Use of Fourier-Transform Infrared Spectroscopy (FT-IR) for Monitoring Experimental Helicobacter pylori Infection and Related Inflammatory Response in Guinea Pig Model

Infections due to Gram-negative bacteria Helicobacter pylori may result in humans having gastritis, gastric or duodenal ulcer, and even gastric cancer. Investigation of quantitative changes of soluble biomarkers, correlating with H. pylori infection, is a promising tool for monitoring the course of infection and inflammatory response. The aim of this study was to determine, using an experimental model of H. pylori infection in guinea pigs, the specific characteristics of infrared spectra (IR) of sera from H. pylori infected (40) vs. uninfected (20) guinea pigs. The H. pylori status was confirmed by histological, molecular, and serological examination. The IR spectra were measured using a Fourier-transform (FT)-IR spectrometer Spectrum 400 (PerkinElmer) within the range of wavenumbers 3000–750 cm⁻¹ and converted to first derivative spectra. Ten wavenumbers correlated with H. pylori infection, based on the chi-square test, were selected for a K-nearest neighbors (k-NN) algorithm. The wavenumbers correlating with infection were identified in the W2 and W3 windows associated mainly with proteins and in the W4 window related to nucleic acids and hydrocarbons. The k-NN for detection of H. pylori infection has been developed based on chemometric data. Using this model, animals were classified as infected with H. pylori with 100% specificity and 97% sensitivity. To summarize, the IR spectroscopy and k-NN algorithm are useful for monitoring experimental H. pylori infection and related inflammatory response in guinea pig model and may be considered for application in humans.     

Proteomic Helicobacter pylori biomarkers discriminative of low-grade gastric MALT lymphoma and duodenal ulcer

To date no reliable diagnostic method exists to predict, among the very large and clinically heterogeneous group of Helicobacter pylori‐infected patients, the extremely small group at risk for developing low‐grade gastric MALT lymphoma (LG‐MALT). Search of proteomic biomarkers holds promise for the classification of the H. pylori strains with regard to this severe clinical outcome. In the present study 69 H. pylori strains isolated from patients with two different H. pylori‐associated diseases, duodenal ulcer (DU, n=29) and LG‐MALT (n=40) were used. Protein expression patterns of the strains were analyzed by using the high‐throughput methodology SELDI. Selected proteins were purified by means of chromatographic and electrophoretic methods in view of further sequencing by LC‐MS/MS. Univariate analysis (Mann–Whitney test) of the protein expression patterns generated nine significant biomarkers that can discriminate between H. pylori strains from patients with DU and LG‐MALT. These biomarkers are of low molecular weight, ranging from 6 to 26.6 kDa. Among them, two are overexpressed in LG‐MALT strains and seven – in DU strains. Two biomarker proteins, one overexpressed in LG‐MALT strains (13.2 kDa) and another one – overexpressed in DU strains (26.6 kDa), were purified to homogeneity and identified by using LC‐MS/MS as a 50S ribosomal protein L7/L12 and a urease subunit, respectively. These biomarkers can be included in novel protein arrays for the differential diagnosis of H. pylori‐associated clinical outcomes.     

胃复康颗粒通过NLRP3炎性小体通路改善Hp胃炎的作用

目的：探讨乳酸菌素对幽门螺杆菌（Helicobacter pylori,H. pylori）感染胃炎小鼠炎症和肠道菌群的影响。方法：通过口服H. pylori混悬液制备H. pylori感染小鼠模型。将H. pylori感染成功的小鼠随机分为模型组和乳酸菌素组,进行干预4周。革兰氏染色、Warthin-Starry银染色和H. pylori免疫组化染色验证小鼠胃黏膜H. pylori的定植,HE染色观察小鼠胃黏膜组织病理学改变,免疫组化法测定小鼠胃黏膜iNOS、IL-1β和3-Nitrotyrosine的表达,16S rRNA测序分析肠道菌群结构。结果：造模组小鼠H. pylori定植成功;乳酸菌素能改善H. pylori感染性胃炎小鼠胃组织病理形态;抑制胃黏膜中iNOS、IL-1β和3-Nitrotyrosine的表达。相较于H. pylori感染组,乳酸菌素组小鼠的肠道菌群组成结构具有明显差异。乳酸菌素可通过调节厚壁菌门、拟杆菌门、放线菌门和疣微菌门的组成,增加肠道菌群的多样性。在属水平上,乳酸菌素可促进g_norank_f_Muribaculaceae、阿克曼氏菌属（Akkermansia）和另枝菌属（Alistipes）等产生短链脂肪酸细菌的生长,抑制杜氏杆菌属（Dubosiella）等炎症相关细菌的增殖,改善肠道菌群组成结构。结论：乳酸菌素能够恢复由H. pylori感染破坏的肠道菌群结构,促进有益菌的增殖,降低炎症反应并缓解胃黏膜氧化损伤,对H. pylori感染性胃炎小鼠发挥保护作用。

     

Sprouting and Solid-State Bioprocessing by Rhizopus oligosporus Increase the In Vitro Antibacterial Activity of Aqueous Soybean Extracts Against Helicobacter pylori

Helicobacter pylori infection has been implicated as a major cause of gastric inflammation, peptic ulcer disease, and gastric cancer. While antibiotics have been the mainstay of current therapies for gastrointestinal disease linked to H. pylori infection, negative side-effects and antibiotic resistance issues have strengthened the need for alternative therapeutic strategies. In the search for new antimicrobial agents, much recent research has focused on the potential of dietary phenolic compounds. In this study, soybean extracts enriched for phenolic content via sprouting or solid-state bioprocessing by the dietary fungus Rhizopus oligosporus were investigated for in vitro antibacterial activity against H. pylori. Helicobacter pylori growth inhibition by soybean extracts was increased most effectively by 2 d sprouting or 2 d R. oligosporus bioprocessing. Anti-H. pylori activity was not associated with antioxidant activity, but was linked to extracts when activity of the phenolic-polymerizing enzymes guaiacol peroxidase (in sprouted soybean extracts) and laccase (in R. oligosporus-bioprocessed soybean extracts) were the highest. This suggests the potential involvement of polymeric phenolics in the anti-H. pylori activity of soybean extracts and possible mechanisms for such action are discussed.     

幽门螺杆菌球形转化的超微结构研究

延长培养时间诱导幽门螺杆菌（Ｈｐ）的球形转化，以电镜结合光镜观察了Ｈｐ的常规涂片、负染色、金属投影及超薄切片样品。发现螺杆状Ｈｐ可通过分节或芽生过程生成球形菌。少数球形Ｈｐ能进行二分裂，表明其具有存活力和繁殖力。绝大多数已呈球形Ｈｐ的陈旧培养，若更换培养基重新传代，Ｈｐ又呈螺杆状，证实作为一个群体球形Ｈｐ是可逆转的。本文也讨论了Ｈｐ球形转化在流行病学及临床方面的意义。     

Bacterial Infection and Non-Hodgkin B-Cell Lymphoma: Interactions between Pathogen,Host and the Tumor Environment

Non-Hodgkin B-cell lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms with complex etiopathology, rich symptomatology, and a variety of clinical courses, therefore requiring different therapeutic approaches. The hypothesis that an infectious agent may initiate chronic inflammation and facilitate B lymphocyte transformation and lymphogenesis has been raised in recent years. Viruses, like EBV, HTLV-1, HIV, HCV and parasites, like Plasmodium falciparum, have been linked to the development of lymphomas. The association of chronic Helicobacter pylori (H. pylori) infection with mucosa-associated lymphoid tissue (MALT) lymphoma, Borrelia burgdorferi with cutaneous MALT lymphoma and Chlamydophila psittaci with ocular adnexal MALT lymphoma is well documented. Recent studies have indicated that other infectious agents may also be relevant in B-cell lymphogenesis such as Coxiella burnettii, Campylobacter jejuni, Achromobacter xylosoxidans, and Escherichia coli. The aim of the present review is to provide a summary of the current literature on infectious bacterial agents associated with B-cell NHL and to discuss its role in lymphogenesis, taking into account the interaction between infectious agents, host factors, and the tumor environment.     

Antagonistic activities of lactobacilli against Helicobacter pylori growth and infection in human gastric epithelial cells

Lactobacilli have positive effects on bowel microflora and health in humans and animals. In this study, the antagonistic activities of Lactobacillus gasseri Chen, and L. plantarum 18 were assessed by agar plate diffusion assay and tests that determined the growth and urease activity of Helicobacter pylori cocultured with lactobacilli and the adherence of H. pylori to human gastric epithelial cells in the presence of lactobacilli. The results showed that the 2 Lactobacillus strains had significant anti-H.pylori activity, and this activity may be contributed by the cell-free supernatants (CFS) of lactobacilli and live Lactobacillus strains in vitro. The antagonistic activity of the CFS against H. pylori depended on the pH and the presence of metabolites, such as organic acids and proteases. Our results also indicated that 2 Lactobacillus strains could inhibit H. pylori adherence human gastric epithelial cells. PRACTICAL APPLICATION: Helicobacter pylori causes chronic gastritis, peptic ulcer disease, and gastric cancer, and it infects about 50% of the world's population. Lactobacilli have been reported to have an inhibitory effect on H. pylori and can be used as probiotic to manufacture dairy products preventing H. pylori infection.     

A Comparative Study on Nickel Binding to Hpn-like Polypeptides from Two Helicobacter pylori Strains

Combined potentiometric titration and isothermal titration calorimetry (ITC) methods were used to study the interactions of nickel(II) ions with the N-terminal fragments and histidine-rich fragments of Hpn-like protein from two Helicobacter pylori strains (11637 and 26695). The ITC measurements were performed at various temperatures and buffers in order to extract proton-independent reaction enthalpies of nickel binding to each of the studied protein fragments. We bring up the problem of ITC results of nickel binding to the Hpn-like protein being not always compatible with those from potentiometry and MS regarding the stoichiometry and affinity. The roles of the ATCUN motif and multiple His and Gln residues in Ni(II) binding are discussed. The results provided the possibility to compare the Ni(II) binding properties between N-terminal and histidine-rich part of Hpn-like protein and between N-terminal parts of two Hpn-like strains, which differ mainly in the number of glutamine residues.