scholarly journals Western Blot Method Evaluation for Detection of Helicobacter pylori Infections against H. pylori Ag in Stool Enzyme-Linked Immunoassay in Adult Egyptian Patients

2016 ◽  
Vol 4 (3) ◽  
pp. 352-358
Author(s):  
Mohamed E. Rashed ◽  
Amer M.M. ◽  
Mostafa Elnakeeb ◽  
Waleed Saeed Omer
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Virulence Factors ◽  
Diagnostic Value ◽  
Type I ◽  
Western Blot Method ◽  
Egyptian Patients ◽  
Cytotoxin Associated Gene A ◽  
H Pylori ◽  
Medical Burden

Helicobacter pylori infection is tremendous medical burden especially in developing countries. Various immunological tests are available for diagnosis of H. pylori infection. Western blot method is proven to be promising for Precise, easy reading, sensitive and specific detection of H. pylori infections, besides it also permits the detection for the different virulence factors of CagA / VacA positive strains (type I). The objective of this study is to evaluate the diagnostic value of commercial Western Blot (WB) method in the serological diagnosis of H. pylori infections against the H. pylori Ag in stool (HpSAg) using commercial enzyme-linked immunoassay (ELISA) in adult dyspeptic Egyptian patients. Also we investigated the prevalence of virulence factors, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) in the infected patients. Samples from 46 adult dyspeptic Egyptian patients were tested by the two methods. WB test gave accurate confirmed result with (82.6% accuracy and 89.5% sensitivity) compared to HpSAg test. Also the results indicated a high seroprevalence of cagA- and vacA-positive virulent H. pylori type I strains in adult infected population indicate that such strains may be common in this population and responsible for the majority of H. pylori infection among adult Egyptians. We concluded that WB method could be useful for the confirmatory detection of antibody profiles to H. pylori antigens and virulence factors in adult Egyptian patients.Int J Appl Sci Biotechnol, Vol 4(3): 352-358

scholarly journals A Novel Line Immunoassay Based on Recombinant Virulence Factors Enables Highly Specific and Sensitive Serologic Diagnosis of Helicobacter pylori Infection

2013 ◽  
Vol 20 (11) ◽  
pp. 1703-1710 ◽  
Author(s):  
Luca Formichella ◽  
Laura Romberg ◽  
Christian Bolz ◽  
Michael Vieth ◽  
Michael Geppert ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Immune Responses ◽  
Virulence Factors ◽  
Gastrointestinal Disease ◽  
Individual Risk ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Serologic Test ◽  
Content Type ◽  
H Pylori

ABSTRACTHelicobacter pyloricolonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome.H. pylorivirulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to importantH. pylorivirulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed inEscherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) wereH. pylorinegative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), therecomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, therecomLine assay provides a valuable tool for the diagnosis ofH. pyloriinfection.

scholarly journals Helicobacter pylori Infection and Strain Types in Adult Dyspeptic Patients Undergoing Endoscopy in a Specialized Hospital of Dhaka City

2009 ◽  
Vol 3 (1) ◽  
pp. 4-9
Author(s):  
Sufi HZ Rahman ◽  
M Anisur Rahman ◽  
MS Arfin ◽  
M Mahbub Alam ◽  
TM Bhuiyan ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Helicobacter Pylori Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rapid Urease Test ◽  
Type I ◽  
Urease Test ◽  
H Pylori

Helicobacter pylori infection occurs worldwide with a high prevalence in developing countries. Virulence of H. pylori strains varies in different geographic regions. The aim of this study was to see H. pylori infection and its strain types in adult dyspeptic patients in Bangladesh and to analyze association of H. pylori strain types with clinical disease and severity of histological gastritis. Ninety consecutive adult dyspeptic patients undergoing diagnostic endoscopy were tested for H. pylori infection by culture, rapid urease test (RUT), histology and anti H. pylori IgG ELISA (Enzyme linked immunosorbent assay). H. pylori strain types were determined by Western Blot analysis. Association of strain types with clinical gastro-duodenal diseases and grades of histological gastritis were analyzed by χ2 test. Among the selected patients, 53 (58.9%) were culture positive, 48 (53.3%) were RUT positive, 31 (34.4%) were histology positive and 82 (91.1%) were anti-H. pylori IgG ELISA positive. By Western Blot analysis of the 90 sera samples, 48 (53.3%) showed antibodies to Type I strain of H. pylori, 21 (23.3%) Intermediate strain and 3 (3.3%) Type II strain. Endoscopically, 20 (22.2%) patients were found normal, 27 (30.0%) had gastritis, 9 (10.0%) had duodenitis, 28 (31.1%) had peptic ulcer disease, 4 (4.4%) had gastric carcinoma, and 2 (2.2%) had reflux esophagitis. Histologically, 34.4% had H. pylori, 44.4% had polymorhonuclear neutrophil (PMN), 100% had mononuclear cell (MNC) infiltration of different grades, 1.1% had atrophic gastritis and 2.2% had intestinal metaplasia of moderate grade. H. pylori strain types was not associated with clinical gastro-duodenal diseases or grades of PMN or MNC infiltration (p > 0.05) in these patients. Key words: Helicobacter pylori infection, H. pylori strain types, gastro-duodenal diseases, grades of gastritis   doi: 10.3329/bjmm.v3i1.2963 Bangladesh J Med Microbiol 2009; 03 (01): 4-9

scholarly journals Statins’ Regulation of the Virulence Factors of Helicobacter pylori and the Production of ROS May Inhibit the Development of Gastric Cancer

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1293
Author(s):  
Ting-Yu Lin ◽  
Wen-Hsi Lan ◽  
Ya-Fang Chiu ◽  
Chun-Lung Feng ◽  
Cheng-Hsun Chiu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Treatment Strategies ◽  
Vacuolating Cytotoxin ◽  
Cholesterol Levels ◽  
Cytotoxin Associated Gene A ◽  
H Pylori ◽  
Cellular Components ◽  
Development Of Gastric Cancer

Conventionally, statins are used to treat high cholesterol levels. They exhibit pleiotropic effects, such as the prevention of cardiovascular disease and decreased cancer mortality. Gastric cancer (GC) is one of the most common cancers, ranking as the third leading global cause of cancer-related deaths, and is mainly attributed to chronic Helicobacter pylori infection. During their co-evolution with hosts, H. pylori has developed the ability to use the cellular components of the host to evade the immune system and multiply in intracellular niches. Certain H. pylori virulence factors, including cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and cholesterol-α-glucosyltransferase (CGT), have been shown to exploit host cholesterol during pathogenesis. Therefore, using statins to antagonize cholesterol synthesis might prove to be an ideal strategy for reducing the occurrence of H. pylori-related GC. This review discusses the current understanding of the interplay of H. pylori virulence factors with cholesterol and reactive oxygen species (ROS) production, which may prove to be novel therapeutic targets for the development of effective treatment strategies against H. pylori-associated GC. We also summarize the findings of several clinical studies on the association between statin therapy and the development of GC, especially in terms of cancer risk and mortality.

scholarly journals Simultaneous Detection and Differentiation of Anti-Helicobacter pylori Antibodies by Flow Microparticle Immunofluorescence Assay

2004 ◽  
Vol 11 (1) ◽  
pp. 131-136 ◽  
Author(s):  
F. Bühling ◽  
G. Koch ◽  
T. Wex ◽  
A. Heimburg ◽  
M. Vieth ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Virulence Factors ◽  
Simultaneous Detection ◽  
Immunoblot Analysis ◽  
Measurement Range ◽  
Immunofluorescence Assay ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
H Pylori

ABSTRACT Helicobacter pylori is the key pathogen for gastroduodenal diseases. The clinical outcome of H. pylori infection is influenced by the presence of strain-specific virulence factors that are usually detected by the presence of specific anti-H. pylori antibodies in serum. Apart from the detection of these antibodies by enzyme-linked immunosorbent assay (ELISA), it is desirable to obtain additional information concerning the presence of certain virulence factors of H. pylori that are currently detected by immunoblot analysis. At present, the immunodiagnosis of an H. pylori infection includes two separate methods: ELISA and immunoblot analysis. Here, we report the development and evaluation of a new rapid flow microparticle immunofluorescence assay (FMIA) for detection of anti-H. pylori antibodies in human serum. The assay allows rapid qualitative and quantitative detection of anti-H. pylori antibodies by using crude antigen preparations as well as single recombinant antigens (urease A, urease B, CagA, and alkylhydroxy peroxide reductase) in the same sample with one measurement, and thus it combines the advantages of enzyme immunoassay and Western blot analysis. Seventy-five patient samples were analyzed by FMIA, ELISA, and Western blotting with respect to their immunoreactivity against crude H. pylori extracts and individual H. pylori antigens. Statistical analyses revealed an overall similarity of more than 90% among the results for FMIA, ELISA, and Western blot. Therefore, we conclude that FMIA is a powerful and time- and cost-saving assay system for the detection of antimicrobial antibodies, with higher sensitivity and a larger measurement range than ELISA.

scholarly journals Major virulence factors, VacA and CagA, are commonly positive inHelicobacter pylori isolates in Japan

Gut ◽  
1998 ◽  
Vol 42 (3) ◽  
pp. 338-343 ◽  
Author(s):  
S Maeda ◽  
K Ogura ◽  
H Yoshida ◽  
F Kanai ◽  
T Ikenoue ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Japanese Patients ◽  
Type I ◽  
Activity Type ◽  
Vacuolating Cytotoxin ◽  
Specific Antibodies ◽  
High Prevalence ◽  
H Pylori ◽  
Very High

Background—VacA and CagA proteins have been reported to be major virulence factors of Helicobacter pylori. However, antibodies against these proteins are frequently found in the sera of Japanese patients regardless of their gastroduodenal status.Aim—To evaluate the expression of VacA and CagA proteins by H pylori strains isolated in Japan.Methods—By using specific antibodies raised against recombinant VacA and CagA proteins, the expression of VacA and CagA was evaluated in 68 H pylori strains isolated from Japanese patients; a vacuolating assay and genotyping of thevacA gene were also used in the evaluation. The results were analysed in relation to the gastroduodenal diseases of the hosts.Results—VacA and CagA proteins were expressed in 59/68 (87%) and in 61/68 (90%) isolates respectively. The vacuolating assay was positive in 57/68 (84%) isolates, indicating that most immunologically VacA positive strains produced active cytotoxin. The prevalence of infection with strains expressing CagA and positive for vacuolating activity (Type I) was very high, 54/68 (79%), irrespective of the gastroduodenal status of the host.Conclusion—Most H pylori isolates in Japan are positive for vacuolating cytotoxin and CagA, and thus these virulence factors cannot be used as markers to discern the risk of developing serious gastroduodenal pathologies in the hosts. However, the high prevalence of infection with strains positive for vacuolating cytotoxin and CagA may contribute to the characteristics of H pylori infection in Japan.

scholarly journals High prevalence of cytotoxin positive Helicobacter pylori in patients unrelated to the presence of peptic ulcers in Japan

Gut ◽  
1997 ◽  
Vol 41 (4) ◽  
pp. 463-468 ◽  
Author(s):  
K Ogura ◽  
F Kanai ◽  
S Maeda ◽  
H Yoshida ◽  
M Ogura ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Western Blot ◽  
Gastrointestinal Diseases ◽  
Normal Mucosa ◽  
Peptic Ulcers ◽  
Western Blot Assay ◽  
Vacuolating Cytotoxin ◽  
Western Blot Method ◽  
High Prevalence ◽  
H Pylori

Background—It has been reported that infection with vacuolating cytotoxin positive Helicobacter pyloristrains is associated with gastroduodenal disease in Western countries.Aims—To evaluate the prevalence of cytotoxin producing strains among patients with H pyloriinfection in relation to gastrointestinal diseases in Japan.Patients—Ninety seven patients undergoing endoscopy.Methods—A Western blot assay was conducted to detect serum antibodies against the cytotoxin using recombinant cytotoxin (VacA protein) as an antigen. To obtain a purified recombinant cytotoxin, the vacA gene (2233 nucleotides) was cloned into an expression vector to produce the protein (744 amino acids), which was expressed in Escherichia coli.Results—Serum IgG antibodies to the cytotoxin were present in 85%, 95%, 95%, and 100% of infected patients with gastric ulcer (n=26), duodenal ulcer (n=21), chronic gastritis (n=19), and endoscopically normal mucosa (n=14), respectively.Conclusion—The western blot method using recombinant VacA protein is simple and useful for detecting antibody to vacuolating cytotoxin. This method showed antibodies against cytotoxin were highly prevalent, even in subjects with endoscopically normal mucosa in Japan, indicating that the cytotoxin may not be an independent cause of gastrointestinal diseases induced by H pylori infection.

scholarly journals Riboregulation in the Major Gastric Pathogen Helicobacter pylori

2021 ◽  
Vol 12 ◽  
Author(s):  
Alejandro Tejada-Arranz ◽  
Hilde De Reuse
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Antisense Rna ◽  
Small Rnas ◽  
Genetic Regulation ◽  
Type I ◽  
Control Of Gene Expression ◽  
Ulcer Disease ◽  
Interesting Study ◽  
H Pylori

Helicobacter pylori is a Gram-negative bacterial pathogen that colonizes the stomach of about half of the human population worldwide. Infection by H. pylori is generally acquired during childhood and this bacterium rapidly establishes a persistent colonization. H. pylori causes chronic gastritis that, in some cases, progresses into peptic ulcer disease or adenocarcinoma that is responsible for about 800,000 deaths in the world every year. H. pylori has evolved efficient adaptive strategies to colonize the stomach, a particularly hostile acidic environment. Few transcriptional regulators are encoded by the small H. pylori genome and post-transcriptional regulation has been proposed as a major level of control of gene expression in this pathogen. The transcriptome and transcription start sites (TSSs) of H. pylori strain 26695 have been defined at the genome level. This revealed the existence of a total of 1,907 TSSs among which more than 900 TSSs for non-coding RNAs (ncRNAs) including 60 validated small RNAs (sRNAs) and abundant anti-sense RNAs, few of which have been experimentally validated. An RNA degradosome was shown to play a central role in the control of mRNA and antisense RNA decay in H. pylori. Riboregulation, genetic regulation by RNA, has also been revealed and depends both on antisense RNAs and small RNAs. Known examples will be presented in this review. Antisense RNA regulation was reported for some virulence factors and for several type I toxin antitoxin systems, one of which controls the morphological transition of H. pylori spiral shape to round coccoids. Interestingly, the few documented cases of small RNA-based regulation suggest that their mechanisms do not follow the same rules that were well established in the model organism Escherichia coli. First, the genome of H. pylori encodes none of the two well-described RNA chaperones, Hfq and ProQ that are important for riboregulation in several organisms. Second, some of the reported small RNAs target, through “rheostat”-like mechanisms, repeat-rich stretches in the 5′-untranslated region of genes encoding important virulence factors. In conclusion, there are still many unanswered questions about the extent and underlying mechanisms of riboregulation in H. pylori but recent publications highlighted original mechanisms making this important pathogen an interesting study model.

scholarly journals Helicobacter pylori Virulence Factors—Mechanisms of Bacterial Pathogenicity in the Gastric Microenvironment

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Jacek Baj ◽  
Alicja Forma ◽  
Monika Sitarz ◽  
Piero Portincasa ◽  
Gabriella Garruti ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Virulence Factors ◽  
Premalignant Lesions ◽  
Bacterial Pathogenicity ◽  
Current State ◽  
Genetic And Environmental Factors ◽  
H Pylori ◽  
Stimulation Of

Gastric cancer constitutes one of the most prevalent malignancies in both sexes; it is currently the fourth major cause of cancer-related deaths worldwide. The pathogenesis of gastric cancer is associated with the interaction between genetic and environmental factors, among which infection by Helicobacter pylori (H. pylori) is of major importance. The invasion, survival, colonization, and stimulation of further inflammation within the gastric mucosa are possible due to several evasive mechanisms induced by the virulence factors that are expressed by the bacterium. The knowledge concerning the mechanisms of H. pylori pathogenicity is crucial to ameliorate eradication strategies preventing the possible induction of carcinogenesis. This review highlights the current state of knowledge and the most recent findings regarding H. pylori virulence factors and their relationship with gastric premalignant lesions and further carcinogenesis.

scholarly journals Whole-Genome Sequencing and Comparative Genomics of Three Helicobacter pylori Strains Isolated from the Stomach of a Patient with Adenocarcinoma

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Montserrat Palau ◽  
Núria Piqué ◽  
M. José Ramírez-Lázaro ◽  
Sergio Lario ◽  
Xavier Calvet ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Virulence Factors ◽  
Outer Membrane Proteins ◽  
Whole Genome ◽  
Flagellar Biosynthesis ◽  
H Pylori ◽  
Restriction Modification

Helicobacter pylori is a common pathogen associated with several severe digestive diseases. Although multiple virulence factors have been described, it is still unclear the role of virulence factors on H. pylori pathogenesis and disease progression. Whole genome sequencing could help to find genetic markers of virulence strains. In this work, we analyzed three complete genomes from isolates obtained at the same point in time from a stomach of a patient with adenocarcinoma, using multiple available bioinformatics tools. The genome analysis of the strains B508A-S1, B508A-T2A and B508A-T4 revealed that they were cagA, babA and sabB/hopO negative. The differences among the three genomes were mainly related to outer membrane proteins, methylases, restriction modification systems and flagellar biosynthesis proteins. The strain B508A-T2A was the only one presenting the genotype vacA s1, and had the most distinct genome as it exhibited fewer shared genes, higher number of unique genes, and more polymorphisms were found in this genome. With all the accumulated information, no significant differences were found among the isolates regarding virulence and origin of the isolates. Nevertheless, some B508A-T2A genome characteristics could be linked to the pathogenicity of H. pylori.

scholarly journals Genotyping pattern of the vacuolating cytotoxin A and cytotoxin associated gene A of the Helicobacter pylori strains detected in fecal samples of household dogs

2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Asieh Bolandi ◽  
Saam Torkan ◽  
Iman Alavi
Keyword(s):  
Helicobacter Pylori ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Pcr Amplification ◽  
Rrna Gene ◽  
Fecal Samples ◽  
The Status ◽  
Cytotoxin Associated Gene A ◽  
H Pylori

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.

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