Characteristics of phenotypic antibiotic resistance of Helicobacter pylori and its correlation with genotypic antibiotic resistance: A retrospective study in Ningxia.

BACKGROUND: Geographic differences exist in the antibiotic resistance patterns of Helicobacter pylori. Personalized treatment regimens based on local or individual resistance data are essential. We evaluated the current status of H. pylori resistance in Ningxia, analyzed resistance-related factors, and assessed the concordance of phenotypic and genotypic resistance. METHODS: Strains were isolated from the gastric mucosa of patients infected with H. pylori in Ningxia and relevant clinical information was collected. Phenotypic antibiotic susceptibility assays (Kirby-Bauer disk diffusion) and antibiotic resistance gene detection (Sanger sequencing) were performed. RESULTS: We isolated 1955 H. pylori strains. The resistance rates of H. pylori to amoxicillin, levofloxacin, clarithromycin, and metronidazole were 0.9%, 42.4%, 40.4%, and 94.2%, respectively. Only five tetracycline-resistant and one furazolidone-resistant strain were identified. Overall, 3.3% of the strains were sensitive to all six antibiotics. Multidrug-resistant strains accounted for 22.9%, of which less than 20% were from Wuzhong. Strains isolated from women and patients with nonulcerative disease had higher rates of resistance to levofloxacin and clarithromycin. Higher rates of resistance to metronidazole, levofloxacin, and clarithromycin were observed in the older age group than in the younger age group. The kappa coefficients of phenotypic resistance and genotypic resistance for levofloxacin and clarithromycin were 0.830 and 0.809, respectively, whereas the remaining antibiotics showed poor agreement. CONCLUSION: H. pylori antibiotic resistance is severe in Ningxia. Therefore, furazolidone, amoxicillin, and tetracycline are better choices for the empirical therapy of H. pylori infection in this region. Host sex, age, and the presence of ulcerative diseases may affect antibiotic resistance of the bacteria. Personalized therapy based on genetic testing for levofloxacin and clarithromycin resistance may be a future direction for the eradication therapy of H. pylori infection in Ningxia.

Role of gut microbiota in the pathogenesis and therapeutics of minimal hepatic encephalopathy via the gut-liver-brain axis.

Minimal hepatic encephalopathy (MHE) is a frequent neurological and psychiatric complication of liver cirrhosis. The precise pathogenesis of MHE is complicated and has yet to be fully elucidated. Studies in cirrhotic patients and experimental animals with MHE have indicated that gut microbiota dysbiosis induces systemic inflammation, hyperammonemia, and endotoxemia, subsequently leading to neuroinflammation in the brain via the gut-liver-brain axis. Related mechanisms initiated by gut microbiota dysbiosis have significant roles in MHE pathogenesis. The currently available therapeutic strategies for MHE in clinical practice, including lactulose, rifaximin, probiotics, synbiotics, and fecal microbiota transplantation, exert their effects mainly by modulating gut microbiota dysbiosis. Microbiome therapies for MHE have shown promised efficacy and safety; however, several controversies and challenges regarding their clinical use deserve to be intensively discussed. We have summarized the latest research findings concerning the roles of gut microbiota dysbiosis in the pathogenesis of MHE via the gut-liver-brain axis as well as the potential mechanisms by which microbiome therapies regulate gut microbiota dysbiosis in MHE patients.

Altered gut microbiota is associated with sleep disturbances in patients with minimal hepatic encephalopathy caused by hepatitis B-related liver cirrhosis.

BACKGROUND: Sleep disturbances are prevalent in patients with minimal hepatic encephalopathy (MHE). This study aimed to evaluate the association between sleep disturbances and altered gut microbiota in patients with MHE caused by hepatitis B-related liver cirrhosis. RESEARCH DESIGN AND METHODS: Ninety-eight and 45 patients with MHE were included in exploration and validation cohorts, respectively. Sleep disturbances were assessed using the Chinese version of the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Microbiota in fecal samples were analyzed via amplicon sequencing of bacterial 16S ribosomal RNA genes. RESULTS: The gut microbiomes of MHE patients with sleep disturbances were characterized by lower bacterial diversity and distinct bacterial composition. Relative abundances of Streptococcus salivarius and Veillonella were independent predictors of sleep disturbances in MHE patients and well-distinguished MHE patients with and without sleep disturbances in both the exploration and validation cohorts. Moreover, the relative abundances of S. salivarius were positively correlated with plasma ammonia levels, and functional modules associated with protein digestion and absorption and lipopolysaccharide biosynthesis were enriched in the microbiomes of MHE patients with sleep disturbances. CONCLUSIONS: Both S. salivarius and Veillonella were associated with sleep disturbances in patients with MHE caused by hepatitis B-related liver cirrhosis.

ICOS+ follicular regulatory T cells are implicated in the pathogenesis of ulcerative colitis.

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with a rising incidence worldwide. The precise aetiology is unclear, but aberrant regulatory T cell (Treg) responses have been documented in active UC patients. Follicular regulatory T cell (Tfr) is a recently identified subset of Treg cells. In this study, the role of ICOS in Tfr cells, which is a costimulatory molecule shown to stabilize and promote Treg differentiation, was investigated in UC patients. We found that with increasing UC severity, the frequency of ICOS+ CD4 T cells was increased, but the level of ICOS expression by ICOS+ CD4 T cells was decreased. ICOS+ cells were highly enriched in follicular regulatory T cells (Tfr), which is a subset of Treg cells characterized by CD25+ CD127- CXCR5+ Foxp3+ phenotype. Anti-CD3, anti-CD3/CD28, or anti-CD3/ICOS had all significantly increased the expression of Foxp3 and IL-10, and among the three stimulation methods, anti-CD3/ICOS was most effective at enhancing Foxp3 and IL-10 expression. Moreover, anti-CD3/ICOS-stimulated Tfr cells could suppress conventional T cell proliferation in an IL-10-dependent manner. Interestingly, anti-CD3/ICOS stimulation was less effective in UC-Mild and UC-Active patients compared to that in healthy and UC-Remission patients. In addition, UC patients presented impairment in ICOS upregulation following anti-CD3 stimulation. Overall, these data indicated that ICOS+ Tfr cells were dysregulated in UC patients and the level of dysregulation was associated with the severity of UC, suggesting that ICOS+ Tfr cells could serve as a biomarker of the progression of UC.

Dysregulated microRNA expression profiles in gastric cancer cells with high peritoneal metastatic potential.

Despite significant developments in its clinical treatment, the reported incidence and mortality of gastric cancer have exhibited marked increases. The molecular mechanisms of gastric cancer initiation and progression remain to be fully elucidated. The aim of the present study was to identify novel microRNAs (miRNAs/miRs) with a role in the peritoneal metastasis of gastric cancer by comparing the miRNA expression in the gastric cancer cell line GC9811 with that in its variant GC9811-P, a sub-cell line with a high potential for peritoneal metastasis. A miRNA microarray analysis identified 153 dysregulated miRNAs, including 74 upregulated and 79 downregulated miRNAs. Of these, four significantly upregulated miRNAs (miR-181a-5p, miR-106b-5p, miR-199a-3p and miR-148a-3p) and four downregulated miRNAs (miR-146a-5p, miR-21-5p, miR-222-3p and miR-221-3p) were selected and further confirmed by reverse transcription-quantitative polymerase chain reaction analysis. Furthermore, knockdown of miR-21-5p promoted the migration and invasion of GC9811 cells. Collectively, the results suggested that the miRNA expression profile in GC9811-P vs. GC9811 cells was altered to favor disease progression, and the dysregulated miRNAs, including miR-21-5p, may therefore provide novel biomarkers and potential therapeutic targets for gastric cancer metastasis.

miR­29a­3p represses proliferation and metastasis of gastric cancer cells via attenuating HAS3 levels.

MicroRNA­29a (miR­29a) has recently been in the spotlight as a tumor suppressor whose encoding gene is frequently suppressed in cancers. The aim of the present study was to investigate the biological functions and underlying molecular mechanism by which miR­29a­3p suppresses gastric cancer peritoneum metastasis. Cell proliferation, colony­forming, wound healing and Transwell migration assays were performed in the present study. MiR­29a­3p expression was markedly decreased in gastric cancer cell lines with stronger metastatic potential. Silencing miR­29a­3p expression promoted gastric cancer cell proliferation, colony­forming, migration and invasion. By contrast, overexpression of miR­29a­3p inhibited these biological phenotypes. In addition, it was revealed that miR­29a­3p functioned through downregulating hyaluronan synthase 3 expression. Collectively, dysregulated miR­29a­3p expression in gastric cancer cells was associated with malignant properties primarily relevant to migration and metastasis. The results suggest that miR­29a­3p may be a potential therapeutic target for gastric cancer.

MicroRNA-214 promotes peritoneal metastasis through regulating PTEN negatively in gastric cancer.

BACKGROUND AND OBJECTIVE: We aimed to investigate the effects of microRNA-214 (miR-214) on peritoneal metastasis as well as to elucidate its regulatory mechanism in gastric cancer (GC). METHODS: The expression levels of miR-214 in human GC cell lines MKN-28NM, MKN-28M, GC9811 and GC9811-P were analyzed by quantitative real-time PCR. Lentiviral miR-214, lentiviral miR-214 inhibitor, and empty lentiviral vector were transfected to GC cell lines, respectively. The roles of miR-214 in cell invasion, migration, proliferation and colony-forming ability were then analyzed. Besides, the expression levels of PTEN in different transfected cells were determined by western blot analysis. RESULTS: We found that miR-214 was up-regulated in GC9811-P cells with high metastatic potential to the peritoneum compared with that in GC9811 cells. In addition, in vitro overexpression of miR-214 promoted cell invasion, migration, proliferation and colony-forming ability of GC9811 cells, while down-regulation of miR-214 had opposite effects in GC9811-P cells. Besides, overexpression of miR-214 in GC9811 cells markedly down-regulated PTEN expression, whereas down-regulation of miR-214 in GC9811-P cells significantly increased PTEN expression. CONCLUSIONS: Our findings indicate that miR-214 may promote peritoneal metastasis of GC cells via down-regulation of PTEN, thus leading to the progression of GC.