhanced resistance to C. jejuni cytolethal distending toxin (CDT) in vitro and CDT null C. jejuni showed lower gastric colonization in Muc1(-/-) mice in vivo. We believe this is the first in vivo experimental study to demonstrate that cell surface mucins are a critical component of mucosal defence and that the study provides the foundation for exploration of their contribution to epithelial infectious and inflammatory diseases.

Fatal myocarditis related to Campylobacter jejuni infection: a case report

Infectious myocarditis can be caused by a variety of agents, with enteroviruses being the most common. Myocarditis due to enteric bacteria is rare. We present pathological documentation of a rare case of a Campylobacter jejuni bowel infection leading to rapidly fatal myocarditis.

Prognosis and pathological characteristics of five children with non-Shiga toxin-mediated hemolytic uremic syndrome

BACKGROUND

The three major signs of hemolytic uremic syndrome (HUS) are hemolytic anemia, thrombopenia and acute renal failure. HUS is classified into Shiga toxin-mediated HUS (Stx-HUS) and non-Shiga toxin-mediated HUS (nStx-HUS). The prognosis of nStx-HUS is reported to be less favorable than that of Stx-HUS. Although the association between the prognosis and pathological characteristics of HUS have been reported such that the prognosis was considered to be poor for thrombotic microangiopathy (TMA) with predominant arterial involvement (arterial TMA), good for TMA with predominant glomerular involvement (glomerular TMA) and dependent on the extent of necrosis in cases of renal cortical necrosis, it is not yet clear whether pathological findings are also related to the renal prognosis of nStx-HUS cases. Therefore the purpose of the present paper was to analyze renal biopsy findings and prognosis for five children with nStx-HUS.

METHODS

Clinical records of five cases of nStx-HUS among 74 cases of diagnosed HUS were reviewed, and information and data were summarized.

RESULTS

Histological examination of the kidney led to the diagnosis of arterial TMA in three cases, and glomerular TMA and severe renal cortical necrosis in one case each. Analysis of the relationship between renal histological findings and the prognosis found that three patients with arterial TMA and one patient with severe renal cortical necrosis later developed end-stage renal failure while one patient with glomerular TMA has continued to show normal renal function.

CONCLUSIONS

These findings indicate that pathological findings are closely related to the prognosis in cases of nStx-HUS.

Live, attenuated Salmonella typhimurium vectoring Campylobacter antigens

We describe the evaluation of three live, attenuated deltaphoP/Q Salmonella enteric serovar Typhimurium strains expressing PEB1 minus its signal sequence (PEB1-ss) from three different plasmids: a pBR-based asd plasmid, an arabinose-based runaway plasmid, which each expressed PEB1-ss in the bacterial cytosol, and a PEB1::HlyA fusion plasmid that directs secretion of PEB1-ss into the extracellular milieu. Serum IgG responses specific for PEB1-ss were induced by pBR-derived and runaway plasmids, with 100 and 90% seroconversion, respectively, at a 1:500 dilution of anti-sera as measured by Western blot analysis, while the PEB1-ss::HlyA fusion plasmid induced serum IgG in only 20% of the mice. Although significant levels of anti-PEB serum IgG were induced, no protection against oral Campylobacter jejuni challenge was observed.

Immunoproliferative small intestinal disease (IPSID): a model for mature B-cell neoplasms

Immunoproliferative small intestinal disease (IPSID) was recently added to the growing list of infectious pathogen-associated human lymphomas. Molecular and immunohistochemical studies demonstrated an association with Campylobacter jejuni. IPSID is a variant of the B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), which involves mainly the proximal small intestine resulting in malabsorption, diarrhea, and abdominal pain. Geographically, IPSID is most prevalent in the Middle East and Africa. IPSID lymphomas reveal excessive plasma cell differentiation and produce truncated alpha heavy chain proteins lacking the light chains as well as the first constant domain. The corresponding mRNA lacks the variable heavy chain (V(H)) and the constant heavy chain 1 (C(H)1) sequences and contains deletions as well as insertions of unknown origin. The encoding gene sequence reveals a deletion of V region and parts of C(H)1 domain. Cytogenetic studies demonstrated clonal rearrangements involving predominantly the heavy and light chain genes, including t(9;14) translocation involving the PAX5 gene. Early-stage IPSID responds to antibiotics (30%-70% complete remission). Most untreated IPSID patients progress to lymphoplasmacytic and immunoblastic lymphoma invading the intestinal wall and mesenteric lymph nodes, and may metastasize to a distant organ. IPSID lymphoma shares clinical, morphologic, and molecular features with MALT lymphoma, lymphoplasmacytic lymphoma, and plasma cell neoplasms.

Lymphoglandular complexes are important colonic sites for immunoglobulin A induction against Campylobacter jejuni in a swine disease model

Campylobacter jejuni is a common cause of serious food-borne illness. In an experimental model of human infection, germfree pigs were given C. jejuni, the whipworm Trichuris suis, dual infections with C. jejuni and T. suis, or no infection. In dual-infected pigs, a synergistic effect between C. jejuni and T. suis was observed 27 days after infection, when T. suis fourth-stage larvae were found in the proximal colon. In dual-infected pigs, lymphoglandular complexes (LGCs) in the distal colon were substantially enlarged, and C. jejuni was detected in cells of the follicle-associated epithelium (FAE) and in cells with macrophage morphology within these follicles. In the study reported here, cell types in colonic tissues from these pigs were analyzed by use of immunohistochemical and morphometric analyses for cell surface markers (IgM, IgG, IgA, CD4, CD8, MHC Class II, and macrophage SWC3a). To our knowledge, we provide the first description of cell types in mammalian LGCs, document that they have all elements necessary for antigen processing, and demonstrate the appearance of IgA germinal centers (GC) in LGCs from C. jejuni-infected pigs (single or dual infected). Ileocecal Peyer's patches (ICPP) and mesenteric lymph nodes (MLN) also had IgA GC development if C. jejuni was present, but LGCs had the greatest amount of anti-C. jejuni staining, and appreciable increase in overall follicle size and size and number of GCs committed to IgA production. LGCs are present in humans and other mammals and are important in other enteric infections.

Prolonged diarrhea due to ciprofloxacin-resistant campylobacter infection

BACKGROUND

Campylobacter causes >1 million infections annually in the United States. Fluoroquinolones (e.g., ciprofloxacin) are used to treat Campylobacter infections in adults. Although human infections with ciprofloxacin-resistant Campylobacter have become increasingly common, the human health consequences of such infections are not well described.

METHODS

A case-control study of persons with sporadic Campylobacter infection was conducted within 7 FoodNet sites during 1998-1999. The E-test system (AB Biodisk) was used to test for antimicrobial susceptibility to ciprofloxacin; ciprofloxacin resistance was defined as a ciprofloxacin minimum inhibitory concentration of > or =4 microg/mL. We conducted a case-comparison study of interviewed persons who had an isolate tested.

RESULTS

Of 858 isolates tested, 94 (11%) were ciprofloxacin resistant. Among 290 persons with Campylobacter infection who did not take antidiarrheal medications, persons with ciprofloxacin-resistant infection had a longer mean duration of diarrhea than did persons with ciprofloxacin-susceptible infection (9 vs. 7 days [P=.04]). This difference was even more pronounced among the 63 persons who did not take antidiarrheal medications or antimicrobial agents (12 vs. 6 days [P=.04]). In a multivariable analysis-of-variance model, the persons with ciprofloxacin-resistant infection had a longer mean duration of diarrhea than did the persons with ciprofloxacin-susceptible infection (P=.01); this effect was independent of foreign travel. The association between ciprofloxacin resistance and prolonged diarrhea is consistent across a variety of analytical approaches.

CONCLUSIONS

Persons with ciprofloxacin-resistant Campylobacter infection have a longer duration of diarrhea than do persons with ciprofloxacin-susceptible Campylobacter infection. Additional efforts are needed to preserve the efficacy of fluoroquinolones.

Gastroenteritis in NF-kappaB-deficient mice is produced with wild-type Camplyobacter jejuni but not with C. jejuni lacking cytolethal distending toxin despite persistent colonization with both strains

Campylobacter jejuni continues to be a leading cause of bacterial enteritis in humans. However, because there are no readily available animal models to study the pathogenesis of C. jejuni-related diseases, the significance of potential virulence factors, such as cytolethal distending toxin (CDT), in vivo are poorly understood. Mice deficient in NF-kappaB subunits (p50(-/-) p65(+/-)) in a C57BL/129 background are particularly susceptible to colitis induced by another enterohepatic microaerobe, Helicobacter hepaticus, which, like C. jejuni, produces CDT. Wild-type C. jejuni 81-176 and an isogenic mutant lacking CDT activity (cdtB mutant) were inoculated into NF-kappaB-deficient (3X) and C57BL/129 mice. Wild-type C. jejuni colonized 29 and 50% of the C57BL/129 mice at 2 and 4 months postinfection (p.i.), respectively, whereas the C. jejuni cdtB mutant colonized 50% of the C57BL/129 mice at 2 p.i. but none of the mice at 4 months p.i. Although the C57BL/129 mice developed mild gastritis and typhlocolitis, they had robust immunoglobulin G (IgG) and Th1-promoted IgG2a humoral responses to both the wild-type strain and the C. jejuni cdtB mutant. In contrast, 75 to 100% of the 3X mice were colonized with both the wild type and the C. jejuni cdtB mutant at similar levels at all times examined. Wild-type C. jejuni caused moderately severe gastritis and proximal duodenitis in 3X mice that were more severe than the gastrointestinal lesions caused by the C. jejuni cdtB mutant. Persistent colonization of NF-kappaB-deficient mice with the wild type and the C. jejuni cdtB mutant was associated with significantly impaired IgG and IgG2a humoral responses (P < 0.001), which is consistent with an innate or adaptive immune system defect(s). These results suggest that the mechanism of clearance of C. jejuni is NF-kappaB dependent and that CDT may have proinflammatory activity in vivo, as well as a potential role in the ability of C. jejuni to escape immune surveillance. NF-kappaB-deficient mice should be a useful model to further study the role of CDT and other aspects of C. jejuni pathogenesis.

Campylobacter fetus septic arthritis revealing a malignancy

Campylobacter fetus is a rare cause of bone and joint infection. We report a new case in a patient who also had endocarditis due to the same organism. This type of infection usually occurs in immunocompromised hosts. Investigations in our patient found a cancer of the prostate.

Enhancement of disease and pathology by synergy of Trichuris suis and Campylobacter jejuni in the colon of immunologically naive swine

Campylobacterjejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries, which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on the C. jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections such as Trichuris, which drive type 2 cytokine responses and down-regulate type 1 immune responses. In this study, three-day-old germ-free pigs given dual infections with Trichuris suis and C. jejuni had more frequent, more severe diarrhea and severe pathology than pigs given no pathogens, only T. suis, or only C. jejuni. These pigs had significant hemorrhage and inflammatory cell infiltrates in the proximal colon where adult worms were found, and abscessed lymphoglandular complexes in the distal colon with intracellular C. jejuni. Pigs given only C. jejuni had mild clinical signs and pathology, and bacteria in feces or extracellular sites. Pigs given T. suis or no pathogens had no disease and minimal pathology. Thus, these agents synergized to produce significant disease and pathology, which was site specific.

The study of infectious intestinal disease in England: socio-economic impact

To assess the socio-economic impact of infectious intestinal disease (IID) on the health care sector, cases and their families, cases of IID ascertained from a population cohort component and those presenting to general practices were sent a socio-economic questionnaire 3 weeks after the acute episode. The impact of the illness was measured and the resources used were identified and costed. The duration, severity and costs of illness linked to viruses were less than those linked to bacteria. The average cost per case of IID presenting to the GP was Pound Sterling253 and the costs of those not seeing a GP were Pound Sterling34. The average cost per case was Pound Sterling606 for a case with salmonella, Pound Sterling315 for campylobacter, Pound Sterling164 for rotavirus and Pound Sterling176 for SRSV. The estimated cost of IID in England was Pound Sterling743m expressed in 1994/5 prices. The costs of IID are considerable and the duration of the illness was found to be longer than previous reports have suggested.

Enhancement of disease and pathology by synergy of Trichuris suis and Campylobacter jejuni in the colon of immunologically naive swine

Campylobacter jejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries, which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on the C jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections such as Trichuris, which drive type 2 cytokine responses and down-regulate type 1 immune responses. In this study, three-day-old germ-free pigs given dual infections with Trichuris suis and C jejuni had more frequent, more severe diarrhea and severe pathology than pigs given no pathogens, only T. suis, or only C jejuni. These pigs had significant hemorrhage and inflammatory cell infiltrates in the proximal colon where adult worms were found, and abscessed lymphoglandular complexes in the distal colon with intracellular C jejuni. Pigs given only C jejuni had mild clinical signs and pathology, and bacteria in feces or extracellular sites. Pigs given T. suis or no pathogens had no disease and minimal pathology. Thus, these agents synergized to produce significant disease and pathology, which was site specific.

The impact of sporadic campylobacter and salmonella infection on health and health related behaviour: a case control study

The aim of the work was to explore the impact on general and psychological health of those with a proven bacterial gastrointestinal infection and to compare this with controls from whom no bacterial pathogen was identified. A case control study was conducted using an interviewer-administered questionnaire. Thirty-nine cases from whose faeces salmonella or campylobacter had been cultured were compared with matched controls. Reported gastrointestinal symptoms, general health and self-reported hygiene practices were compared. At the time of acute illness the General Household Questionnaire suggested similar levels of morbidity, though by follow up the controls were substantially more likely to be distressed. Cases were more likely to have changed their food preparation practices, to avoid certain eating places and to have been given advice about food preparation. In this small study a positive diagnosis of salmonella or campylobacter seems to have had a reassuring effect when compared with those for whom no diagnosis was made.

Genetic or chemical hypochlorhydria is associated with inflammation that modulates parietal and G-cell populations in mice

BACKGROUND & AIMS

Reduced gastric acid predisposes the stomach to colonization by bacteria and inflammation. Therefore, we investigated how the chronic gastritis in mice made hypochlorhydric by either gastrin deficiency or omeprazole treatment modulates epithelial cell function.

METHODS

The gastric pathology of 16-week-old wild-type gastrin-expressing (G+/+) and gastrin-deficient (G-/-) mice maintained in conventional housing was compared. G-/- mice were then treated with antibiotics for 20 days. In a separate experiment, G+/+ mice were treated with omeprazole for 2 months or treated with omeprazole and antibiotics.

RESULTS

Compared with the G+/+ animals, the hypochlorhydric G-/- mice showed significant inflammation that resolved after 20 days of antibiotic treatment and correlated with a decrease in bacterial overgrowth. Elevated G- and parietal-cell numbers in the G-/- mice, quantified by flow cytometry, normalized after antibiotic treatment. G+/+ mice treated with omeprazole had increased bacteria and mucosal lymphocytes that resolved after antibiotic therapy. Quantitation of the gastric cells in these omeprazole-treated mice revealed a significant increase in G- and parietal-cell numbers. On resolution of the gastritis, a decrease in parietal and gastrin-expressing (G) cells was observed despite sustained hypochlorhydria in the presence of omeprazole.

CONCLUSIONS

Genetic or chemical hypochlorhydria predisposes the stomach to bacterial overgrowth resulting in inflammation. The specific changes in parietal and G cells correlate with the presence of inflammation and not directly with gastric acid. Thus, the normal stomach responds to inflammation by increasing the number and function of cell types that are able to maximize gastric acid output.

A bacterial toxin that causes DNA damage to modulate cellular responses

Campylobacter jejuni constitutes the leading cause of bacterial diarrhea in the U.S. and all around the world. This common bacterium produces a toxin known as cytolethal distending toxin (CDT) which causes intoxicated cells to enlarge and to stop dividing with a double DNA content characteristic of G2/M arrest. The effect of the toxin on the cell is so striking that it captivated scientists for a long time. However, its mechanism of action had remained elusive.

Increased rectal mucosal enteroendocrine cells, T lymphocytes, and increased gut permeability following acute Campylobacter enteritis and in post-dysenteric irritable bowel syndrome

BACKGROUND AND AIMS

Post-dysenteric irritable bowel syndrome (PD-IBS) develops in up to 25% of patients following Campylobacter enteritis. Our aim was to define the pathological basis of this subgroup of IBS.

METHODS

Twenty one patients (group 1) underwent serial rectal biopsy and gut permeability testing following acute Campylobacter enteritis as did 10 PD-IBS patients (group 2) and 12 asymptomatic controls.

RESULTS

In group 1, enteroendocrine cell (EC) numbers were markedly increased initially and at six and 12 weeks (p<0.001) compared with controls. Gut permeability, as assessed by the lactulose/mannitol ratio, was significantly elevated, initially and at 12 weeks (p<0.005). CD3, CD4, and CD8 lymphocyte counts in the lamina propria and intraepithelial lymphocytes (IEL) were significantly increased initially compared with controls. At visit 1, EC numbers were positively correlated with CD3 counts (r=0.6, p=0.01). At one year, seven subjects (five with persistent loose stools) had rectal biopsies which showed significantly elevated EC, CD3, and IEL counts. In group 2, EC and IEL counts were significantly increased compared with controls (p<0.001), as was gut permeability (p<0.01).

CONCLUSION

Increased EC, T lymphocytes, and gut permeability are acute changes following Campylobacter enteritis which can persist for more than a year and may contribute to PD-IBS.