Andrea Santos

Cytokine expression in pediatric Helicobacter pylori infection

ABSTRACT Helicobacter pylori infection is one of the most common gastrointestinal infections worldwide and almost invariably causes chronic gastritis in the infected host. A predominant Th1 profile has been demonstrated in H. pylori-infected mucosa from adults, but no previous study has evaluated in situ cytokine expression in children. We therefore examined expression of proinflammatory, anti-inflammatory, and regulatory cytokines by immunohistochemistry in cryopreserved antral biopsy specimens from 10 H. pylori-infected and 10 uninfected children and correlated expression of cytokines with histology scores. Concomitant expression of interleukin-8 (IL-8), gamma interferon (IFN-γ), IL-4, transforming growth factor β, and tumor necrosis factor alpha was seen in 8/10 H. pylori-infected cases and in 5/10 noninfected cases; all H. pylori-infected subjects showed staining for at least two of the cytokines. The proportion of epithelial cytokine-specific staining did not differ significantly between the groups, either in surface or glandular epithelium. Furthermore, no significant differences were noticed between intraepithelial or lamina propria lymphocyte staining in the groups. There was, however, a tendency of higher numbers of IFN-γ- and IL-8-positive cells in the H. pylori-infected group. IFN-γ and IL-8 lamina propria lymphocyte expression correlated significantly with antrum chronic inflammation, but there was no correlation between histology scores and epithelial cytokine expression. When the same techniques were used, the cytokine response appeared to be smaller in H. pylori-infected children than in adults, and there was no clear Th1 dominance. These results therefore suggest a different mucosal immunopathology in children. It remains to be determined whether the gastric immune response is downregulated in children with H. pylori infection and whether this is relevant to the outcome of infection.

Human, food and animal Campylobacter spp. isolated in Portugal: High genetic diversity and antibiotic resistance rates

Infections by Campylobacter jejuni and Campylobacter coli are considered the major cause of bacterial gastroenteritis in humans, with food being the main source of infection. In this study, a total of 196 Campylobacter strains (125 isolates from humans, 39 from retail food and 32 from food animal sources) isolated in Portugal between 2009 and 2012 were characterised by multilocus sequence typing (MLST) and flaA short variable region (SVR) typing. Susceptibility to six antibiotics as well as the mechanisms underlying antibiotic resistance phenotypes was also studied. Based on MLST typing, C. coli strains were genetically more conserved, with a predominant clonal complex (CC828), than C. jejuni strains. In contrast, C. coli isolates were genetically more variable than C. jejuni with regard to flaA-SVR typing. A high rate of resistance was observed for quinolones (100% to nalidixic acid, >90% to ciprofloxacin) and, in general, resistance was more common among C. coli, especially for erythromycin (40.2% vs. 6.7%). In addition, most isolates (86%) were resistant to multiple antimicrobial families. Besides the expected point mutations associated with antibiotic resistance, detected polymorphisms in the cmeABC locus likely play a role in the multiresistant phenotype. This study provides for the first time an overview of the genetic diversity of Campylobacter strains from Portugal. It also shows a worrying antibiotic multiresistance rate and the emergence of Campylobacter strains resistant to antibiotics of human use.

Helicobacter pullorum Isolated from Fresh Chicken Meat: Antibiotic Resistance and Genomic Traits of an Emerging Foodborne Pathogen

ABSTRACT Meat and meat products are important sources of human intestinal infections. We report the isolation of Helicobacter pullorum strains from chicken meat. Bacteria were isolated from 4 of the 17 analyzed fresh chicken meat samples, using a membrane filter method. MIC determination revealed that the four strains showed acquired resistance to ciprofloxacin; one was also resistant to erythromycin, and another one was resistant to tetracycline. Whole-genome sequencing of the four strains and comparative genomics revealed important genetic traits within the H. pullorum species, such as 18 highly polymorphic genes (including a putative new cytotoxin gene), plasmids, prophages, and a complete type VI secretion system (T6SS). The T6SS was found in three out of the four isolates, suggesting that it may play a role in H. pullorum pathogenicity and diversity. This study suggests that the emerging pathogen H. pullorum can be transmitted to humans by chicken meat consumption/contact and constitutes an important contribution toward a better knowledge of the genetic diversity within the H. pullorum species. In addition, some genetic traits found in the four strains provide relevant clues to how this species may promote adaptation and virulence.

Ulcerogenic profile of helicobacter pylori pediatric strains: a contribution to get insight into the virulence of the Bacteria

no.: WS1.1 HELICOBACTER PYLORI INFECTION AND MARKERS OF GASTRIC CANCER RISK IN ALASKA NATIVE PEOPLE J. Keck,* K. Miernyk,* L. Bulkow,* J. Kelly, B. McMahon, F. Sacco, T. Hennessy* and M. G. Bruce* *Centers for Disease Control and Prevention, Anchorage, AK, USA; Alaska Native Tribal Health Consortium, Anchorage, AK, USA Background: Alaska Native gastric cancer incidence and mortality rates are 3 to 4-times higher than general US population rates. We evaluated pepsinogen I, pepsinogen I/II ratio, anti-H. pylori and CagA antibodies, and blood group to determine their association with gastric cancer development in Alaska Native people. Methods: We conducted a retrospective case-control study that matched gastric cancers reported to the Alaska Native Tumor Registry from 1969–2008 to three controls on known demographic risk factors for H. pylori infection, using previously collected sera from the Alaska Area Specimen Bank. Conditional logistic regression evaluated the associations between serum markers and gastric cancer. Results: We included 122 gastric cancer cases with sera predating cancer diagnosis (mean = 13 years) and 346 matched controls. One hundred and twelve cases (91.8%) and 285 controls (82.4%) had evidence of previous or ongoing H. pylori infection as measured by anti-H. pylori antibodies. Gastric cancer cases had 2.63-fold increased odds of positive anti-H. pylori antibodies compared with their matched controls (p = .01). In a multivariate model, non-cardia gastric cancer (n = 94) was associated with anti-H. pylori antibodies (adjusted OR 3.92, p = .004) and low pepsinogen I (aOR 6.04, p = .04). We found no association between gastric cancer and blood group, anti-CagA antibodies, or pepsinogen I/II ratio. Conclusions: Alaska Native people with gastric cancer had increased odds of previous H. pylori infection. Low pepsinogen I might function as a pre-cancer marker for non-cardia cancer. Impact: Future research to identify Alaska Native individuals with increased gastric cancer risk includes H. pylori genotype and host characteristic studies. Abstract no.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, Chinano.: WS1.2 CLUSTERING OF HELICOBACTER PYLORI STRAINS FROM GASTRIC CANCER C. Wang, S. Zhan and Q. Dong Qingdao Municipal Hospital, Qingdao City, China Genetic differences between strains play an important role in the determination of clinical outcomes of Helicobacter pylori infection. This study aimed to determine the sequencing types of H. pylori strains from gastric cancer. Materials and Methods: Twenty-two strains of H. pylori were enrolled, including 12 strains from patients with gastric cancer. MLST was used to determine the sequencing type. Results: The seven genetic loci of H. pylori were PCR amplified and sequenced. Those sequences of the seven genes were concatenated, and aligned with the sequences of strains from Europe (5), Africa (5), Asia (5) and other parts of China (16) extracted from the MLST database. A neighbour-joining tree with a kimura 2-parameter model was subsequently constructed. The results showed that all 22 strains, as well as Asia strains from database fell into the HpEastAsia haplogroup which could divided into two groups, groups I and II. Group I consisted of seven cancer strains but only one non-cancer strain of H. pylori, in addition to five strains form database. Fisher’s exact test revealed a statistically significant difference (p = .027). Discussion and Conclusion: The clustering of cancer strains of H. pylori is consistent with a recent report showing that the phylogeopraphic origin of H. pylori is a determinant of gastric cancer risk. This may reflect the consequence of long-term interaction of the bacterium with individual hosts of different genetic ground. The results suggested that the sequencing types could possibly be used to predict the clinical outcomes of H. pylori infection. Abstract no.: WS1.3 LACK OF ASSOCIATION BETWEEN GENE POLYMORPHISMS OF ANGIOTENSIN CONVERTING ENZYME, NOD-LIKE RECEPTOR 1, TOLL-LIKE RECEPTOR 4 AND FAS/FASL WITH THE PRESENCE OF HELICOBACTER PYLORI-INDUCED PREMALIGNANT GASTRIC LESIONS AND GASTRIC CANCER IN CAUCASIANS J. Kupcinskas,* T. Wex, J. Bornschein, M. Selgrad, M. Leja, L. Jonaitis* and P. Malfertheiner *Department of Gastroenterology, Lithuanian University of Health Sciences, Kaunas, Lithuania; Clinic of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, Magdeburg, Germany; Faculty of Medicine, University of Latvia, Digestive Diseases Center, Hospital Lizeners, Riga, Latvia Background: Several polymorphisms of genes involved in the immunological recognition of Helicobacter pylori and regulating apoptosis and proliferation have been linked to gastric carcinogenesis, however reported data are partially conflicting. The aim of our study was to evaluate potential associations between the presence of gastric cancer (GC) and high risk atrophic gastritis (HRAG) and polymorphisms of genes encoding Angiotensin converting enzyme (ACE), Nod-like receptor 1 (NOD1), Toll-like receptor 4 (TLR4) and FAS/FASL. Methods: Gene polymorphisms were analyzed in 574 subjects (GC: n = 114; HRAG: n = 222, controls: n = 238) of Caucasian origin. ACE I/D (rs4646994), NOD1 796G>A (rs5743336), TLR4 3725G>C (rs11536889), FAS 1377G>A (rs2234767), FAS 670A>G (rs1800682) and FASL 844T>C (rs763110) were genotyped by different PCR approaches and RFLP analysis. Results: Frequencies of genotypes in our study are similar to the data reported on subjects of Caucasian ethnicity. There was a tendency for NOD1 796G/G genotype to be associated with increased risk of HRAG (62.4% vs 54.5% in controls, p = .082). FAS 670G/G genotype was more frequent in HRAG when compared to controls, 23.9% and 17.2% respectively, however it failed to reach significance level (p = .077). We did not find any significant associations for all examined polymorphism in relation to GC or HRAG. NOD1 796G>A and TLR4 3725G>C gene polymorphisms were also not linked with Helicobacter pylori seropositivity status. Conclusions: ACE, NOD1, TRL4 and FAS/FASL gene polymorphisms are not linked with gastric carcinogenesis in Caucasians, and therefore they should not be considered as potential biomarkers for identifying individuals with higher risk for GC. Abstract no.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerlandno.: WS1.4 ATROPHIC GASTRITIS BY THE OLGA STAGES AND HELICOBACTER CAGA SEROPOSITIVITY IN GASTRIC CANCER T. Vorobjova,* K. Kull,* H. Saar,* R. Labotkin,* A. Zimmermann and H. Maaroos* *University of Tartu, Tartu, Estonia; University of Bern, Bern, Switzerland Introduction: Operative Link on Gastritis Assessment (OLGA) express extent of gastric atrophy in terms of gastritis staging, which severity should be related to gastric cancer. Aim: To study how the OLGA stages of atrophic gastritis are associated with the morphological type, and Helicobacter pylori CagA positivity in gastric cancer. Patients: Twenty two gastric carcinoma patients (8 male, 14 female; mean age 64 ± 12) were operated on. The intestinal type of carcinoma was diagnosed in 12, diffuse in 8, mixed and indeterminate type in two cases (according to Lauren). Methods: Gastric mucosa samples (altogether up to 15) from the each operation specimen were stained with haematoxylin and eosin. Tissue material was received from the primary tumour and the tumour surrounding antral and corpus mucosa. The stage of atrophy by OLGA was established by combining the extent of histologically scored atrophy with the topography of atrophy. IgG antibodies to H. pylori cell surface proteins and CagA were evaluated using ELISA. Results: Of the 12 patients with intestinal type of gastric cancer eight had OLGA stage III or IV, four had OLGA stage II and nobody had OLGA stage I (p < .05). Five patients with diffuse cancer had OLGA stage I and II, two had III stage and one had IV stage. There was no association of OLGA stage or cancer type with CagA positivity. Conclusion: Gastric cancer patients represented all stages of gastric atrophy from OLGA stage I to OLGA stage IV which was not associated with cancer type and CagA seropositivity. a 2011 Blackwell Publishing Ltd, Helicobacter 16 (Suppl. 1): 77–143 79 WS1 Gastric Cancer