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OBJECTIVES: Clinical studies revealed that early-life adverse events contribute to the development of IBS in adulthood. The aim of our study was to investigate the relationship between prenatal stress (PS), gut microbiota and visceral hypersensitivity with a focus on bacterial lipopeptides containing γ-aminobutyric acid (GABA). DESIGN: We developed a model of PS in mice and evaluated, in adult offspring, visceral hypersensitivity to colorectal distension (CRD), colon inflammation, barrier function and gut microbiota taxonomy. We quantified the production of lipopeptides containing GABA by mass spectrometry in a specific strain of bacteria decreased in PS, in PS mouse colons, and in faeces of patients with IBS and healthy volunteers (HVs). Finally, we assessed their effect on PS-induced visceral hypersensitivity. RESULTS: Prenatally stressed mice of both sexes presented visceral hypersensitivity, no overt colon inflammation or barrier dysfunction but a gut microbiota dysbiosis. The dysbiosis was distinguished by a decreased abundance of Ligilactobacillus murinus, in both sexes, inversely correlated with visceral hypersensitivity to CRD in mice. An isolate from this bacterial species produced several lipopeptides containing GABA including C14AsnGABA. Interestingly, intracolonic treatment with C14AsnGABA decreased the visceral sensitivity of PS mice to CRD. The concentration of C16LeuGABA, a lipopeptide which inhibited sensory neurons activation, was decreased in faeces of patients with IBS compared with HVs. CONCLUSION: PS impacts the gut microbiota composition and metabolic function in adulthood. The reduced capacity of the gut microbiota to produce GABA lipopeptides could be one of the mechanisms linking PS and visceral hypersensitivity in adulthood.
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Microbioma Gastrointestinal , Síndrome del Colon Irritable , Masculino , Femenino , Ratones , Animales , Síndrome del Colon Irritable/microbiología , Disbiosis , Heces/microbiología , InflamaciónRESUMEN
A whole-genome sequencing (WGS) approach was conducted in order to identify the molecular determinants associated with antimicrobial resistance in 12 multidrug-resistant Campylobacter jejuni and Campylobacter coli isolates, with a focus on aminoglycoside resistance determinants. Two variants of a new aminoglycoside phosphotransferase gene [aph(2â³)-Ii1 and aph(2â³)-Ii2 ] putatively associated with gentamicin resistance were found. In addition, the following new genes were identified for the first time in Campylobacter: a lincosamide nucleotidyltransferase gene [lnu(G)], likely associated with lincomycin resistance, and two resistance enzyme genes (spw and apmA) similar to those found in Staphylococcus aureus, which may confer spectinomycin and gentamicin resistance, respectively. A C1192T mutation of the 16S rRNA gene that may be involved in spectinomycin resistance was also found in a C. coli isolate. Genes identified in the present study were located either on the bacterial chromosome or on plasmids that could be transferred naturally. Their role in aminoglycoside resistance remains to be supported by genetic studies. Regarding the other antimicrobial agents studied, i.e., ampicillin, ciprofloxacin, erythromycin, and tetracycline, a perfect correlation between antimicrobial phenotypes and genotypes was found. Overall, our data suggest that WGS analysis is a powerful tool for identifying resistance determinants in Campylobacter and can disclose the full genetic elements associated with resistance, including antimicrobial compounds not tested routinely in antimicrobial susceptibility testing.
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Aminoglicósidos/farmacología , Antibacterianos/farmacología , Infecciones por Campylobacter/microbiología , Campylobacter/genética , Campylobacter/aislamiento & purificación , Farmacorresistencia Bacteriana Múltiple/genética , Genoma Bacteriano/genética , Animales , Proteínas Bacterianas/genética , Campylobacter/clasificación , Campylobacter/efectos de los fármacos , Campylobacter coli/clasificación , Campylobacter coli/efectos de los fármacos , Campylobacter coli/genética , Campylobacter coli/aislamiento & purificación , Campylobacter jejuni/clasificación , Campylobacter jejuni/efectos de los fármacos , Campylobacter jejuni/aislamiento & purificación , ADN Bacteriano/genética , Humanos , Mutación , Filogenia , Plásmidos , ARN Ribosómico 16S/genética , Carne Roja/microbiología , Análisis de Secuencia de ADNRESUMEN
APRIL is a member of the tumor necrosis factor cytokine family involved in the regulation of B-cell immunity. We present a study of the infection by Helicobacter species of transgenic (Tg) C57BL6 mice, ectopically expressing the human form of APRIL. Wild-type (WT) and APRIL Tg mice were infected with Helicobacter felis and Helicobacter pylori and compared with noninfected animals. Mice were euthanized 18 months after infection, and inflammatory responses and histologic alterations were analyzed. Flow cytometry results revealed that WT-infected mice had less leukocyte infiltration than APRIL Tg-infected mice. In WT-infected mice, infiltrates in gastric tissues were predominantly composed of T cells, mainly CD4+ for H. pylori and CD8+ for H. felis. In APRIL Tg-infected mice, leukocyte infiltrates were composed of B cells with few CD4+ T cells for both species. B cells expressed B surface markers compatible with a marginal zone origin. These results were confirmed by immunohistochemistry. B cells in particular were involved in lymphoepithelial lesions, a hallmark of gastric MALT lymphoma. Monoclonality was observed in a few infiltrates in the presence of lymphoepithelial lesions. These results confirm the importance of APRIL in the development of gastric lymphoid infiltrates induced by Helicobacter species in vivo. We believe that APRIL Tg mice infected by Helicobacter species may represent a novel animal model of gastric lymphomagenesis.
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Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Linfoma de Células B de la Zona Marginal/microbiología , Linfoma no Hodgkin/microbiología , Neoplasias Gástricas/microbiología , Animales , Linfocitos B/microbiología , Linfocitos B/patología , Carga Bacteriana , Linfocitos T CD4-Positivos/microbiología , Linfocitos T CD4-Positivos/patología , Modelos Animales de Enfermedad , Femenino , Infecciones por Helicobacter/inmunología , Infecciones por Helicobacter/patología , Humanos , Inmunohistoquímica , Inflamación , Tejido Linfoide/microbiología , Tejido Linfoide/patología , Linfoma de Células B de la Zona Marginal/inmunología , Linfoma de Células B de la Zona Marginal/patología , Linfoma no Hodgkin/inmunología , Linfoma no Hodgkin/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Estómago/microbiología , Estómago/patología , Neoplasias Gástricas/inmunología , Neoplasias Gástricas/patología , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/genética , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/inmunologíaRESUMEN
There is progress in endoscopy techniques. While it is not yet possible to detect Helicobacter pylori directly in the stomach, it becomes easier to detect the mucosal changes induced by the bacteria. Some small changes can also increase the sensitivity of the invasive tests, for example culture or histology, but the wide use of proton-pump inhibitors has a negative impact on these tests. Only molecular methods are able to detect a limited load of bacteria, especially by using real-time PCR but also with new methods, for example dual-priming oligonucleotide-based PCR, loop-medicated isothermal amplification, droplet-digital PCR or a multiple genetic analysis system. Among the noninvasive tests, urea breath test remains a test of major interest, while there are attempts to develop an ammonia breath test and other nanosensor devices. A new antigen stool test, a chemoluminescence immunoassay using the LIAISON apparatus has also been tested for the first time with success. Despite its limitations, serology remains the most popular test to detect H. pylori antibodies. It also allows pepsinogen dosage which is of interest for detecting atrophy.
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Pruebas Diagnósticas de Rutina/métodos , Infecciones por Helicobacter/diagnóstico , Pruebas Respiratorias , Helicobacter pylori/aislamiento & purificación , Humanos , Inmunoensayo , Técnicas de Diagnóstico Molecular/métodosAsunto(s)
Antibacterianos/farmacología , Complejo Burkholderia cepacia/efectos de los fármacos , Burkholderia gladioli/efectos de los fármacos , Fibrosis Quística/microbiología , Bacterias Gramnegativas/efectos de los fármacos , beta-Lactamas/farmacología , Compuestos de Azabiciclo/farmacología , Ceftazidima/farmacología , Cefalosporinas/farmacología , Combinación de Medicamentos , Humanos , Pruebas de Sensibilidad Microbiana , Tazobactam/farmacología , beta-Lactamas/clasificaciónRESUMEN
INTRODUCTION: The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs. METHODS: We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated. RESULTS: Our study comprised 6,774 ESCPM isolates. MALDI-TOF coupled to mass spectrometry was the predominant technique for bacterial identification. Susceptibility to new ß-lactam/ß-lactamase inhibitor combinations and confirmation of AmpC overproduction were routinely tested in 33.3% and 29.6% of the centres, respectively. The most prevalent species were E. cloacae complex (44.8%) and S. marcescens (22.7%). Overall, third-generation cephalosporins (3GC), combined third- and fourth-generation cephalosporins (3GC + 4GC) and carbapenems resistance phenotypes were observed in 15.7%, 4.6%, and 9.5% of the isolates, respectively. AmpC overproduction was the most prevalent resistance mechanism detected (15.8%). Among carbapenemase-producers, carbapenemase type was provided in 44.4% of the isolates, VIM- (22.9%) and OXA-48-enzyme (16%) being the most frequently detected. E. cloacae complex, K. aerogenes and Providencia species exhibited the most notable cumulative antimicrobial resistance profiles, with the former displaying 3GC, combined 3GC + 4GC and carbapenems resistance phenotypes in 15.2%, 7.4%, and 12.8% of the isolates, respectively. K. aerogenes showed the highest rate of both 3GC resistant phenotype (29.8%) and AmpC overproduction (32.1%), while Providencia species those of both carbapenems resistance phenotype (42.7%) and carbapenemase production (29.4%). ESCPM isolates exhibiting both 3GC and combined 3GC + 4GC resistance phenotypes displayed high susceptibility to ceftazidime/avibactam (98.2% and 95.7%, respectively) and colistin (90.3% and 90.7%, respectively). Colistin emerged as the most active drug against ESCPM species (except those intrinsically resistant) displaying both carbapenems resistance phenotype (85.8%) and carbapenemase production (97.8%). CONCLUSIONS: This study presented a current analysis of ESCPM species epidemiology in Europe, providing insights to inform current antibiotic treatments and guide strategies for antimicrobial stewardship and diagnostics.
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Antibacterianos , Proteínas Bacterianas , Infecciones por Enterobacteriaceae , Enterobacteriaceae , Pruebas de Sensibilidad Microbiana , beta-Lactamasas , Humanos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Europa (Continente)/epidemiología , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Estudios Retrospectivos , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Antibacterianos/farmacología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Enterobacteriaceae/enzimología , Enterobacteriaceae/aislamiento & purificación , Hospitales , Inhibidores de beta-Lactamasas/farmacología , Farmacorresistencia Bacteriana MúltipleRESUMEN
BACKGROUND: Endometrial cancer is the most common pelvic gynecological cancer in France. The most frequent symptom is post-menopausal bleeding and is one of the primary reasons for consultation in gynecological emergencies. The treatment is very codified and consists of a surgical intervention for anatomopathological analysis. The latter is frequently reassuring. These interventions are often performed in mild situations and there is currently no element to be sufficiently reassuring to avoid surgery. This study aims to explore the sensitivity of an innovative marker: Human Epididymis 4 (HE4) in the diagnosis approach of endometrial cancer in case of postmenopausal bleedings. METHODS: This is a prospective multicenter diagnostic study with three centers involved. Inclusion criteria are any patient with post-menopausal bleeding who is to undergo hysteroscopy, endometrial biopsy, or endometrial resection. In accordance with the recommendations for the management of post-menopausal bleedings, the medical conduct consists of performing a clinical examination, an ultrasound and, in general, even in case of paraclinical examination reassuring, an anatomopathological analysis. This pathological analysis can be obtained in several ways: biopsy, hysteroscopy-curettage (which is the most frequently performed surgery), and hysterectomy. Our protocol consists of taking a blood sample from each woman who will undergo one of the interventions mentioned above. The dosage of HE4 and CA125 requires the withdrawal of an additional heparinized tube during the preoperative assessment usually performed. This research is therefore classified as non-interventional. The primary outcome is to evaluate the sensitivity of the HE4 marker in patients with postmenopausal bleeding in the diagnosis of endometrial cancer. The secondary outcomes are other parameters (specificity, VPP, VPN) of HE4, Evaluating the diagnostic capabilities of the CA125 marker alone and associated with HE4, as well as those of the REM and REM-B algorithms. We aim to include 100 patients over a period of one year in three centers. DISCUSSION: As of now, there is no biological marker used in routine practice in the diagnosis of endometrial cancer. The ultimate goal of HE4 in endometrial cancer is to avoid surgery for those who are identified as non-sick. This study is the precursor of others for use in routine practice, HE4 would represent a great help to diagnosis if our study demonstrates it as reliable in the management of these patients and avoid many unnecessary and risky surgeries.
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The genotoxin colibactin produced by resident bacteria of the gut microbiota may have tumorigenic effect by inducing DNA double-strand breaks in host cells. Yet, the effect of colibactin on gut microbiota composition and functions remains unknown. To address this point, we designed an experiment in which pregnant mice were colonized with the following: (i) a commensal Escherichia coli strain, (ii) a commensal E. coli strain plus a genotoxic E. coli strain, (iii) a commensal E. coli strain plus a nongenotoxic E. coli mutant strain unable to produce mature colibactin. Then, we analyzed the gut microbiota in pups at day 15 and day 35 after birth. At day 15, mice that were colonized at birth with the genotoxic strain showed lower levels of Proteobacteria and taxa belonging to the Proteobacteria, a modest effect on overall microbial diversity, and no effect on gut microbiome. At day 35, mice that received the genotoxic strain showed lower Firmicutes and taxa belonging to the Firmicutes, together with a strong effect on overall microbial diversity and higher microbial functions related to DNA repair. Moreover, the genotoxic strain strongly affected gut microbial diversity evolution of pups receiving the genotoxic strain between day 15 and day 35. Our data show that colibactin, beyond targeting the host, may also exert its genotoxic effect on the gut microbiota.IMPORTANCE Infections of genotoxic Escherichia coli spread concomitantly with urbanized progression. These bacteria may prompt cell senescence and affect DNA stability, inducing cancer via the production of colibactin, a genotoxin shown capable of affecting host DNA in eukaryotic cells. In this study, we show that the action of colibactin may also be directed against other bacteria of the gut microbiota in which genotoxic E. coli bacteria have been introduced. Indeed, the presence of genotoxic E. coli induced a change in both the structure and function of the gut microbiota. Our data indicate that genotoxic E. coli may use colibactin to compete for gut niche utilization.
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Escherichia coli/fisiología , Microbioma Gastrointestinal , Mutágenos , Péptidos/genética , Animales , Bacterias/clasificación , Daño del ADN , Escherichia coli/genética , Femenino , Interacciones Microbiota-Huesped , Ratones , Péptidos/metabolismo , Policétidos/metabolismo , Embarazo , Organismos Libres de Patógenos Específicos , SimbiosisRESUMEN
INTRODUCTION: Capnocytophaga spp. is a slow-growing bacterium that forms a part of the normal oral flora of dogs and cats. In peritoneal dialysis, only seven cases have been reported. We report the observation of a case of peritonitis with Capnocytophaga spp. in a patient on peritoneal dialysis who lives with a cat. CASE REPORT: A 64-year-old woman with chronic end stage renal disease due to chronic interstitial nephropathy on automated peritoneal dialysis has been admitted for diffuse abdominal pain. The dialysis fluid was cloudy with 11,250 elements/mm3, of leukocytes. Direct examination was negative. The C-reactive protein was 165mg/L. Intraperitoneal probabilistic antibiotic therapy was initiated 1g of cefazolin and 1g of ceftazidime per day. After eight days, aerobic culture was negative, the anaerobic one was positive to gram negative bacilli, but the identification could not be possible with MALDI-TOF mass spectrometry. Antibiotic therapy was continued by ceftazidime for 21 days. The evolution was marked by the improvement of the clinical and biological state of the patient. The germ was finally identified using the genomic 16S rRNA sequencing technique. This is Capnocytophaga spp. Investigation then revealed that the patient's cat sometimes entered her room at the time of connection of peritoneal dialysis. CONCLUSION: The case of our patient once again reveals the diagnostic difficulties posed by Capnocytophaga spp. Innovative techniques, such as MALDI-TOF-MS or genomic sequencing of ribosomal RNA, should be further used in peritoneal dialysis in the diagnosis of peritonitis.
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Capnocytophaga , Infecciones por Bacterias Gramnegativas , Fallo Renal Crónico/terapia , Diálisis Peritoneal , Peritonitis/microbiología , Animales , Gatos , Femenino , Infecciones por Bacterias Gramnegativas/etiología , Humanos , Persona de Mediana EdadRESUMEN
Despite extensive research, the origin of Alzheimer's disease (AD) remains unknown. The role of infectious pathogens has recently emerged. Epidemiological studies have shown that Helicobacter pylori infection increases the risk of developing AD. We hypothesized that H. pylori-induced gastritis may be associated with a systemic inflammation and finally neuroinflammation. C57BL/6 mice were infected with H. pylori (nâ=â15) or Helicobacter felis (nâ=â13) or left uninfected (nâ=â9) during 18 months. Gastritis, amyloid deposition, astroglial and microglial cell area, and systemic and brain cytokines were assessed. The infection (H. felis> H. pylori) induced a severe gastritis and an increased neuroinflammation but without brain amyloid deposition or systemic inflammation.
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Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/microbiología , Encefalitis/etiología , Gastritis/complicaciones , Gastritis/microbiología , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/microbiología , Helicobacter pylori , Inflamación/complicaciones , Inflamación/microbiología , Animales , Astrocitos/patología , Química Encefálica , Citocinas/metabolismo , Helicobacter felis , Ratones , Ratones Endogámicos C57BL , Microglía/patología , Placa Amiloide/patologíaRESUMEN
The roles of the inflammatory response and production of a proliferation-inducing ligand (APRIL) cytokine in gastric mucosa-associated lymphoid tissue (MALT) lymphomagenesis induced by Helicobacter species infection are not clearly understood. We characterized the gastric mucosal inflammatory response associated with gastric MALT lymphoma (GML) and identified APRIL-producing cells in two model systems: an APRIL transgenic mouse model of GML induced by Helicobacter infection (Tg-hAPRIL) and human gastric biopsy samples from Helicobacter pylori-infected GML patients. In the mouse model, polarization of T helper 1 (tbet), T helper 2 (gata3), and regulatory T cell (foxp3) responses was evaluated by quantitative PCR. In humans, a significant increase in april gene expression was observed in GML compared to gastritis. APRIL-producing cells were eosinophilic polynuclear cells located within lymphoid infiltrates, and tumoral B lymphocytes were targeted by APRIL. Together, the results of this study demonstrate that the Treg-balanced inflammatory environment is important for gastric lymphomagenesis induced by Helicobacter species, and suggest the pro-tumorigenic potential of APRIL-producing eosinophils.
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Linfocitos B/inmunología , Eosinófilos/inmunología , Infecciones por Helicobacter , Linfoma de Células B de la Zona Marginal , Linfocitos T/inmunología , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/inmunología , Adulto , Animales , Femenino , Mucosa Gástrica/inmunología , Mucosa Gástrica/patología , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/inmunología , Infecciones por Helicobacter/patología , Humanos , Linfoma de Células B de la Zona Marginal/etiología , Linfoma de Células B de la Zona Marginal/inmunología , Linfoma de Células B de la Zona Marginal/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana EdadRESUMEN
This article summarizes the main findings concerning Helicobacter pylori associated with gastric MALT lymphoma (GML). Considered together, GML strains based on their virulence factor profile appear to be less virulent than those associated with peptic ulcers or gastric adenocarcinoma. A particular Lewis antigen profile has been identified in GML strains and could represent an alternative adaptive mechanism to escape the host immune response thereby allowing continuous antigenic stimulation of infiltrating lymphocytes.
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Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Linfoma de Células B de la Zona Marginal/etiología , Neoplasias Gástricas/etiología , Animales , Antígenos Bacterianos/genética , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Humanos , Lipopolisacáridos/inmunología , Factores de Virulencia/genética , Factores de Virulencia/metabolismoRESUMEN
Helicobacter pylori infection is considered as an excellent model of chronic inflammation-induced tumor development. Our project focuses on gastric MALT lymphoma (GML) related to H. pylori infection and mediated by the chronic inflammatory process initiated by the infection. Recently, microRNAs (miRNAs) have emerged as a new class of gene regulators, which play key roles in inflammation and carcinogenesis acting as oncogenes or tumor suppressors. Their precise characterization in the development of inflammation and their contribution in regulating host cells responses to infection by H. pylori have been little explored. Our goal was to analyze the changes in miRNAs in a GML mouse model using BALB/c mice thymectomized at day 3 post-birth (d3Tx model) and to clarify their implication in GML pathogenesis. PCR array followed by RT-qPCR identified five miRNAs (miR-21a, miR-135b, miR-142a, miR-150, miR-155) overexpressed in the stomachs of GML-developing d3Tx mice infected by H. pylori. The analysis of their putative targets allowed us to identify TP53INP1, an anti-proliferative and pro-apoptotic protein, as a common target of 4 of the 5 up-regulated miRNAs. We postulate that these miRNAs may act in synergy to promote the development of GML. miR-142a was also overexpressed in mouse sera samples and therefore could serve as a diagnostic marker. In situ hybridization on gastric samples with miR-142a revealed a global up-regulation of this miRNA by the tumor microenvironment at the lymphoma stage. Dysregulation of miR-21a, miR-135b, miR-142a, miR-150, miR-155 could play a critical role in the pathogenesis of GML and might offer potential applications as therapeutic targets and novel biomarkers for this disease.
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Infecciones por Helicobacter/complicaciones , Helicobacter pylori/patogenicidad , Linfoma de Células B de la Zona Marginal/inmunología , Linfoma no Hodgkin/inmunología , MicroARNs/biosíntesis , MicroARNs/genética , Neoplasias Gástricas/inmunología , Animales , Apoptosis , Biomarcadores , Carcinogénesis , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Hibridación in Situ , Inflamación/inmunología , Inflamación/microbiología , Linfoma de Células B de la Zona Marginal/genética , Linfoma de Células B de la Zona Marginal/metabolismo , Linfoma no Hodgkin/genética , Linfoma no Hodgkin/metabolismo , Ratones , Ratones Endogámicos BALB C , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismoRESUMEN
It has been postulated that the emergence of autoimmune gastritis in neonatal thymectomised (d3Tx) BALB/c mice may be a consequence of post-surgery deficit in Tregs. In this study, previously obtained samples from d3Tx mice were used in order to determine whether thymectomy creates a deficit in this T cell subset thereby allowing the emergence of autoimmune phenomena as a prerequisite for GML. The splenic Treg reserve and the local recruitment of these cells in the gastric mucosa were investigated using complementary molecular and immunohistochemistry approaches. Higher Foxp3/CD3 ratios were found in the spleen of non-infected d3Tx mice compared to non-thymectomised (NTx) controls. These results indicate a relative enrichment of Tregs following thymectomy in adult mice. The absence of Treg depletion in d3Tx mice is in line with the absence of auto-immune gastritis in non-infected d3Tx mice. Higher levels of T cell and Treg infiltration were also found in the stomach of GML-developing d3Tx mice versus NTx mice. Surprisingly, inflammatory scores inversely correlated with the bacterial inoculum. The presence of a small Treg containing compartment among gastric biopsies of GML developing d3Tx mice may play a role in perseverance of a minimal bacterial numbers thereby maintaining an antigen-dependent stimulation and proliferation.
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Modelos Animales de Enfermedad , Mucosa Gástrica/inmunología , Infecciones por Helicobacter/inmunología , Helicobacter pylori/inmunología , Linfoma de Células B de la Zona Marginal/inmunología , Linfoma no Hodgkin/inmunología , Neoplasias Gástricas/inmunología , Linfocitos T Reguladores/inmunología , Animales , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/patología , Técnicas para Inmunoenzimas , Linfoma de Células B de la Zona Marginal/microbiología , Linfoma de Células B de la Zona Marginal/patología , Linfoma no Hodgkin/microbiología , Linfoma no Hodgkin/patología , Ratones , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patologíaRESUMEN
Antimicrobial susceptibility testing of Campylobacter isolates is of great importance for treatment options especially in systemic diseases. The European Committee for Antimicrobial Susceptibility Testing (EUCAST) recently proposed epidemiological cut-offs (ECOFFs) for a limited number of antimicrobial compounds and for Campylobacter jejuni and Campylobacter coli only. In the present study, the EUCAST method was used after minor modifications to define antimicrobial susceptibility patterns for, 1997 C. jejuni, 419 C. coli and 100 Campylobacter fetus strains received at the French National Reference Center for Campylobacters and Helicobacters. Our results show that the ECOFFs defined by EUCAST for tetracycline and ciprofloxacin can be used for C. jejuni and C. coli. The same ECOFF can be used for erythromycin for the three species. The C. jejuni and C. coli ECOFFs for ciprofloxacin however cannot be applied to C. fetus. We also provide data to categorise two 2 ß-lactams of interest for systemic diseases, ampicillin and amoxicillin+clavulanate, for the three species.
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Antibacterianos/farmacología , Infecciones por Campylobacter/microbiología , Campylobacter/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Campylobacter/clasificación , Campylobacter/genética , Campylobacter/aislamiento & purificación , Infecciones por Campylobacter/tratamiento farmacológico , Europa (Continente) , HumanosRESUMEN
Gastric MALT lymphoma (GML) can be induced by Helicobacter pylori infection in BALB/c mice thymectomised at day 3 post-birth (d3Tx). This represented a unique opportunity to investigate the inflammatory process involved in the recruitment, proliferation and structuration of lymphoid infiltrates in the gastric mucosa of mice developing GML. Complementary molecular and proteomic approaches demonstrated that Th1 and Th2 cytokines were upregulated, along with activators/regulators of the lymphoid response and numerous chemokines. Interleukin-4, interferon γ, lymphotoxin-α and -ß were significantly upregulated and correlated with the inflammatory scores for all the d3Tx mice. GML lesions in d3Tx mice infected with H. pylori were associated with the presence of the inflammatory response. The dysregulation of numerous members of the tumour necrosis factor superfamily was also evident and suggests that they could play an important role in GML pathology, especially in light of their ability to promote and control lymphocyte proliferation.
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Infecciones por Helicobacter/inmunología , Inflamación/inmunología , Linfoma de Células B de la Zona Marginal/inmunología , Neoplasias Gástricas/inmunología , Animales , Citocinas/análisis , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Inflamación/microbiología , Inflamación/patología , Linfoma de Células B de la Zona Marginal/microbiología , Linfoma de Células B de la Zona Marginal/patología , Ratones , Ratones Endogámicos BALB C , Reacción en Cadena de la Polimerasa , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patologíaRESUMEN
Helicobacter pylori (H. pylori) infection triggers a sequence of gastric alterations starting with an inflammation of the gastric mucosa that, in some cases, evolves to gastric cancer. Efficient vaccination has not been achieved, thus it is essential to find alternative therapies, particularly in the nutritional field. The current study evaluated whether curcumin could attenuate inflammation of the gastric mucosa due to H. pylori infection. Twenty-eight C57BL/6 mice, were inoculated with the H. pylori SS1 strain; ten non-infected mice were used as controls. H. pylori infection in live mice was followed-up using a modified 13C-Urea Breath Test (13C-UBT) and quantitative real-time polymerase chain reaction (PCR). Histologically confirmed, gastritis was observed in 42% of infected non-treated mice at both 6 and 18 weeks post-infection. These mice showed an up-regulation of the expression of inflammatory cytokines and chemokines, as well as of toll-like receptors (TLRs) and MyD88, at both time points. Treatment with curcumin decreased the expression of all these mediators. No inflammation was observed by histology in this group. Curcumin treatment exerted a significant anti-inflammatory effect in H. pylori-infected mucosa, pointing to the promising role of a nutritional approach in the prevention of H. pylori induced deleterious inflammation while the eradication or prevention of colonization by effective vaccine is not available.
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Curcumina/farmacología , Gastritis/microbiología , Gastritis/prevención & control , Infecciones por Helicobacter/prevención & control , Animales , Antiinflamatorios/farmacología , Modelos Animales de Enfermedad , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/microbiología , Helicobacter pylori/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Regulación hacia ArribaRESUMEN
BACKGROUND: A gamma-glutamyl transpeptidase (GGT) is produced by up to 31% of strains of Campylobacter jejuni isolates. C. jejuni GGT is close to Helicobacter pylori GGT suggesting a conserved activity but unlike the latter, C. jejuni GGT has not been studied extensively. In line with the data available for H. pylori, our objectives were to purify C. jejuni GGT from the bacteria, and to evaluate its inhibitory and proapoptotic activities on epithelial cells and human lymphocytes. METHODS: C. jejuni GGT was purified from culture supernatants by chromatography. After verification of the purity by using mass spectrometry of the purified enzyme, its action on two epithelial cell lines and human lymphocytes was investigated. Cell culture as well as flow cytometry experiments were developed for these purposes. RESULTS: This study demonstrated that C. jejuni GGT is related to Helicobacter GGTs and inhibits the proliferation of epithelial cells with no proapoptotic activity. C. jejuni GGT also inhibits lymphocyte proliferation by causing a cell cycle arrest in the G0/G1 phase. These effects are abolished in the presence of a specific pharmacological inhibitor of GGT. CONCLUSION: C. jejuni GGT activity is comparable to that of other Epsilonproteobacteria GGTs and more generally to Helicobacter bilis (inhibition of epithelial cell and lymphocyte proliferation, however with no proapoptotic activity). It could therefore be considered as a pathogenicity factor and promote, via the inhibition of lymphocyte proliferation, the persistence of the bacteria in the host. These observations are consistent with a role of this enzyme in the pathophysiology of chronic infections associated with C. jejuni.
RESUMEN
The recently developed rapid immunochromatographic tests (ICT) have the potential to provide a quick and easy diagnosis of Campylobacter enteritis in comparison to culture. In a previous study we found them sensitive but lacking in specificity. The aim of the present study was to focus on the problem of specificity and determine the positive predictive value (PPV) of a positive result of the ImmunoCard Stat! Campy (Meridian Bioscience, Cincinnati, OH, USA). For this purpose, the stools positive by ICT were cultured according to 3 different protocols: Karmali agar, Preston enrichment broth subcultured on Karmali agar, and a filtration method on a blood agar without antibiotics, all incubated for 7 days at 37°C. Out of 609 stools from adults and children with community acquired enteritis, the reference methods detected 25 positive cases (4.1%) (culture: 19, specific PCR and ELISA both positive: 6) and the ICT: 31 including the 25 true positives. The PPV was 80.6%. We conclude that ICT is a good method to screen Campylobacter positive stools but because of its lack of specificity the positive stools must be tested by another method.