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Moaddeb A, Fattahi MR, Firouzi R, Derakhshandeh A, Farshad S. Genotyping of the Helicobacter pylori cagA Gene Isolated From Gastric Biopsies in Shiraz, Southern Iran: A PCR-RFLP and Sequence Analysis Approach. Jundishapur J Microbiol 2016; 9:e30046. [PMID: 27335631 PMCID: PMC4914860 DOI: 10.5812/jjm.30046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/23/2015] [Accepted: 09/23/2015] [Indexed: 01/05/2023] Open
Abstract
Background Cytotoxin-associated gene A (cagA) is an important virulence factor in the pathogenesis of Helicobacter pylori. Objectives The aim of this study was to genotype the H. pylori cagA gene isolated from antral biopsies of patients with stomach symptoms, using a PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. Patients and Methods A total of 161 gastric biopsies were collected from patients with stomach symptoms. After isolation of H. pylori from the biopsy culture, the cagA gene was assessed using PCR. The PCR products were then digested by the HinfI restriction endonuclease enzyme. A sample of each genotype was also subjected to direct sequencing for further analysis. Results From 161 antral biopsies, 61 (37.9%) were positive for H. pylori in culture. Overall, 24 cagA-positives were detected in the isolates. RFLP indicated three different genotypes (I, II, and III) of cagA with a frequency of 62.5%, 25%, and 12.5% among the isolates, respectively. Genotypes I and II of cagA were predominant in patients who had gastritis. However, genotype III was found in three patients with duodenitis and duodenal ulcers. Alignment of the nucleotide sequences of the three isolated genotypes, with H. pylori 26695 as a reference strain, revealed 12 inserted nucleotides in genotype III. When the sequence of genotype III was aligned with 15 additional H. pylori strains available in GenBank, the same inserted nucleotides were detected in six of them. Conclusions Using the PCR-RFLP method, three distinctive H. pylori cagA genotypes were detected in antral biopsies. Genotype I, which was predominant among the isolates, was significantly associated with gastritis. However, the data showed that cagA genotype III may play a role in duodenitis and duodenal ulcers in patients infected with H. pylori.
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Affiliation(s)
- Afsaneh Moaddeb
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran
| | - Mohammad Reza Fattahi
- Gastroentrohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Roya Firouzi
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran
| | - Abdollah Derakhshandeh
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran
| | - Shohreh Farshad
- Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
- Corresponding author: Shohreh Farshad, Clinical Microbiology Research Center, Shiraz University of Medical Sciences, P. O. Box: 7193711351, Shiraz, IR Iran. Tel: +98-7136474304; +98-9173173501, Fax: +98-7136474303, E-mail:
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Ubhayawardana NL, Weerasekera MM, Weerasekera D, Samarasinghe K, Gunasekera CP, Fernando N. Detection of clarithromycin-resistant Helicobacter pylori strains in a dyspeptic patient population in Sri Lanka by polymerase chain reaction-restriction fragment length polymorphism. Indian J Med Microbiol 2016; 33:374-7. [PMID: 26068338 DOI: 10.4103/0255-0857.158557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIM The aim of this study was to investigate the proportion of common clarithromycin-resistant mutation types present in the 23S ribosomal ribonucleic acid (rRNA) gene of H. pylori strains in Sri Lanka. SETTINGS AND DESIGN The study was a cross-sectional, descriptive study where 76 dyspeptic patients who were required to undergo endoscopy examination were included. The study was carried out at a Teaching Hospital in Sri Lanka. SUBJECTS AND METHODS In-house urease test and polymerase chain reaction (PCR) amplification of the glmM gene of H. pylori was performed to confirm the H. pylori infection. Analysis of point mutations in 23S rRNA gene strains were performed by PCR-restriction fragment length polymorphism (RFLP). RESULTS Of the 16 urease-positive biopsies, 94% (n=15) were positive by PCR using the glmM primer. All H. pylori strains yeilded a point mutation at A2142G site of the 23S rRNA gene, while A2143G mutation was not detected. CONCLUSIONS For the first time in Sri Lanka, we reported predominance of A2142G point mutation associated with claritromycin resistance of H. pylori in a Sri Lankan population.
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Affiliation(s)
| | | | | | | | | | - N Fernando
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayawardenepura, Sri Lanka
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Dinda V, Kimang'a A. Co-occurrence of Helicobacter pylori with faecal bacteria in Nairobi river basin: public health implications. Afr Health Sci 2016; 16:177-82. [PMID: 27358630 DOI: 10.4314/ahs.v16i1.24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
INTRODUCTION Overwhelming evidence implicates Helicobacter pylori (H. pylori) as an etiologic agent of gastrointestinal diseases including gastric cancer. The mode of transmission of this pathogen remains poorly understood. OBJECTIVE This investigation is to establish the presence of H. pylori in the waters of the Nairobi river basin and the predictive value the presence of fecal indicator bacteria would have for H. pylori. METHODOLOGY Physical, chemical and biological assessment of water quality of rivers in Nairobi were carried out using standard methods. H. pylori DNA in water was detected using highly specific primers of glmM gene (294pb). RESULTS There was high presence of faecal bacteria in the waters sampled. H. pylori DNA was detected in two domestic wells and one river. The wells were located in two different regions of the water basin but influenced by similar human activities. CONCLUSION The high presence of faecal bacteria in the waters sampled did not parallel the H. pylori detection in the same waters. H. pylori was detected in the Nairobi river basin, but there was no relationship between the numerical levels of fecal bacteria and H. pylori.
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Affiliation(s)
- Victor Dinda
- Masinde Muliro University of Science and Technology, Medical Laboratory Sciences
| | - Andrew Kimang'a
- Jomo Kenyatta Universty of Agriculture & Technology, Medical Microbiology
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Eghbali Z, Mojtahedi A, Moien Ansar M, Fakhrieh Asl S, Aminian K. Detection of 23SrRNA Mutations Strongly Related to Clarithromycin Resistance in Helicobacter pylori Strains Isolated From Patients in the North of Iran. Jundishapur J Microbiol 2016; 9:e29694. [PMID: 27127590 PMCID: PMC4842254 DOI: 10.5812/jjm.29694] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Revised: 11/23/2015] [Accepted: 12/02/2015] [Indexed: 12/11/2022] Open
Abstract
Background: Helicobacter pylori is curved Gram negative and microaerophilic bacilli that have infected half of the world’s population. It is recognized as the causative agent of duodenal ulcer, gastritis peptic ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma and is associated with gastric adenocarcinoma. Resistance to clarithromycin is related to point mutations in 23SrRNA gene on nt 2143 and 2144, when A turns to G, and A2143G is the most important type. These mutations lead to reduced affinity of antibiotics to their ribosomal target and are considered as the main cause of treatment failure. Objectives: The aim of this study was to determine the frequency of A2143G point mutation in 23SrRNA of H.pylori strains isolated from gastric biopsies of patients in Rasht, north of Iran, by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Patients and Methods: A descriptive study was performed on 89 H.pylori strains, which were isolated from gastric biopsies of patients with gastric disorders such as gastritis, peptic ulcer, duodenal ulcer, non-ulcer dyspepsia and gastric adenocarcinoma. Isolated strains were tested for clarithromycin resistance using as breakpoint a minimum inhibitory concentration (MIC) of ≥ 1 mg/L by the E-test. The presence of H.pylori DNA was confirmed by amplifying the ureC (glmM) gene by PCR. Also, point mutation on 23SrRNA gene (A2142G and A2143G) was detected by PCR-RFLP using MboII and BsaI restriction endonucleases in all extracted DNA. Results: Of the 89 H.pylori isolates, eighty-four were susceptible to clarithromycin, while five (5.6%) were resistant. All DNA samples of resistant strains, which were treated with BsaI had A2143G mutation. There was no point mutation in the sensitive strains of H. pylori. Also, we detected no mutation on nt A2142G of resistant strains. Conclusions: In the present study, the frequency of clarithromycin resistance was lower than the other studies conducted in Iran. Resistance frequency in samples isolated from gastric ulcer was higher than other gastric disorders. Women and patients aged more than 60 years old showed the most resistance frequency in this study. All resistant strains had the A2143G genotype.
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Affiliation(s)
- Zahra Eghbali
- Department of Biology, Rasht Branch, Islamic Azad University, Rasht, IR Iran
| | - Ali Mojtahedi
- Department of Microbiology, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, IR Iran
- Corresponding author: Ali Mojtahedi, Microbiology Department, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, IR Iran. Tel: +98-1333690884, Fax: +98-1333690036, E-mail:
| | - Malek Moien Ansar
- Department of Biochemistry and Biophysics, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, IR Iran
| | - Saba Fakhrieh Asl
- Division of Gastroenterology and Liver Disease, Gastric and Liver Disease Research Center, Guilan University of Medical Sciences, Rasht, IR Iran
| | - Keyvan Aminian
- Division of Gastroenterology and Liver Disease, Gastric and Liver Disease Research Center, Guilan University of Medical Sciences, Rasht, IR Iran
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Bakhtiari S, Alvandi A, Pajavand H, Navabi J, Najafi F, Abiri R. Development and Diagnostic Evaluation of Loop-Mediated Isothermal Amplification Using a New Gene Target for Rapid Detection of Helicobacter pylori. Jundishapur J Microbiol 2016; 9:e28831. [PMID: 27540449 PMCID: PMC4976074 DOI: 10.5812/jjm.28831] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 11/18/2015] [Accepted: 11/27/2015] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Helicobacter pylori cause chronic gastritis and subsequent diseases like gastric and duodenal ulcers and gastric adenocarcinoma. Current methods for detecting H. pylori have several disadvantages and it is of utmost importance to develop a simple, quick, accurate, and cost-effective diagnostic test. OBJECTIVES The aim of this study was to set up and evaluate a diagnostic value of loop- mediated isothermal amplification (LAMP) for detecting H. pylori. PATIENTS AND METHODS The analytical sensitivity values (limit of detection) of LAMP and polymerase chain reaction (PCR) were determined using serial dilutions of H. pylori DNA. Analytical specificity of the methods using new designed primers targeted ureC gene was also determined. RESULTS The detection limits of the LAMP and PCR assay were similar and were 10 fg of pure DNA of H. pylori, which is equal to 6 copy numbers of H. pylori genome. Analytical specificity of the tests was 100% because the tests were positive only with H. pylori DNA. CONCLUSIONS The analytical sensitivity of LAMP and PCR methods, using the designed primers, was 8 times more than any other reported methods. The designed methods are specific and sensitive for detection of H. pylori in different clinical and environmental samples.
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Affiliation(s)
- Somaye Bakhtiari
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Amirhooshang Alvandi
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Hamid Pajavand
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Jafar Navabi
- Imam Khomeini Hospital, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Farid Najafi
- Department of Biostatistics and Epidemiology, School of Hygiene, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
| | - Ramin Abiri
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, IR Iran
- Corresponding author: Ramin Abiri, Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, P. O. Box: 6714869914, Kermanshah, IR Iran. Tel: +98-9122773648, Fax: +98-8314274623, E-mail:
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Burd EM, Hinrichs BH. Gastrointestinal Infections. MOLECULAR PATHOLOGY IN CLINICAL PRACTICE 2016. [PMCID: PMC7123654 DOI: 10.1007/978-3-319-19674-9_50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Establishing a specific etiology for gastrointestinal infections can be challenging because of the common clinical features and wide variety of causative microorganisms. In many cases, the etiologic agent cannot be determined using traditional diagnostic methods and may result in unnecessary antibiotic use or prolonged periods of illness. Molecular tests provide many advantages over traditional laboratory methods but, with the exception of a few analytes, are still largely in the developmental phase for gastrointestinal pathogens and are not widely used. The main advantages of molecular tests include increased sensitivity and the ability to detect agents which will not grow in culture. To test for all possible gastrointestinal pathogens at one time would require a large panel that would include a variety of bacterial, viral and parasitic agents. Challenges inherent in developing diagnostic molecular panels include ensuring that all variants of a particular microorganism can be detected as well as the rapid evolution of pathogens. In this chapter, the diagnostic merit of molecular tests as well as available tests will be presented for the major groups of gastrointestinal pathogens.
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Ubhayawardana DNL, Weerasekera MM, Weerasekera DD, Gunasekera TCP, Fernando SN. Proportion of Helicobacter pylori Among Dyspeptic Patients Detected by Molecular Methods in a Teaching Hospital in Sri Lanka. INTERNATIONAL JOURNAL OF ENTERIC PATHOGENS 2015. [DOI: 10.17795/ijep29796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Yari F, Abiri R, Aryan E, Ahmadi Jouybari T, Navabi J, Alvandi A. Loop-Mediated Isothermal Amplification as a Fast Noninvasive Method of Helicobacter pylori Diagnosis. J Clin Lab Anal 2015; 30:464-70. [PMID: 26351213 DOI: 10.1002/jcla.21880] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/07/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Helicobacter pylori infection is etiologically associated with some important health problems such as gastric cancer. Because of the high clinical importance of H. pylori infection, development of a noninvasive test for the detection of H. pylori is desirable. METHODS In this study, a loop-mediated isothermal amplification (LAMP) targeted ureC of H. pylori was evaluated on 100 stool specimens and compared with a stool antigen test. Culture and rapid urease test were considered as gold standards. RESULTS The overall detection rate of the fecal antigen test and LAMP was 58% and 82%, respectively. The analytical sensitivity of the fecal antigen test and LAMP was 500 and 10 H. pylori cells/g and 10 fg DNA/reaction, which is equal to six H. pylori genome. CONCLUSION LAMP technique has been characterized by high sensitivity and low detection limit for the detection of H. pylori in stool specimen. Clinical diagnostic performance of LAMP was better than the stool antigen test.
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Affiliation(s)
- Farideh Yari
- Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran
| | - Ramin Abiri
- Department of Microbiology, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ehsan Aryan
- Antimicrobial Resistance Research Center & Department of Medical Microbiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Touraj Ahmadi Jouybari
- Clinical Research Development Center, Imam Khomeini Hospital and Department of Internal Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Jafar Navabi
- Clinical Research Development Center, Imam Khomeini Hospital and Department of Internal Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Amirhooshang Alvandi
- Department of Microbiology, Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Kalali B, Formichella L, Gerhard M. Diagnosis of Helicobacter pylori: Changes towards the Future. Diseases 2015; 3:122-135. [PMID: 28943614 PMCID: PMC5548244 DOI: 10.3390/diseases3030122] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/18/2015] [Accepted: 06/19/2015] [Indexed: 12/19/2022] Open
Abstract
Since the first evidence demonstrating the dramatically high incidence of H. pylori infection and the subsequent medical challenges it incurs, health management of H. pylori infection has been a high priority for health authorities worldwide. Despite a decreasing rate of infection in western countries, prevalence of H. pylori infection in developing and in some industrial countries is still very high. Whereas treatment and vaccination against H. pylori is a contemporary issue in medical communities, selective treatment and prior high-throughput screening of the subject population is a major concern of health organizations. So far, diagnostic tests are either elaborative and require relatively advanced medical care infrastructure or they do not fulfill the criteria recommended by the Maastricht IV/Florence consensus report. In this review, in light of recent scientific studies, we highlight current and possible future approaches for the diagnosis of H. pylori. We point out that novel non-invasive tests may not only cover the requirements of gold standard methods in H. pylori detection but also offer the potential for risk stratification of infection in a high throughput manner.
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Affiliation(s)
- Behnam Kalali
- Institute of Medical Microbiology, Immunology and Hygiene, TU-Munich, Troger Str.30, 81675 Munich, Germany.
- ImevaX GmbH, Grillparzer Str.18, 81675 Munich, Germany.
| | - Luca Formichella
- Institute of Medical Microbiology, Immunology and Hygiene, TU-Munich, Troger Str.30, 81675 Munich, Germany.
| | - Markus Gerhard
- Institute of Medical Microbiology, Immunology and Hygiene, TU-Munich, Troger Str.30, 81675 Munich, Germany.
- ImevaX GmbH, Grillparzer Str.18, 81675 Munich, Germany.
- German Center for Infection Research (DZIF), Partner site Munich, Troger Str.30, 81675 Munich, Germany.
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Ozbey G, Dogan Y, Demiroren K, Ozercan IH. Prevalence of Helicobacter pylori in children in eastern Turkey and molecular typing of isolates. Braz J Microbiol 2015; 46:505-11. [PMID: 26273266 PMCID: PMC4507543 DOI: 10.1590/s1517-838246220140234] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 09/30/2014] [Indexed: 12/19/2022] Open
Abstract
The objectives of the present study were to determine Helicobacter
pylori via culture, polymerase chain reaction and histopathological
diagnosis in 101 children ranging in age from 4 to 18 years, to identify the
association among restriction fragment length polymorphism types and clinical
disease and to investigate the relationships among different isolates of
H. pylori in different age groups. We observed a high
prevalence of H. pylori infections in children between the ages
of 13 and 18 (75.8%), while children aged 4 to 6 years had the lowest prevalence
of infection (40%). H. pylori was detected in 30.7% (31 of
101), 66.3% (67 of 101) and 63.2% (60 of 95) of children as determined by
culture methods, PCR and histological examination, respectively. H.
pylori isolates with RFLP types I and III were the most common
among children with antral nodularity, whereas RFLP types II and IV were the
least detected types. Interestingly, all isolates from peptic ulcer patients
were type III. Although our results show a high prevalence of H.
pylori infections in the pediatric population in eastern Turkey, no
association was identified between H. pylori infection with
antral nodularity and recurring abdominal pain. In addition, we found low
genetic variation among H. pylori isolates from children and no
association between RFLP types and antral nodularity (p > 0.05).
Additionally, we found that H. pylori isolates with specific
RFLP types were predominant in different age groups.
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Affiliation(s)
- Gokben Ozbey
- Firat University, Vocational School of Health Services, Firat University, Elazig, Turkey, Vocational School of Health Services, Firat University, Elazig, Turkey
| | - Yasar Dogan
- Firat University, Department of Pediatric Gastroenterology, Faculty of Medicine, Firat University, Elazig, Turkey, Department of Pediatric Gastroenterology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Kaan Demiroren
- Firat University, Department of Pediatric Gastroenterology, Faculty of Medicine, Firat University, Elazig, Turkey, Department of Pediatric Gastroenterology, Faculty of Medicine, Firat University, Elazig, Turkey
| | - Ibrahim Hanifi Ozercan
- Firat University, Department of Pathology, Faculty of Medicine, Firat University, Elazig, Turkey, Department of Pathology, Faculty of Medicine, Firat University, Elazig, Turkey
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Mazaheri Assadi M, Chamanrokh P, Whitehouse CA, Huq A. Methods for Detecting the Environmental Coccoid Form of Helicobacter pylori. Front Public Health 2015; 3:147. [PMID: 26075197 PMCID: PMC4446911 DOI: 10.3389/fpubh.2015.00147] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/08/2015] [Indexed: 12/29/2022] Open
Abstract
Helicobacter pylori is recognized as the most common pathogen to cause gastritis, peptic and duodenal ulcers, and gastric cancer. The organisms are found in two forms: (1) spiral-shaped bacillus and (2) coccoid. H. pylori coccoid form, generally found in the environment, is the transformed form of the normal spiral-shaped bacillus after exposed to water or adverse environmental conditions such as exposure to sub-inhibitory concentrations of antimicrobial agents. The putative infectious capability and the viability of H. pylori under environmental conditions are controversial. This disagreement is partially due to the fact of lack in detecting the coccoid form of H. pylori in the environment. Accurate and effective detection methods of H. pylori will lead to rapid treatment and disinfection, and less human health damages and reduction in health care costs. In this review, we provide a brief introduction to H. pylori environmental coccoid forms, their transmission, and detection methods. We further discuss the use of these detection methods including their accuracy and efficiency.
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Affiliation(s)
- Mahnaz Mazaheri Assadi
- Environmental Biotechnology Group, Biotechnology Department, Iranian Research Organization for Science and Technology , Tehran , Iran
| | - Parastoo Chamanrokh
- Maryland Pathogen Research Institute, University of Maryland , College Park, MD , USA
| | | | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland , College Park, MD , USA
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Bayindir T, Toplu Y, Otlu B, Yakupogullari Y, Yildirim O, Kalcioglu MT. Prevalence of the Helicobacter pylori in the tonsils and adenoids. Braz J Otorhinolaryngol 2015; 81:307-11. [PMID: 25900719 PMCID: PMC9452227 DOI: 10.1016/j.bjorl.2014.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Accepted: 08/24/2014] [Indexed: 01/29/2023] Open
Abstract
Introduction There is an ongoing debate about the existence and effects of Helicobacter pylori (Hp) in adenotonsillar tissue. Objective A clinical study was conducted to assess the existence of Hp in the adenoid and/or adenotonsillar tissues, which were surgically excised due to chronic adenotonsillitis. Methods Phosphoglucosamine mutase gene for the detection of Hp and cytotoxin-associated gene as virulence gene were examined in 84 adenotonsillar tissues obtained from 64 patients and patients’ serum by using polymerase chain reaction. Results Hp IgG was detected in 57 (89%) patients’ serum. A total of seven tissue samples from 64 patients (10.9%) were found positive for Hp DNA, of which five were adenoids and two were tonsil tissues. All polymerase chain reaction positive samples were also positive for the cytotoxin-associated gene, which is a virulence determinant for the organism. Conclusion This study suggests that children are exposed to Hp at an early age of their life in this province. Hp may have a role in the pathogenesis of chronic adenotonsillitis, especially in endemic areas.
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Chamanrokh P, Shahhosseiny MH, Mazaheri Assadi M, Nejadsattari T, Esmaili D. Three Tests Used to Identify Non-Culturable Form of Helicobacter pylori in Water Samples. Jundishapur J Microbiol 2015; 8:e16811. [PMID: 26034541 PMCID: PMC4449853 DOI: 10.5812/jjm.8(4)2015.16811] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 06/12/2014] [Accepted: 09/13/2014] [Indexed: 02/06/2023] Open
Abstract
Background: Helicobacter pylori, causing the most common chronic bacterial infection, exist in two forms; bacilli and coccoid. The coccoid form is identified as viable but non-culturable bacteria. Objectives: The current study aimed to conduct culture, polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP) tests to identify coccoid forms of H. pylori. Materials and Methods: The PCR and LAMP tests were optimized using specific primers for glmM gene. The sensitivity and specificity of the tests were determined. The current experimental study was conducted on 10 different strains isolated from clinical cases (H1-H10). The isolates were added to tap water and incubated at three different temperatures for one and two months intervals. After pure-culturing of the bacteria, DNAs were extracted and PCR and LAMP were performed. Results: Ten copies of targeted DNA were required for PCR detection whereas only five copies gave a positive reaction by LAMP assay, with 100% specificity. Of the 10 isolates inoculated in water for one and two months at three different temperatures 4, 22, and 37°C, only three cases (5%) were found positive in the first month; 13 (21.6%) and 29 cases (48.3%) were also positive by PCR and LAMP tests in the first and second months. Conclusions: Results of the current study confirmed that molecular methods such as PCR and LAMP were much more sensitive, rapid, and specific than culturing to identify non-culturable coccoid forms of H. pylori in water.
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Affiliation(s)
- Parastoo Chamanrokh
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, IR Iran
- Corresponding author: Parastoo Chamanrokh, Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, IR Iran. Tel: +98-9372727679, E-mail:
| | - Mohammad Hassan Shahhosseiny
- Department of Microbiology, Shahre Qods Branch, Islamic Azad University, Shahre Qods, IR Iran
- Iranian Gene Fanavar Institute (IGF), Tehran, IR Iran
| | - Mahnaz Mazaheri Assadi
- Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, IR Iran
| | - Taher Nejadsattari
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, IR Iran
| | - Davood Esmaili
- Department of Microbiology, Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
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Yu XW, Xu Q, Xu Y, Gong YH, Yuan Y. Expression of the E-cadherin/β-catenin/tcf-4 pathway in gastric diseases with relation to Helicobacter pylori infection: clinical and pathological implications. Asian Pac J Cancer Prev 2014; 15:215-20. [PMID: 24528029 DOI: 10.7314/apjcp.2014.15.1.215] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To determine the expression of E-cadherin, β-catenin, and transcription factor 4 (TCF4) proteins in gastric diseases with relation to Helicobacter pylori infection. METHODS A total of 309 patients including 60 with superficial gastritis (SG), 57 with atrophic gastritis (AG) and 192 with gastric cancer (GC), were enrolled. The expression of E-cadherin, β-catenin, TCF4 proteins in the gastric mucosa was detected by immunohistochemistry and H. pylori infection by immunohistochemistry and PCR. RESULTS The expression rates of E-cadherin were significantly higher in SG and AG than in GC (P<0.01), while those of β-catenin in the nucleus were significantly lower in SG and AG than in GC (P<0.05). In GC cases, the expression rates of E-cadherin, β-catenin and TCF4 were significantly higher in the intestinal type than in the diffuse type (P<0.05). In GC patients, the expression rate of E-cadherin was significantly higher in the presence of H. pylori than in the absence of infection (P=0.011). Moreover, the expression level of TCF4 and β-catenin protein was significantly higher in the nucleus and cytoplasm in H. pylori positive than in H. pylori negative GC patients, especially in those with the intestinal type (all P < 0.05). CONCLUSION The expression of E-cadherin and β-catenin progressively decreases during the process of GC tumorigenesis, while overexpression of TCF4 occurs. H. pylori infection is associated with a significant increase in the expression of E-cadherin and β-catenin in the cytoplasm and nucleus in GC patients, especially those with the intestinal type.
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Affiliation(s)
- Xiu-Wen Yu
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University), Liaoning Provincial Education Department, Shenyang, China E-mail :
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Alikhani MY, Arebestani MR, Sayedin Khorasani M, Majlesi A, Jaefari M. Evaluation of Helicobacter pylori vacA and cagA Genotypes and Correlation With Clinical Outcome in Patients With Dyspepsia in Hamadan Province, Iran. IRANIAN RED CRESCENT MEDICAL JOURNAL 2014; 16:e19173. [PMID: 25763216 PMCID: PMC4329959 DOI: 10.5812/ircmj.19173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Revised: 06/14/2014] [Accepted: 07/09/2014] [Indexed: 01/04/2023]
Abstract
Background: Helicobacter pylori is known to be a causative agent of chronic active gastritis, peptic ulcer and gastric cancer in human. Diverse genotypes of H. pylori strains have different virulence potency and geographic distribution. Objectives: The purpose of this study was to investigate the association between the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes of H. pylori strains and clinical outcomes in patients referred to Shahid-Beheshti Hospital in Hamadan, Iran. Patients and Methods: In this cross-sectional study, biopsy samples were collected consecutively from 153 patients with gastric cancer (GC), peptic ulcer dyspepsia (PUD) and non-ulcer dyspepsia (NUD) in the gastroenterology department of Shahid-Beheshti Hospital in Hamadan province, the west of Iran. H. pylori infection was confirmed in 83 patients (3 with GC, 27 with PUD, and 53 with NUD) by histology, rapid urease test (RUT) and culture. Genomic DNA was extracted from the bacterial isolate and was further confirmed with 16S rRNA gene sequencing as H. pylori, and characterized based on cagA and vacA genotyping using the polymerase chain reaction (PCR) method. Results: In this study, vacA genotypes s1/m2, s1/m1, s2/m2 and s2/m1 were determined in 43.4%, 19.3%, 13.2% and 6% of the isolated H. pylori, respectively. The vacAs1 genotype was detected in 52 (62.6%) isolates, of which the vacAs1a genotype was detected in 45.2, 40.7, and 66.6% of the isolates from patients with NUD, PUD, and GC, respectively. The cagA-positive genotype was determined in 73 (87.9%) isolates and 10 (12.1%) were negative. The frequency rates of cagA gene were 84.9, 92.6 and 100% in isolates of patients with NUD, PUD, and GC, respectively. The cagA-positive genotype is strongly associated with s1a/m2 and s1a/m1 vacA genotypes. Conclusions: The most predominant VacA genotypes in our areas were s1/m2 and s1/m1, which regard as the genotypes with more virulence intensity. The H. pylorivacAs1a, cagA genotypes have a significant relationship with the presence of PUD and GC in Iranian patients with dyspepsia.
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Affiliation(s)
- Mohammad Yousef Alikhani
- Brucellosis Research Center, Hamadan University of Medical Sceinces, Hamadan, IR Iran
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Mohammad Reza Arebestani
- Brucellosis Research Center, Hamadan University of Medical Sceinces, Hamadan, IR Iran
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
- Corresponding Author: Mohammad Reza Arebestani, Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran. Tel: +98-9188662009, Fax: +98-8118380762, E-mail:
| | - Masood Sayedin Khorasani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Amir Majlesi
- Department of Gastrointestinal Diseases, Beheshti Hospital, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Mohammad Jaefari
- Department of Pathology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran
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FakhreYaseri H, Shakaraby M, Bradaran HR, Soltani Arabshahi SK, Fakhre Yaseri AM. CagA and VacA genotypes in peptic ulcer disease and non-ulcer dyspepsia: a case-control study. Med J Islam Repub Iran 2014; 28:104. [PMID: 25664305 PMCID: PMC4301206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 04/23/2014] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND The cag pathogenicity island includes a number of genes, including cytotoxin-associated protein A (cagA) and vacuolating cytotoxin (vacA) genotypes, which are associated with bacterial virulence. Although the role of cagA and vacA in the virulence of Helicobacter pylori (H. pylori) is well-established in epidemiological studies, the relationship between the cagA and vacA genotypes in Iran has yet to be fully elucidated. This study compared the association between cagA and vacA genotypes between peptic ulcer disease (PUD) patients and non-ulcer dyspeptic (NUD) patients. METHODS This case control study was done on 130 patients with positive H. pylori in histological and Giemsa reports. The case group comprised 65 PUD patients, and the control group included 65 NUD patients. The presence of the cagA and vacA genotypes was determined using polymerase chain reaction (PCR) on biopsy samples, taken via endoscopy. RESULTS Both cagA and vacA genotypes were positive in 51.5% (17) of the PUD group and 20% (6) of the NUD group (p= 0.009), and both cagA and vacA genotypes were negative in 48.5% (16) and 80% (24) of the case and control groups, respectively (p= 0.03). CagA-positive H. pylori was detected in 41.5% (27) and 24.6% (16) of the case and control groups, respectively (p= 0.001), and vacA-positive H. pylori was found in 60% (39) and 46% (30) of the case and control groups, respectively. CONCLUSION Both cagA and vacA genotypes were more prevalent in the PUD patients than in their NUD counterparts among our Iranian samples. It is seems that the determination of these two genotypes in PUD patients is a good screening tool for patient selection for endoscopy and treatment.
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Affiliation(s)
- Hashem FakhreYaseri
- 1. Assistant Professor, Research Center for Gastroenterology and Liver Disease, Department of Internal Medicine and Gastroenterology, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran.
| | - Mehdi Shakaraby
- 2. Associate Professor, Department and Research Center of Immunology, Iran University of Medical Sciences, Tehran, Iran.
| | - Hamid Reza Bradaran
- 3. Associate Professor, Department of Epidemiology, Iran University of Medical Sciences, Tehran, Iran.
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Kim JY, Kim N, Nam RH, Suh JH, Chang H, Lee JW, Kim YS, Kim JM, Choi JW, Park JG, Lee YS, Lee DH, Jung HC. Association of polymorphisms in virulence factor of Helicobacter pylori and gastroduodenal diseases in South Korea. J Gastroenterol Hepatol 2014; 29:984-91. [PMID: 24372834 DOI: 10.1111/jgh.12509] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/04/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Clinical outcomes of Helicobacter pylori (HP) infection have been shown to be dependent on the variability of virulence factors. The aim of this study was to evaluate the prevalence of each virulence factor and the association between polymorphisms of the virulence factors of HP, and the clinical outcome of gastroduodenal diseases in South Korea. METHODS Four hundred one HP colonies were analyzed (75 colonies from 45 controls; 71 colonies from 39 benign gastric ulcer [BGU] patients; 102 colonies from 54 duodenal ulcer [DU] patients; 121 colonies from 77 stomach cancer patients; and 32 colonies from 25 dysplasia patients). Polymerase chain reaction amplifications for vacA, cagA, iceA, oipA, and dupA were performed using DNA extract from HP isolates cultured from mucosal biopsy specimens. dupA was regarded as positive when all of jph0718, jph0719, and dupA were positive. RESULTS Most colonies were composed of vacA s1 (100.0%), i1 (100.0%) and m1 (92.9%), cagA-positive (87.2%), iceA1 (95.8%), oipA-positive (91.2%), and dupA-negative (52.0%) genotypes. dupA was more frequently expressed in BGU (81.3%), DU (74.7%), and dysplasia (41.7%) than control (16.7%) (P < 0.001). Infection by dupA-positive HP showed an increased risk of BGU (odds ratio 33.06, 95% confidence interval 11.91-91.79) and DU (odds ratio 15.60, 95% confidence interval 6.49-37.49). CONCLUSION HP infection in South Koreans appears to be closely related to highly virulent strains (vacA s1/i1/m1, cagA(+), iceA1(+), and oipA(+)), except dupA. dupA has an intimate association with the development of peptic ulcer diseases.
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Affiliation(s)
- Ji Yeon Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine
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Efficacy and pharmacological mechanism of pronase-enhanced low-dose antibiotics for Helicobacter pylori eradication. Antimicrob Agents Chemother 2014; 58:3348-53. [PMID: 24687504 DOI: 10.1128/aac.02319-13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This study examined the efficacy and pharmacological mechanism of pronase-assisted low-dose antibiotics for eradication of Helicobacter pylori. Mongolian gerbils infected with H. pylori received 7-day treatment (omeprazole, different concentrations of pronase, amoxicillin, and clarithromycin), and the efficacy was assessed using the eradication rate and the colonization of H. pylori. In Mongolian gerbils orally administered pronase, the thickness of the gastric mucous layer (GML) was examined using immunohistochemical and alcian blue staining, and the concentrations of amoxicillin in gastric tissue and serum were detected using high-performance liquid chromatography (HPLC). The eradication rates were 80.0% (12/15) in the high-pronase quadruple group (HPQG) and 86.7% (13/15) in the high-antibiotic group (HAG) (P = 1.000). The antibiotic dose in the HPQG was only 1/20 that in the HAG. Thirty minutes after oral treatment with pronase, the sticky protein of the GML was hydrolyzed, and the GML became thinner. Higher amoxicillin concentrations in both the gastric tissue and serum were observed in the pronase group than in the Am10 group. The concentration of amoxicillin in the Am10-plus-Pr108 group in gastric tissue was 3.8 times higher than in the Am10 group in 5 min. Together, these data suggest that pronase significantly reduced the dose of antibiotics used in H. pylori eradication. The pharmacological mechanism is likely pronase removal of the mucus layer, promoting chemical factor (i.e., gastric acid and pepsinogen) distribution and increasing the antibiotic concentrations in the deep GML, which acted on H. pylori collectively. Thus, pronase may enhance the level of antibiotics for eradication of H. pylori in the clinic.
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Qadri Q, Afroze D, Rasool R, Gulzar G, Naqash S, Siddiqi MA, Shah ZA. CagA subtyping in Helicobacter pylori isolates from gastric cancer patients in an ethnic Kashmiri population. Microb Pathog 2014; 66:40-3. [DOI: 10.1016/j.micpath.2013.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 12/23/2013] [Accepted: 12/24/2013] [Indexed: 12/14/2022]
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Kim JH. The Diagnosis of Helicobacter pyloriInfection. THE KOREAN JOURNAL OF HELICOBACTER AND UPPER GASTROINTESTINAL RESEARCH 2014. [DOI: 10.7704/kjhugr.2014.14.4.233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jie-Hyun Kim
- Department of Internal Medicine, Gangnam Severance Hospital,Yonsei University College of Medicine, Seoul, Korea
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Khalifehgholi M, Shamsipour F, Ajhdarkosh H, Ebrahimi Daryani N, Pourmand MR, Hosseini M, Ghasemi A, Shirazi MH. Comparison of five diagnostic methods for Helicobacter pylori. IRANIAN JOURNAL OF MICROBIOLOGY 2013; 5:396-401. [PMID: 25848511 PMCID: PMC4385167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND AND OBJECTIVES Invasive and non-invasive techniques are used to diagnose H. pylori infection. Some factors influence the choice of a diagnostic test, such as the sensitivity and specificity of the tests, the clinical circumstances and the cost-effectiveness of the testing strategy. The aim of this study was to reveal the relationship between different H. pylori infection diagnosis methods, and clarify the application scope of each diagnosis method. MATERIALS AND METHODS patients were included in the study, and specimens including biopsies, blood and stool were taken. Biopsies were evaluated by hematoxylin and eosin, and Giemsa staining. A sequence of 294 bp in the ureC (glmM) gene was amplified. The rapid urease test (RUT) was performed using a non-commercial validated test. Stool samples were analyzed using a polyclonal ELISA stool antigen test. A serological assay for IgG antibodies was performed by a commercial Helicobacter pylori IgG ELISA kit. RESULTS According to the predefined criteria, a total of 46 (50.5%) patients tested were positive by at least 2 of the 3 biopsy-based methods. The best sensitivity (95.6%) belonged to histology and RUT. The sensitivities of other tests including PCR, serology and stool antigen test were 93.5%, 91.3% and 73.9%, respectively. RUT showed the best specificity (100%), and the specificities of the other tests, including PCR, stool antigen test, histology and serology, were 95.6%, 86.7%, 77.8% and 55.6%, respectively. CONCLUSION In view of the better results obtained for invasive vs non-invasive tests, for a more accurate diagnosis, it is advisable not to solely rely on non-invasive methods of H. Pylori diagnosis.
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Affiliation(s)
- Mohammad Khalifehgholi
- Department of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Fereshteh Shamsipour
- Department of Immunochemistry, Monoclonal Antibody Research Center, Avicenna Research Institute, Academic Center for Education, Culture and Research (ACECR), Terhran, Iran
| | - Hossein Ajhdarkosh
- Gastroenterology and Liver Diseases Research Center (GILDRC), Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Naser Ebrahimi Daryani
- Department of Gastroenterology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mostafa Hosseini
- Department of Epidemiology and Biostatistics, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Ghasemi
- Department of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hasan Shirazi
- Department of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
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Pourakbari B, Ghazi M, Mahmoudi S, Mamishi S, Azhdarkosh H, Najafi M, Kazemi B, Salavati A, Mirsalehian A. Diagnosis of Helicobacter pylori infection by invasive and noninvasive tests. Braz J Microbiol 2013; 44:795-8. [PMID: 24516421 PMCID: PMC3910191 DOI: 10.1590/s1517-83822013005000052] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 07/23/2012] [Indexed: 12/12/2022] Open
Abstract
Although several invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection, all of the tests have their limitations. We conducted a study to investigate and compare the suitability of rapid urease test (RUT), serology, histopathology and stool antigen tests with polymerase chain reaction (PCR) for detection of H. pylori, and correlate the diagnostic methods with PCR. Eighty nine patients (61 adults, 28 children) referred to the Firoozgar Hospital and Children Medical Center Hospital for diagnostic upper gastrointestinal endoscopy entered to the study and noninvasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in feces were measured. The biopsies were utilized for histological examination, RUT and PCR. The H. pylori statuses were evaluated by the positivity of ureC PCR in biopsy specimens and 53 subjects had H. pylori positive result. Histopathology showed high overall performance in adults and children with sensitivity and specificity 100% and 90%, respectively. Sensitivity, specificity, and accuracy for stool antigen test were 87.8%, 75% and 82%, respectively. Correlation of RUT, serology (IgG), histopathology and stool antigen tests with PCR were 0.82, 0.32, 0.91 and 0.63, respectively. In conclusion, the RUT and histopathology are as accurate as the PCR of biopsy and stool antigen test can consider as appropriate noninvasive test for detection of H. pylori infection.
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Affiliation(s)
- Babak Pourakbari
- Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mona Ghazi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shima Mahmoudi
- Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Setareh Mamishi
- Pediatric Infectious Diseases Research Center, Tehran University of Medical Sciences, Tehran, Iran. ; Department of Pediatric Infectious Diseases, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Azhdarkosh
- Department of Internal Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehri Najafi
- Department of Pediatric Gastroenterology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahram Kazemi
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Salavati
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Akbar Mirsalehian
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Agarwal S, Jithendra KD. Presence of Helicobacter pylori in subgingival plaque of periodontitis patients with and without dyspepsia, detected by polymerase chain reaction and culture. J Indian Soc Periodontol 2013; 16:398-403. [PMID: 23162336 PMCID: PMC3498711 DOI: 10.4103/0972-124x.100919] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 04/11/2012] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Helicobacter pylori is an important gastrointestinal pathogen that is strongly associated with gastritis as well as peptic ulcer disease. Antimicrobial therapy frequently fails to cure H. pylori infection, which suggests there may be sanctuary sites where the organism resides. This study was aimed to assess the role of oral cavity as a reservoir of H. pylori by evaluating the occurrence of the organism in subgingival plaque of dyspeptic patients by polymerase chain reaction as well as culture. MATERIALS AND METHODS Thirty chronic periodontitis patients whose biopsy specimens were found to be H. pylori positive with rapid urease test and histopathologic examination were considered as cases and 20 chronic periodontitis patients who never had any symptoms of gastritis or peptic ulcer were taken as controls. Subgingival plaque samples were collected and sent to microbiological laboratory for detection of H. pylori by 16S rRNA based polymerase chain reaction as well as culture. RESULTS 60% of the samples were found to be positive with polymerase chain reaction in the case group when compared to 15% in the controls. Also, 30% of the cases were found to be positive with culture compared to none in controls. CONCLUSION A higher frequency of detection of H. pylori in those patients with positive antral biopsy report was seen. Also, polymerase chain reaction was found to be more sensitive than culture for detection. Thus, we conclude that detection of H. pylori in dental plaque of dyspeptic patients cannot be neglected and might represent a risk factor for recolonization of stomach after systemic eradication therapy.
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Affiliation(s)
- Sangita Agarwal
- Department of Periodontology, People's Dental Academy, Bhopal, Madhya Pradesh, India
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von Rosenvinge EC, Song Y, White JR, Maddox C, Blanchard T, Fricke WF. Immune status, antibiotic medication and pH are associated with changes in the stomach fluid microbiota. ISME JOURNAL 2013; 7:1354-66. [PMID: 23466701 DOI: 10.1038/ismej.2013.33] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The stomach acts as a barrier to ingested microbes, thereby influencing the microbial ecology of the entire gastrointestinal (GI) tract. The stomach microbiota and the role of human host and environmental factors, such as health status or medications, in shaping its composition remain largely unknown. We sought to characterize the bacterial and fungal microbiota in the stomach fluid in order to gain insights into the role of the stomach in GI homeostasis. Gastric fluid was collected from 25 patients undergoing clinically indicated upper endoscopy. DNA isolates were used for PCR amplification of bacterial 16S ribosomal RNA (rRNA) genes and fungal internal transcribed spacers (ITS). RNA isolates were used for 16S rRNA cDNA generation and subsequent PCR amplification. While all stomach fluid samples are dominated by the phyla Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Fusobacteria (>99% of sequence reads), the transcriptionally active microbiota shows significant reduction in Actinobacteria (34%) and increase in Campylobacter (444%) (P<0.003), specifically the oral commensal and suspected intestinal pathogen Campylobacter concisus. Bacterial but not fungal diversity is reduced by antibiotic treatment (28%; P<0.02), immunosuppression in transplant recipients and HIV/AIDS patients (42%; P<0.001) and gastric fluid pH >4 (70%; P<0.05). Immunosuppression correlates with decreased abundance of Prevotella (24%), Fusobacterium (2%) and Leptotrichia (6%) and increased abundance of Lactobacillus (3844%) (P<0.003). We have generated the first in-depth characterization of the human gastric fluid microbiota, using bacterial 16S rRNA gene and transcript, and fungal ITS amplicon sequencing and provide evidence for a significant impact of the host immune status on its composition with likely consequences for human health.
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Affiliation(s)
- Erik C von Rosenvinge
- Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Kalaf EA, Al-Khafaji ZM, Yassen NY, AL-Abbudi FA, Sadwen SN. Study of the cytoxin-associated gene a (CagA gene) in Helicobacter pylori using gastric biopsies of Iraqi patients. Saudi J Gastroenterol 2013; 19:69-74. [PMID: 23481132 PMCID: PMC3632013 DOI: 10.4103/1319-3767.108474] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND AIMS The Helicobacter pylori CagA gene is a major virulence factor that plays an important role in gastric pathologies. The size variation of CagA gene, which is dependent on the 3' repeat region, contains one or more Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs and CagA multimerization (CM) motifs. Four segments flanking the EPIYA motifs, EPIYA -A, -B, -C, or -D, were reported to play a crucial role in the pathogenesis of H. pylori infection. The aim was to determine the roles of EPIYA segments and CM motifs in gastroduodenal pathogenesis in an Iraqi population. PATIENTS AND METHODS Gastric biopsies were collected from 210 patients with gastritis, duodenal ulcer (DU), gastric ulcer (GU), and gastric cancer (GC). The EPIYA motif genotyping was determined by polymerase chain reaction and sequencing. The differences in age, gender, and CagA EPIYA motifs of H. pylori between GC, DU, GU and gastritis patients were analyzed using a χ(2) -test. RESULTS A total of 22 (45.8%) strains had three copies of EPIYA (ABC type), 2 (4.16%) had four copies (ABCC type), 6 (12.7%) had five copies (ABCCC type), 13 (27.08%) had two copies (AB type), 3 (6.25%) had the BC, and 2 (4.17%) had AC motif. The alignment of the deduced protein sequences confirmed that there were no East Asian type EPIYA-D sequences in Iraqi strains. A significant association was found between increase in number of EPIYA-C motifs and GU (P ≤ 0.01) compared with gastritis. CONCLUSIONS The structure of the 3' region of the CagA gene in Iraqi strains was Western type with a variable number of EPIYA-C and CM motifs. A significant association was found between increase in number of EPIYA-C motifs and GU compared with gastritis indicating predictive association with the severity of the disease. The GenBank accession numbers for the partial CagA nucleotide sequences determined in this study are JX164093-JX164112.
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Affiliation(s)
- Elham A. Kalaf
- Genetic Engineering and Biotechnology Institute for Post Graduate Studies, Baghdad University,Address for correspondence: Dr. Elham A. Kalaf, Genetic Engineering and Biotechnology Institute for Post Graduate Studies, Baghdad University, Iraq E-mail:
| | - Zahra M. Al-Khafaji
- Genetic Engineering and Biotechnology Institute for Post Graduate Studies, Baghdad University
| | - Nahi Y. Yassen
- Iraqi Center of Cancer and Medical Genetics Researches, Almustanseria University, Baghdad, Iraq
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Smith SI, Fowora MA, Lesi OA, Agbebaku E, Odeigah P, Abdulkareem FB, Onyekwere CA, Agomo CA, Contreras M. Application of stool-PCR for the diagnosis of Helicobacter pylori from stool in Nigeria- a pilot study. SPRINGERPLUS 2012; 1:78. [PMID: 23419882 PMCID: PMC3568462 DOI: 10.1186/2193-1801-1-78] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 12/13/2012] [Indexed: 02/07/2023]
Abstract
There are various methods for detection of Helicobacter pylori and the gold standard for non-invasive detection is the urea breath test (UBT). The aim of the study is therefore to detect H. pylori from the stool of patients with dyspepsia by PCR and compare results obtained with UBT. A total of 97 stool samples from patients presenting with dyspeptic symptoms in Lagos University Teaching Hospital (LUTH) were screened for urea breath test (UBT) and the presence of H. pylori DNA using stool-PCR. Out of 97 stool samples analysed, 38 (39.2%) were positive for Helicobacter spp. and 20 (20.6%) positive for H. pylori by PCR, through amplification of 16S rRNA and glmMgenes respectively. Of the 20 positive by glmM gene, the cagAgene was detected in 8 (40%) samples, while 47 (48.5%) out of 97 stool samples were positive for H. pylori by UBT. The sensitivity and specificity of the glmM gene compared with UBT as the gold standard is 42.6% and 100% respectively. The positive predictive value (PPV) was 100% while the negative predictive value (NPV) was 60%.The method may be useful for detecting H. pylori from stool amongst children especially where most hospitals lack endoscope for children although the method is expensive.
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Affiliation(s)
- Stella I Smith
- Molecular Biology and Biotechnology Division, Nigerian Institute of Medical Research, 6 Edmond Crescent, Yaba, PMB 2013, Lagos, Nigeria
| | - Muinah A Fowora
- Molecular Biology and Biotechnology Division, Nigerian Institute of Medical Research, 6 Edmond Crescent, Yaba, PMB 2013, Lagos, Nigeria
| | - Olufunmilayo A Lesi
- Department of Medicine, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Elizabeth Agbebaku
- Department of Cell Biology and Genetics, University of Lagos, Lagos, Nigeria
| | - Peter Odeigah
- Department of Cell Biology and Genetics, University of Lagos, Lagos, Nigeria
| | | | - Charles A Onyekwere
- Department of Medicine, Lagos State University Teaching Hospital (LASUTH), Ikeja, Nigeria
| | - Chimere A Agomo
- Biochemistry and Nutrition Division, Nigerian Institute of Medical Research, 6 Edmond Crescent, Yaba, Lagos, Nigeria
| | - Monica Contreras
- Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
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Abstract
AIMS Helicobacter pylori (HP) DNA was assayed using a newly fabricated voltammetric handheld circuit equipped with an interfaced graphite pencil electrode (PE) sensor. METHODS Under optimum analytical parameters, the square-wave (SW) stripping detection range attained was 0.1-0.7 mg/L. RESULTS A relative standard deviation of 1.68% (RSD, n = 5) was observed at a 3.2 mg/L HP DNA within a 90 s accumulation time. Under these conditions, the analytical detection limit approached 0.07 mg/L. CONCLUSIONS The developed methods can be applied to HP assays of preliminary stage gastric cancer patient tissues.
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Ramis IB, de Moraes EP, Fernandes MS, Mendoza-Sassi R, Rodrigues O, Juliano CRV, Scaini CJ, da Silva PEA. Evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens of dyspeptic patients. Braz J Microbiol 2012; 43:903-8. [PMID: 24031905 PMCID: PMC3768872 DOI: 10.1590/s1517-83822012000300008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 06/07/2012] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori infects nearly 50% of the world’s population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was to evaluate diagnostic methods, such as in-house urease test, culture and Polymerase Chain Reaction (PCR), for the detection of the H. pylori in gastric biopsy specimens of 144 dyspeptic patients, using as gold standard the association between histology and rapid urease test. According to the gold standard used in this study, 48 (33.3%) patients were infected with H. pylori, while 96 (66.7%) were classified as not infected. The in-house urease test and the PCR were the most sensitive methods (100%), followed by culture (85.4%). However, the inhouse urease test and the culture were the most specific (100%), followed by PCR (75%). In conclusion, this study showed that, in comparison with the combination of histology and rapid urease test, the in-house urease test and the PCR presented 100% of sensitivity in the diagnosis of gastric infection by H. pylori, while the in-house urease test and the culture reached 100% of specificity. These finding suggest that the combination of two or more methods may improve the accuracy of the H. pylori detection.
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Affiliation(s)
- Ivy Bastos Ramis
- Laboratório de Biologia Molecular, Universidade Federal do Rio Grande, Rio Grande , Rio Grande do Sul , Brasil
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80
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Yakoob J, Abbas Z, Khan R, Naz S, Ahmad Z, Islam M, Awan S, Jafri F, Jafri W. Prevalence of non Helicobacter pylori species in patients presenting with dyspepsia. BMC Gastroenterol 2012; 12:3. [PMID: 22226326 PMCID: PMC3276444 DOI: 10.1186/1471-230x-12-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 01/06/2012] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Helicobacter species associated with human infection include Helicobacter pylori, Helicobacter heilmannii and Helicobacter felis among others. In this study we determined the prevalence of H. pylori and non-Helicobacter pylori organisms H. felis and H. heilmannii and analyzed the association between coinfection with these organisms and gastric pathology in patients presenting with dyspepsia. Biopsy specimens were obtained from patients with dyspepsia on esophagogastroduodenoscopy (EGD) for rapid urease test, histology and PCR examination for Helicobacter genus specific 16S rDNA, H. pylori phosphoglucosamine mutase (glmM) and urease B (ureB) gene of H. heilmannii and H. felis. Sequencing of PCR products of H. heilmannii and H. felis was done. RESULTS Two hundred-fifty patients with dyspepsia were enrolled in the study. The mean age was 39 ± 12 years with males 162(65%). Twenty-six percent (66 out of 250) were exposed to cats or dogs. PCR for Helicobacter genus specific 16S rDNA was positive in 167/250 (67%), H. pylori glmM in 142/250 (57%), H. heilmannii in 17/250 (6%) and H. felis in 10/250 (4%), respectively. All the H. heilmannii and H. felis PCR positive patients were also positive for H. pylori PCR amplification. The occurrence of coinfection of H. pylori and H. heilmannii was 17(6%) and with H. felis was 10(4%), respectively. Only one out of 66 exposed to pets were positive for H. heilmannii and two for H. felis. Histopathology was carried out in 160(64%) of 250 cases. Chronic active inflammation was observed in 53(56%) (p = 0.001) of the patients with H. pylori infection alone as compared to 3(37%) (p = 0.73) coinfected with H. heilmannii and H. pylori and 3(60%) coinfected with H. felis and H. pylori (p = 0.66). Intestinal metaplasia was observed in 3(3%)(p = 1.0) of the patients with H. pylori infection alone as compared to 2(25%) (p = 0.02) coinfected with H. heilmannii and H. pylori and 1(20%) coinfected with H. felis and H. pylori (p = 0.15). CONCLUSION The prevalence of H. heilmannii and H. felis was low in our patients with dyspepsia. Exposure to pets did not increase the risk of H. heilmannii or H. felis infection. The coinfection of H. pylori with H. heilmannii was seen associated with intestinal metaplasia, however this need further confirmation.
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Affiliation(s)
- Javed Yakoob
- Department of Medicine, The Aga Khan University, Karachi, Pakistan.
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81
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Varbanova M, Malfertheiner P. Bacterial load and degree of gastric mucosal inflammation in Helicobacter pylori infection. Dig Dis 2011; 29:592-9. [PMID: 22179216 DOI: 10.1159/000333260] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Helicobacter pylori induces an inflammatory immune response in the gastric mucosa. The degree of gastric mucosal inflammation and its topographic distribution are key factors in the diversity of H. pylori-related complications. Here we summarize substantial evidence reported in the literature concerning the impact of H. pylori density on gastric inflammation, the development of severe complications, and its relation to H. pylori suppression therapy. Most studies demonstrate a significant correlation between H. pylori density and the grade of acute and chronic inflammation, taking into account the limitations of each method for density assessment. Overall, high bacterial loads are associated with increased acute mucosal damage and long-term changes in the gastric mucosa. The influence of H. pylori density reduction on the improvement of gastric mucosal changes was observed in studies using 'clearance' therapies. Mucosal agents provoke a significant, but not persistent, reduction in gastritis activity. Treatments suppressing the density and virulence of H. pylori could become strategies to prevent H. pylori-associated disease in the future.
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Affiliation(s)
- M Varbanova
- Department of Gastroenterology, Hepatology and Infectious Diseases, Otto von Guericke University, Magdeburg, Germany
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82
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Helicobacter pylori homB, but not cagA, is associated with gastric cancer in Iran. J Clin Microbiol 2011; 49:3191-7. [PMID: 21734027 DOI: 10.1128/jcm.00947-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
While several distinct virulence factors of Helicobacter pylori have been shown to be associated with different clinical outcomes, there is still much to learn about the role of different bacterial factors in gastric carcinogenesis. This study looked at the distribution of the cagA, homA, and homB genes in strains isolated from patients suffering from gastroduodenal diseases in Iran and assessed if there was any association between disease state and the presence of the aforementioned virulence factors. Genomic DNA from 138 H. pylori strains was isolated and genotyped via PCR. Strains were obtained from dyspeptic patients (35 from gastritis patients, 62 from peptic ulcer patients, and 41 from gastric cancer patients) at the Teaching Touba Clinic and Imam Hospital of the Mazandaran University of Medical Sciences in Sari, Iran. The overall prevalence rates of cagA, homA, and homB were 58%, 54%, and 43%, respectively. Stratification of patients showed a significant difference in the prevalence of H. pylori virulence genes across the disease states. The frequency of homB was statistically significantly higher in gastric cancer patients (78%) than in patients suffering from peptic ulcers (20%) or gastritis (43%) (P < 0.0001). The presence of homB was also associated with the presence of cagA (r = 0.243). These data suggest that in this population the presence of homB may be a predictor of more virulent strains of H. pylori and influence the severity of disease manifestation.
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83
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Abdel-Monem MH, Magdy EA, Nour YA, Harfoush RA, Ibreak A. Detection of Helicobacter pylori in adenotonsillar tissue of children with chronic adenotonsillitis using rapid urease test, PCR and blood serology: a prospective study. Int J Pediatr Otorhinolaryngol 2011; 75:568-72. [PMID: 21324534 DOI: 10.1016/j.ijporl.2011.01.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 01/14/2011] [Accepted: 01/18/2011] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Contradictory results have been reported regarding Helicobacter pylori (H. pylori) detection in adenotonsillar tissue. The aims of this study were to investigate whether adenotonsillar tissue of symptomatic children with chronic adenotonsillitis harbors the H. pylori organism, using two biopsy-based invasive methods namely; rapid urease test (RUT) and polymerase chain reaction (PCR) as well as blood serology and to compare the results obtained from each of these methods to the "gold standard". METHODS This prospective clinical study was carried out on 20 children aged between 2 and 10 years scheduled for tonsillectomy +/- adenoidectomy in a tertiary referral center. Exclusion criteria included: use of antacids, H(2) blockers or antibiotics during the previous month before surgery and adenotonsillectomy for obstructive sleep apnea. Core biopsy samples from resected adenotonsillar tissue was tested for H. pylori detection using both RUT and PCR assay for the ureC gene. Preoperative patient venous blood samples were also tested for H. pylori IgG antibodies. As a "gold standard", examined tissue was considered to be H. pylori infected if the two biopsy specimen-based methods (RUT and PCR) yielded positive results. RESULTS Thirty adenotonsillectomy specimens were tested (20 tonsils and 10 adenoids). RUT was positive in 16 (53.3%) specimens (12 tonsils and 4 adenoids). According to the "gold standard", 11/16 were considered false-positive, yielding this test sensitivity 100% and specificity 56%. The ureC gene sequence was detected by PCR in 5 (16.6%) specimens (3 tonsils and 2 adenoids), all of which were also positive by RUT, thus were considered H. pylori infected. Accordingly, PCR had a 100% sensitivity and specificity. Serology testing was positive for H. pylori IgG antibodies in 4/20 patients (20%), only two of them were found to have H. pylori infected adenotonsillar tissue. CONCLUSIONS Based on our findings it seems that adenotonsillar tissue may constitute an extra-gastric reservoir for H. pylori in symptomatic children with chronic adenotonsillitis. RUT was found to be of less accuracy than PCR in H. pylori detection in an extra-gastric location, thus results of previous studies using this test alone for detection of oral H. pylori should be treated with caution.
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Affiliation(s)
- Mohamed H Abdel-Monem
- Department of Otorhinolaryngology-Head & Neck Surgery, Faculty of Medicine, Alexandria University, Alexandria, Egypt
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84
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Zou QH, Li RQ. Helicobacter pylori in the oral cavity and gastric mucosa: a meta-analysis. J Oral Pathol Med 2011; 40:317-24. [DOI: 10.1111/j.1600-0714.2011.01006.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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85
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Smith SI, Fowora MA, Otegbayo JA, Abdulkareem FB, Omonigbehin EA, Adegboyega A, Contreras M, Haas R. Comparison of PCR with other diagnostic techniques for the detection of H. pylori infection in patients presenting with gastroduodenal symptons in Nigeria. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2011; 2:178-184. [PMID: 21686132 PMCID: PMC3110392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 01/11/2011] [Indexed: 05/30/2023]
Abstract
The study was aimed at comparing PCR methods of direct detection from biopsy using the boiling method and one other method with two known gold standards (histology and CLO test) for the diagnosis of H. pylori in Nigeria. A total of 168 biopsies (three from antrum and one from corpus each) were taken from 42 patients presenting with various gastroduodenal symptons after informed consent was obtained from them.The biopsies were analysed using the CLO test kit and histology, while the boiling method as described by Holmes and Quigley (1981) was used to obtain DNA and then PCR using the 16S rRNA gene, glmM gene and cagA gene. With CLO test 15/42 (35.71%) were positive, histology 13/42 (30.95%) were positive, 16S rRNA 22/42 (52.38%) were positive, glmM 19/42 (45.24%) were positive, cagA 19/42 (45.24%) were positive. The sensitivity and specificity of the PCR tests with CLO as the gold standard showed that the tests were 100% sensitive and varied between 74.1% to 84.1% in specificity. The PPV and NPV showed that the NPV was almost 100%, while the PPV was between 68.2% and 75%. Using the histology as the gold standard, the sensitivity was almost 100% while the specificity, the PPV were reduced in comparison to the CLO test. The PCR test using the glmM gene appears to be the most reliable test for diagnosis of H. pylori in Nigeria most especially where culture is difficult due to the power outages.
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86
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Maldonado-Contreras A, Goldfarb KC, Godoy-Vitorino F, Karaoz U, Contreras M, Blaser MJ, Brodie EL, Dominguez-Bello MG. Structure of the human gastric bacterial community in relation to Helicobacter pylori status. ISME JOURNAL 2010; 5:574-9. [PMID: 20927139 DOI: 10.1038/ismej.2010.149] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The human stomach is naturally colonized by Helicobacter pylori, which, when present, dominates the gastric bacterial community. In this study, we aimed to characterize the structure of the bacterial community in the stomach of patients of differing H. pylori status. We used a high-density 16S rRNA gene microarray (PhyloChip, Affymetrix, Inc.) to hybridize 16S rRNA gene amplicons from gastric biopsy DNA of 10 rural Amerindian patients from Amazonas, Venezuela, and of two immigrants to the United States (from South Asia and Africa, respectively). H. pylori status was determined by PCR amplification of H. pylori glmM from gastric biopsy samples. Of the 12 patients, 8 (6 of the 10 Amerindians and the 2 non-Amerindians) were H. pylori glmM positive. Regardless of H. pylori status, the PhyloChip detected Helicobacteriaceae DNA in all patients, although with lower relative abundance in patients who were glmM negative. The G2-chip taxonomy analysis of PhyloChip data indicated the presence of 44 bacterial phyla (of which 16 are unclassified by the Taxonomic Outline of the Bacteria and Archaea taxonomy) in a highly uneven community dominated by only four phyla: Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Positive H. pylori status was associated with increased relative abundance of non-Helicobacter bacteria from the Proteobacteria, Spirochetes and Acidobacteria, and with decreased abundance of Actinobacteria, Bacteroidetes and Firmicutes. The PhyloChip detected richness of low abundance phyla, and showed marked differences in the structure of the gastric bacterial community according to H. pylori status.
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87
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Structure of the human gastric bacterial community in relation to Helicobacter pylori status. ISME JOURNAL 2010. [PMID: 20927139 DOI: 10.1038/ismej] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The human stomach is naturally colonized by Helicobacter pylori, which, when present, dominates the gastric bacterial community. In this study, we aimed to characterize the structure of the bacterial community in the stomach of patients of differing H. pylori status. We used a high-density 16S rRNA gene microarray (PhyloChip, Affymetrix, Inc.) to hybridize 16S rRNA gene amplicons from gastric biopsy DNA of 10 rural Amerindian patients from Amazonas, Venezuela, and of two immigrants to the United States (from South Asia and Africa, respectively). H. pylori status was determined by PCR amplification of H. pylori glmM from gastric biopsy samples. Of the 12 patients, 8 (6 of the 10 Amerindians and the 2 non-Amerindians) were H. pylori glmM positive. Regardless of H. pylori status, the PhyloChip detected Helicobacteriaceae DNA in all patients, although with lower relative abundance in patients who were glmM negative. The G2-chip taxonomy analysis of PhyloChip data indicated the presence of 44 bacterial phyla (of which 16 are unclassified by the Taxonomic Outline of the Bacteria and Archaea taxonomy) in a highly uneven community dominated by only four phyla: Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Positive H. pylori status was associated with increased relative abundance of non-Helicobacter bacteria from the Proteobacteria, Spirochetes and Acidobacteria, and with decreased abundance of Actinobacteria, Bacteroidetes and Firmicutes. The PhyloChip detected richness of low abundance phyla, and showed marked differences in the structure of the gastric bacterial community according to H. pylori status.
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Al-Ali J, Al-Asfar F, Dhar R, Dhar PM, Kusum K. Diagnostic performance of gastric imprint smear for determination of Helicobacter pylori infection. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2010; 24:603-6. [PMID: 21037989 PMCID: PMC2975473 DOI: 10.1155/2010/156310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 04/12/2010] [Indexed: 11/17/2022]
Abstract
BACKGROUND Despite the availability of several methods (invasive and noninvasive) for the diagnosis of Helicobacter pylori infection, no test is considered to be the 'gold standard'. Endoscopy-based tests are regarded as the reference method in most studies. OBJECTIVE To evaluate the diagnostic performance of imprint cytology smears of antral biopsies compared with Gram-stained smears, the rapid urease test and culture methods, separately and in combination. METHODS Antral biopsies were obtained from consecutive patients undergoing upper gastrointestinal endoscopy at a single centre. The biopsies were examined for the presence of H pylori by Gram-stained smear, the rapid urease test, culture methods and imprint cytology smear. RESULTS A total of 273 biopsies were studied. All tests were positive in 36% of the patients. Of 252 biopsies tested, 73% were positive using the imprint cytology technique. Using Gram-stained smear, the rapid urease test and culture methods individually, the sensitivity and specificity of imprint cytology smears for the detection of H pylori were found to be 92.7% and 50%; 92.7% and 49%; and 92.4% and 38.5%, respectively. Combining the three microbiological methods resulted in a sensitivity of 92.1%, a specificity of 51.0% and an efficiency of 71.7% for imprint cytology smears. CONCLUSIONS Endoscopic examination provides useful clinical information. Imprint gastric cytology can be used as a rapid test to establish the diagnosis of H pylori infection at the time endoscopy is performed, enabling the endoscopist to start treatment with immediate effect.
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Affiliation(s)
- Jaber Al-Ali
- Department of Medicine, Faculty of Medicine, Kuwait University, Kuwait.
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89
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Assumpção MB, Martins LC, Melo Barbosa HP, Barile KADS, Almeida SSD, Assumpção PP, Corvelo TCDO. Helicobacter pylori in dental plaque and stomach of patients from Northern Brazil. World J Gastroenterol 2010; 16:3033-9. [PMID: 20572307 PMCID: PMC2890944 DOI: 10.3748/wjg.v16.i24.3033] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To establish whether virulence factor genes vacA and cagA are present in Helicobacter pylori (H. pylori) retrieved from gastric mucosa and dental plaque in patients with dyspepsia.
METHODS: Cumulative dental plaque specimens and gastric biopsies were submitted to histological examination, rapid urease test and polymerase chain reaction (PCR) assays to detect the presence of cagA and vacA polymorphisms.
RESULTS: Detection of H. pylori from dental plaque and gastric biopsy samples was greater by PCR compared to histological examination and the rapid urease test. DNA from H. pylori was detected in 96% of gastric mucosa samples and in 72% of dental plaque samples. Sixty-three (89%) of 71 dental plaque samples that were H. pylori-positive also exhibited identical vacA and cagA genotypes in gastric mucosa. The most common genotype was vacAs1bm1 and cagA positive, either in dental plaque or gastric mucosa. These virulent H. pylori isolates were involved in the severity of clinical outcome.
CONCLUSION: These pathogenic strains were found simultaneously in dental plaque and gastric mucosa, which suggests that gastric infection is correlated with the presence of H. pylori in the mouth.
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90
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Detection of Helicobacter pylori by phenotypic and genotypic methods. Dig Dis Sci 2010; 55:1643-8. [PMID: 19693671 DOI: 10.1007/s10620-009-0928-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 07/16/2009] [Indexed: 12/16/2022]
Abstract
AIMS This research evaluated the utilization of a urease in-house test, culture and molecular method (ureA PCR) as a diagnostic tool for Helicobacter pylori infection. Furthermore, we assessed the presence of the cagA gene in the specimens and in isolated strains that were positive for ureA by PCR positive. RESULTS Sensitivity and specificity, respectively, were 100 and 95.8% for the urease in-house test 93.3 and 95.8 for the ureA PCR assay of the specimen and 100 and 100% for the culture. The presence of the cagA gene was observed in eight (53%) ureA-positive samples. CONCLUSIONS In this study, we found that the PCR technique has applicability in the study of cagA, and other genes related to the H. pylori pathogen. This method can be applied to samples directly from biopsy or isolated from the bacteria.
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91
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Linke S, Lenz J, Gemein S, Exner M, Gebel J. Detection of Helicobacter pylori in biofilms by real-time PCR. Int J Hyg Environ Health 2010; 213:176-82. [PMID: 20427237 DOI: 10.1016/j.ijheh.2010.03.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 03/23/2010] [Accepted: 03/25/2010] [Indexed: 12/18/2022]
Abstract
Helicobacter pylori is a cause of peptic ulcer disease and a causative agent of gastric cancer. Currently, a possible waterborne route of transmission or a possible survival in drinking water biofilms is discussed. H. pylori, like many other bacterial strains, has the ability to enter the viable but nonculturable state (vbnc) in case of unfavorable conditions. Therefore it is necessary to develop new analysis tools for vbnc bacteria. We established a fast and reliable method to detect H. pylori in drinking water biofilms by quantitative real-time PCR which makes it redundant to use difficult cultivation methods for nonculturable bacteria. With this method it was possible to identify water biofilms as a niche for H. pylori. The real-time PCR analysis targets the ureA subunit of the Helicobacter pylori urea gene which showed high specificity and sensitivity. The quantitative real-time PCR was used to detect H. pylori in biofilms of different age, unspiked and spiked with predetermined levels of cells. The drinking water biofilms were generated in a silicone-tube model. The DNA-sequences for probe and primers showed no cross-homologies to other related bacteria and it was possible to detect less than 10 genomic units of H. pylori. This novel method is a useful tool for a fast screening of drinking water biofilms for H. pylori. The results suggest that drinking water biofilms may act as a reservoir for H. pylori which raises new concerns about the role of biofilms as vectors for pathogens like Helicobacter pylori.
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Affiliation(s)
- S Linke
- Institute for Hygiene and Public Health, University of Bonn, Sigmund-Freud-Strasse 25, Klinikgelände 35, 53105 Bonn, Germany.
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Prevalence and genotypes of Helicobacter pylori in gastric biopsy specimens from patients with gastroduodenal pathologies in the Cukurova Region of Turkey. J Clin Microbiol 2009; 47:4150-3. [PMID: 19846654 DOI: 10.1128/jcm.00605-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The effects of Helicobacter pylori genotypes on clinical prognosis in the Cukurova region of Turkey were investigated by PCR. The prevalence of type I strains carrying the s1c allele, unlike in neighboring regions and countries, was found to be significantly higher in patients with gastritis and/or gastric ulcers (P = 0.001), and that of type I strains carrying the s1a allele was found to be significantly higher in patients with duodenal ulcers (P < 0.001). The cagA gene was strongly associated with the more virulent vacA genotypes (P < 0.001).
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93
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Helicobacter pylori genotyping findings from multiple cultured isolates and mucosal biopsy specimens: strain diversities of Helicobacter pylori isolates in individual hosts. Eur J Gastroenterol Hepatol 2009; 21:522-8. [PMID: 19373969 DOI: 10.1097/meg.0b013e3283196af0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To determine whether the genotypes of virulent genes in Helicobacter pylori isolates and mucosal biopsy specimens differ in individuals, and to investigate whether different isolates from single hosts show strain differences. METHODS Sixty-one Korean patients with H. pylori infection were enrolled. PCR and DNA sequencing for cagA, vacA, iceA, and oipA were performed using DNA extracted from H. pylori isolates cultured (2.6 H. pylori isolates per host) directly from antral mucosal biopsy specimens. Strain diversities were analyzed in 234 H. pylori isolates obtained from 43 hosts with at least two H. pylori isolates from antrum and body, respectively, and random amplified polymorphic DNA fingerprinting was carried out on isolates obtained from patients who showed genotype diversity. RESULTS The patients with inconsistent genotyping results between H. pylori isolates and mucosal biopsies were as follows: 16.4% for cagA, 19.7% for vacA m, 47.5% for vacA s1, 6.6% for vacA i-region, 34.4% for iceA, and 21.3% for oipA. Genotyping of H. pylori isolates from same hosts showed diversity in 58.1% (25/43 patients). When random amplified polymorphic DNA -PCR fingerprinting was carried out on 104 H. pylori isolates from 19 patients who showed genotype diversity among their isolates, 68.4% (13 of 19 patients) of patients were found to be colonized by multiple H. pylori strains. CONCLUSION This study shows that the genotypes of virulent genes from biopsy samples produced different results when compared with those obtained from H. pylori isolates, especially for vacA s1, and iceA. In addition, about 60% of our patients were infected by multiple H. pylori strains.
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Yáñez MA, Barberá VM, Soria E, Catalán V. Quantitative detection of Helicobacter pylori in water samples by real-time PCR amplification of the cag pathogenicity island gene, cagE. J Appl Microbiol 2009; 107:416-24. [PMID: 19302298 DOI: 10.1111/j.1365-2672.2009.04219.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
AIMS A new real-time PCR assay that simultaneously amplifies a 102-bp fragment of the cagE gene from Helicobacter pylori and a new internal positive control containing a specific sequence of the gyrB gene from Aeromonas hydrophila, was developed and validated for the detection of H. pylori in environmental samples. METHODS AND RESULTS The specificity, limits of detection and quantification, repeatability, reproducibility, and accuracy of the method were calculated. The resulting values confirmed the applicability of the method for the quantitative detection of H. pylori. The feasibility of the method was also evaluated by testing 13 pyloric antrum-positive biopsies and 69 water samples, including potable (10), surface (19) and wastewater (40) matrices. The results showed that all the biopsies and 3 of the 40 wastewater samples analysed were positive. CONCLUSIONS This real-time PCR method provides a sensitive, specific, and accurate method for the rapid quantification of H. pylori in environmental samples. SIGNIFICANCE AND IMPACT OF THE STUDY The PCR diagnostic system proposed in this work, provides a suitable tool for the quantitative detection of H. pylori in environmental samples and can be useful for verifying the role of water as a potential route of its transmission.
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95
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Comparaison de quatre paires d’amorces différentes dans la détection d’Helicobacter pylori dans les biopsies gastriques et les prélèvements oraux. ACTA ACUST UNITED AC 2009; 57:30-5. [DOI: 10.1016/j.patbio.2008.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 07/03/2008] [Indexed: 12/16/2022]
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96
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Eyigor M, Eyigor H, Gultekin B, Aydin N. Detection of Helicobacter pylori in adenotonsiller tissue specimens by rapid urease test and polymerase chain reaction. Eur Arch Otorhinolaryngol 2009; 266:1611-3. [PMID: 19130070 DOI: 10.1007/s00405-008-0903-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 12/17/2008] [Indexed: 12/13/2022]
Abstract
In recent studies, there have been many arguments concerning Helicobacter pylori being reservoir in adenotonsillar tissue. In this study, our objective was to detect whether adenoid and/or tonsillar tissue of patients diagnosed with chronic adenotonsillitis was a reservoir for H. pylori. This study was performed with 47 patients with the diagnosis of chronic tonsillitits and adenoid hypertrophy. Helicobacter pylori was searched by rapid urease test (RUT) and polymerase chain reaction (PCR). Presence of H. pylori glmM gene (formerly named as ureC gene) was tested using ureC and ureC2 primers. Fifty-five specimens used in the study were made up of 35 adenoid and 20 tonsil tissues. Rapid urease test was positive in three (5.5%) specimens. Helicobacter pylori was not detected in any of the patients by PCR. Further studies are needed to clarify the possible role of H. pylori in upper aerodigestive tract diseases such adenotonsillitis.
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Affiliation(s)
- Mete Eyigor
- Department of Microbiology and Clinical Microbiology, Faculty of Medicine, Adnan Menderes University, Aydin, Turkey,
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97
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Abstract
BACKGROUND Several putative virulence factors for Helicobacter pylori have been identified including cagA, vacA, and iceA. The aims of the present study were to study the distribution of cagA, vacA, and iceA genotypes in children with H. pylori gastritis and to examine the association of genotypes with severity of gastritis. METHODS H. pylori DNA was extracted from antral biopsy specimens from 33 children with H. pylori gastritis. Specific polymerase chain reaction assays were used for three genes: cagA, vacA, and iceA. The features of gastritis were graded in accordance with the updated Sydney System. RESULTS Of the 33 children, 31 (94%) were cagA positive. Twenty-four (72%) had s1c genotype and nine (27%) had s1a. The m1 genotype was seen in 27 (82%) and m2 was found in five (15%). The iceA1 genotype was detected in 25 (76%). Scores of neutrophil activity, chronic inflammation, and H. pylori density were independent of cagA, vacA and iceA status. CONCLUSION The cagA-positive vacA s1c/m1 iceA1 genotype was predominant in Korean children with recurrent abdominal pain and H. pylori gastritis. The cagA, vacA and iceA genotype were not associated with the severity of gastritis.
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Affiliation(s)
- Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
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98
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Reszka E, Jegier B, Wasowicz W, Lelonek M, Banach M, Jaszewski R. Detection of infectious agents by polymerase chain reaction in human aortic wall. Cardiovasc Pathol 2008; 17:297-302. [DOI: 10.1016/j.carpath.2007.11.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 10/08/2007] [Accepted: 11/05/2007] [Indexed: 01/24/2023] Open
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99
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High occurrence of Helicobacter pylori in raw goat, sheep and cow milk inferred by glmM gene: a risk of food-borne infection? Int J Food Microbiol 2008; 124:43-7. [PMID: 18372071 DOI: 10.1016/j.ijfoodmicro.2008.02.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 01/27/2008] [Accepted: 02/14/2008] [Indexed: 12/26/2022]
Abstract
Helicobacter pylori is an organism widespread in humans and sometimes responsible for serious illnesses, such as gastric and duodenal ulcers, MALToma and even gastric cancer. It has been hypothesized that the infection route by H. pylori involves multiple pathways including food-borne transmission, as the microorganism has been detected from foods such as sheep and cow milk. This work reports the results of a survey conducted in order to investigate the presence of H. pylori in raw goat, sheep and cow milk produced in Southern Italy, employing a Nested Polymerase Chain Reaction (Nested-PCR) assay for the detection of the phosphoglucosamine mutase gene (glmM), as screening method followed by conventional bacteriological isolation. Out of the 400 raw milk samples examined, 139 (34.7%) resulted positive for the presence of glmM gene, but no strains were isolated. In this work H. pylori DNA has been firstly detected from 41 (25.6%) raw goat milk samples. The results deserve further investigations on the contamination source/s of the milk samples and on the major impact that it may have on consumers.
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100
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Singh V, Mishra S, Rao GRK, Jain AK, Dixit V, Gulati AK, Mahajan D, McClelland M, Nath G. Evaluation of nested PCR in detection of Helicobacter pylori targeting a highly conserved gene: HSP60. Helicobacter 2008; 13:30-4. [PMID: 18205663 PMCID: PMC2752369 DOI: 10.1111/j.1523-5378.2008.00573.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To comparatively evaluate a new nested set of primers designed for the detection of Helicobacter pylori targeting a highly conserved heat shock protein gene (Hsp60). METHODS A total of 60 subjects having peptic ulcer diseases were tested for the detection of H. pylori using rapid urease test (RUT), histology, culture, and polymerase chain reaction (PCR) in their antral biopsy specimens. A newly designed Hsp60 gene-based primer set was evaluated against commonly used PCR primers for detection of H. pylori. RESULTS Forty-six of the 60 study subjects were found positive for culture isolation and all the 46 culture-positive specimens were also positive with Hsp60 gene PCR. Of the 46 culture-positive specimens, 44 were positive for 16S rRNA gene, ureC gene, RUT, and histology whereas only 29 were positive with ureA gene PCR. Of the 14 culture-negative subjects, 10 were positive with 16S rRNA gene, 4 were positive with ureC (glmM) gene PCR, and 2 were positive with RUT and 1 was positive on histology. CONCLUSION This study shows that nested amplification targeting Hsp60 gene is the most sensitive and specific with LR+ and LR- values of proportional, variant and 0, respectively, when compared with the other three PCR methods. Also, HSP60 gene-specific nested protocol was the most appropriate for detection of H. pylori in clinical specimens. This is particularly valuable because it can be used as a noninvasive method for detecting H. pylori infection in young children and also, in follow-up studies with peptic ulcer patients, on samples like feces and saliva.
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Affiliation(s)
- Varsha Singh
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Shrutkirti Mishra
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - GRK Rao
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Ashok Kumar Jain
- Department of Gastroenterology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - V.K. Dixit
- Department of Gastroenterology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Anil Kumar Gulati
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Divya Mahajan
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Michael McClelland
- Cell and Molecular Biology Laboratory, Sidney Kimmel Cancer Center, San Diego, CA, USA
| | - Gopal Nath
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.,Corresponding author & Reprint request Mailing address: Gopal Nath Professor, Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi-221005,India. Phone: 91-9335058394 Fax: 91-542 2367568
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