scholarly journals Helicobacter pylori Infection, Virulence Genes’ Distribution and Accompanying Clinical Outcomes: The West Africa Situation

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Eric Gyamerah Ofori ◽  
Cynthia Ayefoumi Adinortey ◽  
Ansumana Sandy Bockarie ◽  
Foster Kyei ◽  
Emmanuel Ayitey Tagoe ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
West Africa ◽  
Clinical Outcomes ◽  
Virulence Factors ◽  
Alcohol Exposure ◽  
The Body ◽  
African Countries ◽  
Genetic Characteristics ◽  
The Status ◽  
H Pylori

Data on Helicobacter pylori (H. pylori) infection and virulence factors in countries across West Africa are scattered. This systematic review seeks to present an update on the status of H. pylori infection focusing on prevalence rate, distribution of virulent genes, and their link to clinical outcomes across countries in the western part of Africa. This information is expected to broaden the knowledge base of clinicians and researchers regarding H. pylori infection and associated virulence factors in West African countries. Search Method. A comprehensive search of the scientific literature in PubMed and ScienceDirect was conducted using the search terms including “Helicobacter pylori infection in West Africa”. Databases were sourced from January 1988 to December 2018. Results. Data on the incidence of H. pylori infection and related pathological factors were found for some countries, whereas others had no information on it. Smoking, alcohol, exposure to high levels of carcinogens and diet were reported to be involved in the pathogenesis of gastroduodenal diseases and gastric cancer. Besides the environmental factors and genetic characteristics, there are important characteristics of H. pylori such as the ability to infect, replicate, and persist in a host that have been associated with the pathogenesis of various gastroduodenal diseases. Concluding Remarks. This systematic search has provided information so far available on H. pylori virulence factors and clinical outcomes in West Africa. Accordingly, this piece has identified gaps in the body of knowledge highlighting the need for more studies to clarify the role of H. pylori virulence factors and associated clinical outcomes in the burden of this bacterial infection in West Africa, as data from these countries do not give the needed direct relation.

scholarly journals The Prevalence ofHelicobacter pyloriVirulence Factors in Bhutan, Vietnam, and Myanmar Is Related to Gastric Cancer Incidence

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tran Thi Huyen Trang ◽  
Seiji Shiota ◽  
Miyuki Matsuda ◽  
Tran Thanh Binh ◽  
Rumiko Suzuki ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Virulence Factors ◽  
Cancer Incidence ◽  
The Status ◽  
The Difference ◽  
H Pylori ◽  
Significant Health ◽  
Development Of Gastric Cancer

Gastric cancer is a significant health problem in Asia. Although the prevalence ofHelicobacter pyloriinfection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized thatH. pylorivirulence factors contribute to the differences. The status ofcagA,vacA,jhp0562, andβ-(1,3)galT(jhp0563)was examined in 371H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive forcagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that thecagA,vacAs1,vacAm1, andjhp0562-positive/β-(1,3)galT-negative genotype may play a role in the development of gastric cancer.

A multi-method and structure-based in silico vaccine designing against Helicobacter pylori employing immuno-informatics approach

2020 ◽  
Vol 17 ◽  
Author(s):  
Anam Naz ◽  
Tahreem Zaheer ◽  
Hamza Arshad Dar ◽  
Faryal Mehwish Awan ◽  
Ayesha Obaid ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Vaccine Development ◽  
Amino Acid Sequences ◽  
The Body ◽  
New Drugs ◽  
Toll Like Receptor ◽  
Peptide Vaccines ◽  
Hla Alleles ◽  
Vaccine Candidates ◽  
H Pylori

Background: Helicobacter pylori infection and its treatment still remains a challenge to human health worldwide. A variety of antibiotics and combination therapies are currently used to treat H. pylori induced ulcers and carcinoma; however, no effective treatment is available to eliminate the pathogen from the body. Additionally, antibiotic resistance is also one of the main reasons for prolonged and persistent infection. Aim of the study: Until new drugs are available for this infection, vaccinology seems the only alternative opportunity to exploit against H. pylori induced diseases. Methods: Multiple epitopes prioritized in our previous study have been tested for their possible antigenic combinations, and results in 169-mer and 183-mer peptide vaccines containing the amino acid sequences of 3 and 4 epitopes respectively, along with adjuvant (Cholera Toxin Subunit B adjuvant at 5’ end) and linkers (GPGPG and EAAAK). Results: Poly-epitope proteins proposed as potential vaccine candidates against H. pylori include SabAHP0289-Omp16-VacA (SHOV), VacA-Omp16-HP0289-FecA (VOHF), VacA-Omp16-HP0289-SabA (VOHS), VacA-Omp16-HP0289-BabA (VOHB), VacA-Omp16-HP0289-SabA-FecA (VOHSF), VacAOmp16-HP0289-SabA-BabA (VOHSB) and VacA-Omp16-HP0289-BabA-SabA (VOHBS). Structures of these poly-epitope peptide vaccines have been modelled and checked for their affinity with HLA alleles and receptors. These proposed poly-epitope vaccine candidates bind efficiently with A2, A3, B7 and DR1 superfamilies of HLA alleles. They can also form stable and significant interactions with Toll-like receptor 2 and Toll-like receptor 4. Conclusion: Results suggest that these multi-epitopic vaccines can elicit a significant immune response against H. pylori and can be tested further for efficient vaccine development.

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 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 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.

scholarly journals Prevalence of vacA, cagA, and iceA Virulence Factors of Helicobacter Pylori Isolated from Gastro-duodenal Patients

2020 ◽  
Vol 14 (1) ◽  
pp. 72-79
Author(s):  
Ahmed Husham Salman ◽  
Aumed Arshad Hawezy
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Gastric Lymphoma ◽  
Signs And Symptoms ◽  
Molecular Technique ◽  
Peptic Ulcers ◽  
Back Ground ◽  
H Pylori ◽  
Pcr Test

Back ground: Helicobacter pylori are bacteria colonize in the human epithelial cells of the gastrointestinal tract. Its infection causes different diseases, including chronic gastritis, peptic ulcers, gastric lymphoma and adenocarcinoma. H. pylori have many virulence factors attributing in one or more biological functions. Objective: Detecting the prevalence of virulence factor genes vacA, cagA, iceA among strain of H. pylori using molecular technique (PCR). Materials and methods: Sixty patients (27 male and 33 female), aged 18 and above included in the present study who showed signs and symptoms of H. pylori, and undergo endoscopy between period of November 2019 and February 2020. RUT and PCR test done to detect the presence of H. pylori infection, also PCR used to detect the three virulence factors. Results: Result showed that 44 patients, 21 (47.7%) male and 23 (52.3%) female were detected as positive H. pylori infections, among them 13 (29.5%) above 50 years, and 31 (70.4%) were below 50 years. While prevalence of the virulence factors vacA, cagA, and iceA were (100%), (84.1%), and (34.1%) respectively. Conclusion: It can be concluded that the frequency and prevalence of these genes are differed and showed significant differences among them. Also, PCR test is sensitive and accurate for detection of H. pylori virulence genes.

scholarly journals New Insights into Bioactive Compounds from the Medicinal Plant Spathodea campanulata P. Beauv. and Their Activity against Helicobacter pylori

Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 258
Author(s):  
Corinne Raïssa Ngnameko ◽  
Lucia Marchetti ◽  
Barbara Zambelli ◽  
Antonio Quotadamo ◽  
Davide Roncarati ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Medicinal Plant ◽  
Virulence Factors ◽  
Crude Extract ◽  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
High Performance Liquid Chromatographic ◽  
Chemical Components ◽  
Interesting Compound ◽  
H Pylori

The medicinal plant Spathodea campanulata P. Beauv. (Bignoniaceae) has been traditionally applied for the prevention and treatment of diseases of the kidney and urinary system, the skin, the gastrointestinal tract, and inflammation in general. The present work shows for the first time how chemical components from this plant inhibit Helicobacter pylori growth by urease inhibition and modulation of virulence factors. The crude extract and the main fractions of S. campanulata bark were tested on H. pylori isolated strains and the active ones were further fractionated. Fractions and sub-fractions of the plant crude extract were characterized by ultra-high-performance liquid chromatographic tandem high resolution-mass spectrometry detection (UHPLC-HRMS). Several phenolics and triterpenoids were identified. Among the sub-fractions obtained, SB2 showed the capacity to inhibit H. pylori urease in a heterologous bacterial model. One additional sub-fraction (SE3) was able to simultaneously modulate the expression of two adhesins (HopZ and BabA) and one cytotoxin (CagA). The flavonol kaempferol was identified as the most interesting compound that deserves further investigation as a new hit for its capacity to modulate H. pylori virulence factors.

scholarly journals Vitamin B6 Is Required for Full Motility and Virulence in Helicobacter pylori

mBio ◽  
2010 ◽  
Vol 1 (3) ◽  
Author(s):  
Alexandra Grubman ◽  
Alexandra Phillips ◽  
Marie Thibonnier ◽  
Maria Kaparakis-Liaskos ◽  
Chad Johnson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Virulence Factors ◽  
Bacterial Pathogens ◽  
Therapeutic Targets ◽  
Vitamin B ◽  
Human Pathogens ◽  
Chronic Colonization ◽  
H Pylori

ABSTRACTDespite recent advances in our understanding of howHelicobacter pyloricauses disease, the factors that allow this pathogen to persist in the stomach have not yet been fully characterized. To identify new virulence factors inH. pylori, we generated low-infectivity variants of a mouse-colonizingH. pyloristrain using the classical technique ofin vitroattenuation. The resulting variants and their highly infectious progenitor bacteria were then analyzed by global gene expression profiling. The gene expression levels of five open reading frames (ORFs) were significantly reduced in low-infectivity variants, with the most significant changes observed for ORFs HP1583 and HP1582. These ORFs were annotated as encoding homologs of theEscherichia colivitamin B6biosynthesis enzymes PdxA and PdxJ. Functional complementation studies withE. coliconfirmedH. pyloriPdxA and PdxJ to bebona fidehomologs of vitamin B6biosynthesis enzymes. Importantly,H. pyloriPdxA was required for optimal growthin vitroand was shown to be essential for chronic colonization in mice. In addition to having a well-known metabolic role, vitamin B6is necessary for the synthesis of glycosylated flagella and for flagellum-based motility inH. pylori. Thus, for the first time, we identify vitamin B6biosynthesis enzymes as novel virulence factors in bacteria. Interestingly,pdxAandpdxJorthologs are present in a number of human pathogens, but not in mammalian cells. We therefore propose that PdxA/J enzymes may represent ideal candidates for therapeutic targets against bacterial pathogens.IMPORTANCEApproximately half of the world’s population is infected withH. pylori, yet howH. pyloribacteria establish chronic infections in human hosts remains elusive. From gene array studies, we identified two genes as representing potentially novel colonization factors forH. pylori. These genes encoded enzymes involved in the synthesis of vitamin B6, an important molecule for many metabolic reactions in living organisms. Little is currently known regarding vitamin B6biosynthesis in human pathogens. We showed that mutantH. pyloribacteria lacking an enzyme involved inde novovitamin B6biosynthesis, PdxA, were unable to synthesize motility appendages (flagella) and were unable to establish chronic colonization in mice. Thus, this work identifies vitamin B6biosynthesis enzymes as novel virulence factors for bacterial pathogens. Interestingly, a number of human pathogens, but not their mammalian hosts, possess these genes, which suggests that Pdx enzymes may represent ideal candidates for new therapeutic targets.

A review of the possible bacterial determinants of clinical outcome inHelicobacter pyloriinfection

1998 ◽  
Vol 44 (3) ◽  
pp. 201-210 ◽  
Author(s):  
Carlo A Fallone ◽  
Alan N Barkun ◽  
Markus U Göttke ◽  
Robin N Beech
Keyword(s):  
Helicobacter Pylori ◽  
Clinical Outcome ◽  
Virulence Factors ◽  
Bacterial Virulence ◽  
Disease Outcome ◽  
Future Research ◽  
Susceptible Host ◽  
Ulcer Disease ◽  
Increased Risk ◽  
H Pylori

Helicobacter pylori is present in 40-60% of the population and approximately 10-20% of these infected individuals suffer from a H. pylori associated disease such as peptic ulcer disease or gastric cancer. This article reviews the potential bacterial determinants responsible for and markers predictive of both the acquisition of H. pylori infection and subsequent clinical outcome; i.e., asymptomatic infection or disease. The acquisition of H. pylori infection depends on exposure (hence the increased risk in lower socioeconomic groups and developing nations) to viable bacteria with at least a functional urease gene in a susceptible host. Once infection occurs, bacterial virulence factors, including the vacuolating cytotoxin, and genes of the cag pathogenicity island, as well as nonbacterial factors may determine disease outcome. Future research is being directed at discovering other bacterial virulence factors responsible for the different clinical outcomes of H. pylori infection. This will be greatly enhanced by the recent release of the complete genome sequence of H. pylori. The determination of the relative importance of each of these recognized and other as yet unrecognized factors responsible for disease outcome will assist in the appropriate targeting of patients in the treatment of H. pylori infection.Key words: Helicobacter pylori, genetics, virulence, bacterial.

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