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1.
Mol Cell ; 80(2): 175-177, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33065017

RESUMO

Eisenbart et al. (2020) find an SSR-associated sRNA, NikS, that is subject to variable repeat-controlled expression. NikS regulates H. pylori virulence by post-transcriptionally repressing pathogenicity factors, including CagA and VacA, via base-pairing to their mRNAs.


Assuntos
Helicobacter pylori , Fatores de Virulência , DNA , Regulação Bacteriana da Expressão Gênica , Helicobacter pylori/genética , RNA Bacteriano/genética , Virulência/genética
2.
Anticancer Res ; 40(11): 6387-6398, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33109577

RESUMO

BACKGROUND/AIM: Helicobacter pylori (Hp) infection affects a substantial proportion of the world population and is a major risk factor of gastric cancer (GC). The caveats of common Hp-tests can be evaded by a serological biomarker test (GastroPanel®, Biohit Oyj, Helsinki), the most comprehensive Hp-test on the market. The clinical validation of Helicobacter pylori IgG ELISA of the new-generation GastroPanel® test is reported. The aim of the study is to validate the clinical performance of the Helicobacter pylori IgG ELISA test in diagnosis of biopsy-confirmed Hp-infection in gastroscopy referral patients. PATIENTS AND METHODS: A cohort of 101 patients (mean age=50.1 years) referred for gastroscopy at the outpatient Department of Gastroenterology (SM Clinic, St. Petersburg) were examined by two test versions to validate the new-generation GastroPanel®. All patients were examined by gastroscopy and biopsies, which were stained with Giemsa for specific identification of Hp in the antrum (A) and corpus (C). RESULTS: Biopsy-confirmed Hp-infection was found in 64% of patients, most often confined to antrum. The overall agreement between Hp IgG ELISA and gastric biopsies in Hp-detection was 91% (95%CI=84.1-95.8%). Hp IgG ELISA diagnosed biopsy-confirmed Hp (A&C) with sensitivity (SE) of 92.3%, specificity (SP) of 88.6%, positive predictive value (PPV) of 93.8% and negative predictive value (NPV) of 86.1%, with AUC=0.904 (95%CI=0.842-0.967). In ROC analysis for Hp detection (A&C), Hp IgG ELISA shows AUC=0.978 (95%CI=0.956-1.000). CONCLUSION: The Hp IgG ELISA test successfully concludes the clinical validation process of the new-generation GastroPanel® test, which retains the unrivalled diagnostic performance of all its four biomarkers, extensively documented for the first-generation test in different clinical settings.


Assuntos
Anticorpos Antibacterianos/isolamento & purificação , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Imunoglobulina G/isolamento & purificação , Adolescente , Adulto , Anticorpos Antibacterianos/genética , Anticorpos Antibacterianos/imunologia , Biópsia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Gastrinas/genética , Gastrinas/isolamento & purificação , Gastrite Atrófica/diagnóstico , Gastrite Atrófica/genética , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Gastroscopia/métodos , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Pepsinogênio A/genética , Pepsinogênio A/isolamento & purificação , Pepsinogênio C/genética , Pepsinogênio C/isolamento & purificação , Encaminhamento e Consulta , Estômago/microbiologia , Estômago/patologia , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia , Adulto Jovem
3.
Mol Cell ; 80(2): 210-226.e7, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33002424

RESUMO

Many bacterial pathogens regulate their virulence genes via phase variation, whereby length-variable simple sequence repeats control the transcription or coding potential of those genes. Here, we have exploited this relationship between DNA structure and physiological function to discover a globally acting small RNA (sRNA) regulator of virulence in the gastric pathogen Helicobacter pylori. Our study reports the first sRNA whose expression is affected by a variable thymine (T) stretch in its promoter. We show the sRNA post-transcriptionally represses multiple major pathogenicity factors of H. pylori, including CagA and VacA, by base pairing to their mRNAs. We further demonstrate transcription of the sRNA is regulated by the nickel-responsive transcriptional regulator NikR (thus named NikS for nickel-regulated sRNA), thereby linking virulence factor regulation to nickel concentrations. Using in-vitro infection experiments, we demonstrate NikS affects host cell internalization and epithelial barrier disruption. Together, our results show NikS is a phase-variable, post-transcriptional global regulator of virulence properties in H. pylori.


Assuntos
Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , RNA Bacteriano/genética , Sequências Repetitivas de Ácido Nucleico/genética , Fatores de Virulência/metabolismo , Proteínas de Bactérias/metabolismo , Sequência de Bases , Contagem de Colônia Microbiana , Endocitose/efeitos dos fármacos , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Helicobacter pylori/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Níquel/farmacologia , Fenótipo , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética/efeitos dos fármacos
4.
Acta Gastroenterol Belg ; 83(3): 385-392, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33094584

RESUMO

INTRODUCTION: As a component of the cag T4SS, the cagL gene is involved in the translocation of CagA into host cells and is essential for the formation of cag PAI-associated pili between H. pylori and gastric epithelial cells. AIM: We aimed to investigate the clinical association of the cagL gene with other virulence factors (VacA, CagA, EPIYA-C, and BabA protein) of H. pylori strains isolated from GC, duodenal ulcer (DU), and non-ulcer dyspepsia (NUD) cases. METHODS: The patient group (PG), including 47 patients (22 GC and 25 DU) and a 25 control group (CG= NUD) were included. Amplification of the H. pylori cagL, cagA, vacA, and babA2 genes and typing of EPIYA motifs were performed by PCR methods. RESULTS: Sixty-one (84.7%) H. pylori strains were detected with cagL (93.6% in SG, 68% in CG). We detected a significant difference between SG and CG for the presence of cagL (p=0.012) but no statistical comparison was done for (≥2) EPIYA-C repeats In the comparison of H. pylori strains with cagA/vacAs1m1 and cagA/ vacAs1m2 and babA2 for the presence of cagL, we could not detect a significant difference (p=1). CONCLUSION: We detected a significant difference between groups for the presence of cagL genotype (p=0.012). The vacAs1m1 (OR: 2.829), genotypes increased the GC and DU risk by 2.8 times, while multiple (≥2) EPIYA-C repeats incresed the GC and DU risk by 3.524 times. Gender (to be female) (OR: 0.454) decreased the GC and DU risk by inversly decreased in the multivariate analysis.


Assuntos
Neoplasias Duodenais , Úlcera Duodenal , Dispepsia , Infecções por Helicobacter , Helicobacter pylori , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Neoplasias Duodenais/genética , Neoplasias Duodenais/microbiologia , Úlcera Duodenal/genética , Úlcera Duodenal/microbiologia , Dispepsia/genética , Dispepsia/microbiologia , Feminino , Infecções por Helicobacter/complicações , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Humanos , Masculino , Úlcera
6.
Medicine (Baltimore) ; 99(32): e20761, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32769862

RESUMO

The regimens containing levofloxacin (LVX) have been recommended as an alternate to standard triple therapy to treat Helicobacter pylori infections and H pylori mixed infection always lead to H pylori chronic infection. Although the molecular mechanism of LVX resistance with gyrA gene mutation has been clearly understood in H pylori, other genes involved in antibiotic resistance remain unclear. Efflux pump plays an important role in clinically relevant multidrug resistance. Furthermore, the relationship between the strains with different LVX level-resistances from individuals is also unknown.Helicobacter pylori monoclonal strains were isolated from patients with eradication failure. E test was used to detect the minimal inhibitory concentration of LVX. One lower-level LVX-resistant clone and 2 higher-level LVX-resistant clones from the same patient were selected to sequence the complete genomes. Single-nucleotide variants (SNVs) and mutations were extracted and analyzed from gryA and resistance-nodulation-division family efflux genes.Two clones with higher-level resistance had the mutation pattern of Asn87Lys and one lower-level LVX-resistant clone had an Asp91Asn mutation. Compared to clones with higher-level resistance, the higher genetic variations were found in genes belonging to the resistance-nodulation-division family in H pylori strains with lower-level resistance to LVX. There were significantly more SNVs of Hp0970 (hefE) and Hp1329 (hefI) in the lower-level LVX-resistant clone than those in the higher-level LVX-resistant clones (P = .044).The mutation pattern of the Asn87Lys of the gyrA gene confers a higher resistance to LVX than that of the Asp91Asn in H pylori. Increase in the number of SNVs of the Hp0970 (hefE) and Hp1329 (hefI) genes change the resistance to LVX. Twelve mutations verified by Sanger sequencing in Hp0970 (hefE) and Hp1329 (hefI) may decrease resistant levels to LVX.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Levofloxacino/farmacologia , Mutação/genética , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
7.
Eur J Clin Microbiol Infect Dis ; 39(10): 1821-1830, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32557327

RESUMO

Helicobacter pylori (H. pylori) infection is associated with some gastric diseases, such as gastritis, peptic ulcer, and gastric cancer. CagA and VacA are known virulence factors of H. pylori, which play a vital role in severe clinical outcomes. Additionally, the expression of outer membrane proteins (OMPs) helps H. pylori attach to gastric epithelial cells at the primary stage and increases the virulence of H. pylori. In this review, we have summarized the paralogs of H. pylori OMPs, their genomic loci, and the different receptors of OMPs identified so far. We focused on five OMPs, BabA (HopS), SabA (HopP), OipA (HopH), HopQ, and HopZ, and one family of OMPs: Hom. We highlight the coexpression of OMPs with other virulence factors and their relationship with clinical outcomes. In conclusion, OMPs are closely related to the pathogenic processes of adhesion, colonization, persistent infection, and severe clinical consequences. They are potential targets for the prevention and treatment of H. pylori-related diseases.


Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Fatores de Virulência/metabolismo , Células Epiteliais/microbiologia , Expressão Gênica , Humanos , Fatores de Virulência/genética
8.
Environ Pollut ; 264: 114768, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32434114

RESUMO

Wastewater has become one of the most important and least expensive water for the agriculture sector, as well as an alternative to the overexploitation of water resources. However, inappropriate treatment before its reuse can result in a negative impact on the environment, such as the presence of pathogens. This poses an increased risk for environmental safety, which can subsequently lead to an increased risk for human health. Among all the emerging wastewater pathogens, bacteria of the genus Helicobacter are some of the most disturbing ones, since they are directly related to gastric illness and hepatobiliary and gastric cancer. Therefore, the aim of this study was to determine the presence of potentially pathogenic Helicobacter spp. in treated wastewater intended for irrigation. We used a next generation sequencing approach, based on Illumina sequencing in combination with culture and other molecular techniques (qPCR, FISH and DVC-FISH), to analyze 16 wastewater samples, with and without an enrichment step. By culture, one of the direct samples was positive for H. pylori. FISH and DVC-FISH techniques allowed for detecting viable Helicobacter spp., including H. pylori, in seven out of eight samples of wastewater from the tertiary effluents, while qPCR analysis yielded only three positive results. When wastewater microbiome was analyzed, Helicobacter genus was detected in 7 samples. The different molecular techniques used in the present study provided evidence, for the first time, of the presence of species belonging to the genus Helicobacter such as H. pylori, H. hepaticus, H. pullorum and H. suis in wastewater samples, even after disinfection treatment.


Assuntos
Helicobacter pylori/genética , Helicobacter , Humanos , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase em Tempo Real , Águas Residuárias
9.
Postgrad Med ; 132(6): 512-520, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32281451

RESUMO

Objectives: Helicobacter pylori (H. pylori) infection caused by antibiotic-resistant strains represents a major public health threat that aggressively promotes gastric cancer progression. Antibiotic resistance evaluation is immensely important to counteract its emergence. Here we merely determine the prevalence of antibiotic resistance in H. pylori isolates and its correlation with cagA motifs and the homB gene. Methods: The antibiotic resistance pattern was investigated on 128 H. pylori isolated strains utilizing the disk diffusion method and study the correlation between it and the presence of pathogenic genes, cagA EPIYA motifs and homB gene, were accurately detected using the PCR. Results: The resistance rates to four antibiotics were 70.1% for metronidazole, 35.5% for amoxicillin, 7.2% for clarithromycin and 8.2% for tetracycline. Resistance phenotypes were separated into two groups, single resistance (63.2%) and multi-resistance (12.5%). The prevalence of cagA-ABCC resistant strains and homB+ resistant strains was significantly higher in cancer (p = 0.04 and p = 0.01, respectively) than those of other diseases. The prevalence of cagA-homB + resistance strains was 21.8% and had a significant correlation with PUD. A significant relationship was observed between amoxicillin resistant rate with ABC-homB (p = 0.0006). Conclusion: The Resistance rate to selected antibiotics in Shiraz is higher than years ago. The presence of cagA-homB + is associated with antibiotic resistance and also homB can be used as a marker to antibiotic resistance status prediction in H. pylori isolated in this area.


Assuntos
Antibacterianos , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Adulto , Antibacterianos/classificação , Antibacterianos/farmacologia , Feminino , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
10.
J Nanobiotechnology ; 18(1): 63, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32316990

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) infect more than half of the world population, and they cause different serious diseases such as gastric carcinomas. This study aims to design a vaccine on the basis of cagW against H. pylori infection. After pcDNA3.1 (+)-cagW-CS-NPs complex is produced, it will be administered into the muscles of healthy BALB/c mice in order to study the effect of this DNA vaccine on the interleukin status of mice, representing its effect on the immune system. After that, the results will be compared with the control groups comprising the administration of cagW-pCDNA3.1 (+) vaccine, the administration of chitosan and the administration of PBS in the muscles of mice. METHODS: The cagW gene of H. pylori was amplified by employing PCR, whose product was then cloned into the pcDNA3.1 (+) vector, and this cloning was confirmed by PCR and BamHI/EcoRV restriction enzyme digestion. CagW gene DNA vaccine was encapsulated in chitosan nanoparticles (pcDNA3.1 (+)-cagW-CS-NPs) using a complex coacervation method. The stability and in vitro expression of chitosan nanoparticles were studied by DNase I digestion and transfection, and the immune responses elicited in specific pathogen-free (SPF) mice by the pcDNA3.1 (+)-cagW-CS-NPs were evaluated. Apart from that, the protective potential pcDNA3.1 (+)-cagW-CS-NPs was evaluated by challenging with H. pylori. RESULTS: The pcDNA3.1 (+)-cagW-CS-NPs comprises cagW gene of H. pylori that is encapsulated in chitosan nanoparticles, produced with good morphology, high stability, a mean diameter of 117.7 nm, and a zeta potential of + 5.64 mV. Moreover, it was confirmed that chitosan encapsulation protects the DNA plasmid from DNase I digestion, and the immunofluorescence assay showed that the cagW gene could express in HDF cells and maintain good bioactivity at the same time. In comparison to the mice immunized with the control plasmid, in vivo immunization revealed that mice immunized with pcDNA3.1 (+)-cagW-NPs showed better immune responses and prolonged release of the plasmid DNA. CONCLUSIONS: This research proves chitosan-DNA nanoparticles as potent immunization candidates against H. pylori infection and paves the way for further developments in novel vaccines encapsulated in chitosan nanoparticles.


Assuntos
Proteínas de Bactérias/genética , Infecções por Helicobacter/prevenção & controle , Vacinas de DNA/imunologia , Fatores de Virulência/genética , Animais , Anticorpos Antibacterianos/sangue , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Quitosana/química , Modelos Animais de Doenças , Infecções por Helicobacter/patologia , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Imunidade Celular , Interferon gama/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Plasmídeos/genética , Plasmídeos/metabolismo , Transfecção/métodos
11.
Aliment Pharmacol Ther ; 51(8): 770-780, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32133670

RESUMO

BACKGROUND: Incidence and mortality of gastric cancer (GC) are high in Mongolia despite Helicobacter pylori in the Mongolian population being less virulent. AIM: To evaluate gastric bacterial microbiota profiles in patients with GC and its precursor histological conditions. METHODS: We conducted a case-control study among 48 GC and 120 noncancer patients (20 normal gastric mucosa [control], 20 gastritis, 40 with atrophy and 40 intestinal metaplasia [IM]). We performed 16S rRNA gene amplicon sequencing and compared taxonomic and functional prediction profiles based on the diagnosis group and H pylori infection status. RESULTS: The highest overall bacterial alpha diversity metrics were observed in the control group, followed by the IM and cancer groups. The gastritis and atrophy groups had the least diversity. Lactobacilli and Enterococci were the dominant genus in several cancer patients especially in the absence of H pylori. In addition, Carnobacterium, Glutamicibacter, Paeniglutamicibacter, Fusobacterium and Parvimonas were associated with GC regardless of H pylori infection. Firmicutes were decreased in the gastritis and atrophy groups and increased in the IM and cancer groups. The functional metabolic activity of the Embden-Meyerhof-Parnas pathway and the utilization of sugar, were significantly increased in cancer group compared with the noncancer group. CONCLUSION: Microbial factors other than H pylori may play a role in Mongolian GC. We identified novel associations between GC and the genera Enterococcus, Lactobacillus, Carnobacterium, Glutamicibacter, Paeniglutamicibacter, Fusobacterium, and Parvimonas.


Assuntos
Mucosa Gástrica/patologia , Microbioma Gastrointestinal , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/microbiologia , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologia , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Estudos de Casos e Controles , Estudos Transversais , Feminino , Mucosa Gástrica/microbiologia , Gastrite/epidemiologia , Gastrite/microbiologia , Microbioma Gastrointestinal/genética , Infecções por Helicobacter/complicações , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/genética , Humanos , Incidência , Masculino , Metaplasia/complicações , Metaplasia/epidemiologia , Metaplasia/patologia , Pessoa de Meia-Idade , Mongólia/epidemiologia , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , Neoplasias Gástricas/patologia
12.
PLoS One ; 15(3): e0230366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32203539

RESUMO

Posttranslational generation of disulfide bonds catalyzed by bacterial Dsb (disulfide bond) enzymes is essential for the oxidative folding of many proteins. Although we now have a good understanding of the Escherichia coli disulfide bond formation system, there are significant gaps in our knowledge concerning the Dsb systems of other bacteria, including Campylobacter jejuni, a food-borne, zoonotic pathogen. We attempted to gain a more complete understanding of the process by thorough analysis of C8J_1298 functioning in vitro and in vivo. C8J_1298 is a homodimeric thiol-oxidoreductase present in wild type (wt) cells, in both reduced and oxidized forms. The protein was previously described as a homolog of DsbC, and thus potentially should be active in rearrangement of disulfides. Indeed, biochemical studies with purified protein revealed that C8J_1298 shares many properties with EcDsbC. However, its activity in vivo is dependent on the genetic background, namely, the set of other Dsb proteins present in the periplasm that determine the redox conditions. In wt C. jejuni cells, C8J_1298 potentially works as a DsbG involved in the control of the cysteine sulfenylation level and protecting single cysteine residues from oxidation to sulfenic acid. A strain lacking only C8J_1298 is indistinguishable from the wild type strain by several assays recognized as the criteria to determine isomerization or oxidative Dsb pathways. Remarkably, in C. jejuni strain lacking DsbA1, the protein involved in generation of disulfides, C8J_1298 acts as an oxidase, similar to the homodimeric oxidoreductase of Helicobater pylori, HP0231. In E. coli, C8J_1298 acts as a bifunctional protein, also resembling HP0231. These findings are strongly supported by phylogenetic data. We also showed that CjDsbD (C8J_0565) is a C8J_1298 redox partner.


Assuntos
Campylobacter jejuni/enzimologia , Dissulfetos/metabolismo , Proteínas Periplásmicas/metabolismo , Proteína Dissulfeto Redutase (Glutationa)/metabolismo , Sequência de Aminoácidos , Campylobacter jejuni/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Helicobacter pylori/enzimologia , Helicobacter pylori/genética , Oxirredução , Periplasma/enzimologia , Proteínas Periplásmicas/genética , Filogenia , Proteína Dissulfeto Redutase (Glutationa)/genética
13.
PLoS One ; 15(3): e0230220, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32163505

RESUMO

Helicobacter pylori is a Gram-negative bacterium that causes chronic atrophic gastritis and peptic ulcers and it has been associated with the development of gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT). One of the more remarkable characteristics of H. pylori is its ability to survive in the hostile environment of the stomach. H. pylori regulates the expression of specific sets of genes allowing it to survive high acidity levels and nutrient scarcity. In the present study, we determined the expression of virulence associated protein D (VapD) of H. pylori inside adenocarcinoma gastric (AGS) cells and in gastric biopsies. Using qRT-PCR, VapD expression was quantified in intracellular H. pylori-AGS cell cultures at different time points and in gastric mucosa biopsies from patients suffering from chronic atrophic gastritis, follicular gastritis, peptic ulcers, gastritis precancerous intestinal metaplasia and adenocarcinoma. Our results show that vapD of H. pylori presented high transcription levels inside AGS cells, which increased up to two-fold above basal values across all assays over time. Inside AGS cells, H. pylori acquired a coccoid form that is metabolically active in expressing VapD as a protection mechanism, thereby maintaining its permanence in a viable non-cultivable state. VapD of H. pylori was expressed in all gastric biopsies, however, higher expression levels (p = 0.029) were observed in gastric antrum biopsies from patients with follicular gastritis. The highest VapD expression levels were found in both antrum and corpus gastric biopsies from older patients (>57 years old). We observed that VapD in H. pylori is a protein that is only produced in response to interactions with eukaryotic cells. Our results suggest that VapD contributes to the persistence of H. pylori inside the gastric epithelial cells, protecting the microorganism from the intracellular environment, reducing its growth rate, enabling long-term infection and treatment resistance.


Assuntos
Proteínas de Bactérias/genética , Gastrite Atrófica/etiologia , Helicobacter pylori/genética , Glicoproteínas de Membrana/genética , Estômago/microbiologia , Estômago/patologia , Adenocarcinoma/etiologia , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Técnicas de Cocultura/métodos , Feminino , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Gastroscopia/métodos , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Humanos , Intestinos/microbiologia , Intestinos/patologia , Masculino , Metaplasia/microbiologia , Metaplasia/patologia , Pessoa de Meia-Idade , Úlcera Péptica/metabolismo , Úlcera Péptica/patologia , Lesões Pré-Cancerosas/etiologia , Lesões Pré-Cancerosas/microbiologia , Lesões Pré-Cancerosas/patologia , Antro Pilórico/microbiologia , Antro Pilórico/patologia , Neoplasias Gástricas/etiologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia , Virulência/genética , Adulto Jovem
14.
BMC Oral Health ; 20(1): 84, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32197614

RESUMO

BACKGROUND: There have been reports of Helicobacter pylori (H. pylori) in the oral cavity and it has been suggested that the oral cavity may be a reservoir for H. pylori reflux from the stomach. High-throughput sequencing was used to assess the structure and composition of oral microbiota communities in individuals with or without confirmed H. pylori infection. METHODS: Saliva samples were obtained from 34 H. pylori infected and 24 H. pylori uninfected subjects. Bacterial genomic DNA was extracted and examined by sequencing by amplification of the 16S rDNA V3-V4 hypervariable regions followed by bioinformatics analysis. Saliva sampling was repeated from 22 of the 34 H. pylori infected subjects 2 months after H. pylori eradication. RESULTS: High-quality sequences (2,812,659) clustered into 95,812 operational taxonomic units (OTUs; 97% identity). H. pylori was detected in the oral cavity in infected (12/34), uninfected (11/24) and eradicated (15/22) subjects by technique of high-throughput sequencing, occupying 0.0139% of the total sequences. Alpha diversity of H. pylori infected subjects was similar to that of uninfected subjects (Shannon: 1417.58 vs. 1393.60, p > 0.05, ACE: 1491.22 vs. 1465.97, p > 0.05, Chao 1: 1417.58 vs. 1393.60, p > 0.05, t-test). Eradication treatment decreased salivary bacterial diversity (Shannon, p = 0.015, ACE, p = 0.003, Chao 1, p = 0.002, t-test). Beta diversity analysis based on unweighted UniFrac distances showed that the salivary microbial community structure differed between H. pylori infected and uninfected subjects (PERMANOVAR, pseudo-F: 1.49, p = 0.033), as well as before and after H. pylori eradication (PERMANOVAR, pseudo-F: 3.34, p = 0.001). Using LEfSe analysis, 16 differentially abundant genera were defined between infected and uninfected subjects, 12 of which had a further alteration after successful eradication. CONCLUSIONS: Our study using high-throughput sequencing showed that H. pylori was present commonly in the oral cavity with no clear relation to H. pylori infection of the stomach. Both H. pylori infection and eradication therapy caused alterations in community and structure of the oral microbiota. TRIAL REGISTRATION: clinicaltrials.gov, NCT03730766. Registered 2 Nov 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/ NCT03730766.


Assuntos
Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Microbiota , Saliva/microbiologia , DNA Bacteriano/genética , Amplificação de Genes , Helicobacter pylori/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Boca/microbiologia , RNA Ribossômico 16S/genética
15.
Cancer Sci ; 111(5): 1596-1606, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32198795

RESUMO

Chronic infection with Helicobacter pylori cagA-positive strains is causally associated with the development of gastric diseases, most notably gastric cancer. The cagA-encoded CagA protein, which is injected into gastric epithelial cells by bacterial type IV secretion, undergoes tyrosine phosphorylation at the Glu-Pro-Ile-Tyr-Ala (EPIYA) segments (EPIYA-A, EPIYA-B, EPIYA-C, and EPIYA-D), which are present in various numbers and combinations in its C-terminal polymorphic region, thereby enabling CagA to promiscuously interact with SH2 domain-containing host cell proteins, including the prooncogenic SH2 domain-containing protein tyrosine phosphatase 2 (SHP2). Perturbation of host protein functions by aberrant complex formation with CagA has been considered to contribute to the development of gastric cancer. Here we show that SHIP2, an SH2 domain-containing phosphatidylinositol 5'-phosphatase, is a hitherto undiscovered CagA-binding host protein. Similar to SHP2, SHIP2 binds to the Western CagA-specific EPIYA-C segment or East Asian CagA-specific EPIYA-D segment through the SH2 domain in a tyrosine phosphorylation-dependent manner. In contrast to the case of SHP2, however, SHIP2 binds more strongly to EPIYA-C than to EPIYA-D. Interaction with CagA tethers SHIP2 to the plasma membrane, where it mediates production of phosphatidylinositol 3,4-diphosphate [PI(3,4)P2 ]. The CagA-SHIP2 interaction also potentiates the morphogenetic activity of CagA, which is caused by CagA-deregulated SHP2. This study indicates that initially delivered CagA interacts with SHIP2 and thereby strengthens H. pylori-host cell attachment by altering membrane phosphatidylinositol compositions, which potentiates subsequent delivery of CagA that binds to and thereby deregulates the prooncogenic phosphatase SHP2.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Células Epiteliais/metabolismo , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/metabolismo , Motivos de Aminoácidos , Animais , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Linhagem Celular , Membrana Celular/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Transição Epitelial-Mesenquimal , Mucosa Gástrica/microbiologia , Mucosa Gástrica/patologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Humanos , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/química , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases/genética , Fosforilação , Ligação Proteica , Transporte Proteico , Proteína Tirosina Fosfatase não Receptora Tipo 11/química , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Domínios de Homologia de src
16.
Biochem Biophys Res Commun ; 525(3): 806-811, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32164943

RESUMO

Helicobacter pylori, a pathogenic bacterium that colonizes in the human stomach, harbors DNA repair genes to counter the gastric environment during chronic infection. In addition, H. pylori adapts to the host environment by undergoing antigenic phase variation caused by genomic mutations. The emergence of mutations in nucleotide sequences is one of the major factors underlying drug resistance and genetic diversity in bacteria. However, it is not clear how DNA repair genes contribute to driving the genetic change of H. pylori during chronic infection. To elucidate the physiological roles of DNA repair genes, we generated DNA repair-deficient strains of H. pylori (ΔuvrA, ΔuvrB, ΔruvA, Δnth, ΔmutY, ΔmutS, and Δung). We performed susceptibility testing to rifampicin in vitro and found that ΔmutY exhibited the highest mutation frequency among the mutants. The number of bacteria colonizing the stomach was significantly lower with ΔmutY strain compared with wild-type strains in a Mongolian gerbil model of H. pylori infection. Furthermore, we performed a genomic sequence analysis of the strains isolated from the Mongolian gerbil stomachs eight weeks after infection. We found that the isolated ΔmutY strains exhibited a high frequency of spontaneous G:C to T:A mutations. However, the frequency of phase variations in the ΔmutY strain was almost similar to the wild-type strain. These results suggest that MutY may play a role in modes of gastric environmental adaptation distinct from phase variation.


Assuntos
Adaptação Fisiológica , DNA Glicosilases/genética , Helicobacter pylori/genética , Mutação/genética , Estômago/microbiologia , Animais , Proteínas de Bactérias/genética , Reparo do DNA/genética , Modelos Animais de Doenças , Gerbillinae , Infecções por Helicobacter/microbiologia , Helicobacter pylori/crescimento & desenvolvimento , Taxa de Mutação , NF-kappa B/metabolismo
17.
J Med Microbiol ; 69(2): 218-227, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32011229

RESUMO

Introduction. Gastric cancer is a health disparity in the Alaska Native people. The incidence of Helicobacter pylori infection, a risk factor for non-cardia gastric adenocarcinoma, is also high. Gastric cancer is partially associated with the virulence of the infecting strain.Aim. To genotype the vacA s, m and i and cag pathogenicity island (cagPAI) genes in H. pylori from Alaskans and investigate associations with gastropathy.Methodology. We enrolled patients with gastritis, peptic ulcer disease (PUD) and intestinal metaplasia (IM) in 1998-2005 and patients with gastric cancer in 2011-2013. Gastric biopsies were collected and cultured and PCR was performed to detect the presence of the right and left ends of the cagPAI, the cagA, cagE, cagT and virD4 genes and to genotype the vacA s, m and i regions.Results. We recruited 263 people; 22 (8 %) had no/mild gastritis, 121 (46 %) had moderate gastritis, 40 (15%) had severe gastritis, 38 (14 %) had PUD, 30 (11 %) had IM and 12 (5 %) had gastric cancer. H. pylori isolates from 150 (57%) people had an intact cagPAI; those were associated with a more severe gastropathy (P≤0.02 for all comparisons). H. pylori isolates from 77 % of people had either the vacA s1/i1/m1 (40 %; 94/234) or s2/i2/m2 (37 %; 86/234) genotype. vacA s1/i1/m1 was associated with a more severe gastropathy (P≤0.03 for all comparisons).Conclusions. In this population with high rates of gastric cancer, we found that just over half of the H. pylori contained an intact cagPAI and 40 % had the vacA s1/i1/m1 genotype. Infection with these strains was associated with a more severe gastropathy.


Assuntos
Proteínas de Bactérias/genética , Ilhas Genômicas , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alaska , Nativos do Alasca/estatística & dados numéricos , Proteínas de Bactérias/metabolismo , Feminino , Helicobacter pylori/isolamento & purificação , Helicobacter pylori/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/microbiologia , Neoplasias Gástricas/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Adulto Jovem
18.
Helicobacter ; 25(2): e12680, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32057175

RESUMO

BACKGROUND: The aim of this work was to find a reliable nested PCR for the detection of Helicobacter pylori in biopsy, stool, and saliva specimens. MATERIALS AND METHODS: Novel nested PCR was elaborated and validated on 81 clinical biopsy, stool, and saliva samples from the same individual and compared to available H pylori assays: histology, rapid urease test (RUT), stool antigen test (SAT), 13 C-urea breath test (UBT). RESULTS: The efficiency and selectivity of 17 published nested polymerase chain reactions (PCR) available for Helicobacter pylori detection were re-evaluated. Most of them had serious limitations and mistakes in primer design. Hence, we elaborated a nested PCR for the unambiguous identification of H pylori in biopsy, stool, and saliva, using primers targeted to variable regions of the 16S ribosomal RNA (rRNA) gene. Moreover, we determined the detection limit by adding a known number of cells. This number was as low as 0.5 cells in a PCR vial, but due to the DNA isolation procedures, it required 1-5 × 103 cells/g or ml of specimen. The sensitivity for nested PCR from stomach biopsies was on the same scale as 13 C-UBT (93.8%), but it was much lower in amplifications from stool (31.3%). Sequencing of all obtained PCR products exclusively confirmed H pylori-specific DNA sequences. CONCLUSIONS: Elaborated nested PCR assay can serve as an auxiliary method for controversial samples (patients with bleeding or taking proton-pump inhibitor) in laboratories with basic equipment. The sensitivity and specificity for the amplification from gastric biopsies was almost like 13 C-UBT. Despite the good sensitivity, the threshold occurrence and the ability to survive in the oral cavity aside from and independent of the stomach is the reason why H pylori DNA cannot be reliably detected in saliva, stool, and some biopsy samples.


Assuntos
Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carga Bacteriana , Biópsia , Fezes/microbiologia , Feminino , Gastroscopia , Helicobacter pylori/genética , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S , Saliva/microbiologia , Sensibilidade e Especificidade , Adulto Jovem
19.
Helicobacter ; 25(2): e12684, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32074664

RESUMO

BACKGROUND: Resistant Helicobacter pylori to commonly used antimicrobial agents are associated with severe upper gastrointestinal disorders. To provide an epidemiological picture of H pylori and characterize the resistance pattern and genetic variation of clinical isolates, stomach biopsies from patients with functional dyspepsia were evaluated in northeast of Iran. MATERIALS AND METHODS: In this study, 80 patients were recruited. Finally, fifty H pylori strains were isolated from antrum and corpus biopsies by culturing on Columbia agar. All strains were identified by standard laboratory procedures. Susceptibility testing of antibiotics was performed using minimum inhibitory concentration test. Allele-specific primer (ASP)-PCR of 23S rRNA which associated with clarithromycin resistance was done among resistant strains. Moreover, cagA gene and polymorphism in vacA were detected. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) was applied to investigate the genetic variations among all strains. RESULTS: Antibiotic resistance pattern of H pylori strains was as follows: 68% (34/50) to metronidazole, 50% (25/50) to rifampicin, 30% (15/50) to amoxicillin, 28% (14/50) to levofloxacin, 22% (11/50) to clarithromycin, and 16% (8/50) to tetracycline. Multidrug-resistant strains were observed in 19 strains (38%). ASP-PCR of 23S rRNA showed four strains had A2143G mutation, six strains had A2142G mutation, and one strain had a Wt+A2143G mutation. Amplification of virulence-associated genes revealed that cagA was present in 27 isolates (54%) and vacA in 36 isolates (72%). The most common genotype of H pylori was vacA s1am2 (40%) followed by vacA s2m2 (14%), vacA s1am1 (12%), vacA s1bm1 (4%), and vacA s1bm2 (2%). DNA fingerprinting pattern indicated a high heterogeneity among isolated strains. CONCLUSION: An alarming level of resistance to metronidazole and rifampicin and high heterogeneity among H pylori isolates highlighted the importance of continued monitoring of antimicrobial susceptibility and epidemiological surveillance of this pathogen.


Assuntos
Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Helicobacter , Helicobacter pylori , Virulência/genética , Adulto , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Biópsia , Feminino , Variação Genética , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , RNA Ribossômico 23S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Estômago/microbiologia
20.
Proc Natl Acad Sci U S A ; 117(5): 2645-2655, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964836

RESUMO

The main risk factor for stomach cancer, the third most common cause of cancer death worldwide, is infection with Helicobacter pylori bacterial strains that inject cytotoxin-associated gene A (CagA). As the first described bacterial oncoprotein, CagA causes gastric epithelial cell transformation by promoting an epithelial-to-mesenchymal transition (EMT)-like phenotype that disrupts junctions and enhances motility and invasiveness of the infected cells. However, the mechanism by which CagA disrupts gastric epithelial cell polarity to achieve its oncogenicity is not fully understood. Here we found that the apoptosis-stimulating protein of p53 2 (ASPP2), a host tumor suppressor and an important CagA target, contributes to the survival of cagA-positive H. pylori in the lumen of infected gastric organoids. Mechanistically, the CagA-ASPP2 interaction is a key event that promotes remodeling of the partitioning-defective (PAR) polarity complex and leads to loss of cell polarity of infected cells. Blockade of cagA-positive H. pylori ASPP2 signaling by inhibitors of the EGFR (epidermal growth factor receptor) signaling pathway-identified by a high-content imaging screen-or by a CagA-binding ASPP2 peptide, prevents the loss of cell polarity and decreases the survival of H. pylori in infected organoids. These findings suggest that maintaining the host cell-polarity barrier would reduce the detrimental consequences of infection by pathogenic bacteria, such as H. pylori, that exploit the epithelial mucosal surface to colonize the host environment.


Assuntos
Antígenos de Bactérias/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Bactérias/metabolismo , Células Epiteliais/citologia , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Organoides/microbiologia , Antígenos de Bactérias/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas de Bactérias/genética , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Interações Hospedeiro-Patógeno , Humanos , Organoides/metabolismo , Ligação Proteica , Estômago/microbiologia
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