Detection of Helicobacter pylori in gastric biopsies, saliva and dental plaques of dyspeptic patients from Marília, São Paulo, Brazil: presence of vacA and cagA genes

Rasmussen, Lucas Trevizani; Lábio, Roger Willian de; Neto, Agostinho Caleman; Silva, L. C.; Queiroz, V. F.; Smith, Marília de Arruda Cardoso; Payão, Spencer Luíz Marques

doi:10.1590/s1678-91992012000200008

Cited by 15 publications

(15 citation statements)

References 35 publications

(39 reference statements)

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“…Humans are the major reservoir of H. pylori, where the bacteria appears to occur along certain areas of the gastrointestinal tube, including dental plaque, the esophagus, stomach, and gastric metaplasia into small intestine and large intestine [7, 17, 32–35]. …”

Section: Results and Discusionmentioning

confidence: 99%

Isolation and characterization of Helicobacter pylori recovered from gastric biopsies under anaerobic conditions

Perez-Perez

Van²,

Huong

et al. 2016

Diagnostic Microbiology and Infectious Disease

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Background and Aim H. pylori can survive long incubation periods under anaerobic conditions, and should be possible to isolate under anaerobic conditions. Our aim was to isolate H. pylori in anaerobic conditions, from gastric biopsies of H. pylori infected patients. Methods We enrolled 27 patients with bleeding (erosive) gastritis (mean age 36.3 years, 55.6% male) from Hanoi, Vietnam. H. pylori status was confirmed by qPCR. Results H. pylori were recovered under anaerobic and micro-aerobic conditions from gastric biopsies in 16 patients. Anaerobic conditions yielded significantly higher H. pylori recovery rates than micro-aerobic conditions (81.3% vs. 31.3%, p=0.01). H. pylori isolates were characterized by PCR for specific virulence markers and the genotypes were similar to those previously described in this region of the world. Conclusions H. pylori can be isolated under anaerobic conditions. These findings may provide new insight into the physiology of this human pathogen and help to identify the route of H. pylori transmission.

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Section: Results and Discusionmentioning

confidence: 99%

Isolation and characterization of Helicobacter pylori recovered from gastric biopsies under anaerobic conditions

Perez-Perez

Van²,

Huong

et al. 2016

Diagnostic Microbiology and Infectious Disease

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“…TNF -α-308 G > A (rs1800620), one of the most frequently studied polymorphisms on this gene, seems to have an influence on transcriptional activities and may contribute to the development of gastric disease [ 11 ]. Furthermore, previous studies showed that H. pylori virulence markers, such as cag A, vac A, and dup A genes, play important roles in gastric mucosal inflammation and injury through activated inflammatory cell infiltration [ 12 – 14 ].…”

Section: Introductionmentioning

confidence: 99%

Lack of association among TNF-α gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Zabaglia¹,

Ferraz²,

Pereira³

et al. 2015

J Venom Anim Toxins Incl Trop Dis

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BackgroundTumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of the TNF-α gene.MethodsOne hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61♂ and 73♀, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF-α was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2-ΔΔCT).ResultsThe analysis revealed an increase in TNF-α gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF-α gene expression.ConclusionsHelicobacter pylori induces a large increase in TNF-α expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF-α pathway may play an important role in the progression from gastritis to gastric cancer

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“…Moreover, cagA gene is present in approximately 60 to 70% of H. pylori strains and several epidemiological studies have revealed that its presence is correlated with a higher risk of developing peptic ulceration, gastric atrophy and gastric cancer [ 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

Association among H. pylori virulence markers dupA, cagA and vacA in Brazilian patients

Pereira¹,

Ferraz²,

Zabaglia³

et al. 2014

J Venom Anim Toxins incl Trop Dis

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BackgroundOnly a few Helicobacter pylori-infected individuals develop severe gastric diseases and virulence factors of H. pylori appear to be involved in such clinical outcomes. Duodenal ulcer promoting gene A (dupA) is a novel virulence factor of Helicobacter pylori that is associated with duodenal ulcer development and reduced risk for gastric carcinoma in some populations. The aims of the present study were to determine the presence of dupA gene and evaluate the association among dupA and other virulence factors including cagA and vacA in Brazilian patients. Gastric biopsies were obtained from 205 dyspeptic patients (100 children and 105 adults). DNA was extracted and analyzed for the presence of H. pylori and its virulence factors using the polymerase chain reaction method.ResultsPatients with gastritis tested positive for H. pylori more frequently. The dupA gene was detected in 41.5% of them (85/205); cagA gene was found in 98 isolates (47.8%) and vacA genotype s1/m1 in 50.2%, s1/m2 in 8.3%, s2/m2 in 36.6%, s2/m1 in 0.5% and s1/s2/m1/m2 in 4.4%. We also verified a significant association between cagA and dupA genes [p = 0.0003, relative risk (RR) 1.73 and confidence interval [CI] = 1.3–2.3]. The genotypes s1/m1 were also associated with dupA gene (p = 0.0001, RR: 1.72 and CI: 1.3–2.2). The same associations were found when analyzing pediatric and adult groups of patients individually.ConclusionOurs results suggest that dupA is highly frequent in Brazilian patients and is associated with cagA gene and vacA s1/m1 genotype, and it may be considered an important virulence factor in the development of gastric diseases in adults or children.

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Detection of Helicobacter pylori in gastric biopsies, saliva and dental plaques of dyspeptic patients from Marília, São Paulo, Brazil: presence of vacA and cagA genes

Cited by 15 publications

References 35 publications

Isolation and characterization of Helicobacter pylori recovered from gastric biopsies under anaerobic conditions

Isolation and characterization of Helicobacter pylori recovered from gastric biopsies under anaerobic conditions

Lack of association among TNF-α gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Association among H. pylori virulence markers dupA, cagA and vacA in Brazilian patients

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