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1.
Helicobacter ; 25(5): e12726, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32686319

RESUMEN

BACKGROUND: Helicobacter pylori (H pylori) is responsible for various diseases including cancer It co-evolved with humans, and human migrations shaped the expansion and the diversity of strains around the world. The risk of developing a disease depends on virulence factors, mainly the cytotoxin-associated gene A protein (CagA). The aim of this study was to determine the cagA status in H pylori strains from Mauritanian patients and to search for a relationship with endoscopic and histologic findings. MATERIAL AND METHODS: H pylori was searched in gastric biopsies taken during endoscopy in patients with gastro-duodenal symptoms. RT-PCR was used for the diagnosis and resistance to clarithromycin. The cagA status was determined with PCR and the EPIYA-cagA polymorphism with sequencing. RESULTS: At all, 76/78 (97.4%) biopsies were positive. The rate of clarithromycin resistance was 4/76 (5.26%) due to the A2143G mutation, with a mixed population in 2 cases. The cagA gene was present in 23/76 (30.26%) biopsies, and the EPIYA motif was ABC in 21 (91.3%). High bacterial load and inflammation were significantly associated with cagA-positive status (P < .01). Phylogenetic analysis of the glmM and hspA genes highlighted a mixture of African and European genes in strains of H pylori isolated from patients of Moor origin. CONCLUSION: We report a high prevalence of H pylori infection in Mauritanian patients, a low rate of clarithromycin resistance (5.26%) and high bacterial load and inflammation associated with cagA-positive status. The phylogenetic analysis highlights the mix of different populations leading to the Moor ethnicity.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/microbiología , Helicobacter pylori , Factores de Virulencia/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Claritromicina/farmacología , Farmacorresistencia Bacteriana/genética , Femenino , Infecciones por Helicobacter/epidemiología , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Helicobacter pylori/patogenicidad , Humanos , Masculino , Mauritania/epidemiología , Persona de Mediana Edad , Adulto Joven
2.
Int J Mol Sci ; 19(2)2018 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-29364158

RESUMEN

Helicobacter pylori (Hp) is one of the most important human pathogens that can cause duodenal and gastric ulcers, gastritis and stomach cancer. Hp infection is considered to be a cause of limiting access to bariatric surgery. The aim of this study was to determine the prevalence of Hp in patients with obesity going into bariatric surgery and to reveal the relationship between Hp and clinical data. The study group was formed of 68 preoperative bariatric surgery patients (body mass index (BMI) 44.7 ± 4.8). Gastric biopsies (antrum and corpus) were used for histological and molecular (caqA and glmM genes) examinations. The PCR method revealed Hp infection in 64.7% of obese patients that is higher in comparison with histological analysis (55.9%). The prevalence of cagA and glmM genes in antrum mucosa was 45.6% and 47.0% while in the corpus it was 41.2% and 38.3%, respectively. The coincidence of both cagA and glmM virulence genes in the antrum and corpus mucosa was 33.8% and 22.1%, respectively. Either of the genes was found in 58.8% of antrum and 57.3% of corpus mucosa. Presence of caqA and glmM genes was in association with active and atrophic chronic gastritis. In conclusion, our study demonstrated that two thirds of morbidly obese patients undergoing bariatric surgery are infected with Hp and have a high prevalence of cagA and glmM virulence genes that points out the necessity for diagnostics and treatment of this infection before surgery.


Asunto(s)
Cirugía Bariátrica , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/etiología , Helicobacter pylori , Adulto , Anciano , Cirugía Bariátrica/efectos adversos , Biomarcadores , Biopsia , Pesos y Medidas Corporales , Femenino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Gastritis/complicaciones , Gastritis/patología , Gastritis/cirugía , Genes Bacterianos , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Obesidad/cirugía , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Virulencia/genética
3.
Helicobacter ; 21(4): 325-33, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26667241

RESUMEN

BACKGROUND: Epidemiologic studies of the carcinogenic stomach bacterium Helicobacter pylori have been limited by the lack of noninvasive detection and genotyping methods. We developed a new stool-based method for detection, quantification, and partial genotyping of H. pylori using droplet digital PCR (ddPCR), which allows for increased sensitivity and absolute quantification by PCR partitioning. MATERIALS AND METHODS: Stool-based ddPCR assays for H. pylori 16S gene detection and cagA virulence gene typing were tested using a collection of 50 matched stool and serum samples from Costa Rican volunteers and 29 H. pylori stool antigen-tested stool samples collected at a US hospital. RESULTS: The stool-based H. pylori 16S ddPCR assay had a sensitivity of 84% and 100% and a specificity of 100% and 71% compared to serology and stool antigen tests, respectively. The stool-based cagA genotyping assay detected cagA in 22 (88%) of 25 stools from CagA antibody-positive individuals and four (16%) of 25 stools from CagA antibody-negative individuals from Costa Rica. All 26 of these samples had a Western-type cagA allele. Presence of serum CagA antibodies was correlated with a significantly higher load of H. pylori in the stool. CONCLUSIONS: The stool-based ddPCR assays are a sensitive, noninvasive method for detection, quantification, and partial genotyping of H. pylori. The quantitative nature of ddPCR-based H. pylori detection revealed significant variation in bacterial load among individuals that correlates with presence of the cagA virulence gene. These stool-based ddPCR assays will facilitate future population-based epidemiologic studies of this important human pathogen.


Asunto(s)
Antígenos Bacterianos/análisis , Carga Bacteriana/métodos , Proteínas Bacterianas/análisis , Heces/microbiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Factores de Virulencia/análisis , Adolescente , Adulto , Anciano , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Niño , Preescolar , Costa Rica , Femenino , Técnicas de Genotipaje/métodos , Helicobacter pylori/genética , Humanos , Lactante , Masculino , Persona de Mediana Edad , ARN Ribosómico 16S/genética , Sensibilidad y Especificidad , Estados Unidos , Factores de Virulencia/genética , Adulto Joven
4.
Cureus ; 16(7): e64164, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39119398

RESUMEN

Introduction The development of diseases associated with Helicobacter pylori (H. pylori) infection is closely linked to its virulence genes, which vary by geographic region. This study aimed to determine the prevalence of H. pylori cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene A (vacA) genes and their genotypes in patients with gastrointestinal diseases. Methods Patients diagnosed with gastrointestinal disease based on endoscopic findings were recruited for the study. Gastric biopsies were collected to screen for H. pylori infection using polymerase chain reaction (PCR). Subsequently, infected samples were tested for cagA and vacA genes, and their genotypes were analyzed by sequencing. Results Among 250 cases, 56% (140/250) exhibited gastrointestinal diseases. Of these cases, 32.1% (45/140) were infected with H. pylori. Regarding gene detection, 40 (88.9%) samples were positive for cagA, while all samples were positive for vacA. For cagA, the Western type with the ABC pattern was the most prominent. There was a statistically significant association between cagA genotypes and clinical outcomes, with the Western type being more prevalent in gastritis patients. For vacA, there was a high prevalence of the s1 and i1, while the m1 and m2 showed similar prevalence. In our combined analysis, the dominant vacA genotype combinations were s1m1i1 (46.7%). There were no statistical differences between the vacA genotypes and clinical outcomes (P > 0.05). Conclusion This study revealed a high prevalence of H. pylori cagA and vacA genes, but there were variations in their genotypes. A correlation was observed between the Western-type cagA and gastritis; however, no association was found between vacA genotypes and clinical outcomes.

5.
Front Microbiol ; 15: 1351784, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38298891

RESUMEN

Helicobacter pylori (H. pylori) infection may alter the host's resistance to tsutsugamushi disease pathogens through the Th1 immune response, leading to potential synergistic pathogenic effects. A total of 117 scrub typhus cases at Beihai People's Hospital and affiliated hospitals of Youjiang University for Nationalities and Medical Sciences were studied from January to December 2022, alongside 130 healthy individuals forming the control group. All participants underwent serum H. pylori antibody testing. The prevalence of H. pylori infection was significantly higher among scrub typhus patients (89.7%) compared to healthy individuals (54.6%) (p < 0.05). Moreover, type I H. pylori infection was notably more prevalent in scrub typhus cases (67.5%) compared to healthy individuals (30%) (p < 0.05). Multifactorial analysis demonstrated type I H. pylori infection as an independent risk factor for scrub typhus (adjusted odds ratio: 2.407, 95% confidence interval: 1.249-4.64, p = 0.009). Among scrub typhus patients with multiple organ damage, the prevalence of type I H. pylori infection was significantly higher (50.6%) than type II H. pylori infection (15.4%) (χ2 = 4.735, p = 0.030). These results highlight a higher incidence of H. pylori infection in scrub typhus patients compared to the healthy population. Additionally, type I H. pylori strain emerged as an independent risk factor for scrub typhus development. Moreover, individuals infected with type I H. pylori are more susceptible to multiple organ damage. These findings suggest a potential role of H. pylori carrying the CagA gene in promoting and exacerbating scrub typhus.

6.
J Dent Sci ; 19(2): 1036-1043, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38618069

RESUMEN

Background/purpose: The oral cavity is considered a reservoir of Helicobacter pylori associated with gastric infection. It aimed to examine the prevalence of H. pylori strains from the oral cavity and gastric tissue of patients with different stage of gastric-diseases. Strains were further characterized for virulence genes, adhesion ability, and inflammation responses. Materials and methods: 11 non-disease, 15 gastritis, and 15 gastric cancer participated in the study. After clinical examination, gastric biopsies, saliva and plaque samples were collected and H. pylori levels were examined by real-time PCR and cultivation. The cagA and vacA genes were investigated from the culture strains. Adhesion ability and pro-inflammatory responses were analyzed in comparison between the presence of virulent genes and disease status. Results: Relatively poor periodontal condition was found among gastric cancer patients. Prevalence of H. pylori-positive was 84.8% and 19.5% by real-time PCR and cultivation, respectively. The cagA and vacA gene-positive strains were 52.6% and 5.3%, respectively, which were found more in gastric cancer patients. The cagA gene-positive strains were found to be higher in gastric cancer patients, and strains had significantly higher adhesion ability and pro-inflammation expressions than the cagA gene-negative strains. Conclusion: Colonization by H. pylori in oral cavity was confirmed, and the cagA gene-positive strains play a crucial role in both adhesion and inflammatory responses. The presence of H. pylori and its virulence gene in oral cavity should be received attention. An eradication of such strains from oral cavity may help to prevent the transmission and recolonization to gastric organs.

7.
World J Gastroenterol ; 29(19): 2950-2960, 2023 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-37274796

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis. AIM: To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen. METHODS: H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation. RESULTS: The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%-70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175-0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: -0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026-0.537). CONCLUSION: This study's low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Humanos , Claritromicina/uso terapéutico , Metronidazol/uso terapéutico , Antibacterianos/uso terapéutico , Helicobacter pylori/genética , Virulencia/genética , Egipto/epidemiología , Quimioterapia Combinada , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/epidemiología , Amoxicilina/uso terapéutico , Genotipo
8.
Afr Health Sci ; 22(1): 573-580, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36032427

RESUMEN

Background: H. pylori infection induce atrophic gastritis (AG) and intestinal metaplasia (IM) that can lead to gastric cancer (GC). The severity of gastric lesions is related to H. pylori genetic diversity. The oncogenic potential of H. pylori cagA virulence factor is linked to its high polymorphic EPIYA motifs. Objectives: Our aim was to evaluate the association of EPIYA motifs with the risk of AG and IM in Casablanca population. Methods: A total of 210 patients suffering from gastric lesions (chronic gastritis, AG, and IM) was enrolled. H. pylori infection and the type of lesions were diagnosed by ureC PCR and histological examination, respectively. Detection of the cagA gene, and the type of EPIYA motifs, were carried out by PCR. Results: The prevalence of H. pylori and cagA gene was 95% and 37%, respectively. CagA-positive strains were associated with the risk of IM. The EPIYA motifs detected were: EPIYA-ABC (58%), EPIYA-ABCC (22%), and EPIYA-AB (20%). The EPIYA-ABCC motif was associated with the risk of IM (p-value = 0.007), compared to AG (p-value = 0.28). Conclusion: The EPIYA-ABCC motif might be a useful marker for the identification of patients at high risk of developing IM that can lead to GC.


Asunto(s)
Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Antígenos Bacterianos , Proteínas Bacterianas , Carcinogénesis , Humanos
9.
J Clin Med ; 10(13)2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34201588

RESUMEN

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.

10.
Nan Fang Yi Ke Da Xue Xue Bao ; 41(12): 1816-1821, 2021 Dec 20.
Artículo en Zh | MEDLINE | ID: mdl-35012913

RESUMEN

OBJECTIVE: To establish a multiplex PCR-based method for detecting Helicobacter pylori (Hp) 16S rRNA gene and cagA gene in saliva samples for investigating the prevalence of Hp in the oral cavity of Hp-infected patients with digestive tract diseases. METHODS: Bioinformatics technique was used to design specific primers for Hp 16S rRNA and cagA genes for Hp detection using multiplex PCR, with recombinant cloning plasmids serving as the standard positive control. Oral saliva samples were collected from 156 patients with digestive tract diseases, and Hp 16S rRNA and cagA genes were detected using the established multiplex PCR system. RESULTS: The established multiplex PCR system showed a strong specificity and a high sensitivity for detecting Hp 16S rRNA gene and cagA gene, with the lowest detection limit of 103 copies/µL. The recombinant plasmids pGMT-16s and pGMT-cagA could be used as standard positive controls for the identification of Hp. Among the 156 saliva samples, 87.2% were positive for Hp 16S rRNA gene and 23.1% for Hp cagA gene. CONCLUSION: Hp is highly prevalent in saliva specimens of Hp-infected patients with digestive tract diseases. The presence of Hp in the oral cavity may importantly contribute to Hp infection in the digestive tract and recurrence after treatment.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Antígenos Bacterianos , Proteínas Bacterianas/genética , Helicobacter pylori/genética , Humanos , Reacción en Cadena de la Polimerasa Multiplex , ARN Ribosómico 16S , Saliva
11.
Indian J Med Microbiol ; 39(4): 495-499, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34172322

RESUMEN

PURPOSE: Globally, H. pylori virulence factors cagA and vacA genotypes and its variation is leading to the austere form of the gastroduodenal disease. Our objectives were to detect H. pylori in dyspeptic patients from biopsy samples with the validation of the various existing diagnostic tools and to screen the cagA, vacA genotypes profile from biopsy specimens and how it impacts in progression of gastroduodenal disease in southern India. METHODS: 374 patients who attended endoscopy unit at Kasturba Hospital, Manipal with their consent obtained their biopsies. H. pylori were detected by HPE, Culture, RUT and PCR and its virulence gene were patterned with PCR. RESULTS: The positive rate of H. pylori by HPE, RUT, Culture and PCR were 51.33%, 47.1%, 32.4% and 50.3% respectively and comparison by Bayesian LCMs analysis showed PCR is superior among them. The frequency of H. pylori virulence gene viz cagPAI (cagA) were 80.9%, and vacA alleles-s1m1 (42%), s1m2 (33%) and s2m2 (25%) genotypes by PCR respectively. Four combinations of cagA/vacA genotypes were noted, majority of strains harboured cagA+/vacA s1m1 genotypes (42.6%), interestingly this hyper-virulent strain more frequently seen in severe gastroduodenal disease whereas cagPAI negative strains as well as cagA-/vacA s2m2 combinations (19.1%) are seen most commonly in functional dyspepsia cases and depicted significant association by Chi-square test. CONCLUSIONS: This study validates and compares the existing diagnostic methods for detecting H. pylori in biopsies. Also, it reveals some pattern of virulence gene combination will play a vital role in disease progression.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Teorema de Bayes , Genotipo , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Humanos , India/epidemiología , Factores de Virulencia/genética
12.
Open Access Maced J Med Sci ; 5(2): 137-141, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-28507617

RESUMEN

BACKGROUND: Helicobacter pylori vacA and cagA genes are associated with higher virulence. Vascular Endothelial Growth Factor (VEGF) is one important marker for neo-angiogenesis. AIM: The purpose of this study was to investigate the relationship between VEGF serum levels with cagA and vacA genes in H. pylori infection. METHODS: A cross-sectional study was done on eighty patients that consecutive admitted to endoscopy unit. The diagnosis of H. pylori infection was based on rapid urease test. Serum samples were obtained to determine circulating VEGF level. Polymerase chain reaction was done to examine H. pylori vacA and cagA genes. Data analysis were carried-out using SPSS version 22. RESULTS: A total of 80 patients were examined. There were 45 (56.3%) patients infected with Helicobacter pylori. There were 33 (73.3%) patients with H. pylori cagA positive. Serum VEGF levels in patients with the H. pylori positive were significantly higher compared to the patients that have no H. pylori. Serum levels of VEGF were significantly higher in cagA positive than negative. CONCLUSION: Serum VEGF level is correlated with H. pylori infection and its virulence status. The more virulence of H. pylori, cagA gene, the higher serum VEGF levels were found.

14.
Artículo en Inglés | MEDLINE | ID: mdl-28879170

RESUMEN

HIGHLIGHTS What is already known about this subject?Celiac disease (CD) has a high clinical and histological diversity and the mechanisms underlying this phenomenon remain elusive.H. pylori is a bacterium that chronically infect gastric and duodenal mucosa activating both a Th1/Th17 and T-reg pathways.The role of H. pylori (and the effect of their virulence factors) in CD have not yet completely elucidated.What are the new findings?cagA+ H. pylori strains are associated to milder histological damage in infected CD patients.In active-CD patients the presence of cagA+ H. pylori is associated to an increase in T-reg markers, contrasting with a downregulation in cagA+ infected potential-CD individuals.How might it impact on clinical practice in the foreseeable future?The identification of microbiological factors that could modulate inflammation and clinical expression of CD may be used in the future as preventive strategies or as supplementary treatment in patients that cannot achieve complete remission, contributing to the better care of these patients. Background: Mechanisms underlying the high clinical and histological diversity of celiac disease (CD) remain elusive. Helicobacter pylori (Hp) chronically infects gastric and duodenal mucosa and has been associated with protection against some immune-mediated conditions, but its role (specifically of cagA+ strains) in CD is unclear. Objective: To assess the relationship between gastric Hp infection (cagA+ strains) and duodenal histological damage in patients with CD. Design: Case-control study including patients with active-CD, potential-CD and non-celiac individuals. Clinical presentation, HLA genotype, Hp/cagA gene detection in gastric mucosa, duodenal histology, Foxp3 positive cells and TGF-ß expression in duodenal lamina propria were analyzed. Results: We recruited 116 patients, 29 active-CD, 37 potential-CD, and 50 non-CD controls. Hp detection was similar in the three groups (~30-40%), but cagA+ strains were more common in infected potential-CD than in active-CD (10/11 vs. 4/10; p = 0.020) and non-CD (10/20; p = 0.025). Among active-CD patients, Foxp3 positivity was significantly higher in subjects with cagA+ Hp+ compared to cagA- Hp+ (p < 0.01) and Hp- (p < 0.01). In cagA+ Hp+ individuals, Foxp3 positivity was also higher comparing active- to potential-CD (p < 0.01). TGF-ß expression in duodenum was similar in active-CD with cagA+ Hp+ compared to Hp- and was significantly downregulated in cagA+ potential-CD subjects compared to other groups. Conclusion: Hp infection rates were similar among individuals with/without CD, but infection with cagA+ strains was associated with milder histological damage in celiac patients infected by Hp, and in active-CD cases with higher expression of T-reg markers. Results suggest that infection by cagA+ Hp may be protective for CD progression, or conversely, that these strains are prone to colonize intestinal mucosa with less severe damage.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Enfermedad Celíaca/complicaciones , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/patología , Helicobacter pylori/patogenicidad , Adolescente , Adulto , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Estudios de Casos y Controles , Niño , Preescolar , Chile , Duodeno/microbiología , Duodeno/patología , Femenino , Factores de Transcripción Forkhead/metabolismo , Mucosa Gástrica/microbiología , Mucosa Gástrica/patología , Genes Bacterianos/genética , Genotipo , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Humanos , Lactante , Masculino , Persona de Mediana Edad , Factor de Crecimiento Transformador beta/metabolismo , Factores de Virulencia , Adulto Joven
15.
World J Gastrointest Oncol ; 8(1): 40-54, 2016 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-26798436

RESUMEN

Gastric carcinoma (GC) develops in only 1%-3% of Helicobacter pylori (H. pylori) infected people. The role in GC formation of the bacterial genotypes, gene polymorphisms and host's factors may therefore be important. The risk of GC is enhanced when individuals are infected by strains expressing the oncoprotein CagA, in particular if CagA has a high number of repeats containing the EPIYA sequence in its C'-terminal variable region or particular amino acid sequences flank the EPIYA motifs. H. pylori infection triggers an inflammatory response characterised by an increased secretion of some chemokines by immunocytes and colonised gastric epithelial cells; these molecules are especially constituted by proteins composing the interleukin-1beta (IL-1ß) group and tumour necrosis factor-alpha (TNF-α). Polymorphisms in the promoter regions of genes encoding these molecules, could account for high concentrations of IL-1ß and TNF-α in the gastric mucosa, which may cause hypochlorhydria and eventually GC. Inconsistent results have been attained with other haplotypes of inflammatory and anti-inflammatory cytokines. Genomic mechanisms of GC development are mainly based on chromosomal or microsatellite instability (MSI) and deregulation of signalling transduction pathways. H. pylori infection may induce DNA instability and breaks of double-strand DNA in gastric mucocytes. Different H. pylori strains seem to differently increase the risk of cancer development run by the host. Certain H. pylori genotypes (such as the cagA positive) induce high degrees of chronic inflammation and determine an increase of mutagenesis rate, oxidative-stress, mismatch repair mechanisms, down-regulation of base excision and genetic instability, as well as generation of reactive oxygen species that modulate apoptosis; these phenomena may end to trigger or concur to GC development.

16.
J Microbiol Biotechnol ; 25(7): 1146-53, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25791852

RESUMEN

This study was conducted to assess the relationship between occurrence of gastric cancer and peptic ulcer, and the presence of H. pylori cagA gene and anti-CagA IgG, and to estimate the value of these antibodies in detecting infection by cagA gene-positive H. pylori strains in Saudi patients. The study included 180 patients who were subjected to upper gastrointestinal endoscopy in Taif province and Western region of Saudi Arabia (60 gastric cancer, 60 peptic ulcer, and 60 with non-ulcer dyspepsia). Gastric biopsy specimens were obtained and tested for H. pylori infection by rapid urease test and culture. PCR was performed on the isolated strains and biopsy specimens for detection of the cagA gene. Blood samples were collected and tested for CagA IgG by ELISA. H. pylori infection was detected among 72.8% of patients. The cagA gene and anti-CagA IgG were found in 63.4% and 61.8% of H. pylori-infected patients, respectively. They were significantly (p < 0.01) higher in patients with gastric cancer and peptic ulcer compared with those with non-ulcer dyspepsia. Detection of the CagA IgG was 91.6% sensitive, 89.6% specific, and 90.8% accurate compared with detection of the cagA gene. Its positive and negative predictive values were 93.8% and 86%, respectively. The study showed a significant association between the presence of the cagA gene and gastric cancer and peptic ulcer disease, and between anti-CagA IgG and the cagA gene in Saudi patients. However, a further larger study is required to confirm this finding.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Úlcera Péptica/microbiología , Pruebas Serológicas/métodos , Neoplasias Gástricas/microbiología , Adulto , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Biopsia , Endoscopía Gastrointestinal , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/aislamiento & purificación , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Valor Predictivo de las Pruebas , Arabia Saudita , Sensibilidad y Especificidad
17.
Adv Pharm Bull ; 3(1): 57-62, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24312813

RESUMEN

PURPOSE: The purpose of this research was to analyze cagA and vacA genotypes status in H. pylori isolates and relationship with clinical outcomes. METHODS: Gastric biopsy specimens were cultured for H. pylori isolation and cagA and vacA genes were detected in these isolates. Data were collected and the results were analyzed using χ2 and Fishers exact tests by SPSS software version. 16. RESULTS: Of the total 115 H. pylori isolates, 79 (68.7 %) were cagA positive and 82 (71.3%) of isolates contained the s1 allele which 33 (28.7%) were subtype s2. s1m2 was the most frequent vacA allelic combination in the H. pylori isolates examined (63 cases), followed by s2m2 (31 cases), s1m1 (19 cases) and s2m1 (2 case). Strains cagA positive were more frequent in peptic ulcer diseases patients than non ulcer diseases patients, as 47 (59.5%) and 32 (40.5%), while cagA negative were low, as 15 (41.7%) and 21 (58.3%), respectively. CONCLUSION: We found that the cagA and vacA status were not related to clinical outcomes in this area. Overall, in the present study, vacA s1/m2, cagA-positive strains were predominant irrespective of clinical outcome, but s2/m1 was rare.

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