Gastrointestinal Microbiota Changes in Patients With Gastric Precancerous Lesions

BackgroundGastric microbiota may be involved in gastric cancer. The relationship between gastrointestinal microbes and the risk of gastric cancer is unclear. This study aimed to explore the gastric and intestinal bacteria associated with gastritis and gastric precancerous lesions. We conducted a case-control study by performing 16S rRNA gene analysis of gastric biopsies, juices, and stool samples from 148 cases with gastritis or gastric precancerous lesions from Anhui and neighboring provinces, China. And we validated our findings in public datasets.ResultsAnalysis of microbial sequences revealed decreased bacterial alpha diversity in gastric bacteria during the progression of gastritis. Helicobacter pylori was the main contributor to the decreased microbial composition and diversity in the gastric mucosa and had little influence on the microbiota of gastric juice and feces. The gastric mucosal genera Gemella, Veillonella, Streptococcus, Actinobacillus, and Hemophilus had the higher degree of centrality across the progression of gastric precancerous lesions. And Acinetobacter may contribute to the occurrence of intraepithelial neoplasia. In addition, the microbial model of H. pylori-positive gastric biopsies and feces showed value in the prediction of gastric precancerous lesions.ConclusionsThis study identified associations between gastric precancerous lesions and gastric microbiota, as well as the changes in intestinal microbiota, and explored their values in the prediction of gastric precancerous lesions.

A COMPARATIVE STUDY OF HEMATOXYLIN & EOSIN, SPECIAL STAINS AND IMMUNOHISTOCHEMISTRY FOR DETECTION OF HELICOBACTER PYLORI IN CASES OF GASTRITIS

Background: The role of Helicobacter Pylori in the pathogenesis of Gastritis-Peptic ulcer syndrome and its association with the development of upper gastrointestinal tract malignancy warrant efcient method for the identication of the bacteria in biopsy specimens. Four methods - Hematoxylin and Eosin, Giemsa, Toluidine Blue and Immunohistochemistry were compared to detect the presence of Helicobacter pylori. The prevalence of H.Pylori in gastric biopsies was also evaluated. Aim Of The Study: The aim is to evaluate the prevalence of H.Pylori in cases of gastritis and compare the efcacy of Hematoxylin and Eosin, Giemsa , Toluidine blue and Immunohistochemistry for the detection of H.pylori in cases of gastritis. Materials And Methods: This Retrospective study was done in the Department of Pathology. A total of 40 cases of gastritis were randomly selected for this study and all the four methods were applied. Results: Helicobacter pylori infection showed an overall prevalence rate of about 75%. When compared with Immunohistochemistry, Sensitivity and specicity of Hematoxylin and Eosin was 66.67% and 100% respectively. Giemsa showed sensitivity of about 86.67% and specicity of about 100%. Toluidine blue showed sensitivity of about 80% and specicity of about 100%. Conclusion: Hence in the present study Giemsa was more reliable and cost effective stain when compared with Hematoxylin & Eosin, Toluidine blue and immunohistochemistry. However, Immunohistochemistry carries the highest level of sensitivity in the detection of Helicobacter Pylori especially when the density of organism is low and in clinically suspected cases of Helicobacter Pylori with negative Giemsa staining

Occurrence of Helicobacter Pylori in Specimens of Chronic Gastritis and Gastric Adenocarcinoma Patients: A Retrospective Study at University Teaching Hospital, Kigali, Rwanda

Introduction: Helicobacter pylori (H. pylori) infection is the major cause of gastroduodenal diseases in populations of different ages.We conducted aretrospective studyusing archived tissue samples to determine the prevalence of H. pylori infection among patients diagnosed with gastritis and gastric adenocarcinoma by histopathology cases in one hospital in Rwanda. Materials and methods: Cases of chronic gastritis and gastric adenocarcinoma histologically diagnosed in a tertiary hospital in Rwanda over the period of 2016-2018 were studied for the presence of H. pylori using immunohistochemistry. Diagnosis of positive cases considered immunoreactivity as well as bacterial morphology, including spiral, rod-shaped, angulated and coccoid forms. Results: Three hundred and seven cases were included in this study; chronic gastritis and gastric adenocarcinoma representing 39% and 61%, respectively. The overall frequency of H. pylori infection was 77.5% (80% among chronic gastritis cases versus 76% among gastric adenocarcinoma cases). Prevalence of H. pylori infection in chronic gastritis and adenocarcinoma did not significantly associate with age and sex. Conclusion: The prevalence of H. pylori was high among chronic gastritis and gastric adenocarcinoma cases in Rwanda. Pathologists should investigate the presence of H. pylori in gastric biopsies. Our data shows immunohistochemistry method is feasible and adequate to facilitate detection of H. pylori, which may guide timely treatment.

Gastric Helicobacter suis Infection Partially Protects against Neurotoxicity in A 6-OHDA Parkinson’s Disease Mouse Model

The exact etiology of Parkinson’s disease (PD) remains largely unknown, but more and more research suggests the involvement of the gut microbiota. Interestingly, idiopathic PD patients were shown to have at least a 10 times higher prevalence of Helicobacter suis (H. suis) DNA in gastric biopsies compared to control patients. H. suis is a zoonotic Helicobacter species that naturally colonizes the stomach of pigs and non-human primates but can be transmitted to humans. Here, we investigated the influence of a gastric H. suis infection on PD disease progression through a 6-hydroxydopamine (6-OHDA) mouse model. Therefore, mice with either a short- or long-term H. suis infection were stereotactically injected with 6-OHDA in the left striatum and sampled one week later. Remarkably, a reduced loss of dopaminergic neurons was seen in the H. suis/6-OHDA groups compared to the control/6-OHDA groups. Correspondingly, motor function of the H. suis-infected 6-OHDA mice was superior to that in the non-infected 6-OHDA mice. Interestingly, we also observed higher expression levels of antioxidant genes in brain tissue from H. suis-infected 6-OHDA mice, as a potential explanation for the reduced 6-OHDA-induced cell loss. Our data support an unexpected neuroprotective effect of gastric H. suis on PD pathology, mediated through changes in oxidative stress.

Biochemical and resistance profile of Helicobacter pylori isolated in N’Djamena in Chad

Helicobacter pylori infection and resistance to antibiotics is a public health problem. The objective of this study was to determine the prevalence and rates of resistance to antibiotics used in the protocol for the management of patients with Helicobacter pylori infection. Spanning a period from February 2020 to February 2021, it was an observational diagnostic study on gastric biopsies and stool including 97 patients admitted for endoscopy. It was carried out according to standard methods of medical microbiology. Of 97 patients whose mean age was 46.10 years with extremes of 16 and 85 years, an infection prevalence of 60.82% was observed. 44.07% of infected patients were between 16 and 39 years old, 33.90% between 40 and 63 years old, and 22.03% between 63 and 85 years old. Significant differences were observed between the proportions of positive (81.44%) and negative (18.56%) cultures, between infection with H. pylori (75%) and other microbial agents (25.35%) with probabilities of 0.01 and 0.02 respectively. The most resistant antibiotics were: Metronidazole, Clarithromycin, Levofloxacin, Tetracycline and Amoxicillin with resistance rates of 74.58%, 16.95%, 13.56%, 8.47%, and 5.08% respectively. The frequencies of antibiotic resistance revealed 74.58% for Metronidazole, 16.95% for Clarithromycin, 13.56% for Levofloxacin, 8.47% for Tetracycline, and 5.08% for Amoxicillin. This study made it possible to determine a significant proportion of H. pylori infection and to shed light on the resistance to the antibiotics used in the eradicating treatment of the bacteria. From this study, we retain that the prescription of Metronidazole is prohibited in Chad. Keywords: Helicobacter pylori, Resistance, Antibiotic, Chad.

Evaluation of Invasive and Molecular Methods in the Diagnosis of Helicobacter Pylori From Gastric Biopsies of Sudanese Patients. A Comparative Approach

The continuous rise in the number of patients suffering from Helicobacter pylori is probably due to the changes in modern life. Nowadays patients suffering from gastrointestinal problems are diagnosed through invasive and noninvasive techniques. The choice of a diagnostic test is influenced by factors such as the tests' sensitivity and specificity, the clinical conditions, and the cost-effectiveness of the testing strategy. This study aimed to compare molecular detection methods of H. pylori by polymerase chain reaction (PCR) targeting the 16S rRNA, ureA and glmM genes with an invasive histopathological technique. A total of 290 patients from various hospitals in Khartoum State were recruited in this study between March 2018 and January 2020. Two gastric biopsies were collected from each patient for PCR and histopathology.A total of 103 (35.5%) samples were positive by histopathological examination, 88 (30.3%) by 16SrRNA, 39 (13.4%) by glmM gene, and 56 (19.3%) by ureA gene. The highest sensitivity was observed in 16SrRNA (46.6%), followed by ureA (35%), and glmM (24.3%). While the best specificity was observed in glmM gene (92.5%), followed by ureA (89.3%) and 16SrRNA (78.6%). In conclusion, the PCR test targeting the16SrRNA gene exhibited the best results for molecular detection of H. pylori compared to other genes.

Minimum inhibitory concentrations of commonly used antibiotics against Helicobacter Pylori: A multicenter study in South China

Aim To determine the minimum inhibitory concentrations (MICs) of commonly used antibiotics against Helicobacter Pylori (H. pylori) in South China and compare their resistance rates by using EUCAST breakpoints and other breakpoints. Methods Patients who had not previously received H. pylori treatment in clinical centers in South China were enrolled in this study from 2017 to 2020. Gastric biopsies were obtained for H. pylori culture. The MICs of amoxicillin (AMX), clarithromycin (CLA), metronidazole (MTZ), levofloxacin (LEV), tetracycline (TET) and furazolidone (FZD) were tested by broth microdilution method and assessed by two different breakpoints. ATCC43504 standard strain served as a control. Results A total of 208 H. pylori strains were isolated from patients’ biopsy samples. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for H. pylori were 0.0156-256mg/L (MIC50 0.125mg/L, MIC90 4mg/L), 0.0156- >256 mg/L (MIC50 0.0312mg/L, MIC90 64mg/L), 0.0156- >256mg/L (MIC50 8mg/L, MIC90 256mg/L), 0.0156-256mg/L (MIC50 0.25mg/L, MIC90 16mg/L), 0.0156-256mg/L (MIC50 0.0625mg/L, MIC90 4mg/L), and 0.0156- >256mg/L (MIC50 0.0312mg/L, MIC90 2mg/L), respectively. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for ATCC43504 strain were 0.25mg/L, 0.0625mg/L, 64mg/L, 0.5mg/L, 1mg/L and 0.25mg/L, respectively. The resistance rate of FZD was 11.05%. The overall resistance rates according to EUCAST breakpoints and other breakpoints were 57.21% and 14.90% for AMX (p<0.001), 38.94% and 38.94% for CLA (p = 1), 39.42% and 50.96% for MTZ (p<0.001), 12.98% and 10.58% for TET (p = 0.025), 35.10% and 35.10% for LEV (p = 1), respectively. Conclusions Our results demonstrate that AMX, FZD, and TET, but not MTZ, CLR or LEV, showed good anti-H. pylori activity in vitro in South China. When different breakpoints were used, similar results were found with CLA, and LEV, but not with AMX, MTZ, or TET.