A role for Campylobacter jejuni-induced enteritis in inflammatory bowel disease?

Evaluation of the anti-inflammatory, antinociceptive, and antipyretic potential of ethanolic extract of Aristida depressa Retz through in vitro, in vivo, and in silico models

Uncontrolled inflammation is a crucial factor in the development of many diseases. Anti-inflammatory molecules based on natural sources are being actively studied, among which Aristida depressa Retz (Ar.dp) has been traditionally used as a paste to heal inflammation. The present study aimed to evaluate the anti-inflammatory, analgesic, and antipyretic potential of an ethanolic extract of A. depressa through a battery of in vivo and in vitro models. The ethanolic extract of A. depressa was prepared by maceration and chemically characterized using high-performance liquid chromatography, which revealed the presence of quercetin, vanillic acid, chlorogenic acid, p-coumaric acid, m-coumaric acid, ferulic acid, cinnamic acid, and sinapic acid; its antioxidant capacity was then screened with the DPPH in vitro assay, which indicated moderate scavenging capacity. A protein denaturation assay was next performed to evaluate the in vitro anti-inflammatory potential of Ar.dp, which showed significant inhibition (44.44%) compared to the standard drug (diclofenac sodium), with 89.19% inhibition at a concentration of 1 mg/mL. The in vivo safety profile of Ar.dp was evaluated in accordance with the OECD-425 acute toxicity guidelines and found to be safe up to 5 g/kg. The in vivo anti-inflammatory potentials of Ar.dp were evaluated at three different doses (125, 250, and 500 mg/kg) in acute (carrageenan-induced edema: 84.60%, histamine-induced paw edema: 84%), sub-chronic (cotton-pellet-induced granuloma: 57.54%), and chronic (complete-Freund's-adjuvant-induced arthritis: 82.2%) models. Our results showed that Ar.dp had significant (p < 0.05) anti-inflammatory effects over diclofenac sodium in the acute and chronic models. Histopathology studies indicated reduced infiltration of paw tissues with inflammatory cells in Ar.dp-treated animals. Similarly, Ar.dp showed significant (p < 0.05) analgesic (yeast-induced-pyrexia model: 23.53%) and antipyretic (acetic-acid-induced writhing model: 51%) effects in a time-dependent manner. In silico studies on the interactions of COX-1 and COX-2 with the eight ligands mentioned earlier confirmed the inhibition of enzymes responsible for inflammation and fever. Based on the findings of the present study, it is concluded that Ar.dp has anti-inflammatory, analgesic, and antipyretic properties that are likely linked to its pharmacologically active phenolic bioactive molecules.

Guillain-Barré syndrome in ulcerative colitis and SARS-CoV-2 infection: a case report and literature review

Aim: Guillain-Barré syndrome (GBS) occurrence is rare during inflammatory bowel disease (IBD) and SARS-CoV-2 infection. Its association with thrombotic vascular events, which are common during these two entities, is extremely rare. Case report: We report an exceptional association of GBS and cerebral venous thrombosis in a 28-year-old woman with active ulcerative colitis and no previous history of SARS-CoV-2 vaccination. Mildly symptomatic SARS-CoV-2 infection was diagnosed during etiological investigations of cerebral venous thrombosis. GBS symptoms began 10 days later with clinical and electrical abnormalities consistent with axonal GBS. Other GBS causes were excluded. Favorable outcomes were noted after intravenous immunoglobulin perfusion with full recovery 12 months later. Conclusion: Greater attention should be focused on IBD patients with SARS-CoV-2 infection regardless of its severity.

Epigenetic modification of m6A methylation: Regulatory factors, functions and mechanism in inflammatory bowel disease

Although the exact cause of inflammatory bowel disease (IBD) is still unknown, there is a lot of evidence to support the notion that it results from a combination of environmental factors, immune system issues, gut microbial changes, and genetic susceptibility. In recent years, the role of epigenetics in the pathogenesis of IBD has drawn increasing attention. The regulation of IBD-related immunity, the preservation of the intestinal epithelial barrier, and autophagy are all significantly influenced by epigenetic factors. The most extensive epigenetic methylation modification of mammalian mRNA among them is N6-methyladenosine (m6A). It summarizes the general structure and function of the m6A regulating factors, as well as their complex effects on IBD by regulating the intestinal mucous barrier, intestine mucosal immunity, epidermal cell death, and intestinal microorganisms.This paper provides key insights for the future identification of potential new targets for the diagnosis and treatment of IBD.

Biological Potential and Bioaccessibility of Encapsulated Curcumin into Cetyltrimethylammonium Bromide Modified Cellulose Nanocrystals

Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.

The interaction of bile acids and gut inflammation influences the pathogenesis of inflammatory bowel disease

Bile acids (BA) are amphipathic molecules originating from cholesterol in the liver and from microbiota-driven biotransformation in the colon. In the gut, BA play a key role in fat digestion and absorption and act as potent signaling molecules on the nuclear farnesoid X receptor (FXR) and membrane-associated G protein-coupled BA receptor-1 (GPBAR-1). BA are, therefore, involved in the maintenance of gut barrier integrity, gene expression, metabolic homeostasis, and microbiota profile and function. Disturbed BA homeostasis can activate pro-inflammatory pathways in the gut, while inflammatory bowel diseases (IBD) can induce gut dysbiosis and qualitative and/or quantitative changes of the BA pool. These factors contribute to impaired repair capacity of the mucosal barrier, due to chronic inflammation. A better understanding of BA-dependent mechanisms paves the way to innovative therapeutic tools by administering hydrophilic BA and FXR agonists and manipulating gut microbiota with probiotics and prebiotics. We discuss the translational value of pathophysiological and therapeutic evidence linking BA homeostasis to gut inflammation in IBD.

Gut Bacterial Community Determines the Therapeutic Effect of Ginsenoside on Canine Inflammatory Bowel Disease by Modulating the Colonic Mucosal Barrier

Inflammatory bowel disease (IBD) comprises systemic inflammatory conditions primarily affecting the gastrointestinal tract, including Crohn's disease and ulcerative colitis. This research aims to analyze the clinical symptoms and pathogenesis of a Dextran sodium sulfate (DSS)-induced canine IBD model and evaluate the restorative effect of ginsenoside from a pathogenesis perspective. We established the DSS-induced canine IBD model and studied the pathological mechanisms. Additionally, we examined the therapeutic effect of ginsenosides by assessing the Canine Inflammatory Bowel Disease Activity Index (CIBDAI), C-reactive protein (CRP) levels, colonic tissue morphology, protein expression, and mucosal bacterial community analysis. Our findings revealed a total ginsenoside content of 22.7% in the ginsenoside extract. Animal experiments demonstrated that dogs with IBD exhibited decreased mental state, significantly increased CIBDAI and CRP levels, disrupted colonic epithelial tissue structure, decreased expression of mucin, tight junctions, and adherens junctions, as well as reduced diversity of the colonic mucosal bacterial community. Furthermore, correlation analysis highlighted a total of 38 bacterial strains correlated with physiological indices. Significantly, ginsenoside treatment could improve these symptoms and reverse the relative abundance of some bacterial communities. In conclusion, alterations in the properties of the colonic mucus layer or the reduction in MUC2, its core component, in dogs with IBD can lead to bacterial penetration of the mucus layer and subsequent contact with intestinal epithelial cells, resulting in inflammation. Remarkably, ginsenoside intervention showcased the capacity to positively influence the relative abundance of bacteria and impact the colonic mucus layer properties, thereby offering promising prospects for IBD management and recovery.

Prospective Application of Nanoencapsulated Bacillus amyloliquefaciens on Broiler Chickens' Performance and Gut Health with Efficacy against Campylobacter jejuni Colonization

Probiotics as novel antibiotics' substitutes are verified to provide barriers for hindering the colonization of enteric bacterial pathogens with nutritional benefits. For enhancement of the probiotics' effectiveness, their integration within nanomaterials is a paramount tool to support the progress of new compounds with functional features. Therefore, we addressed the impact of effective delivery of probiotics (Bacillus amyloliquefaciens) loaded nanoparticles (BNPs) on performance and Campylobacter jejuni (C. jejuni) shedding and colonization in poultry. Two hundred Ross broiler chickens were divided into four groups fed various BNP levels: BNPs I, BNPs II, BNPs III, and BNPs-free diets for 35 days. Nanoparticles delivery of probiotics within broiler diets improved growth performance as reflected by higher body weight gain and superior feed conversion ratio, especially in BNPs II- and BNPs III-fed groups. In parallel, the mRNA expression levels of digestive enzymes encoding genes (AMY2a, PNLIP, CELA1, and CCK) achieved their peaks in BNPs III-fed group (1.69, 1.49, 1.33, and 1.29-fold change, respectively) versus the control one. Notably, with increasing the levels of BNPs, the abundance of beneficial microbiota, such as Bifidobacterium and Lactobacillus species, was favored over harmful ones, including Clostridium species and Enterobacteriaceae. Birds fed higher levels of BNPs displayed significant improvement in the expression of barrier functions-linked genes including DEFB1, FABP-2, and MUC-2 alongside substantial reduction in cecal colonization and fecal shedding of C. jejuni. From the aforementioned positive effects of BNPs, we concluded their potential roles as growth promoters and effective preventive aids for C. jejuni infection in poultry.

The Role of Temperate Phages in Bacterial Pathogenicity

Bacteriophages are viruses that infect bacteria and archaea and are classified as virulent or temperate phages based on their life cycles. A temperate phage, also known as a lysogenic phage, integrates its genomes into host bacterial chromosomes as a prophage. Previous studies have indicated that temperate phages are beneficial to their susceptible bacterial hosts by introducing additional genes to bacterial chromosomes, creating a mutually beneficial relationship. This article reviewed three primary ways temperate phages contribute to the bacterial pathogenicity of foodborne pathogens, including phage-mediated virulence gene transfer, antibiotic resistance gene mobilization, and biofilm formation. This study provides insights into mechanisms of phage–bacterium interactions in the context of foodborne pathogens and provokes new considerations for further research to avoid the potential of phage-mediated harmful gene transfer in agricultural environments.

Etiology of IBD—Is It Still a Mystery?

Inflammatory bowel diseases (IBD), including colitis ulcerosa and Crohn’s disease, are chronic diseases of the gastrointestinal tract for which the cause has not been fully understood. However, it is known that the etiology is multifactorial. The multidirectional network of interactions of environmental, microbiological and genetic factors in predisposed persons lead to an excessive and insufficiently inhibited reaction of the immune system, leading to the development of chronic inflammation of the gastrointestinal walls, the consequence of which is the loss of the function that the intestine performs, inter alia, through the process of fibrosis. Detailed knowledge of the pathways leading to chronic inflammation makes it possible to pharmacologically modulate disorders and effectively treatthese diseases. In this review, we described the primary and adaptive immune system response in the gut and the known immune pathogenetic pathways leading to the development of IBD. We also described the process leading to intestinal tissue fibrosis, which is an irreversible consequence of untreated IBD.

Campylobacter jejuni Serine Protease HtrA Induces Paracellular Transmigration of Microbiota across Polarized Intestinal Epithelial Cells

Campylobacter jejuni represents an eminent zoonotic germ responsible for foodborne infections causing campylobacteriosis. In addition, infections with C. jejuni constitute a risk factor for the occurrence of inflammatory bowel disease (IBD). In the latter case, patients show inflammatory reactions not only against C. jejuni, but also against the non-infectious microbiota. However, the involved mechanisms and molecular basis are still largely unclear. We recently reported that C. jejuni breaches the intestinal epithelial barrier by secretion of serine protease HtrA (high temperature requirement A), which cleaves several major tight and adherens junction proteins. In the present study, we aimed to study if HtrA-expressing C. jejuni may also trigger the transepithelial migration of non-pathogenic gastrointestinal microbiota. Using confocal immunofluorescence and scanning electron microscopy, we demonstrate that C. jejuni wild-type (wt) as well as the isogenic ∆htrA mutant bind to the surface of polarized intestinal Caco-2 epithelial cells, but do not invade them at the apical side. Instead, C. jejuni wt, but not ∆htrA mutant, disrupt the cellular junctions and transmigrate using the paracellular route between neighboring cells. Using transwell filter systems, we then co-incubated the cells with C. jejuni and non-invasive microbiota strains, either Escherichia coli or Lactococcus lactis. Interestingly, C. jejuni wt, but not ∆htrA mutant, induced the efficient transmigration of these microbiota bacteria into the basal compartment. Thus, infection of the intestinal epithelium with C. jejuni causes local opening of cellular junctions and paracellular translocation in an HtrA-dependent manner, which paves the way for transmigration of microbiota that is otherwise non-invasive. Taken together, these findings may have impacts on various Campylobacter-associated diseases such as IBD, which are discussed here.

Epidemiologic Changes in Over 10 Years of Community-Acquired Bacterial Enteritis in Children

PURPOSE

Community-acquired bacterial enteritis (CABE) is a common problem in developed countries. It is important to understand the epidemiologic changes in bacterial pathogens for prevention and treatment. Therefore, we studied the epidemiologic changes in CABE in Korean children.

METHODS

A total of 197 hospitalized pediatric patients aged <19 years that presented with dysentery symptoms and showed positive polymerase chain reaction results for bacterial species in stool samples, were enrolled in this study for 10 years (June 2010 to June 2020). We classified patients in phase I (06, 2010-06, 2015) and phase II (07, 2015-06, 2020) and analyzed their epidemiologic and clinical characteristics.

RESULTS

The most common pathogens were Campylobacter species (42.6%) and Salmonella species were the second most common pathogens (23.9%). The abundance of pathogens decreased in the following order: Clostridium difficile (9.6%), Shigella (5.6%), and Clostridium perfringens (5.6%). Escherichia coli O157:H7 was found to be the rarest pathogen (2.0%). Campylobacter species showed an increase in the infection rate from 32.1% in phase I to 49.6% in phase II (p=0.0011). Shigella species showed a decline in the infection rate in phase I from 14.1% to 0.0% in phase II (p<0.001). C. difficile and C. perfringens showed an increase in infection rate in phase II compared to phase I, but the difference was not statistically significant.

CONCLUSION

The infection rate of Campylobacter species in CABE has been rising more recently, reaching almost 50%. This study may help establish policies for prevention and treatment of CABE in Korean children.

Stabilizing Genetically Unstable Simple Sequence Repeats in the Campylobacter jejuni Genome by Multiplex Genome Editing: a Reliable Approach for Delineating Multiple Phase-Variable Genes

Hypermutable simple sequence repeats (SSRs) are major drivers of phase variation in Campylobacter jejuni. The presence of multiple SSR-mediated phase-variable genes encoding enzymes that modify surface structures, including capsular polysaccharide (CPS) and lipooligosaccharide (LOS), generates extreme cell surface diversity within bacterial populations, thereby promoting adaptation to selective pressures in host environments. Therefore, genetically controlling SSR-mediated phase variation can be important for achieving stable and reproducible research on C. jejuni. Here, we show that natural "cotransformation" is an effective method for C. jejuni genome editing. Cotransformation is a trait of naturally competent bacteria that causes uptake/integration of multiple different DNA molecules, which has been recently adapted to multiplex genome editing by natural transformation (MuGENT), a method for introducing multiple mutations into the genomes of these bacteria. We found that cotransformation efficiently occurred in C. jejuni. To examine the feasibility of MuGENT in C. jejuni, we "locked" different polyG SSR tracts in strain NCTC11168 (which are located in the biosynthetic CPS/LOS gene clusters) into either the ON or OFF configurations. This approach, termed "MuGENT-SSR," enabled the generation of all eight edits within 2 weeks and the identification of a phase-locked strain with a highly stable type of Penner serotyping, a CPS-based serotyping scheme. Furthermore, extensive genome editing of this strain by MuGENT-SSR identified a phase-variable gene that determines the Penner serotype of NCTC11168. Thus, MuGENT-SSR provides a platform for genetic and phenotypic engineering of genetically unstable C. jejuni, making it a reliable approach for elucidating the mechanisms underlying phase-variable expression of specific phenotypes. IMPORTANCE Campylobacter jejuni is the leading bacterial cause of foodborne gastroenteritis in developed countries and occasionally progresses to the autoimmune disease Guillain-Barré syndrome. A relatively large number of hypermutable simple sequence repeat (SSR) tracts in the C. jejuni genome markedly decreases its phenotypic stability through reversible changes in the ON or OFF expression states of the genes in which they reside, a phenomenon called phase variation. Thus, controlling SSR-mediated phase variation can be important for achieving stable and reproducible research on C. jejuni. In this study, we developed a feasible and effective approach for genetically manipulate multiple SSR tracts in the C. jejuni genome using natural cotransformation, a trait of naturally transformable bacterial species that causes the uptake and integration of multiple different DNA molecules. This approach will greatly help to improve the genetic and phenotypic stability of C. jejuni to enable diverse applications in research and development.

Gastrointestinal biofilms in health and disease

Microorganisms colonize various ecological niches in the human habitat, as they do in nature. Predominant forms of multicellular communities called biofilms colonize human tissue surfaces. The gastrointestinal tract is home to a profusion of microorganisms with intertwined, but not identical, lifestyles: as isolated planktonic cells, as biofilms and in biofilm-dispersed form. It is therefore of major importance in understanding homeostatic and altered host-microorganism interactions to consider not only the planktonic lifestyle, but also biofilms and biofilm-dispersed forms. In this Review, we discuss the natural organization of microorganisms at gastrointestinal surfaces, stratification of microbiota taxonomy, biogeographical localization and trans-kingdom interactions occurring within the biofilm habitat. We also discuss existing models used to study biofilms. We assess the contribution of the host-mucosa biofilm relationship to gut homeostasis and to diseases. In addition, we describe how host factors can shape the organization, structure and composition of mucosal biofilms, and how biofilms themselves are implicated in a variety of homeostatic and pathological processes in the gut. Future studies characterizing biofilm nature, physical properties, composition and intrinsic communication could shed new light on gut physiology and lead to potential novel therapeutic options for gastrointestinal diseases.

The Campylobacter jejuni CiaD effector co-opts the host cell protein IQGAP1 to promote cell entry

Campylobacter jejuni is a foodborne pathogen that binds to and invades the epithelial cells lining the human intestinal tract. Maximal invasion of host cells by C. jejuni requires cell binding as well as delivery of the Cia proteins (Campylobacter invasion antigens) to the host cell cytosol via the flagellum. Here, we show that CiaD binds to the host cell protein IQGAP1 (a Ras GTPase-activating-like protein), thus displacing RacGAP1 from the IQGAP1 complex. This, in turn, leads to the unconstrained activity of the small GTPase Rac1, which is known to have roles in actin reorganization and internalization of C. jejuni. Our results represent the identification of a host cell protein targeted by a flagellar secreted effector protein and demonstrate that C. jejuni-stimulated Rac signaling is dependent on IQGAP1.

Inflammatory Immune Responses and Gut Microbiota Changes Following Campylobacter coli Infection of IL-10-/- Mice with Chronic Colitis

Human infections with the food-borne enteropathogens Campylobacter are progressively rising. Recent evidence revealed that pre-existing intestinal inflammation facilitates enteropathogenic infection subsequently exacerbating the underlying disease. Given that only little is known about C. coli-host interactions and particularly during intestinal inflammation, the aim of the present study was to survey gastrointestinal colonization properties, gut microbiota changes and pro-inflammatory sequelae upon peroral C. coli-infection of IL-10^-/- mice with chronic colitis. C. coli colonized the gastrointestinal tract of mice with varying efficiencies until day 28 post-infection and induced macroscopic and microscopic inflammatory changes as indicated by shorter colonic lengths, more distinct histopathological changes in the colonic mucosa and higher numbers of apoptotic colonic epithelial cells when compared to mock-infected controls. Furthermore, not only colonic innate and adaptive immune cell responses, but also enhanced systemic TNF-α secretion could be observed following C. coli as opposed to mock challenge. Notably, C. coli induced intestinal inflammatory sequelae were accompanied with gut microbiota shifts towards higher commensal enterobacterial loads in the infected gut lumen. Moreover, the pathogen translocated from the intestinal tract to extra-intestinal tissue sites in some cases, but never to systemic compartments. Hence, C. coli accelerates inflammatory immune responses in IL-10^-/- mice with chronic colitis.

The microbiome in inflammatory bowel diseases: from pathogenesis to therapy

Inflammatory bowel disease (IBD) has become a global disease with accelerating incidence worldwide in the 21st century while its accurate etiology remains unclear. In the past decade, gut microbiota dysbiosis has consistently been associated with IBD. Although many IBD-associated dysbiosis have not been proven to be a cause or an effect of IBD, it is often hypothesized that at least some of alteration in microbiome is protective or causative. In this article, we selectively reviewed the hypothesis supported by both association studies in human and pathogenesis studies in biological models. Specifically, we reviewed the potential protective bacterial pathways and species against IBD, as well as the potential causative bacterial pathways and species of IBD. We also reviewed the potential roles of some members of mycobiome and virome in IBD. Lastly, we covered the current status of therapeutic approaches targeting microbiome, which is a promising strategy to alleviate and cure this inflammatory disease.

A meta-analysis of dietary carbohydrate intake and inflammatory bowel disease risk: evidence from 15 epidemiology studies

BACKGROUND AND PURPOSE

epidemiological studies that assess the association of dietary total carbohydrate intake and inflammatory bowel disease risk (IBD) have yielded controversial results. Therefore, this study of various epidemiological studies was conducted in order to explore this relationship.

METHODS

a systematic literature search of the PubMed, Embase, Web of Science and Medline databases was performed up to September 2017. Cohort, case-control or cross-sectional design studies were included that reported the association of dietary carbohydrate intake and IBD risk. Summary odds ratio (OR) and the corresponding 95% CI were calculated using the random effects model.

RESULTS

a total of eight articles with 15 individual studies that included 1,361 cases were eligible according to the inclusion criteria. Dietary carbohydrate intake had a non-significant relationship with the risk of IBD (OR = 1.091, 95% CI = 0.817-1.455, I2 = 31.6%, pfor heterogeneity = 0.116). The pooled OR and 95% CI for ulcerative colitis (UC) and Crohn's disease (CD) with regard to dietary carbohydrate intake was 1.167 (0.777-1.752) and 1.010 (0.630-1.618), respectively. These associations were also non-significant in both European and Asia populations.

CONCLUSIONS

a higher dietary total carbohydrate intake had a non-significant relationship with IBD risk. Further studies with large populations are needed to verify this relationship.

Intracellular Survival and Translocation Ability of Human and Avian Campylobacter jejuni and Campylobacter coli Strains

Campylobacter acts using complex strategies to establish and promote intestinal infections. After ingestion via contaminated foods, this bacterium invades and can survive within the intestinal cells, also inducing epithelial translocation of non-invasive intestinal bacteria. In this investigation, the ability of human and avian C. jejuni and C. coli isolates to survive within two different intestinal epithelial cells lines, Caco-2 and INT 407, as well as the intestinal translocation phenomenon, was assessed. Our data demonstrated that both C. jejuni and C. coli strains survived in Caco-2 (81.8% and 100% respectively) and INT 407 monolayers (72.7% and 100% respectively) within the first 24 h post-infection period, with a progressive reduction in the prolonged period of 48 h and 72 h post-infection. The translocation of the non-invasive E. coli 60/06 FB was remarkably increased in C. jejuni treated Caco-2 monolayers (2.36 ± 0.42 log cfu/mL) (P < 0.01) and less in those treated with C. coli (1.2 ± 0.34 log cfu/mL), compared to E. coli 60/06 FB alone (0.37 ± 0.14 log cfu/mL). Our results evidenced the ability of both human and avian strains of C. jejuni and C. coli to efficiently survive within intestinal cells and induce the translocation of a non-invasive pathogen. Overall, these findings stress how this pathogen can interact with host cells and support the hypothesis that defects in the intestinal barrier function induced by Campylobacter spp. could have potentially negative implications for human health.

Role of intestinal flora characteristics in traditional Chinese medicine-based diagnosis and treatment of spleen and stomach diseases

Abnormal rise and fall of spleen and stomach Qi will lead to a series of spleen and stomach diseases. Spleen-deficiency syndrome and damp-heat syndrome are important traditional Chinese medicine (TCM) syndromes of spleen-stomach diseases, and they also correlate with imbalance of intestinal flora. Given the correlation between spleen and stomach diseases and intestinal flora, this paper discusses the changes of intestinal flora in common spleen and stomach diseases by reviewing the relevant literature, in order to demonstrate the role of intestinal flora in the diagnosis and treatment of TCM syndromes and promote the objectification of TCM syndromes.

Pathobiont release from dysbiotic gut microbiota biofilms in intestinal inflammatory diseases: a role for iron?

Gut microbiota interacting with an intact mucosal surface are key to the maintenance of homeostasis and health. This review discusses the current state of knowledge of the biofilm mode of growth of these microbiota communities, and how in turn their disruptions may cause disease. Beyond alterations of relative microbial abundance and diversity, the aim of the review is to focus on the disruptions of the microbiota biofilm structure and function, the dispersion of commensal bacteria, and the mechanisms whereby these dispersed commensals may become pathobionts. Recent findings have linked iron acquisition to the expression of virulence factors in gut commensals that have become pathobionts. Causal studies are emerging, and mechanisms common to enteropathogen-induced disruptions, as well as those reported for Inflammatory Bowel Disease and colo-rectal cancer are used as examples to illustrate the great translational potential of such research. These new observations shed new light on our attempts to develop new therapies that are able to protect and restore gut microbiota homeostasis in the many disease conditions that have been linked to microbiota dysbiosis.

Antibiotics in inflammatory bowel diseases: do we know what we're doing?

Despite the revolution in inflammatory bowel disease (IBD) treatment over the past two decades with the advent of biological therapies, there remains a substantial proportion of patients with inadequate or unsustained response to existent therapies. The overwhelming focus of IBD therapeutics has been targeting mucosal immunity, however with the developing evidence base pointing to the role of gut microbes in the inflammatory process, renewed focus should be placed on the impact of manipulating the microbiome in IBD management. This review provides an overview of the evidence implicating bacteria in the pathogenesis of gut inflammation in IBD and provides an overview of the evidence of antibiotics in IBD treatment. We also suggest a potential role of antibiotics in clinical practice based on available evidence and clinical experience.

Antibiotics in IBD: Still a Role in the Biological Era?

Despite compelling evidence pointing to a critical role of gut microflora in inflammatory bowel disease (IBD) pathogenesis, the role of antibiotics in clinical practice remains limited, largely due to heterogeneous trials with often conflicting evidence. In this review, we revisit previous randomized controlled trials and high-quality uncontrolled studies in an effort to better elucidate the role of antibiotics in contemporary treatment algorithms. The most established role of antibiotics is in perianal Crohn's disease (CD), utilizing ciprofloxacin with or without metronidazole often as an adjunct to biological therapy. Evidence also points to a likely modest role of various antibiotic classes in mild to moderate luminal CD, including ciprofloxacin, metronidazole, azithromycin, and rifaximin. The benefit of metronidazole in preventing postoperative recurrence in CD is well reported; however, the long-term benefit of this intervention remains uncertain. The use of antibiotics in ulcerative colitis (UC) is even more controversial, but studies using broad-spectrum oral antibiotic cocktails have reported a possible role in acute severe colitis and chronic persistent UC. Similarly, the role of oral vancomycin and gentamicin in very early-onset IBD has interesting preliminary results. Adverse events of antibiotics, the resulting alterations in the microbiome with its associated unknown long-term sequela, and the emergence of antibiotic-resistant strains must be carefully balanced. Therefore, although antibiotics may be underused in the treatment of IBD, their integration into clinical practice must be approached judiciously and individually.

Campylobacter jejuni and Pseudomonas coinfection in the setting of ulcerative colitis

A 66-year-old woman presented with 2 days of fever and severe diarrhoea. She has a history of ulcerative colitis (UC), well controlled with medication. She also has a history of Ehlers-Danlos syndrome, infective endocarditis following aortic valve replacement and pulmonary embolism. She had complained of passing stool with traces of blood about 30 times per day. Stool testing for Clostridium difficile, routine culture and microscopy was done. She was started on ceftriaxone. CT scan revealed thick-walled colon consistent with UC flare. Flexible sigmoidoscopy showed active continuous colitis extending from the rectum to the proximal descending colon. Campylobacter jejuni was isolated from the stool and blood cultures yielded Pseudomonas aeruginosa. The antibiotic was transitioned to intravenous piperacillin/tazobactam and azithromycin followed by 2 weeks of intravenous cefepime. Her diarrhoea was controlled, and she was discharged for follow-up in 2 months.

An adapted in vitro assay to assess Campylobacter jejuni interaction with intestinal epithelial cells: Taking into stimulation with TNFα

Campylobacter jejuni is the most prevalent foodborne bacterial infection agent. This pathogen seems also involved in inflammatory bowel diseases in which pro-inflammatory cytokines, such as tumor necrosis factor α (TNFα), play a major role. C. jejuni pathogenicity has been extensively studied using in vitro cell culture methods, and more precisely "healthy" cells. In fact, no information is available regarding the behavior of C. jejuni in contact with TNFα-stimulated cells. Therefore, this research was designed to investigate the effect of TNFα on C. jejuni interaction with human intestinal epithelial cells (HT29 and HT29-MTX). To ensure IL-8 production induced by TNFα, human rtTNFα was added to HT29 and HT29-MTX before adhesion and invasion assays. About 10⁸ CFU bacteria of C. jejuni strains cells were added to measure their adherence and invasion abilities using TNFα-stimulated cells versus non stimulated cells. Exposure to TNFα results in IL-8 overproduction by intestinal epithelial cells. In addition, the effect of TNFα pre-treatment on C. jejuni adhesion and internalization into eukaryotic cells is strain-dependent. Indeed, the adhesion/invasion process is affected in <50% of the strains tested when TNFα is added to the intestinal cells. Interestingly, TNFα affects more strains in their ability to adhere to and invade the mucus-secreting HT29-MTX cells. Among the 10 strains tested, the aero-tolerant C. jejuni Bf strain is one of the most virulent. These results suggest that the TNFα signalling pathway could participate in the internalization of C. jejuni in human intestinal cells and can help in understanding the pathogenicity of this microorganism in contact with TNFα-stimulated cells.

Neonatal Colonic Inflammation Epigenetically Aggravates Epithelial Inflammatory Responses to Injury in Adult Life

BACKGROUND & AIMS

Early life adversity is considered a risk factor for the development of gastrointestinal diseases, including inflammatory bowel disease. We hypothesized that early life colonic inflammation causes susceptibility to aggravated overexpression of interleukin (IL)1β.

METHODS

We developed a 2-hit rat model in which neonatal inflammation (NI) and adult inflammation (AI) were induced by trinitrobenzene sulfonic acid.

RESULTS

Aggravated immune responses were observed in NI + AI rats, including a sustained up-regulation of IL1β and other cytokines. In parallel with exacerbated loss of inhibitor of kappa B alpha expression, NI + AI rats showed hyperacetylation of histone H4K12 and increased V-Rel Avian Reticuloendotheliosis Viral Oncogene Homolog A binding on the IL1B promoter, accompanied by high levels of norepinephrine/epinephrine. Propranolol, a β-blocker, markedly ameliorated the inflammatory response and IL1β overexpression by mitigating against epigenetic modifications. Adrenalectomy abrogated NI-induced disease susceptibility whereas yohimbine sensitized the epithelium for exacerbated immune response. The macrophages of NI rats produced more IL1β than controls after exposure to lipopolysaccharide (LPS), suggesting hypersensitization; incubation with LPS plus Foradil (Sigma, St. Louis, MO), a β2-agonist, induced a greater IL1β expression than LPS alone. Epinephrine and Foradil also exacerbated LPS-induced IL1β activation in human THP-1-derived macrophages, by increasing acetylated H4K12, and these increases were abrogated by propranolol.

CONCLUSIONS

NI sensitizes the colon epithelium for exacerbated IL1β activation by increasing stress hormones that induce histone hyperacetylation, allowing greater access of nuclear factor-κB to the IL1B promoter and rendering the host susceptible to aggravated immune responses. Our findings suggest that β blockers have a therapeutic potential for inflammatory bowel disease susceptibility and establish a novel paradigm whereby NI induces epigenetic susceptibility to inflammatory bowel disease.

Vaccination of active component US military personnel against Salmonella Typhi

INTRODUCTION

Vaccination against Salmonella Typhi is one of the leading public health interventions reducing the risk of typhoid fever. There are two available licensed vaccines, Vivotif, oral live-attenuated, and Typhim Vi, intramuscular Vi capsular polysaccharide. The US military is a high risk travel population commonly vaccinated for S. Typhi. We describe the use of S. Typhi vaccination in this population and the acute reactogenicity profile of these vaccines.

METHODS

Data were obtained from the Defense Medical Surveillance System and vaccination identified between 1998 and 2011 from vaccination codes. Clinical outcomes were assessed for four weeks post vaccination. Adverse event rates and odds ratios were estimated across the two vaccine types.

RESULTS

A total of 1.9million predominately male military personnel received 3.6 million S. Typhi vaccinations with 94.3% of vaccinees receiving the Vi capsule vaccine though variability in the vaccine administered was observed. Receipt of other vaccinations in the 6months surrounding the S. Typhi vaccine was common. Rates of nausea (195 per 100,000 vaccinations), headache (13 per 100,000 vaccinations) and fever (40 per 100,000 vaccinations) were significantly higher following Vi capsule vaccination compared to receipt of Vivotif (130, 2, 10 per 100,000 vaccinations, respectively). In contrast the rates of rash and non-infectious diarrhea (186 and 426 per 100,000 vaccinations, respectively) were increased in those receiving Vivotif compared to the Vi capsule vaccine.

DISCUSSION

The US military is a major consumer of S. Typhi vaccines. The parenterally administered vaccine appears to be more amenable, though we were limited in our ability to assess the reasons for its higher usage. While we observed a higher rate of several adverse events in subjects receiving the intramuscular vaccination, the overall rate of these events was low. Future studies assessing more long-term health outcomes are warranted.

MOMP from Campylobacter jejuni Is a Trimer of 18-Stranded β-Barrel Monomers with a Ca2+ Ion Bound at the Constriction Zone

The Gram-negative organism Campylobacter jejuni is the major cause of food poisoning. Unlike Escherichia coli, which has two major porins, OmpC and OmpF, C. jejuni has one, termed major outer membrane protein (MOMP) through which nutrients and antibiotics transit. We report the 2.1-Å crystal structure of C. jejuni MOMP expressed in E. coli and a lower resolution but otherwise identical structure purified directly from C. jejuni. The 2.1-Å resolution structure of recombinant MOMP showed that although the protein has timeric arrangement similar to OmpC, it is an 18-stranded, not 16-stranded, β-barrel. The structure has identified a Ca^2 + bound at the constriction zone, which is functionally significant as suggested by molecular dynamics and single-channel experiments. The water-filled channel of MOMP has a narrow constriction zone, and single-molecule studies show a monomeric conductivity of 0.7 ± 0.2 nS and a trimeric conductance of 2.2 ± 0.2 nS. The ion neutralizes negative charges at the constriction zone, reducing the transverse electric field and reversing ion selectivity. Modeling of the transit of ciprofloxacin, an antibiotic of choice for treating Campylobacter infection, through the pore of MOMP reveals a trajectory that is dependent upon the presence metal ion.

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The crystal structure of MOMP, the general diffusion porin of Campylobacter, has been determined.

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The protein is an 18-stranded β-barrel that is different than the 16-stranded OmpC and OmpF proteins from E. coli, but like them, MOMP is trimeric.

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The protein has a central pore size and conductivity intermediate between OmpC and OmpF.

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A Ca^2 + ion bound at the constriction zone influences the biophysical properties of porin.

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The trajectory of the transit of the antibiotic ciprofloxacin through the pore is dependent on the presence of a metal ion.

Polyphosphate and associated enzymes as global regulators of stress response and virulence in Campylobacter jejuni

Campylobacter jejuni (C. jejuni), a Gram-negative microaerophilic bacterium, is a predominant cause of bacterial foodborne gastroenteritis in humans worldwide. Despite its importance as a major foodborne pathogen, our understanding of the molecular mechanisms underlying C. jejuni stress survival and pathogenesis is limited. Inorganic polyphosphate (poly P) has been shown to play significant roles in bacterial resistance to stress and virulence in many pathogenic bacteria. C. jejuni contains the complete repertoire of enzymes required for poly P metabolism. Recent work in our laboratory and others have demonstrated that poly P controls a plethora of C. jejuni properties that impact its ability to survive in the environment as well as to colonize/infect mammalian hosts. This review article summarizes the current literature on the role of poly P in C. jejuni stress survival and virulence and discusses on how poly P-related enzymes can be exploited for therapeutic/prevention purposes. Additionally, the review article identifies potential areas for future investigation that would enhance our understanding of the role of poly P in C. jejuni and other bacteria, which ultimately would facilitate design of effective therapeutic/preventive strategies to reduce not only the burden of C. jejuni-caused foodborne infections but also of other bacterial infections in humans.

Multiplex detection of nine food-borne pathogens by mPCR and capillary electrophoresis after using a universal pre-enrichment medium

Routine microbiological quality analyses in food samples require, in some cases, an initial incubation in pre-enrichment medium. This is necessary in order to ensure that small amounts of pathogenic strains are going to be detected. In this work, a universal pre-enrichment medium has been developed for the simultaneous growth of Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Cronobacter sakazakii, Escherichia coli, Enterobacteriaceae family (38 species, 27 genera), Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. (two species, 13 strains). Growth confirmation for all these species was achieved in all cases, with excellent enrichments. This was confirmed by plating on the corresponding selective agar media for each bacterium. This GVUM universal pre-enrichment medium could be useful in food microbiological analyses, where different pathogenic bacteria must be detected after a pre-enrichment step. Following, a mPCR reaction for detection of all these pathogens was developed, after designing a set of nine oligonucleotide pairs from specific genetic targets on gDNA from each of these bacteria, covering all available strains already sequenced in GenBank for each pathogen type. The detection limits have been 1 Genome Equivalent (GE), with the exception of the Fam. Enterobacteriaceae (5 GEs). We obtained amplification for all targets (from 70 to 251 bp, depending on the bacteria type), showing the capability of this method to detect the most important industrial and sanitary food-borne pathogens from a universal pre-enrichment medium. This method includes an initial pre-enrichment step (18 h), followed by a mPCR (2 h) and a capillary electrophoresis (30 min); avoiding the tedious and long lasting growing on solid media required in traditional analysis (1–4 days, depending on the specific pathogen and verification procedure). An external testing of this method was conducted in order to compare classical and mPCR methods. This evaluation was carried out on five types of food matrices (meat, dairy products, prepared foods, canned fish, and pastry products), which were artificially contaminated with each one of the microorganisms, demonstrating the equivalence between both methods (coincidence percentages between both methods ranged from 78 to 92%).

Campylobacter jejuni increases flagellar expression and adhesion of noninvasive Escherichia coli: effects on enterocytic Toll-like receptor 4 and CXCL-8 expression

Campylobacter jejuni is the most common cause of bacterium-induced gastroenteritis, and while typically self-limiting, C. jejuni infections are associated with postinfectious intestinal disorders, including flares in patients with inflammatory bowel disease and postinfectious irritable bowel syndrome (PI-IBS), via mechanisms that remain obscure. Based on the hypothesis that acute campylobacteriosis may cause pathogenic microbiota dysbiosis, we investigated whether C. jejuni may activate dormant virulence genes in noninvasive Escherichia coli and examined the epithelial pathophysiological consequences of these alterations. Microarray and quantitative real-time PCR analyses revealed that E. coli adhesin, flagellum, and hemolysin gene expression were increased when E. coli was exposed to C. jejuni-conditioned medium. Increased development of bacterial flagella upon exposure to live C. jejuni or C. jejuni-conditioned medium was observed under transmission electron microscopy. Atomic force microscopy demonstrated that the forces of bacterial adhesion to colonic T84 enterocytes, and the work required to rupture this adhesion, were significantly increased in E. coli exposed to C. jejuni-conditioned media. Finally, C. jejuni-modified E. coli disrupted TLR4 gene expression and induced proinflammatory CXCL-8 gene expression in colonic enterocytes. Together, these data suggest that exposure to live C. jejuni, and/or to its secretory-excretory products, may activate latent virulence genes in noninvasive E. coli and that these alterations may directly trigger proinflammatory signaling in intestinal epithelia. These observations shed new light on mechanisms that may contribute, at least in part, to postcampylobacteriosis inflammatory disorders.

Risk factors and clinical implication of superimposed Campylobacter jejuni infection in patients with underlying ulcerative colitis

Background and aims: Superimposed Campylobacter jejuni infection (CJI) has been described in patients with ulcerative colitis (UC). Its risk factors and impact on the disease course of UC are not known. Our aims were to evaluate the risk factors for CJI in UC patients and the impact of the bacterial infection on outcomes of UC.

Methods: Out of a total of 918 UC patients tested, 21 (2.3%) of patients were found to be positive for CJI (the study group). The control group comprised 84 age-matched UC patients who had tested negative for CJI. Risk factors for CJI and UC-related outcomes at 1 year after diagnosis of CJI were compared between the two groups.

Results: Ten patients (47.6%) with CJI required hospital admission at the time of diagnosis, including eight for the management of “UC flare”. Treatment with antibiotics resulted in improvement in symptoms in 13 patients (61.9%). On multivariate analysis, hospital admission in the preceding year was found to be an independent risk factor for CJI [odds ratio (OR): 3.9; 95% confidence interval (CI): 1.1–14.1] and there was a trend for chronic liver disease as a strong risk factor (OR: 5.0; 95% CI: 0.9–28.3). At 1-year follow up, there was a trend for higher rates of UC-related colectomy (28.8% vs. 14.3%; P = 0.11), and mortality (9.5% vs. 1.2%; P = 0.096) in the study group.

Conclusion: Recent hospitalization within 1 year was found to be associated with increased risk for CJI in UC patients. There was a trend for worse clinical outcomes of UC with in patients with superimposed CJI, which was frequently associated with UC flare requiring hospital admission.

Intestinal Microbiome, Small Intestinal Bacterial Overgrowth and Inflammatory Bowel Diseases - What are the Connections?

IBD (inflammatory bowel diseases) represent chronic idiopathic inflammatory diseases, prone to relapse in the digestive tract; it is estimated that they result from the interaction of the intestinal microbiome with the intestinal immune system. The inflammatory microbiome exerts multiple beneficial roles. Perhaps the central element to developing IBD is dysbiosis; there is still an incompletely established association between intestinal microbiome changes in patients with IBD and SIBO (small intestinal bacterial overgrowth). Influencing the intestinal microbiome may play an adjuvant therapeutic role in the treatment of IBD. We present a synthesis of the connections between the entities mentioned above.

High frequency, spontaneous motA mutations in Campylobacter jejuni strain 81-176

Campylobacter jejuni is an important cause of bacterial diarrhea worldwide. The pathogenesis of C. jejuni is poorly understood and complicated by phase variation of multiple surface structures including lipooligosaccharide, capsule, and flagellum. When C. jejuni strain 81-176 was plated on blood agar for single colonies, the presence of translucent, non-motile colonial variants was noted among the majority of opaque, motile colonies. High-throughput genomic sequencing of two flagellated translucent and two opaque variants as well as the parent strain revealed multiple genetic changes compared to the published genome. However, the only mutated open reading frame common between the two translucent variants and absent from the opaque variants and the parent was motA, encoding a flagellar motor protein. A total of 18 spontaneous motA mutations were found that mapped to four distinct sites in the gene, with only one class of mutation present in a phase variable region. This study exemplifies the mutative/adaptive properties of C. jejuni and demonstrates additional variability in C. jejuni beyond phase variation.

Seroprevalence of campylobacteriosis and relevant post-infectious sequelae

Post-infectious sequelea such as Guillain Barré syndrome (GBS), reactive arthritis (RA), and inflammatory bowel disease (IBD) may arise as a consequence of acute Campylobacter-enteritis (AE). However, reliable seroprevalence data of Campylobacter-associated sequelae has not been established. The objectives of this study were, first, to identify the most specific and sensitive test antigen in an optimized ELISA assay for diagnosing a previous Campylobacter-infection and, second, to compare the prevalence of anti-Campylobacter antibodies in cohorts of healthy blood donors (BD), AE, GBS, RA, and IBD patients with antibodies against known GBS, RA and IBD triggering pathogens. Optimized ELISAs of single and combined Campylobacter-proteins OMP18 and P39 as antigens were prepared and sera from AE, GBS, RA and IBD patients and BD were tested for Campylobcter-specific IgA and IgG antibodies. The results were compared with MIKROGEN™-recomLine Campylobacter IgA/IgG and whole cell lysate-immunoblot. Antibodies specific for Helicobacter pylori, Mycoplasma pneumoniae, Yersinia enterocolitica, and Borrelia afzelii were tested with commercial immunoblots. ROC plot analysis revealed AUC maxima in the combination of OMP18 and P39 for IgA and in the P39-antigen for IgG. As a result, 34–49 % GBS cases, 44–62 % RA cases and 23–40 % IBD cases were associated with Campylobacter-infection. These data show that Campylobcater-seropositivity in these patient groups is significantly higher than other triggering pathogens suggesting that it plays an important role in development of GBS and RA, and supports the hypothesis that recurrent acute campylobacteriosis triggers IBD.

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.

Pathogen-specific risk of celiac disease following bacterial causes of foodborne illness: a retrospective cohort study

BACKGROUND

The US CDC recently estimated over 2 million foodborne illnesses annually are caused by 4 major enteropathogens: non-typhoid Salmonella spp., Campylobacter spp., Shigella spp., and Yersinia enterocolitica. While recent data suggest functional gastrointestinal disorders are associated with these infections, studies linking foodborne illness to celiac disease (CD) are limited. We utilized a US Department of Defense medical encounter database to evaluate the risk of CD following select foodborne infections.

METHODS

We identified subjects with acute gastroenteritis between 1998 and 2009 attributed to Salmonella (nontyphoidal) spp., Shigella spp., Campylobacter spp., or Y. enterocolitica and matched each with up to 4 unexposed subjects. Exposed and unexposed subjects were followed for incident CD diagnosis for their entire military record duration (or a minimum of 1 year). Relative risks were calculated using modified Poisson regression to determine the relationship between pathogen-attributable gastroenteritis and CD while controlling for covariates.

RESULTS

A total of 1,753 pathogen-specific gastroenteritis cases (Campylobacter: 738; Salmonella: 624; Shigella: 376; Yersinia: 17) were identified and followed for a median of 3.8 years. The incidence (per 100,000 person-years) of CD was 0.05. We found a suggested risk of CD after Campylobacter, but not other foodborne infection etiologies.

CONCLUSIONS

These data support a previous study demonstrating increased risk of CD following Campylobacteriosis and highlight the need for additional research into how infections might trigger CD in susceptible individuals.

Campylobacter jejuni colonization is associated with a dysbiosis in the cecal microbiota of mice in the absence of prominent inflammation

Background

Campylobacter jejuni causes enterocolitis in humans, but does not incite disease in asymptomatic carrier animals. To survive in the intestine, C. jejuni must successfully compete with the microbiota and overcome the host immune defense. Campylobacter jejuni colonization success varies considerably amongst individual mice, and we examined the degree to which the intestinal microbiota was affected in mice (i.e. a model carrier animal) colonized by C. jejuni at high relative to low densities.

Methods

Mice were inoculated with C. jejuni or buffer, and pathogen shedding and intestinal colonization were measured. Histopathologic scoring and quantification of mRNA expression for α-defensins, toll-like receptors, and cytokine genes were conducted. Mucosa-associated bacterial communities were characterized by two approaches: multiplexed barcoded pyrosequencing and terminal restriction fragment length polymorphism analysis.

Results

Two C. jejuni treatments were established based on the degree of cecal and colonic colonization; C. jejuni Group A animals were colonized at high cell densities, and C. jejuni Group B animals were colonized at lower cell densities. Histological examination of cecal and colonic tissues indicated that C. jejuni did not incite visible pathologic changes. Although there was no significant difference among treatments in expression of mRNA for α-defensins, toll-like receptors, or cytokine genes, a trend for increased expression of toll-like receptors and cytokine genes was observed for C. jejuni Group A. The results of the two methods to characterize bacterial communities indicated that the composition of the cecal microbiota of C. jejuni Group A mice differed significantly from C. jejuni Group B and Control mice. This difference was due to a reduction in load, diversity and richness of bacteria associated with the cecal mucosa of C. jejuni Group A mice.

Conclusions

High density colonization by C. jejuni is associated with a dysbiosis in the cecal microbiota independent of prominent inflammation.

Symptomatic and asymptomatic Campylobacter infections associated with reduced growth in Peruvian children

Background

Although diarrheal illnesses are recognized as both a cause and effect of undernutrition, evidence for the effect of specific enteropathogens on early childhood growth remains limited. We estimated the effects of undernutrition as a risk factor for campylobacteriosis, as well as associations between symptomatic and asymptomatic Campylobacter infections and growth.

Methodology/Principal Findings

Using data from a prospective cohort of 442 children aged 0–72 months, the effect of nutritional status on the incidence of Campylobacter infection was estimated using uni- and multivariate Poisson models. Multivariate regression models were developed to evaluate the effect of Campylobacter infection on weight gain and linear growth. Overall, 8.3% of diarrheal episodes were associated with Campylobacter (crude incidence rate = 0.37 episodes/year) and 4.9% of quarterly asymptomatic samples were Campylobacter positive. In univariate models, the incidence of Campylobacter infection was marginally higher in stunted than non-stunted children (IRR 1.270, 95% CI (0.960, 1.681)(p = 0.095). When recent diarrheal burdens were included in the analysis, there was no difference in risk between stunted and unstunted children. Asymptomatic and symptomatic Campylobacter infections were associated with reduced weight gain over a three-month period (65.5 g (95% CI: −128.0, −3.0)(p = 0.040) and 43.9 g (95% CI:−87.6, −1.0)(p = 0.049) less weight gain, respectively). Symptomatic Campylobacter infections were only marginally associated with reduced linear growth over a nine month period (−0.059 cm per episode, 95% CI: −0.118, 0.001)(p = 0.054), however relatively severe episodes were associated with reduced linear growth (−0.169 cm/episode, 95% CI −0.310, −0.028)(p = 0.019).

Conclusions/Significance

Our findings suggest that Campylobacter is not as benign as commonly assumed, and that there is evidence to support expanding the indications for antibiotic therapy in campylobacteriosis in children.

Campylobacter is a common cause of diarrheal disease among children at risk for growth failure in the developing world. We evaluated risk factors for Campylobacter infection as well as the association between symptomatic and asymptomatic Campylobacter infections and child growth over three and nine-month periods. Undernourished (stunted) children were more likely to experience a Campylobacter infection, but adjusting for a recent history of diarrheal disease attenuated this relationship. Both symptomatic and asymptomatic infections were associated with poorer weight gain and symptomatic Campylobacter infections were marginally associated with poorer linear growth on an order similar to what has been reported for other bacterial pathogens and less than what has been reported for some protozoal and parasitic infections. In a subset of severe infections that made up about twenty percent of total illnesses, the associations were poorer growth were of greater magnitude. Campylobacter infections are frequently viewed as benign, but our study suggests that this is not always the case. Rapid diagnostics for Campylobacter jejuni and coli could attenuate acquired linear growth deficits in populations where campylobacteriosis is highly endemic by facilitating improved case management.

Crohn's disease-associated adherent-invasive Escherichia coli adhesion is enhanced by exposure to the ubiquitous dietary polysaccharide maltodextrin

Crohn's disease (CD) is associated with intestinal dysbiosis evidenced by an altered microbiome forming thick biofilms on the epithelium. Additionally, adherent-invasive E. coli (AIEC) strains are frequently isolated from ileal lesions of CD patients indicating a potential role for these strains in disease pathogenesis. The composition and characteristics of the host microbiome are influenced by environmental factors, particularly diet. Polysaccharides added to food as emulsifiers, stabilizers or bulking agents have been linked to bacteria-associated intestinal disorders. The escalating consumption of polysaccharides in Western diets parallels an increased incidence of CD during the latter 20^th century. In this study, the effect of a polysaccharide panel on adhesiveness of the CD-associated AIEC strain LF82 was analyzed to determine if these food additives promote disease-associated bacterial phenotypes. Maltodextrin (MDX), a polysaccharide derived from starch hydrolysis, markedly enhanced LF82 specific biofilm formation. Biofilm formation of multiple other E. coli strains was also promoted by MDX. MDX-induced E. coli biofilm formation was independent of polysaccharide chain length indicating a requirement for MDX metabolism. MDX exposure induced type I pili expression, which was required for MDX-enhanced biofilm formation. MDX also increased bacterial adhesion to human intestinal epithelial cell monolayers in a mechanism dependent on type 1 pili and independent of the cellular receptor CEACAM6, suggesting a novel mechanism of epithelial cell adhesion. Analysis of mucosa-associated bacteria from individuals with and without CD showed increased prevalence of malX, a gene essential for MDX metabolism, uniquely in the ileum of CD patients. These findings demonstrate that the ubiquitous dietary component MDX enhances E. coli adhesion and suggests a mechanism by which Western diets rich in specific polysaccharides may promote dysbiosis of gut microbes and contribute to disease susceptibility.

The chronic gastrointestinal consequences associated with campylobacter

Campylobacteriosis is a leading cause of acute infectious diarrhea in the developing world, where it causes considerable mortality, and in developed countries, where it accounts for significant healthcare and other costs. Evidence has emerged from basic science, clinical, and epidemiological domains that suggests that Campylobacter infection is not limited to acute illness but is also involved in the development of well-described extraintestinal sequelae, such as the Guillain-Barré syndrome and reactive arthritis, and may also contribute to the pathogenesis of chronic gastrointestinal conditions. This review will focus on the role of Campylobacter infection as a risk factor for the development of chronic gastrointestinal sequelae, such as functional gastrointestinal disorders, with which irritable bowel syndrome has been most frequently associated, inflammatory bowel disease, and celiac disease.

The effect of bifid triple viable on immune function of patients with ulcerative colitis

Objective. To study effect and its mechanism of Bifid Triple Viable for initially treating ulcerative colitis with 5-aminosalicylic acid. Methods. 82 patients, who were firstly diagnosed as ulcerative colitis, were randomized into experiment group (41 cases, treated with Bifid Triple Viable and Etiasa) and control group (41 cases, treated with Etiasa). The clinic symptom score, colon mucosa inflammation score, and some immune indices were detected and compared between two groups before and two months after treatment. Results. Two months after treatment, the clinical symptom score, colon mucosa inflammation score, and IL-1β expression in colon mucosa decreased significantly (P < 0.01), and IL-10 and IgA expressions in colon mucosa increased significantly (P < 0.01). Those differences were more marked in experiment group than control group (P < 0.05). However, peripheral blood T cell subgroup, immunoglobulins, and complements had no significant difference between two groups two months after treatment, but the ratio of peripheral blood CD4+ T cell to CD8+ T cell in experiment group increased more than that in control group (P < 0.05). Conclusion. Bifid Triple Viable contributed to Etiasa to treat ulcerative colitis in inducing remission period, which was perhaps related to affecting the patient's immune function.

The incidence and risk of celiac disease in a healthy US adult population

OBJECTIVES

Celiac disease (CD) is an increasingly common disease that may affect as many as 1% of the North American population. Recent population-based data suggest a substantial increase in the prevalence of CD over the last several decades. Several factors are hypothesized as possible disease triggers including intercurrent illnesses, such as gastroenteritis, surgeries, and trauma. We used the active duty US military, a unique healthy worker population with essentially complete medical diagnostic coding, as an opportunity to describe trends in CD and deployment-related risk factors.

METHODS

Using electronic medical encounter data (1999-2008) on active duty US military (over 13.7 million person-years), a matched, nested case-control study describing the epidemiology and risk determinants of CD (based on ≥2 ICD-9 medical encounters) was conducted. Incidence and duration of CD-related medical care were estimated, and conditional logistic regression was utilized to evaluate CD risk following infectious gastroenteritis (IGE) occurring within 3 years before CD diagnosis while controlling for other risk factors.

RESULTS

A total of 455 incident cases of CD were identified and age, gender, and time matched to 1,820 controls. The incidence of CD increased five-fold from 1.3 per 100,000 in 1999 to 6.5 per 100,000 in 2008, with the highest rates of increase among those over 34 years of age (average annual increase of 0.8 cases per 100,000). A total of 172 IGE episodes, predominately of "viral etiology" (60.5%), were documented. In multivariate models, a significant association between IGE and CD was found (Odds ratio (OR): 2.06, 95% confidence interval (CI) 1.43, 2.97). Risk generally increased with temporal proximity to, and non-viral etiology of, exposure. Other notable risk factors for CD in multivariate models were Caucasian race (OR: 3.1, P<0.001), non-Army service (OR: 1.5, P=0.001), and greater than a high-school education (OR: 1.3, P=0.05).

CONCLUSIONS

Incidence of CD diagnosis in the US military is increasing, particularly among those in the fourth and fifth decades of life and appears higher than other population-based estimates. An association between antecedent IGE and risk of CD was noted, but the potential for exposure misclassification cannot be ruled out and further study is needed to link pathogen-specific exposure to incident CD anti-gluten antibody development or symptom onset.

Recent advances in small bowel diseases: Part I

As is the case in all parts of gastroenterology and hepatology, there have been many advances in our knowledge and understanding of small intestinal diseases. Over 1000 publications were reviewed for 2008 and 2009, and the important advances in basic science as well as clinical applications were considered. In Part I of this Editorial Review, seven topics are considered: intestinal development; proliferation and repair; intestinal permeability; microbiotica, infectious diarrhea and probiotics; diarrhea; salt and water absorption; necrotizing enterocolitis; and immunology/allergy. These topics were chosen because of their importance to the practicing physician.