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.

Therapeutic Oral Application of Carvacrol Alleviates Acute Campylobacteriosis in Mice Harboring a Human Gut Microbiota.

Human Campylobacter jejuni infections are rising globally. Since antibiotics are usually not indicated in acute campylobacteriosis, antibiotic-independent intervention measures are desirable. The phenolic compound carvacrol constitutes a promising candidate molecule given its antimicrobial and immune-modulatory features. To test the disease-alleviating effects of oral carvacrol treatment in acute murine campylobacteriosis, IL-10-/- mice harboring a human gut microbiota were perorally infected with C. jejuni and treated with carvacrol via the drinking water. Whereas C. jejuni stably established in the gastrointestinal tract of mice from the placebo cohort, carvacrol treatment resulted in lower pathogen loads in the small intestines on day 6 post infection. When compared to placebo, carvacrol ameliorated pathogen-induced symptoms including bloody diarrhea that was accompanied by less distinct histopathological and apoptotic cell responses in the colon. Furthermore, innate and adaptive immune cell numbers were lower in the colon of carvacrol- versus placebo-treated mice. Notably, carvacrol application dampened C. jejuni-induced secretion of pro-inflammatory mediators in intestinal, extra-intestinal and systemic organs to naive levels and furthermore, resulted in distinct shifts in the fecal microbiota composition. In conclusion, our preclinical placebo-controlled intervention study provides evidence that therapeutic carvacrol application constitutes a promising option to alleviate campylobacteriosis in the infected vertebrate host.

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.

Isolation of Campylobacter hepaticus from free-range poultry with spotty liver disease in New Zealand.

Case history: In October 2019, a free-range egg laying flock suffering an outbreak of spotty liver disease was investigated. Eight 32-week-old hens were examined post-mortem. Clinical and pathological findings: Five of the eight hens had sparse, focal, gross hepatic lesions typical of spotty liver disease. Histopathology of the liver showed random, focal hepatic necrosis, lymphoplasmacytic cholangitis/pericholangitis and, in one hen, severe lymphoplasmacytic cholecystitis. Campylobacter-like organisms were grown from all eight bile samples which were confirmed by PCR as Campylobacter hepaticus. The genome of C. hepaticus isolates from the outbreak were sequenced and compared to those of isolates from Australia and the United Kingdom. Phylogenetic analysis based on single nucleotide polymorphisms showed that the C. hepaticus isolates from this outbreak were most closely related to isolates from Australia. Diagnosis: Campylobacter hepaticus focal hepatic necrosis. Clinical relevance: This is the first report of an outbreak of spotty liver disease confirmed to be caused by C. hepaticus in poultry in New Zealand. Therefore infection with C. hepaticus should be considered as a differential diagnosis for mortality in laying hens around peak lay in New Zealand.

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.

Mining whole genome sequence data to efficiently attribute individuals to source populations.

Whole genome sequence (WGS) data could transform our ability to attribute individuals to source populations. However, methods that efficiently mine these data are yet to be developed. We present a minimal multilocus distance (MMD) method which rapidly deals with these large data sets as well as methods for optimally selecting loci. This was applied on WGS data to determine the source of human campylobacteriosis, the geographical origin of diverse biological species including humans and proteomic data to classify breast cancer tumours. The MMD method provides a highly accurate attribution which is computationally efficient for extended genotypes. These methods are generic, easy to implement for WGS and proteomic data and have wide application.

(-)-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.

An antibiotic depleted microbiome drives severe Campylobacter jejuni-mediated Type 1/17 colitis, Type 2 autoimmunity and neurologic sequelae in a mouse model.

The peripheral neuropathy Guillain-Barré Syndrome can follow Campylobacter jejuni infection when outer core lipooligosaccharides induce production of neurotoxic anti-ganglioside antibodies. We hypothesized that gut microbiota depletion with an antibiotic would increase C. jejuni colonization, severity of gastroenteritis, and GBS. Microbiota depletion increased C. jejuni colonization, invasion, and colitis with Type 1/17 T cells in gut lamina propria. It also stimulated Type 1/17 anti-C. jejuni and -antiganglioside-antibodies, Type 2 anti-C. jejuni and -antiganglioside antibodies, and neurologic phenotypes. Results indicate that both C. jejuni strain and gut microbiota affect development of inflammation and GBS and suggest that probiotics following C. jejuni infection may ameliorate inflammation and autoimmune disease.

The Rho-Independent Transcription Terminator for the porA Gene Enhances Expression of the Major Outer Membrane Protein and Campylobacter jejuni Virulence in Abortion Induction.

Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. Its porA gene encodes the major outer membrane protein (MOMP) that is abundantly expressed and has important physiological functions, including a key role in systemic infection and abortion induction in pregnant animals. Despite the importance of porA in C. jejuni pathogenesis, mechanisms modulating its expression levels remain elusive. At the 3' end of the porA transcript, there is a Rho-independent transcription terminator (named T porA in this study). Whether T porA affects the expression and function of MOMP remains unknown and is investigated in this study. Green fluorescent protein (GFP) fusion constructs with the porA promoter at the 5' end and an intact T porA or no T porA at the 3' end of the gfp coding sequence revealed that both the transcript level of gfp and its fluorescence signals were more than 2-fold higher in the construct with T porA than in the one without T porA Real-time quantitative PCR (qRT-PCR) analysis of the porA mRNA and immunoblot detection of MOMP in C. jejuni showed that disruption of T porA significantly reduced the porA transcript level and the expression of MOMP. An mRNA decay assay demonstrated that disruption of T porA resulted in a shortened transcript half-life of the upstream gfp or porA gene, indicating that T porA enhances mRNA stability. In the guinea pig model, the C. jejuni construct with an interrupted T porA was significantly attenuated in abortion induction. Together, these results indicate that T porA enhances the expression level of MOMP by stabilizing its mRNA and influences the virulence of C. jejuni.

A review of the novel thermophilic Campylobacter, Campylobacter hepaticus, a pathogen of poultry.

In 2015, a novel thermophilic Campylobacter was isolated from cases of spotty liver disease in laying hens in the UK. In 2016, it was isolated from laying hens in Australia where it was formally named Campylobacter hepaticus and confirmed as the cause of spotty liver disease. It has also been isolated from laying hens in America. It is fastidious, grows slowly on first isolation and does not grow on media used to routinely isolate Campylobacter. Spotty liver disease is an acute, randomly distributed, focal, necrotic hepatitis causing mortality in up to 10% of a flock and a 10%-15% fall in egg production. It occurs mainly in free-range hens or hens reared on the ground at around the time of peak lay. The incidence of the disease has increased in countries where there is an increase in keeping free-range laying hens. It is similar to the condition avian vibrionic hepatitis which was reported in America, Europe and Australasia in the 1950s to 1970s and the agent isolated from cases of avian vibrionic hepatitis and C. hepaticus appear to be very similar. It is not known if C. hepaticus is zoonotic but whole genome sequencing shows that it is most closely related to the known zoonotic campylobacters Campylobacter jejuni and Campylobacter coli. Human exposure to C. hepaticus is likely through similar exposure routes. Analysis of the whole genome showed a reduction in the genes for iron metabolism compared to C. jejuni. A requirement for iron was confirmed as it showed reduced growth in an iron depletion assay and this may explain its tissue tropism. With a move towards free-range egg production in many countries, the incidence of C. hepaticus hepatitis is likely to increase, but the identification of the causal agent will provide opportunities for the development of control methods.

Protease Activity of Campylobacter jejuni HtrA Modulates Distinct Intestinal and Systemic Immune Responses in Infected Secondary Abiotic IL-10 Deficient Mice.

Even though human Campylobacter jejuni infections are progressively increasing worldwide, the underlying molecular mechanisms of pathogen-host-interactions are still not fully understood. We have recently shown that the secreted serine protease HtrA plays a key role in C. jejuni cellular invasion and transepithelial migration in vitro, and is involved in the onset of intestinal pathology in murine infection models in vivo. In the present study, we investigated whether the protease activity of HtrA had an impact in C. jejuni induced acute enterocolitis. For this purpose, we perorally infected secondary abiotic IL-10-/- mice with wildtype C. jejuni strain NCTC11168 (11168WT) or isogenic bacteria carrying protease-inactive HtrA with a single point mutation at S197A in the active center (11168HtrA-S197A). Irrespective of the applied pathogenic strain, mice harbored similar C. jejuni loads in their feces and exhibited comparably severe macroscopic signs of acute enterocolitis at day 6 postinfection (p.i.). Interestingly, the 11168HtrA-S197A infected mice displayed less pronounced colonic apoptosis and immune cell responses, but enhanced epithelial proliferation as compared to the 11168WT strain infected controls. Furthermore, less distinct microscopic sequelae in 11168HtrA-S197A as compared to parental strain infected mice were accompanied by less distinct colonic secretion of pro-inflammatory cytokines such as MCP-1, IL-6, TNF, and IFN-γ in the former as compared to the latter. Strikingly, the S197A point mutation was additionally associated with less pronounced systemic pro-inflammatory immune responses as assessed in serum samples. In conclusion, HtrA is a remarkable novel virulence determinant of C. jejuni, whose protease activity is not required for intestinal colonization and establishment of disease, but aggravates campylobacteriosis by triggering apoptosis and pro-inflammatory immune responses.

Campylobacter jejuni capsule types in a Peruvian birth cohort and associations with diarrhoeal disease severity.

Campylobacter jejuni is a leading cause of bacterial diarrhoea worldwide. The objective of this study was to examine the association between C. jejuni capsule types and clinical signs and symptoms of diarrhoeal disease in a well-defined birth cohort in Peru. Children were enrolled in the study at birth and followed until 2 years of age as part of the Malnutrition and Enteric Infections birth cohort. Associations between capsule type and clinical outcomes were assessed using the Pearson's χ2 and the Kruskal-Wallis test statistics. A total of 318 C. jejuni samples (30% from symptomatic cases) were included in this analysis. There were 22 different C. jejuni capsule types identified with five accounting for 49.1% of all isolates. The most common capsule types among the total number of isolates were HS4 complex (n = 52, 14.8%), HS5/31 complex (n = 42, 11.9%), HS15 (n = 29, 8.2%), HS2 (n = 26, 7.4%) and HS10 (n = 24, 6.8%). These five capsule types accounted for the majority of C. jejuni infections; however, there was no significant difference in prevalence between symptomatic and asymptomatic infection (all p > 0.05). The majority of isolates (n = 291, 82.7%) were predicted to express a heptose-containing capsule. The predicted presence of methyl phosphoramidate, heptose or deoxyheptose on the capsule was common.

Investigating the Suitability of a Laboratory Mouse Model to Study the Pathogenesis of Abortifacient Campylobacter jejuni.

The aim of this study was to assess whether pregnant mice represent a useful model to study the reproductive pathology of Campylobacter jejuni IA3902 using the end point of positive microbial culture of the organism from the fetoplacental unit. Pregnant BALB/c and CD-1 mice (14 days' gestation) were inoculated orally and intraperitoneally (IP) with 1 × 109 colony-forming units/ml of C. jejuni IA3902. The organism was recovered by microbial culture from the fetoplacental unit in 10 of 10 BALB/c and 10 of 10 CD-1 IP-inoculated pregnant mice and in 29% (2/7) BALB/c and 38% (3/8) CD-1 orally inoculated pregnant mice. Gross reproductive lesions included necrosuppurative placentitis, fetal resorption, intrauterine fetal death, stillborn pups (dead neonates), and multifocal hepatitis. Histological changes consisted of locally extensive neutrophilic and necrotizing placentitis with intralesional bacterial colonies of C. jejuni, ulcerative endometritis, random multifocal hepatitis, and rare cholecystitis. Immunohistochemistry for the major outer membrane protein of C. jejuni revealed moderate to large numbers of the organism at the periphery of the placental discs, within trophoblasts and extracellularly, with invasion into the placental disc largely via the vascular network. The organism is trophic for neutral mucin, iron, and L-fucose within the murine placenta. C. jejuni IA3902 has affinity for the murine reproductive tract, specifically the fetoplacental unit, where it results in a necrotizing placentitis with positive microbial recovery after both IP and oral challenge in BALB/c and CD-1 pregnant mice.

The epidemiology of non-typhoidal Salmonella gastroenteritis and Campylobacter gastroenteritis in pediatric inpatients in northern Taiwan.

BACKGROUND: Campylobacter and Non-typhoidal Salmonella (NTS) are the two most common bacterial pathogens associated with acute gastroenteritis in children. This study aims to elucidate the epidemiology of Campylobacter and NTS gastroenteritis and develop a scoring system to differentiate them. MATERIALS AND METHODS: This retrospective study enrolled 886 children ≤18 years of age, hospitalized due to acute gastroenteritis with stool culture-proven Campylobacter or NTS infection from July 2012 to December 2015. Pearson's chi-square test and multivariate logistic regression were used to compare clinical manifestations and laboratory data. Receiver operating characteristic curves were plotted to evaluate the scoring system. RESULTS: Seasonality was found in NTS gastroenteritis from May to September, but no seasonality in Campylobacter gastroenteritis. Campylobacter jejuni and Salmonella serogroup B were the most common pathogens. The median ages were 68.2 and 18.5 months and the incidence rates of bacteremia were 0.6% and 7.1% in the Campylobacter and NTS groups, respectively. Salmonella serogroup C2 infection had the highest risk of bacteremia (OR: 5.9, 95% CI: 2.8-12.7, p < 0.001). Multivariate analysis showed significant differences in sex, age, fever, dehydration, immature WBC, CRP and Na between the two groups. A score of ≥2 points indicated Campylobacter gastroenteritis, with sensitivity 75%, specificity 77%. The positive and negative predictive values were of 73.3% and 93.9% after validation. CONCLUSION: Campylobacter gastroenteritis is associated with older age and male sex, while NTS gastroenteritis is associated with moderate to severe dehydration and bacteremia. Salmonella serogroup C2 infection has the highest risk of bacteremia.

[Systematic Review of the Burden of Campylobacter-associated Disease]. / Systematischer Review zur Krankheitslast durch Campylobacter spp.

Bacteria of the genus Campylobacter spp. are one of the most common causes of gastroenteritis and can lead to serious sequelae. Several studies have estimated the disease burden of Campylobacter spp. with the quantitative metric of disability-adjusted life years (DALY). The aim of this systematic review is to give an overview of the information available about different countries and periods for which DALYs were calculated and how the different results are comparable. One of the most important transmission pathways for Campylobacter spp. is food. Therefore, special attention was given to studies that only estimated the foodborne disease burden of Campylobacter bacteria. With a systematic search for the period 1/1996-6/2016, one worldwide and 21 country-specific publications of the WHO were identified. Because of the different methods and the quality of the different data sets, the estimated results of all Campylobacter health outcomes of the country-specific studies vary from 0.4 DALYs per 100000 people in France to 109 DALY per population in Poland. The calculation of the attributable foodborne disease burden was based on the estimations of the incidences of all Campylobacter health outcomes with the associated uncertainty for each result. So the estimations of the foodborne disease burden show a large range from 0.5 DALYs per 100000 people in Greek to 21.2 DALYs per 100000 people in New Zealand. This span can only be partially explained by the country-specific variability in the food production, the consumption behavior and the incidence of Campylobacter bacteria.

Synthesis of the Core Oligosaccharides of Lipooligosaccharides from Campylobacter jejuni: A Putative Cause of Guillain-Barré Syndrome.

The chemical synthesis of the highly branched core oligosaccharides of lipooligosaccharides (LOSs) found in Campylobacter jejuni, which causes Guillain-Barré syndrome by a preceding infection, is described. The target LOS mimics, consisting of eight or nine monosaccharides, were classified into three groups as key building blocks: ganglioside-core tetra-/pentasaccharides (GM1-/GD1a-like), l-glycero-d-manno-heptose-containing trisaccharides, and 3-deoxy-d-manno-2-octulosonic acid (KDO) residues. These synthetic fragments were obtained from commercially available monosaccharides. Less obtainable l-glycero-d-manno-heptose and KDO residues, as key components of the LOSs, were synthesized from p-methoxyphenyl d-mannoside and di-O-isopropylidene-protected d-mannose, respectively. The synthesis of α-KDO glycoside, as one of the most difficult stereocontrolled glycosidic constructions, was achieved by treating a 2,3-ene derivative of KDO with phenylselenyl trifluoromethanesulfonate as a suitable α-directing reagent. All synthetic blocks were constructed through a convergent synthetic route, which resulted in the first synthesis of structurally challenging LOS core glycans containing ganglioside GM1 and GD1a-core sequences.

Epidemiologic characteristics and clinical course of children with acute gastroenteritis hospitalized in the Department of Pediatric Infectious Diseases and Hepatology at John Paul II Hospital in Krakow

INTRODUCTION: Acute gastroenteritis (AGE) is considered one of the most common reasons for hospitalization and the third leading cause of death related to infectious diseases in children. The incidence and prevalence of campylobacteriosis is lower in Poland than in other parts of the European Union. THE AIM OF THE STUDY: The aim of the study was to investigate the epidemiology and clinical features of AGE in hospitalized children. MATERIALS AND METHODS: The study population comprised 462 consecutive patients with AGE, hospitalized in the Department of Pediatric Infectious Diseases and Hepatology at John Paul II Hospital in Krakow during 2016. After admission in the hospital, the patients' stool samples were collected and tested for viral or bacterial pathogens. The specimens were analyzed using classical cultural methods and qualitative immunochromatographic assays for pathogens screening. The patients' age, sex, etiological factor, seasonal distribution, hospital length of stay and symptoms of disease were collected retrospectively. RESULTS: The median age of AGE patients was 3.0 years [1.5-5.5]. Eighty percent of all AGE cases occurred in patients under 5 years of age (p<0.001). Rotavirus was the leading cause of AGE and Campylobacter was the most common bacterial pathogen (p=0.001, p=0.05 respectively). The average length of hospital stay was 3.1 ± 1.6 days. The longest hospitalization stays were related to patients with enteropathogenic Escherichia coli and Salmonella (p<0.001 for all). A seasonal pattern was observed for etiological factors of AGE (p<0.001). Fever, diarrhea and pathological stool contaminations occurred more frequently in patients with bacterial AGE (p<0.001 for all). SUMMARY AND CONCLUSIONS: This study showed that routine diagnosis of Campylobacter in all children with AGE is associated with a higher than reported prevalence of campylobacteriosis.

Host cellular unfolded protein response signaling regulates Campylobacter jejuni invasion.

Campylobacter jejuni is a major cause of bacterial foodborne illness in humans worldwide. Bacterial entry into a host eukaryotic cell involves the initial steps of adherence and invasion, which generally activate several cell-signaling pathways that induce the activation of innate defense systems, which leads to the release of proinflammatory cytokines and induction of apoptosis. Recent studies have reported that the unfolded protein response (UPR), a system to clear unfolded proteins from the endoplasmic reticulum (ER), also participates in the activation of cellular defense mechanisms in response to bacterial infection. However, no study has yet investigated the role of UPR in C. jejuni infection. Hence, the aim of this study was to deduce the role of UPR signaling via induction of ER stress in the process of C. jejuni infection. The results suggest that C. jejuni infection suppresses global protein translation. Also, 12 h of C. jejuni infection induced activation of the eIF2α pathway and expression of the transcription factor CHOP. Interestingly, bacterial invasion was facilitated by knockdown of UPR-associated signaling factors and treatment with the ER stress inducers, thapsigargin and tunicamycin, decreased the invasive ability of C. jejuni. An investigation into the mechanism of UPR-mediated inhibition of C. jejuni invasion showed that UPR signaling did not affect bacterial adhesion to or survival in the host cells. Further, Salmonella Enteritidis or FITC-dextran intake were not regulated by UPR signaling. These results indicated that the effect of UPR on intracellular intake was specifically found in C. jejuni infection. These findings are the first to describe the role of UPR in C. jejuni infection and revealed the participation of a new signaling pathway in C. jejuni invasion. UPR signaling is involved in defense against the early step of C. jejuni invasion and thus presents a potential therapeutic target for the treatment of C. jejuni infection.