ABSTRACT
BACKGROUND: Helicobacter pylori infection-associated gastric adenocarcinoma is influenced by various factors, including the digestive microbiota. Lactic acid bacteria role in digestive carcinogenesis has been discussed, and some Lactobacillaceae family species have been shown to act against H. pylori-induced inflammation and colonization. However, their effects on H. pylori-related carcinogenesis have not yet been studied. Lactobacillaceae family effects on the epithelial-to-mesenchymal transition (EMT), emergence of cells with cancer stem cell (CSC) properties and the pro-inflammatory response of gastric epithelial cells to H. pylori infection were investigated. MATERIALS AND METHODS: A co-culture model of AGS gastric epithelial cells infected with a carcinogenic strain of H. pylori associated with 18 different probiotic strains candidates were used. Different EMT indicators and CSC properties were studied, including quantification of the mesenchymal phenotype, tumorsphere formation, EMT marker expression, and tight junction evaluation with immunofluorescence microscopy. The effect of the strains on the pro-inflammatory response to H. pylori was also evaluated by quantifying interleukin-8 (IL-8) production using ELISA. RESULTS: Among the strains tested, Lactobacillus gasseri BIO6369 and Lacticaseibacillus rhamnosus BIO5326 induced a 30.6% and 38.4% reduction in the mesenchymal phenotype, respectively, caused a significant decrease in Snail and Zeb1 EMT marker expression and prevented the loss of tight junctions induced by H. pylori infection. A separate co-culture with a Boyden chamber maintained the effects induced by the two strains. H. pylori-induced IL-8 production was also significantly reduced in the presence of L. gasseri BIO6369 and L. rhamnosus BIO5326. CONCLUSION: Lactobacillus gasseri BIO6369 and L. rhamnosus BIO5326 strains decreased epithelial-to-mesenchymal transition and inflammation induced by H. pylori infection, suggesting that these species may have a protective effect against H. pylori-induced gastric carcinogenesis.
Subject(s)
Epithelial Cells , Epithelial-Mesenchymal Transition , Helicobacter Infections , Helicobacter pylori , Lacticaseibacillus rhamnosus , Lactobacillus gasseri , Probiotics , Stomach Neoplasms , Humans , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Helicobacter pylori/physiology , Helicobacter pylori/pathogenicity , Stomach Neoplasms/microbiology , Stomach Neoplasms/pathology , Lacticaseibacillus rhamnosus/physiology , Epithelial Cells/microbiology , Coculture Techniques , CarcinogenesisABSTRACT
BACKGROUND: Central catheter-related bloodstream infections (CRBIs) can lead to severe complications, including suppurative thrombophlebitis, endocarditis, and metastatic infections. While complications due to CRBIs caused by Staphylococcus aureus (SA) are well-known, there are limited data regarding CRBIs caused by other bacteria. METHODS: This 2-year retrospective single-center study of patients with CRBIs from a tertiary care hospital examined the hematogenous complications associated with CRBIs according to patient characteristics, central venous catheter (CVC) types, and causative bacteria. RESULTS: All in all, 254 patients with confirmed CRBIs were included; 285 bacteria types were isolated, mainly Enterobacteriaceae (n = 94), coagulase-negative Staphylococci (CNS, n = 82), SA (n = 45), and non-fermenting Gram-negative bacteria (NGB, n = 45). Among the patients, 35 developed at least one hematogenous complication (14 %), including suppurative thrombophlebitis (n = 15), endocarditis (n = 7) and metastatic infections (n = 16). In multivariate analysis, hemodialysis, persistent bacteremia for at least 3 days, and CRBIs caused by SA were associated with increased risk for hematogenous complications, while previous curative anticoagulant treatment was associated with reduced risk. Diabetes, CVC maintenance, and hematogenous complications were associated with increased 3-month mortality. CONCLUSION: A thorough investigation of hematogenous complications should be envisioned in patients with persistent bacteremia, particularly those with SA infections and those on hemodialysis.
Subject(s)
Bacteremia , Central Venous Catheters , Endocarditis , Staphylococcal Infections , Thrombophlebitis , Humans , Central Venous Catheters/adverse effects , Retrospective Studies , Staphylococcus aureus , Risk Factors , Thrombophlebitis/etiology , Thrombophlebitis/complications , Bacteremia/epidemiology , Bacteremia/microbiology , Endocarditis/complicationsABSTRACT
Resistance in Helicobacter pylori to tetracycline is rare. We describe the case of an H. pylori strain with a high level of resistance to tetracycline (minimum inhibitory concentration = 12 mg/L). However, despite tetracycline resistance, bismuth quadritherapy was effective. Analysis of the patient's antibiotic treatment history over the previous 25 years revealed repeated 3-month courses of tetracycline for the treatment of acne, suggesting in vivo selection pressure responsible for the emergence of the triple mutation (AGAâTTC) in 16S rDNA associated with tetracycline resistance. This is a rare event but one worth monitoring, especially in view of the widespread use of bismuth quadritherapy for probabilistic treatment in countries where it is available.
Subject(s)
Anti-Bacterial Agents , Helicobacter Infections , Helicobacter pylori , Humans , Anti-Bacterial Agents/pharmacology , Helicobacter Infections/drug therapy , Helicobacter pylori/genetics , Bismuth/pharmacology , Bismuth/therapeutic use , Microbial Sensitivity Tests , Tetracycline/pharmacology , Tetracycline/therapeutic use , Tetracycline Resistance/genetics , Drug Therapy, Combination , Metronidazole/pharmacologyABSTRACT
PCR detection of Helicobacter pylori infection in gastric biopsies allows the detection of this bacterium and the mutations associated with macrolide resistance. The aim of this study was to evaluate the performance of RIDA®GENE H. pylori PCR (r-Biopharm) on the ELITe InGenius System (Elitech). Two hundred gastric biopsies were obtained. These biopsies were ground in nutrient broth. Two hundred microliters of this suspension was treated with proteinase K, and then, 200 µL was transferred to an ELITe InGenius sample tube and tested using RIDA®GENE H. pylori PCR reagents. In-house H. pylori PCR was used as a reference. The sensitivity of RIDA®GENE H. pylori PCR with ELITe InGenius was 100%, the specificity was 98% (95% confidence interval (CI), 95.3-100%), the PPV was 98% (95% CI, 95.3-100%), and the NPV was 100% for the detection of H. pylori. All of these parameters were 100% for the categorization of macrolide resistance. The adaptation of RIDA®GENE H. pylori PCR reagents on the ELITe InGenius System was successful. This PCR is easy to use on this system.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Scrapie , Humans , Sheep/genetics , Animals , Helicobacter pylori/genetics , Clarithromycin , Helicobacter Infections/microbiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial/genetics , Macrolides/therapeutic use , Polymerase Chain Reaction , Biopsy , Microbial Sensitivity TestsABSTRACT
Helicobacter cinaedi bacteremia caused recurring multifocal cellulitis in a patient in France who had chronic lymphocytic leukemia treated with ibrutinib. Diagnosis required extended blood culture incubation and sequencing of the entire 16S ribosomal RNA gene from single bacterial colonies. Clinicians should consider H. cinaedi infection in cases of recurrent cellulitis.
Subject(s)
Bacteremia , Helicobacter Infections , Helicobacter , Humans , Cellulitis/diagnosis , Cellulitis/microbiology , Helicobacter/genetics , Bacteremia/microbiology , Helicobacter Infections/diagnosisABSTRACT
BACKGROUND: Severe non-AIDS bacterial infections (SBIs) are among the leading causes of hospital admissions among persons with human immunodeficiency virus (PWH) in regions with high antiretroviral therapy coverage. METHODS: This large prospective cohort study of PWH examined the types of infections, bacterial documentation, and evolution of antibiotic resistance among PWH hospitalized with SBIs over an 18-year period. RESULTS: Between 2000 and 2017, 459 PWH had at least 1 SBI with bacterial documentation. Among the 847 SBIs, there were 280 cases of bacteremia, 269 cases of pneumonia, and 240 urinary tract infections. The 1025 isolated bacteria included Enterobacteriaceae (n = 394; mainly Escherichia coli), Staphylococcus aureus (n = 153), and Streptococcus pneumoniae (n = 82). The proportion of S. pneumoniae as the causative agent in pneumonia and bacteremia decreased sharply over time, from 34% to 8% and from 21% to 3%, respectively. The overall antibiotic resistance of S. aureus and S. pneumoniae decreased progressively but it increased for Enterobacteriaceae (from 24% to 48% for amoxicillin-clavulanate, from 4% to 18% for cefotaxime, and from 5% to 27% for ciprofloxacin). Cotrimoxazole prophylaxis was associated with higher nonsusceptibility of S. pneumoniae to amoxicillin and erythromycin, higher nonsusceptibility of Enterobacteriaceae to ß-lactams and fluoroquinolones, and a higher risk of extended-spectrum ß-lactamase-producing Enterobacteriaceae. CONCLUSIONS: The bacterial resistance pattern among PWH between 2014 and 2017 was broadly similar to that in the general population, with the exception of a higher resistance profile of Enterobacteriaceae to fluoroquinolones. The use of cotrimoxazole as prophylaxis was associated with an increased risk of antibiotic resistance.
Subject(s)
Acquired Immunodeficiency Syndrome , Bacteremia , Staphylococcal Infections , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Trimethoprim, Sulfamethoxazole Drug Combination , HIV , Staphylococcus aureus , Prospective Studies , Drug Resistance, Bacterial , Bacteria , Enterobacteriaceae , Escherichia coli , Staphylococcal Infections/drug therapy , Fluoroquinolones , Amoxicillin-Potassium Clavulanate Combination , Acquired Immunodeficiency Syndrome/drug therapy , Bacteremia/epidemiology , Bacteremia/drug therapy , Microbial Sensitivity Tests , beta-LactamasesABSTRACT
BACKGROUND: Cancer stem cells (CSCs) are at the origin of tumour initiation and progression in gastric adenocarcinoma (GC). However, markers of metastasis-initiating cells remain unidentified in GC. In this study, we characterized CD44 variants expressed in GC and evaluated the tumorigenic and metastatic properties of CD44v3+ cells and their clinical significance in GC patients. METHODS: Using GC cell lines and patient-derived xenografts, we evaluated CD44+ and CD44v3+ GC cells molecular signature and their tumorigenic, chemoresistance, invasive and metastatic properties, and expression in patients-derived tissues. RESULTS: CD44v3+ cells, which represented a subpopulation of CD44+ cells, were detected in advanced preneoplastic lesions and presented CSCs chemoresistance and tumorigenic properties in vitro and in vivo. Molecular and functional analyses revealed two subpopulations of gastric CSCs: CD44v3+ CSCs with an epithelial-mesenchymal transition (EMT)-like signature, and CD44+/v3- CSCs with an epithelial-like signature; both were tumorigenic but CD44v3+ cells showed higher invasive and metastatic properties in vivo. CD44v3+ cells detected in the primary tumours of GC patients were associated with a worse prognosis. CONCLUSION: CD44v3 is a marker of a subpopulation of CSCs with metastatic properties in GC. The identification of metastasis-initiating cells in GC represents a major advance for further development of anti-metastatic therapeutic strategies.
Subject(s)
Carcinoma , Stomach Neoplasms , Humans , Stomach Neoplasms/pathology , Neoplastic Stem Cells/metabolism , Carcinoma/pathology , Hyaluronan Receptors , Epithelial-Mesenchymal TransitionABSTRACT
Aliarcobacter butzleri is an emerging gastrointestinal pathogen found in many countries worldwide. In France, it has become the third most commonly isolated bacterial species from the stools of patients with intestinal infections. No interpretative criteria for antimicrobial susceptibility testing have been proposed for A. butzleri, and most strains are categorized using the recommendations of the Clinical and Laboratory Standards Institute or the European Committee on Antimicrobial Susceptibility Testing for Campylobacter or Enterobacterales. In the present study, the genomes of 30 resistant A. butzleri isolates were analyzed to propose specific epidemiological cut-off values for ampicillin, ciprofloxacin, erythromycin, and tetracycline. The identification of a ß-lactamase and the T85I GyrA mutation associated with ampicillin and ciprofloxacin resistance, respectively, allowed us to adjust the disk diffusion (DD) and MIC cut-off values for these molecules. However, epidemiological cut-off values for erythromycin and tetracycline could not be estimated due to the absence of known resistance mechanisms. The present study paves the way for building a consensus for antimicrobial susceptibility testing for this concerning pathogen. IMPORTANCE Aliarcobacter butzleri is an emerging and concerning intestinal pathogen. Very few studies have focused on this particular species, and antimicrobial susceptibility testing (AST) is based on methods that have been mostly developed for Campylobacter spp. In fact, no disk diffusion and E-tests adapted cut-offs for A. butzleri are available which leads to misinterpretations. We have shown here that NGS approach to identify genes and mutations in close relation to phenotypic resistance levels is a robust way to solve that issue and precisely differentiate WT and NWT A. butzleri isolates for frequently used antimicrobials. MIC and DD cut-off values have been significantly adjusted and answer the need for a global consensus regarding AST for A. butzleri.
Subject(s)
Arcobacter , Ampicillin , Anti-Bacterial Agents/pharmacology , Arcobacter/genetics , Ciprofloxacin , Drug Resistance, Bacterial/genetics , Erythromycin , Humans , Microbial Sensitivity Tests , Tetracycline/pharmacologyABSTRACT
The discovery of Helicobacter pylori in 1982 drew to an end the stomach being considered as a sterile organ. Later, the progress in molecular methods, especially Next Generation Sequencing and metagenomics, has highlighted the fact that a diverse microbiota including five major phyla could also be present in the stomach. However, when present, H. pylori is the essential species and it influences the other bacterial communities in terms of richness and evenness. It is now well accepted that H. pylori is the main risk factor for gastric cancer, especially the strains harboring the cag pathogenicity island and the CagA oncoprotein, but the need for other factors from the host and the environment can explain the important difference between those infected and those developing gastric cancer. Several studies showed a difference between the gastric microbiota of patients at various stages of development of gastric premalignant and malignant lesions, showing globally a reduced microbial diversity and an increase in the presence of intestinal commensals, especially with nitrosative functions. Other studies showed an increase in oral microbiota. These data suggest that the gastric microbiota other than H. pylori may play a role in the last steps of gastric carcinogenesis. It must also be noted that in a limited number of cases, a virus: the Epstein Barr Virus is responsible for the evolution toward gastric cancer, while in others the mycobiota also needs to be explored. Finally, the use of mice models allowed an exploration of the role of different gastric microbiota in addition to H. pylori.
Subject(s)
Epstein-Barr Virus Infections , Helicobacter Infections , Helicobacter pylori , Microbiota , Stomach Neoplasms , Humans , Mice , Animals , Stomach Neoplasms/etiology , Helicobacter Infections/complications , Helicobacter Infections/microbiology , Helicobacter Infections/pathology , Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human , Helicobacter pylori/geneticsABSTRACT
PCR detection of Helicobacter pylori infection in gastric biopsies allows the detection of this bacterium and the mutations associated with macrolide resistance. The aim of this study was to evaluate the performance of RIDA®GENE H. pylori PCR (r-Biopharm) on a BD MAX™ System (Becton Dickinson). Two hundred ten gastric biopsies obtained were included. These biopsies were ground in nutrient broth. Two hundred microliters of this suspension was treated with proteinase K; 200 µL was transferred to a BD MAX™ sample tube then tested using RIDA®GENE H. pylori PCR reagents. In-house H. pylori PCR was used as a reference. The sensitivity of RIDA®GENE H. pylori PCR with BD MAX™ was 100%, the specificity was 99.08% (95% confidence interval (CI), 97.21-100%), the PPV was 99.02% (95% CI, 97.09-100%), and the NPV was 100% for the detection of H. pylori. The sensitivity was 97.14% (95% CI, 93.87-100%), the specificity was 100%, the PPV was 100%, and the NPV was 98.48% (95% CI, 96.08-100%) for categorization of macrolides resistance. The adaptation of RIDA®GENE H. pylori PCR on the BD MAX™ System is of considerable interest for microbiologists who seek to establish this assay in their laboratories.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Scrapie , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Automation , Biopsy , Clarithromycin , Drug Resistance, Bacterial/genetics , Helicobacter Infections/diagnosis , Helicobacter Infections/drug therapy , Helicobacter pylori/genetics , Humans , Macrolides/therapeutic use , Microbial Sensitivity Tests , Polymerase Chain Reaction , Sheep/geneticsABSTRACT
BACKGROUND AND OBJECTIVES: The present study describes the successful adaptation of an in-house Polymerase Chain Reaction (PCR) for Helicobacter pylori detection coupled with the main mutations associated with resistance to clarithromycin in ready-to-use PCR microwell strips. MATERIALS AND METHODS: These microwell strips can be used on LightCycler® 480, and are delivered with nine microliters of the reaction mixture dispensed into 8-well microwell strips. An extraction control PCR targeting the ß-globin household gene is amplified in the same run as H pylori detection. RESULTS AND CONCLUSION: These microwell strips can be stored at -20°C for 1 year and left at room temperature and in the light for up to 4 h with no impact on the PCR results. Microwell strips can also undergo a thaw and refreeze cycle without impacting the PCR results. These PCR microwell strips are available for purchase from Eurogentec.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Anti-Bacterial Agents/pharmacology , Clarithromycin/pharmacology , Drug Resistance, Bacterial/genetics , Helicobacter Infections/diagnosis , Helicobacter pylori/genetics , Humans , Macrolides/pharmacology , Microbial Sensitivity Tests , Mutation , Polymerase Chain Reaction , RNA, Ribosomal, 23SABSTRACT
Glutamoptosis is the induction of apoptotic cell death as a consequence of the aberrant activation of glutaminolysis and mTORC1 signaling during nutritional imbalance in proliferating cells. The role of the bioenergetic sensor AMPK during glutamoptosis is not defined yet. Here, we show that AMPK reactivation blocks both the glutamine-dependent activation of mTORC1 and glutamoptosis in vitro and in vivo. We also show that glutamine is used for asparagine synthesis and the GABA shunt to produce ATP and to inhibit AMPK, independently of glutaminolysis. Overall, our results indicate that glutamine metabolism is connected with mTORC1 activation through two parallel pathways: an acute alpha-ketoglutarate-dependent pathway; and a secondary ATP/AMPK-dependent pathway. This dual metabolic connection between glutamine and mTORC1 must be considered for the future design of therapeutic strategies to prevent cell growth in diseases such as cancer.
Subject(s)
Apoptosis/physiology , Cell Proliferation/physiology , Glutamine/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Signal Transduction/physiology , AMP-Activated Protein Kinases/metabolism , Adenosine Triphosphate/metabolism , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , HCT116 Cells , HEK293 Cells , Humans , Male , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Sirolimus/analogs & derivatives , Sirolimus/pharmacology , Xenograft Model Antitumor Assays/methodsABSTRACT
Antimicrobial resistance in campylobacters has been described worldwide. The emergence of multiresistant isolates, particularly among Campylobacter coli isolates, is concerning. New resistance mechanisms appear frequently, and DNA-sequence-based methods such as whole-genome sequencing (WGS) have become useful tools to monitor their emergence. The genomes of 51 multiresistant French Campylobacter sp. clinical strains from 2018 to 2019 were analyzed to identify associated resistance mechanisms. Analyses of erythromycin-resistant strains revealed 23S rRNA mutations among most of them and two different methyltransferases in 4 strains: Erm(B) and a novel methyltransferase, named Erm(N) here. The erm(B) gene was found in multidrug-resistant genomic islands, whereas erm(N) was inserted within CRISPR arrays of the CRISPR-cas9 operon. Moreover, using PCR screening in erythromycin-resistant strains from our collection, we show that erm(N) was already present in 3 French clinical strains 2 years before its first report in 2018 in Quebec, Canada. Bacterial transformations confirmed that the insertion of erm(N) into a CRISPR-cas9 operon can confer macrolide resistance. Campylobacter species are easily able to adapt to their environment and acquire new resistance mechanisms, and the emergence of methyltransferases in campylobacters in France is a matter of concern in the coming years.
Subject(s)
Campylobacter coli , Campylobacter jejuni , Anti-Bacterial Agents/pharmacology , Campylobacter coli/genetics , Campylobacter jejuni/genetics , Drug Resistance, Bacterial/genetics , Erythromycin/pharmacology , Macrolides , Methyltransferases/genetics , Microbial Sensitivity TestsABSTRACT
OBJECTIVE: To describe the characteristics, management and outcomes of hospitalised patients with Clostridioides difficile infection (CDI) treated with and without fidaxomicin. METHODS: This prospective, multicentre, observational study (DAFNE) enrolled hospitalised patients with CDI, including 294 patients treated with fidaxomicin (outcomes recorded over a 3-month period) and 150 patients treated with other CDI therapies during three 1-month periods. The primary endpoint was baseline and CDI characteristics of fidaxomicin-treated patients. RESULTS: At baseline, the fidaxomicin-treated population included immunocompromised patients (39.1%) and patients with severe (59.2%) and recurrent (36.4%) CDI. Fidaxomicin was associated with a high rate of clinical cure (92.2%) and low CDI recurrence (16.3% within 3 months). Clinical cure rates were ≥90% in patients aged ≥65 years, those receiving concomitant antibiotics and those with prior or severe CDI. There were 121/296 (40.9%) patients with adverse events (AEs), 5.4% with fidaxomicin-related AEs and 1.0% with serious fidaxomicin-related AEs. No fidaxomicin-related deaths were reported. CONCLUSIONS: Fidaxomicin is an effective and well-tolerated CDI treatment in a real-world setting in France, which included patients at high risk of adverse outcomes.Trial registration: Description of the use of fidaxomicin in hospitalised patients with documented Clostridium difficile infection and the management of these patients (DAFNE), NCT02214771, www.ClinicalTrials.gov.
Subject(s)
Clostridioides difficile , Clostridium Infections , Aminoglycosides/adverse effects , Anti-Bacterial Agents/adverse effects , Clostridioides , Clostridium Infections/drug therapy , Fidaxomicin , France , Humans , Prospective Studies , VancomycinABSTRACT
Gastric cancer's bad incidence, prognosis, cellular and molecular heterogeneity amongst others make this disease a major health issue worldwide. Understanding this affliction is a priority for proper patients' management and for the development of efficient therapeutical strategies. This review gives an overview of major scientific advances, made during the past 5-years, to improve the comprehension of gastric adenocarcinoma. A focus was made on the different actors of gastric carcinogenesis, including, Helicobacter pylori cancer stem cells, tumour microenvironment and microbiota. New and recent potential biomarkers were assessed as well as emerging therapeutical strategies involving cancer stem cells targeting as well as immunotherapy. Finally, recent experimental models to study this highly complex disease were discussed, highlighting the importance of gastric cancer understanding in the hard-fought struggle against cancer relapse, metastasis and bad prognosis.
Subject(s)
Adenocarcinoma/metabolism , Carcinogenesis , Stomach Neoplasms/metabolism , Animals , Biomarkers/metabolism , Biomarkers, Tumor , Cell Line, Tumor , Helicobacter Infections/complications , Helicobacter pylori , Humans , Immunotherapy , Liquid Biopsy , Mice , Neoplasm Metastasis , Neoplasm Recurrence, Local/pathology , Neoplastic Stem Cells/cytology , Prognosis , Recurrence , Risk Factors , Stomach Neoplasms/microbiology , Tumor MicroenvironmentABSTRACT
Metformin is widely prescribed to treat type 2 diabetes. Diabetes patients treated with metformin have a decreased risk of cancers, including gastric cancer. Among the factors influencing digestive carcinogenesis, gut microbiota interactions have been intensively studied. Metformin exhibits direct antimicrobial activity toward Helicobacterpylori, which plays a crucial role in gastric carcinogenesis. Mice were infected with H. pylori and treated for 12 days with either metformin or phosphate-buffered saline (PBS) as a control. At the end of the treatment period, the mice were euthanized and cecal and intestinal contents and stool were collected. The gut microbiota of the three different digestive sites (stool, cecal, and intestinal contents) were characterized through 16S RNA gene sequencing. In mice infected with H. pylori, metformin significantly decreased alpha diversity indices and led to significant variation in the relative abundance of some bacterial taxa including Clostridium and Lactobacillus, which were directly inhibited by metformin in vitro. PICRUSt analysis suggested that metformin modifies functional pathway expression, including a decrease in nitrate reducing bacteria in the intestine. Metformin significantly changed the composition and predicted function of the gut microbiota of mice infected with H. pylori; these modifications could be implicated in digestive cancer prevention.
ABSTRACT
Campylobacter spp. enteritis is the most frequent bacterial enteritis in both adults and children and is sometimes a source of severe complications. Its diagnosis by culture suffers from a lack of sensitivity and delays the result, preventing an early initiation of optimal antibiotic therapy in some cases. Our aim was to test a new rapid immuno-enzymatic method for Campylobacter spp. diagnosis in comparison to a composite reference standard (CRS). Stool samples from the French National Reference Center for Campylobacter and Helicobacter were tested with the CAMPYLOBACTER QUIK CHEK™ (Abbott). The CRS used to consider a case positive for Campylobacter spp. was a positive culture and, in case of a negative culture, a positive result obtained with both an ELISA and a molecular test. One hundred and eight stools were included: 53 were positive according to the CRS. If performed alone, culture would have missed 5 cases which the CAMPYLOBACTER QUIK CHEK™ detected. Finally, the CAMPYLOBACTER QUIK CHEK™ showed a sensitivity of 96.2% and a specificity of 94.5% and is relevant for clinical practice. Given the characteristics of the new method, it can be used as a screening method for Campylobacter spp. detection.
ABSTRACT
BACKGROUND: The main cause of gastric cancer is the infection by the bacterium Helicobacter pylori which induces a chronic inflammation and an epithelial-to-mesenchymal transition (EMT) leading to the emergence of cells with cancer stem cell (CSC) properties. However, the underlying mechanisms have not been fully characterized. Moreover, H. pylori modulates the host cell autophagic process, but a few studies have investigated the role of this process in tumoral transformation. The aim of this study was to determine whether H. pylori-induced autophagy has a role in CSC emergence. METHODS: Autophagic flux in response to H. pylori infection was characterized in AGS cell line expressing the tandem-tagged mCherry-GFP-LC3 protein and using a ratiometric flow cytometry analysis. Then, AGS and MKN45 cell lines were treated with bafilomycin or chloroquine, two pharmaceutical well-known inhibitors of autophagy, and different EMT and CSC characteristics were analyzed. RESULTS: First, a co-expression of the gastric CSC marker CD44 and the autophagic marker LC3 in mice and human stomach tissues infected with H. pylori was observed. Then, we demonstrated in vitro that H. pylori was able to activate the autophagy process with a reduced autophagic flux. Finally, infected cells were treated with autophagy inhibitors, which reduced (i) appearance of mesenchymal phenotypes and migration ability related to EMT and (ii) CD44 expression as well as tumorsphere formation capacities reflecting CSC properties. CONCLUSION: In conclusion, all these data show that H. pylori-induced autophagy is implicated in gastric CSC emergence and could represent an interesting therapeutic target.
Subject(s)
Autophagy/physiology , Helicobacter Infections/microbiology , Helicobacter pylori/physiology , Neoplastic Stem Cells/microbiology , Stomach Neoplasms/microbiology , Animals , Cell Line, Tumor , Epithelial-Mesenchymal Transition , Helicobacter Infections/complications , Humans , Hyaluronan Receptors/metabolism , Mice , Microtubule-Associated Proteins/metabolism , Stomach/cytology , Stomach/microbiologyABSTRACT
BACKGROUND AND OBJECTIVES: Surveillance of Helicobacter pylori resistance to antibiotics was carried out in France in 2014, 2016, and 2018. We report here the results of the 2018 survey as well as the evolution over the 5-year period. MATERIALS AND METHODS: In this observational study, gastric biopsies were obtained by 62 gastroenterologists randomly selected in 5 regions of France and sent to a central laboratory where culture, antimicrobial susceptibility testing, and a real-time PCR were performed in order to detect H pylori and its mutations associated with clarithromycin resistance. RESULTS AND CONCLUSION: During the year 2018, 951 patients were included: 55.3% women, mean age: 52.4 years ± 15.7, 71.6% born in France. Among them, 359 patients were H pylori positive by both culture and real-time PCR, and 7 more by PCR only. There were 244 naive patients, 110 previously treated patients, and unknown for 5. Primary resistance to clarithromycin was 20.9% [16.3-26.4], to levofloxacin 17.6% [13.4-22.9], and to metronidazole 58.6% [52.3%-64.6%]. Secondary resistance for these antibiotics was 56.4%, 22.7%, and 87.3%, respectively. There was no resistance to amoxicillin and tetracycline and very low resistance to rifampicin (1.2%) in both naive and treated patients. Primary resistance to clarithromycin decreased from 22.2% to 20.3% between 2014 and 2016, and appears to be stable since then. This can be linked to a stable consumption of macrolides over the 3-year time period. Primary levofloxacin resistance was relatively stable while metronidazole resistance increased. Interestingly, in both naive and treated patients, amoxicillin and rifampicin resistance were rare.