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Background Various observational studies have examined a potential relationship between Helicobacter pylori colonization and inflammatory bowel diseases (IBDs); however, results are inconclusive. This systematic review evaluates articles reporting an association between human H. pylori colonization and IBD. Methods A systematic search of studies was conducted to evaluate a possible relationship between H. pylori colonization and IBD. Seven databases and different types of gray literature were searched. After screening for relevant articles, selection and data extraction were done. After that, the data were analyzed, and pooled odds ratios (ORs) were calculated, using meta-analysis. Heterogeneity, sensitivity, and subgroups analyses were conducted. Funnel plots followed by Begg and Egger tests were done to assess the publication bias. Results Among 58 studies, including 13,549 patients with IBD and 506,554 controls, the prevalence of H. pylori colonization was 22.74% and 36.30%, respectively. A significant negative association was observed between H. pylori colonization and IBD (pooled OR: 0.45, 95% confidence interval 0.39-0.53, P≤0.001). The random-effect model showed significant statistical heterogeneity in the included studies (I=79%). No publication bias was observed. Among subgroups, ORs were notably different when the data were stratified by the age difference between patient and control group, and by study regions and/or continent. Finally, the meta-regression analysis showed significant results, in terms of the age difference and region variables. Conclusions In this meta-analysis, all statistical data support the theory that H. pylori has a protective role in IBD. However, more primary studies using proper methodology are needed to confirm this association.

Microbial induced acid corrosion is accounted for ~40 % of the degradation of subsurface wastewater infrastructure globally. While fundamental process understanding has increased significantly within the last decades, to date no sustainable building material exists, which meets the long-term requirements in such aggressive and corrosive environments. This work describes a novel model based on field studies, conducted in various Austrian sewer networks, intertwining biological, mineralogical and hydro-chemical factors. Additionally, an extensive field testing campaign over the duration of 18 months, conducted on different geopolymer concretes (GPC), particularly designed for the latter environments will be presented. Innovative GPCs were tested regarding their microstructural behavior, microbial accessibility and hydro-chemical alterations over time and compared to commercially produced cement based products, including OPC and CAC concretes. Additionally, the system specific environmental parameters, such as relevant gas concentrations (H2S, CO2, CH4), relative humidity and temperature were constantly monitored.

Microbial induced concrete corrosion (MICC) is recognized as one of the main degradation mechanisms of subsurface infrastructure worldwide, raising the demand for sustainable construction materials in corrosive environments. This review aims to summarize the key research progress acquired during the last decade regarding the understanding of MICC reaction mechanisms and the development of durable materials from an interdisciplinary perspective. Special focus was laid on aspects governing concrete - micoorganisms interaction since being the central process steering biogenic acid corrosion. The insufficient knowledge regarding the latter is proposed as a central reason for insufficient progress in tailored material development for aggressive wastewater systems. To date no cement-based material exists, suitable to withstand the aggressive conditions related to MICC over its entire service life. Research is in particular needed on the impact of physiochemical material parameters on microbial community structure, growth characteristics and limitations within individual concrete speciation. Herein an interdisciplinary approach is presented by combining results from material sciences, microbiology, mineralogy and hydrochemistry to stimulate the development of novel and sustainable materials and mitigation strategies for MICC. For instance, the application of antibacteriostatic agents is introduced as an effective instrument to limit microbial growth on concrete surfaces in aggressive sewer environments. Additionally, geopolymer concretes are introduced as highly resistent in acid environments, thus representing a possible green alternative to conventional cement-based construction materials.

Campylobacter species are pathogens of both humans and animals and show a worldwide distribution. Campylobacter jejuni and C. coli are the most common causes of human gastroenteritis. The acute clinical illness ranges from mild watery diarrhea in developed countries to severe inflammatory diarrhea characterized by abdominal pain, fever, nausea, and bloody stool in developing countries. Major medical complications of C. jejuni infections include Guillain-Barre syndrome (GBS) and reactive arthritis. Campylobacter are fastidious organisms and C. jejuni does not replicate outside a warm-blooded host. However, the infectious dose is low (

Background Helicobacter pylori are successful colonizers of the human gastric mucosa. Colonization increases the risk of peptic ulcer disease and adenocarcinoma. However, potential benefits of H. pylori colonization include protection against early-onset asthma and against gastrointestinal infections. Campylobacter jejuni are a leading cause of bacterial diarrhea and complications include Guillain-Barré syndrome. Here, we describe the development of reliable serological assays to detect antibodies against those two bacteria in Rhesus macaques and investigated their distribution within a social group of monkeys. Methods Two cohorts of monkeys were analyzed. The first cohort consisted of 30 monkeys and was used to establish an enzyme-linked immunosorbent assay (ELISA) for H. pylori antibodies detection. To evaluate colonization of those macaques, stomach biopsies were collected and analyzed for the presence of H. pylori by histology and culture. C. jejuni ELISAs were established using human serum with known C. jejuni antibody status. Next, plasma samples of the 89 macaques (Cohort 2) were assayed for antibodies and then statistically analyzed. Results An H. pylori IgG ELISA, which was 100% specific and 93% sensitive, was established. In contrast, the IgA ELISA was only 82% specific and 61% sensitive. The CagA IgG assay was 100% sensitive and 61% of the macaques were positive. In cohort 2, 62% macaques were H. pylori sero-positive and 52% were CagA positive. The prevalence of H. pylori IgG and CagA IgG increased with monkey age as described for humans. Of the 89 macaques 52% showed IgG against C. jejuni but in contrast to H. pylori, the sero-prevalence was not associated with increasing age. However, there was a drop in the IgG (but not in IgA) mean values between infant and juvenile macaques, similar to trends described in humans. Conclusions Rhesus macaques have widespread exposure to H. pylori and C. jejuni, reflecting their social conditions and implying that Rhesus macaques might provide a model to study effects of these two important human mucosal bacteria on a population.