Application of Stool-PCR test for diagnosis of Helicobacter pylori infection in children

Falsafi, Tahereh; Favaedi, Raha; Mahjoub, Fatemeh; Najafi, Moslem

doi:10.3748/wjg.15.484

Cited by 47 publications

(39 citation statements)

References 26 publications

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“…H. pylori density, gastritis, and inflammation were graded according to a modified Sydney system. Gastritis was scored as absent (normal), mild, moderate, or severe; the cases of gastritis with follicular formation were classified as follicular gastritis that was either associated with activity or was without activity (19,21 Identification of the 16sRNA gene, vacA alleles, and cagA gene was performed according to a protocol previously adopted (22). For this purpose, DNA was extracted using phenol-chloroform and boiling methods according to previously described protocols (22).…”

Section: Histological Examinationmentioning

confidence: 99%

“…Gastritis was scored as absent (normal), mild, moderate, or severe; the cases of gastritis with follicular formation were classified as follicular gastritis that was either associated with activity or was without activity (19,21 Identification of the 16sRNA gene, vacA alleles, and cagA gene was performed according to a protocol previously adopted (22). For this purpose, DNA was extracted using phenol-chloroform and boiling methods according to previously described protocols (22). PCR primers for 16srRNA, vacA, and cagA (Faza Biotech Inc., Iran) were designed on the basis of published sequences of H. pylori (23,24), as demonstrated in Table 1.…”

Section: Histological Examinationmentioning

confidence: 99%

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Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome

Falsafi¹,

Khani²,

Mahjoub³

et al. 2015

Turk J Med Sci

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Background/aim: More than 50% of Iranian children are infected with Helicobacter pylori; however, no data exist about the association of vacA/cagA genotype/status with disease outcomes in them. We analyzed association of vacA/cagA genotypes/status of children's isolates with gastric inflammation status as the first step in H. pylori pathogenesis. Materials and methods:Antral biopsies for culture and histopathology were taken from 328 children in 1997-2009. vacA (s, m) alleles and cagA statuses of the isolates were determined by PCR. Histopathology was performed according to the Sydney system; gastritis was scored as normal, mild, moderate, severe, and follicular.Results: A total of 159 culture-positive cases, with no mixed infections, were enrolled in the study. Of them, 60% were cagA-positive; 21.4%, 37.1%, 16.3%, and 25.2% cases were s1m1, s1m2, s2m1, and s2m2, respectively. Histopathology showed normal (4.4%), mildchronic (31.4%), moderate-chronic (38.4%), severe-chronic (10.7%), and follicular gastritis (15.1%) cases. Thirty-four (21.4%) of the children had ulcers. Correlation (P < 0.05) was observed between more severe (moderate, severe, follicular) status and both vacAs1 allele and cagA-positive status. No significant relation was observed between genotype/status of vacA/cagA and ulcers (P > 0.05). Conclusion: vacAs1and cagA are associated with more severe gastric inflammation in Iranian children. Association of vacAs1 and cagA with more severe pathology in Iran may be similar to that of other parts of the world.

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Section: Histological Examinationmentioning

confidence: 99%

Section: Histological Examinationmentioning

confidence: 99%

Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome

Falsafi¹,

Khani²,

Mahjoub³

et al. 2015

Turk J Med Sci

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“…Since H. pylori has to pass through stool, scientists invested ample time to develop a stool test for it. Although there are few reports on successful culture of H. pylori in stool [70] or detection of H. pylori in stool by PCR [71], none of those procedures have been very successful. H. pylori often becomes non-cultivable due to biliary salts and other inhibitors [72].…”

Section: Stool Antigen Assaymentioning

confidence: 99%

An update of laboratory diagnosis of Helicobacter pylori in the Kingdom of Saudi Arabia

Somily

Morshed

2015

J Infect Dev Ctries

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Helicobacter pylori is a micro-aerophilic, slow-growing, Gram-negative spiral bacterium that colonizes the mucous lining of the human stomach. Infection with this bacterium has been identified as a cause of gastritis, peptic ulcer disease, and gastric mucosa-associated lymphoid tissue lymphoma. Globally, the prevalence of H. pylori-related infection is high compared to any other infectious diseases, and the rate of prevalence much higher in developing countries than in developed nations. This review article aims to describe the trend of H. pylori-related works in the Kingdom of Saudi Arabia (KSA) and the use of various laboratory tests for the diagnosis of H. pylori-related infections in adults and children. Therefore, published literature was referenced in the explanation and discussion of the different methods used to diagnose H. pylori-related disease, including papers published in the KSA and other Middle Eastern countries. The PubMed (http://www.ncbi.nlm.nih.gov/pubmed?cmd=search) search engine was used extensively. Culture and histopathology tests have been employed widely to detect this pathogen at the early stage. However, over the years, an array of tests including the rapid urease test, serology, the urea breath test, the fecal antigen test, and molecular testing have been developed to diagnose and better manage H. pylori-associated diseases since the discovery of this novel pathogen.

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“…This was followed by a final extension of 72°C for 10 min (Falsafi et al, 2009). Each PCR product was separated on a 2% Agarose gel and 50 bp ladder was used as DNA molecular weight standard.…”

Section: Pcr Amplification Of the H Pylori Caga Genementioning

confidence: 99%

Helicobacter pylori vacA genotyping in relation to cagA status, ultra-structure of gastric mucosa and clinical outcomes in Egyptian patients

Diab¹,

Shemis²,

El-Ghannam³

et al. 2016

Afr. J. Microbiol. Res.

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Helicobactor pylori (H. pylori) has been strongly associated with gastritis, peptic ulcer and is linked to an increased risk of gastric cancer. The cytotoxin-associated gene product (cagA) and the vacuolating cytotoxin (vacA) have been implicated as two major virulence factors of H. pylori. Since there is an increasing evidence that genetic variability of H. pylori may have clinical importance, we aimed to evaluate different vacA genotypes and reveal its relationship with endoscopic and transmission electron microscopy (TEM) findings among H. pylori infected Egyptian patients. Forty H. pylori infected patients possessing vacA gene who underwent upper endoscopic examination were considered to be infected with H. pylori when rapid urease test and detection of 16S rRNA in gastric biopsy recorded positive. Both vacA and cagA genotypes were detected by polymerase chain reaction (PCR). The TEM was performed to assess the ultra-structure of the gastric mucosa. Four vacA genotypes were identified, the most prominent was the s2/m2 allele combination (52.5%) followed by s1/m1 (27.5%), s1/m2 (17.5%) and s2/m1 genotype was found just in one H. pylori strain (2.5%). There were significant correlations between vacA s2/m2 and gastritis (65.2%), and vacA s1/m1 and peptic ulceration (57%). The cagA gene was associated with 38% of vacA genotypes and 60% of which were significantly associated with vacA s1/m1 genotype with the development of severe gastritis reaching up to gastric ulcer. The TEM revealed H. pylori spiral and coccoid forms, cytoplasmic vacuolar degeneration caused by vacA, swollen mitochondria and dilated rough endoplasmic reticulum. In Egypt where prevalence of H. pylori infection is high, genotyping of H. pylori virulence factors can help to predict patients who are at a high risk of related gastroduodenal diseases. Although H. pylori with vacA s2/m2 genotype is mostly related to low level of virulent strains yet, significant crosstalk between H. pylori strains harboring both vacA s1/m1 and cagA gene provides crucial insights into virulence of high level.

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Application of Stool-PCR test for diagnosis of Helicobacter pylori infection in children

Abstract: Association between higher score of H pylori in histology and a positive stool-PCR make it a very useful test for detection of H pylori active infection in children. We also suggest that a simple stool-PCR method can be a useful test for detection of H pylori virulence genes in stool.

Cited by 47 publications

References 26 publications

Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome

Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome

An update of laboratory diagnosis of Helicobacter pylori in the Kingdom of Saudi Arabia

Helicobacter pylori vacA genotyping in relation to cagA status, ultra-structure of gastric mucosa and clinical outcomes in Egyptian patients

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