vacA Genotypes Research Articles

Associations between biofilm formation and virulence factors among clinical Helicobacter pylori isolates

IntroductionHelicobacter pylori (H. pylori) causes several gastrointestinal diseases. Its virulence factors contributing to disease development include biofilm formation, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) proteins that induce host tissue damage. In addition, urease activity enables H. pylori growth in the gastric acidic environment. This work aimed to characterize bacterial factors associated with biofilm production among 89 clinical H. pylori isolates, collected from patient gastric biopsies. MethodsBiofilm production was detected using the crystal violet method. PCR was performed to determine vacA genotype (s1m1, s1m2, s2m1 and s2m2) and cagA gene presence. Urease activity was measured via the phenol red method. Susceptibility to six antibiotics was assessed by the Etest method. ResultsMost H. pylori isolates produced biofilm. No association was found between biofilm-formation capacity and cagA presence or vacA genotype. Urease activity levels varied across isolates; no association was found between biofilm-formation and urease activity. Clarithromycin resistance was measured in 49 % of the isolates. Isolates susceptible to tetracycline were more commonly strong biofilm producers. In contrast, a significantly higher rate of strong biofilm producers was observed among resistant isolates to amoxicillin, levofloxacin and rifampicin, compared to susceptible isolates. Non-biofilm producers were more common among isolates sensitive to rifampicin and metronidazole, compared to resistant isolates. ConclusionsFurther studies are needed to understand the factors that regulate biofilm production in order to search for treatments for H. pylori biofilm destruction.

Genotypes and Phylogenetic Analysis of Helicobacter pylori Clinical Bacterial Isolates

Helicobacter pylori is a human pathogen bacterium associated with gastritis, peptic ulcer, and gastric cancer. It can be identified through the 16S rRNA gene and characterized through cagA and vacA virulence genes. Clinical cultures of H. pylori were isolated and identified from human stomach biopsies. The isolates were characterized according to their colonial and microscopic morphology, and molecular genotyping was conducted to determine the bacterial virulence. A phylogenetic analysis of the 16S rRNA gene sequencing was performed. In addition, multilocus sequence typing analysis was performed to determine the phylogeographic nature of the isolated strains. Three bacterial isolates were selected from 22 gastric biopsies, identified as H. pylori through colonial morphology, Gram staining, urease, catalase, and oxidase tests and identification of the ureC gene through end-point PCR. Amplification of 16S rRNA, urea, and tonB genes was performed, as well. Differences between the cagA and vacA genotypes were determined among the isolates. The phylogenetic analysis confirmed the identity of the three isolates as the specie Helicobacter pylori. Different genotypes were obtained for each H. pylori strain, and all the clinical isolates showed the vacA s2/m2 genotype, indicating an absence of the VacA cytotoxin. Only HCGDL-MR01 is a cagA gene carrier with a greater risk to develop a serious disease, such as stomach cancer and peptic ulcer. The multilocus sequence typing placed all the strains within the hpEurope population structure.

Virulence gene polymorphisms in Shandong Helicobacter pylori strains and their relevance to gastric cancer.

Helicobacter pylori (H. pylori) virulence factors, particularly the cagA and vacA genotypes, play important roles in the pathogenic process of gastrointestinal disease. The cagA and vacA genotypes of 87 H. pylori strains were determined by PCR and sequencing. The EPIYA and CM motif patterns were analyzed and related to clinical outcomes. We examined the associations between the virulence genes of H. pylori and gastrointestinal diseases in Shandong, and the results were analyzed via the chi-square test and logistic regression model. Overall, 76 (87.36%) of the strains carried the East Asian-type CagA, with the ABD types being the most prevalent (90.79%). However, no significant differences were observed among the different clinical outcomes. The analysis of CagA sequence types revealed 8 distinct types, encompassing 250 EPIYA motifs, including 4 types of EPIYA or EPIYA-like sequences. Additionally, 28 CM motifs were identified, with the most prevalent patterns being E (66.67%), D (16.09%), and W-W (5.75%). Notably, a significant association was discovered between strains with GC and the CM motif pattern D (P < 0.01). With respect to the vacA genotypes, the strains were identified as s1, s2, m1, m2, i1, i2, d1, d2, c1, and c2 in 87 (100%), 0 (0), 26 (29.89%), 61 (70.11%), 73 (83.91%), 14 (16.09%), 76 (87.36%), 11 (12.64%), 18 (20.69%), and 69 (79.31%), respectively. Specifically, the vacA m1 and c1 genotypes presented a significantly greater prevalence in strains from GC compared to CG (P < 0.05). Following adjustment for age and sex, the vacA c1 genotype demonstrated a notable association with GC (OR = 5.174; 95% CI, 1.402-20.810; P = 0.012). This association was both independent of and more pronounced than the correlations between vacA m1 and GC. CagA proteins possessing CM motif pattern D were more frequently observed in patients with GC (P < 0.01), implying a potentially higher virulence of CM motif pattern D than the other CM motif patterns. Moreover, a strong positive association was identified between the vacA c1 genotype and GC, indicating that the vacA c1 genotype is a robust risk indicator for GC among male patients aged ≥55 years in Shandong.

Helicobacter pylori Cytotoxin-Associated Gene A (cagA) and Vacuolating Cytotoxin Gene A (vacA) Genotypes in Gastrointestinal Patients From Central Thailand.

Introduction The development of diseases associated with Helicobacter pylori(H. pylori) infection is closely linked to its virulence genes, which vary by geographic region. This study aimed to determine the prevalence of H. pylori cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene A (vacA) genes and their genotypes in patients with gastrointestinal diseases. Methods Patients diagnosed with gastrointestinal disease based on endoscopic findings were recruited for the study. Gastric biopsies were collected to screen for H. pylori infection using polymerase chain reaction (PCR). Subsequently, infected samples were tested forcagAand vacA genes, and their genotypes were analyzed by sequencing. Results Among 250 cases, 56% (140/250) exhibited gastrointestinal diseases. Of these cases, 32.1% (45/140) were infected with H. pylori. Regarding gene detection, 40 (88.9%)samples were positive for cagA, while all samples were positive for vacA. For cagA, the Western type with the ABC pattern was the most prominent. There was a statistically significant association between cagA genotypes and clinical outcomes, with the Western type being more prevalent in gastritis patients. For vacA, there was a high prevalence of the s1 and i1, while the m1 and m2 showed similar prevalence. In our combined analysis, the dominant vacA genotype combinations were s1m1i1 (46.7%). There were no statistical differences between the vacA genotypesand clinical outcomes (P > 0.05). Conclusion This study revealed a high prevalence of H. pylori cagA and vacA genes, but there were variations in their genotypes. A correlation was observed between the Western-type cagA and gastritis; however, no association was found between vacA genotypes and clinical outcomes.

Helicobacter pylori cagA, vacA, and iceA genotypes and clinical outcomes: a cross-sectional study in central Vietnam.

Helicobacter pylori is the most common cause of gastroduodenal diseases. The concept that cagA-positive H. pylori is a risk factor for gastric cancer appears to be true only for H. pylori strains from Western countries. Other virulent genes may have a synergistic interaction with cagA during pathogenesis. This study aims to investigate H. pylori cagA, vacA, and iceA prevalence, genotypes, and their association to clinical outcomes in Vietnamese patients. The cagA status and vacA and iceA genotypes were determined using the PCR technique on DNA extracted from gastric biopsies of 141 patients with gastroduodenal diseases. After performing molecular analysis for cagA, vacA, and iceA genes, samples with mixed H. pylori strains, positivity, or negativity for both cagA and cagPAI-empty site, or unidentified genotypes were excluded. Finally, 107 samples were examined. The presence of the cagA, vacA, and iceA genes were detected in 77.6%, 100%, and 80.4% of cases, respectively. Notably, cagA( +) with EPIYA-ABD, vacA s1i1m1, vacA s1i1m2, iceA1, and iceA2 accounted for 73.8%, 44.9%, 33.6%, 48.6%, and 31.8% of cases, respectively. Four iceA2 subtypes (24-aa, 59-aa, 94-aa, and 129-aa variants) were found, with the 59-aa variant the most prevalent (70.6%). The cagA( +)/vacAs1i1m1/iceA1 and cagA( +)/vacAs1i1m2/iceA1 combinations were found in 26.2% and 25.1% of cases, respectively. A multivariable logistic regression analysis was performed, after adjusting for age and gender, with the gastritis group was used as a reference control. Statistically significant associations were found between the vacA s1i1m2 genotype, the iceA1 variant, and the cagA( +)/vacAs1i1m2/iceA1 combination and gastric cancer; the adjusted ORs were estimated as 18.02 (95% CI: 3.39-95.81), 4.09 (95% CI: 1.1-15.08), and 16.19 (95% CI: 3.42-76.66), respectively. Interestingly, for the first time, our study found that vacA s1i1m2, but not vacA s1i1m1, was a risk factor for gastric cancer. This study illustrates the genetic diversity of the H. pylori cagA, vacA, and iceA genes across geographical regions and contributes to understanding the importance of these genotypes for clinical outcomes.

Helicobacter pylori cagA, vacA, iceA and babA Genotypes from Peruvian Patients with Gastric Intestinal Metaplasia.

We explored the clinical-stage association of gastric intestinal metaplasia (IM) compared to cases of chronic non-atrophic gastritis (CNAG) and its relationship with virulence genotypes of Helicobacter pylori (H. pylori) clinical isolates from patients with dyspepsia in Peru. This study was cross-sectional and included 158 H. pylori clinical isolates; each isolate corresponded to a different Peruvian patient, genotyped by polymerase chain reaction to detect cagA gene and EPIYA motifs, the vacA gene (alleles s1, s2, i1, i2, d1, d2, m1, m2 and subtypes s1a, s1b and s1c), the iceA gene (alleles 1 and 2), and the babA gene (allele 2). We observed that 38.6% presented with IM and that all clinical isolates were CagA positive. The EPIYA-ABC motif was predominant (68.4%), and we observed a high frequency for the vacA gene alleles s1 (94.9%), m1 (81.7%), i1 (63.9%), and d1 (70.9%). Strains with both iceA alleles were also detected (69.6%) and 52.2% were babA2 positive. In addition, it was observed that the cagA+/vacAs1m1 (PR: 2.42, 1.14 to 5.13, p < 0.05) and cagA+/vacAs1am1 (PR: 1.67, 1.13 to 2.45, p < 0.01) genotypes were associated with IM. Our findings revealed the cagA and vacA risk genotypes predominance, and we provided clinically relevant associations between Peruvian patients with H. pylori infection and IM clinical stage.

Helicobacter pylori vacA affects the expression of COX-2 in the duodenal mucosa of patients with duodenitis.

Duodenitis refers to inflammation that occurs in the duodenum. Helicobacter pylori (Hp) is a known risk factor for duodenitis. This paper attempted to analyze the correlation between Hp virulence genotypes and the initiation and development of duodenal bulbar inflammation (DBI) to lay the foundation for the management of duodenitis induced by Hp infection. Total RNA was extracted from duodenal samples of 156 Hp-positive patients [70 with DBI and 86 with duodenal bulbar ulcer (DBU)] and 80 Hp-free DBI patients, followed by RT-qPCR detection of COX-2 mRNA expression and the presence of virulence factors. The cagA positive (62.2%), vacAs1 (21.79%), vacAm2 (23.72%), vacAs1m2 (19.87%) and iceA1 (55.80%) genotypes were dominant in 156 Hp-positive samples. Statistical difference was observed in vacAs and vacA mixtures between DBI and DBU patients. Gastric metaplasia had an association with vacA allelotypes, and its occurrence had strong correlations with vacAs1 and vacAs1m2 genotypes. The vacAs1 and vacAs1m2 genotypes were correlated with gastric metaplasia occurrence (all p<0.05). There were significant correlations between vacAs and vacA mixtures with cagA genotypes, and between iceA genotypes with vacA mixtures (all p<0.05). COX-2 was strongly expressed in Hp-infected duodenal mucosa and showed correlations with vacA genotype. COX-2 was differentially expressed in vacAs1- and vacAs2-positive patients. COX-2 was more highly upregulated in vacAs1m1- and vacAs1m2-positive patients than vacAs2m2-positive patients. Overall, Hp virulence genotype vacA was correlated with DBI and DBU initiation and development.

Detection of vacA gene alleles frequency in Helicobacter pylori strains from patients with gastric diseases in Zliten city Libya

Helicobacter pylori (H. pylori) has worldwide distribution, leading to various gastric diseases, including chronic gastritis, peptic ulcer and gastric cancer. A vacA gene, which encodes a vacuolating cytotoxin is one of the most known virulence gene of the bacterium. The aim of this study was to evaluate the most common vacA alleles (s1 and s2) in H. pylori strains isolated from Libyan patients and its relationship with ages and gastritis lesions. Gastric biopsies were obtained from patients for DNA extraction. vacA genotypes were analyzed by PCR and agarose electrophoresis. s1 and s2 genotypes were also confirmed by DNA sequencing. The allele s2 occurred in 81% of the all examined group, which represent the most frequently observed of the signal encoding region. Whereas s1 genotype had the lowest frequency 19%. Statistically significant differences in s1 and s2 alleles in relation to a ages were not detected. This study showed that there was a relationship between the presence of vacA gene and progression of gastritis. the predominant vacA gene alleles in Zliten city is s2 allele.

Study of vacuolating cytotoxin A (vacA) genotypes of ulcerogenic and non-ulcerogenic strains of Helicobacter pylori and its association with gastric disease

Globally, Helicobacter pylori (H. pylori), a stomach pathogen, is present in around 50 % of the population. This bacterial infection produces persistent inflammation, which significantly raises the risk of duodenal, gastric ulcer, and stomach cancer. The goal of this study is to identify the vacA genotypes in H. pylori and analyze how they relate to medical conditions brought on by the bacteria and clarithromycin resistance. PCR was used to describe 115 endoscopic stomach samples from infected patients and identify vacA gene. Of the 115 research participants, H. pylori was found in 81 (70.4 %) of them. Of the isolated cultures, only 38 (69.1 %) were resistant to clarithromycin. VacA was discovered in 55 (67.9 %) of the samples that had H. pylori in them. Patients with gastritis were more likely to have s2m2 strains of infection (66.7 %), while those with gastric and duodenal ulcers were more likely to have s1m1 strains (64.7 %). VacA-positive H. pylori strains (60 % n = 33) were more resistantto clarithromycin versus (19.2 % n = 5) for vacA-negative bacteria. Clarithromycin resistance was significantly linked to vacA s2m2 in H. pylori isolates (75.9 %). According to the study's results, the vacA variants s1m1 and s2m2 have a strong connection with the emergence of H. pylori infections that cause peptic ulcer disease in the population of Iraq. Genetic testing is essential in predicting both the course of treatment and the outcome of H. pylori disease.

Relationship between antibiotic resistance and the cagA and vacA genotypes among Helicobacter pylori strain isolates from patients in Xi'an.

The issue of drug resistance of Helicobacter pylori is becoming increasingly serious. To analyze the correlation between the cagA and vacA genotypes of H. pylori strains and their resistance to metronidazole, levofloxacin, and clarithromycin in patients in Xi'an, we studied 117 H. pylori strains isolated from patients in Xi'an. Antibiotic susceptibility testing of H. pylori was performed. The cagA and vacA genotypes were investigated using PCR. Among 117 strains of H. pylori, the rate of detection of cagA was 91.45% (107/117), among which the detection rate of East Asian-type cagA was 85.05% (91/107) and that of Western-type cagA was 14.95% (16/107). There were only two genotypes of vacA: s1m1 and s1m2. The detection rate of vacAs1m1 was 47.01% (55/117) and that of vacAs1m2 was 52.99% (62/117). The dominant strains in Xi'an were cagA + vacAs1m2 strains. The metronidazole resistance rate of vacAs1m2 H. pylori strains was significantly higher than that of vacAs1m1 H. pylori strains (91.94% vs. 69.09%, P = 0.002). The levofloxacin resistance rate of Western-type cagA strains was significantly higher than that of East Asian-type cagA strains (56.25% vs. 20.88%, P = 0.004). The metronidazole resistance rate of cagA + vacAs1m2 H. pylori strains was significantly higher than that of cagA + vacAs1m1 H. pylori strains (91.23% vs. 66.00%, P = 0.001). Our results showed that Western-type cagA strains were more likely to develop levofloxacin resistance than East Asian-type cagA strains. VacAs1m2 strains were more prone to metronidazole resistance than vacAs1m1 strains.

Helicobacter pylori virulence genotypes in Bogotá River and wastewater treatment plants in Colombia.

Helicobacter pylori is a bacterium that infects 70%-80% of the population in Colombia, causing chronic gastritis in all those infected and gastric cancer in 1%-2% of those infected. In Colombia, some studies have identified the presence of vacA and cagA genes in environmental samples such as treated, surface, and wastewater, but they have not been evaluated in the Bogotá River. For this, the aim of this study was to identify the virulence genotypes of H. pylori present in samples from the Bogotá River and domestic wastewater treatment plants (WWTPs). A total of 75 water samples (51 from the Bogotá River and 24 from wastewater treatment plants) were collected. The presence of H. pylori DNA and its virulence genotypes was determined by polymerase chain reaction (PCR). The presence of H. pylori DNA was demonstrated in 44% (33/75) of the samples, obtaining 63.6% (21/33) from the Bogotá River and 36.4% (12/33) from the WWTPs. The most prevalent H. pylori genotype was cagA (-) and vacAm1/s1/i1 being the most virulent of the vacA gene. This is the first study in Colombia that determines the cagA and vacA genotypes in surface water and WWTPs, indicating the circulation of virulent genotypes in the population. The presence of this pathogen in the waters can be represent a risk to the health of the surrounding population since these waters are reused by the communities for different purposes.

RETRACTED ARTICLE: Helicobacter pylori strains isolated from raw poultry meat: frequency and molecular characteristics

Even though Helicobacter pylori (H. pylori) is a serious pathogen, its origin is unknown. Poultry (Chicken, Turkey, Quebec, Goose, and Ostrich) are consumed as a regular protein source by a large number of people across the world; therefore, sanitary ways of delivering poultry for food are important for global health. As a result, we looked at the distribution of the pathogenicity cagA, vacA, babA2, oipA, and iceA in H. pylori isolates in poultry meat, as well as their antimicrobial resistance. Wilkins Chalgren anaerobic bacterial medium was used to cultivate 320 raw poultry specimens. Disk diffusion and Multiplex-PCR were used to investigate antimicrobial resistance and genotyping patterns, separately. H. pylori was found in 20 of 320 (6.25%) raw poultry samples. The highest incidence of H. pylori was found in chicken raw meat (15%), whereas the fewest was found in Goose and Quebec (0.00%). Resistance to ampicillin (85%), tetracycline (85%), and amoxicillin (75%) were greatest in H. pylori isolates. The percentage of H. pylori isolates with a MAR value of more than 0.2 was 17/20 (85%). The most prevalent genotypes discovered were VacA s1a (75%), m1a (75%), s2 (70%) and m2 (65%), and cagA (60%). The most typically discovered genotype patterns were s1am1a (45%), s2m1a (45%), and s2m2 (30%). BabA2, OipA + , and OipA− genotypes were found in 40%, 30%, and 30% of the population. In summary, the poultry flesh was polluted by H. pylori, with the babA2, vacA, and cagA genotypes being more prevalent. The simultaneous occurrence of vacA, cagA, iceA, oipA, and babA2 genotypes in antibiotic-resistant H. pylori bacteria implies a serious public health concern about raw poultry eating. In the future, researchers should look into H. pylori's resistance to multiple antibacterial drugs in Iran.

Susceptibility patterns and virulence genotypes of Helicobacter pylori affecting eradication therapy outcomes among Egyptian patients with gastroduodenal diseases.

Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis. To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen. H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation. The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%-70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175-0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: -0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026-0.537). This study's low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.

Helicobacter pylori Strains Isolated from Raw Poultry Meat in the Shahrekord Region, Iran: Frequency and Molecular Characteristics

Even though Helicobacter pylori (H. pylori) is a serious pathogen, its origin is unknown. Poultry (chicken, turkey, quail, goose, and ostrich) is consumed as a regular protein source by many people across the world; therefore, sanitary ways of delivering poultry for food are important for global health. As a result, the distribution of the virulence genes cagA, vacA, babA2, oipA, and iceA in H. pylori isolates in poultry meat, as well as their antibacterial resistance, was investigated. A Wilkins Chalgren anaerobic bacterial medium was used to cultivate 320 samples of raw poultry meat. Disk diffusion and multiplex-PCR were used to investigate both antimicrobial resistance and genotyping patterns. H. pylori was found in 20 of 320 (6.25 %) raw chicken meat samples. The highest incidence of H. pylori was found in chicken raw meat (15%), whereas no isolate was recovered from goose or quail raw meat (0.00%). Resistance to ampicillin (85%), tetracycline (85%), and amoxicillin (75%) were the most commonly detected in the tested H. pylori isolates. The percentage of H. pylori isolates with a multiple antibiotic resistance (MAR) index value of more than 0.2 was 17/20 (85%). The most prevalent genotypes detected were VacA (75%), m1a (75%), s2 (70%) and m2 (65%), and cagA (60%). The most typically detected genotype patterns were s1am1a (45 %), s2m1a (45 %), and s2 m2 (30%). babA2, oipA+, and oipA- genotypes were found in 40%, 30%, and 30% of the population, respectively. In summary, fresh poultry meat was polluted by H. pylori, with the babA2, vacA, and cagA genotypes being more prevalent. The simultaneous occurrence of vacA, cagA, iceA, oipA, and babA2 genotypes in antibiotic-resistant H. pylori bacteria raises a serious public health concern regarding the consumption of raw poultry. Future research should evaluate antimicrobial resistance among H. pylori isolates in Iran.

The Relationship between Gastroduodenal Pathologies and Helicobacter pylori cagL (Cytotoxin-Associated Gene L) Polymorphism.

The polymorphisms in the region between 58 and 62 amino acids of the 194-amino acid CagL protein (CagL hypervariable motif) affect the binding affinity of CagL to integrin α5β1 (ITGA5B1) receptor in host epithelial cells and have an effect on the development of various gastrointestinal diseases. We aimed to evaluate the associations of gastroduodenal pathologies, with the polymorphisms of cagL gene of Helicobacter pylori (H. pylori) and also associations between vacA genotypes and cagL polymorphisms. A total of 19 gastric cancer, 16 duodenal ulcer, and 26 non-ulcer dyspepsia patients were included in this case-control study. All cases had H. pylori. A fragment of 651 bp from gene cagL (hp0539) and cagA, vacA genes was amplified by polymerase chain reaction. Purified polymerase chain reaction products were sequenced by Sanger sequencing, and nucleotide sequences were translated into amino acid sequences. All of the H. pylori strains had cagL and cagA genes. In the 16 (84%) gastric cancer cases, the D58 amino acid polymorphism was significant than the 4 (15.4%) duodenal ulcer cases (P = .029), and the D58/K59 amino acid polymorphism was significant in 12 (63.1%) of the gastric cancer cases than 1 (3.85%) duodenal ulcer case (P = .008). D58/K59 and DKIGQ (n = 10; 52.63%) were the most common polymorphisms in the gastric cancer and were associated with the vacA genotype s1/m2, respectively (P = .022 and P = .008). The D58/K59 amino acid polymorphism was found to have a significant Odds Ratio (OR) value of 8.9 (P = .0017) in multivariate logistic regression analysis. The risk of gastric cancer development is 8.9 times higher with D58/K59 polymorphism.

A Genetic and Immunohistochemical Analysis of Helicobacter pylori Phenotypes and p27 Expression in Adenocarcinoma Patients in Jordan

Stomach (gastric) cancer is one of the most prevalent and deadly cancers worldwide and most gastric cancers are adenocarcinomas. Based on prior research, there is an association between Helicobacter pylori (H. pylori) infection together with the frequency of duodenal ulcer, distal gastric adenocarcinoma, mucosa-associated lymphoid tissue (MALT) lymphoma, and antral gastritis. Helicobacter pylori virulence and toxicity factors have been identified before that significantly influence the clinical outcomes of H. pylori infection and gastric adenocarcinoma. However, it remains unclear exactly how different strains of H. pylori affect gastric adenocarcinoma. Current research suggests this involves tumor suppressor genes, like p27 but also H. pylori toxic virulence proteins. Therefore, we quantified known H. pylori genotypes within adenocarcinoma patients to establish the prevalence of known toxins that include cytotoxin-associated gene A (cagA) as well as vacuolating cytotoxin A (vacA) within patients of variable adenocarcinoma diagnosis. This analysis used gastrectomy samples validated for DNA viability. The incidence of H. pylori in adenocarcinoma patients in Jordan was established to be 54.5% positive (ureA gene positive) with cagA genotype occurrence at 57.1%, but also in this population study vacA gene ratios found to be 24.7%:22.1%:14.3%:14.3%. (vacAs1:vacAs2:vacAm1:vacAm2). Using immunohistochemistry (IHC), we confirmed with statistical significance that p27 was dysregulated and suppressed, within nearly all H. pylori vacA genotypes. In addition, within 24.6% of H. pylori samples analyzed was a different bacterial genotype, and curiously that p27 protein expression was retained in 12% of tested adenocarcinoma H. pylori samples. This is suggestive that p27 could be used as a prognostic indicator but also that an unknown genotype could be contributing to the regulatory effects of p27 protein within this bacterial and cellular environment that may include other virulence factors and unknown immune system regulatory changes.

Clinical relevance and distribution of Helicobacter pylori virulence factors in isolates from Chinese patients.

At present, the relationship between virulence factors of Helicobacter pylori (H. pylori) and gastrointestinal diseases is still under discussion. This study investigated the association between distinct virulence factors in H. pylori and different gastrointestinal diseases. Gastric biopsy specimens were obtained from 160 patients with different gastrointestinal diseases in China, including 77 patients with chronic gastritis (CG), 36 with peptic ulcer disease (PUD), and 38 with gastric carcinoma (GC). The presence of certain virulence genes was determined by polymerase chain reaction (PCR), and the results were analyzed using chi-squared tests. A total of 160 H. pylori strains were successfully isolated from gastric biopsy specimens. Overall, all strains of H. pylori were cagA, cagE positive, and the most common vacA genotypes were s1 (98.8%) and m2 (68.1%). The positive rates of the jhp0562, jhp0563, homA, homB, hopQI, and hopQII genes were 99.4%, 32.5%, 33.1%, 71.3%, 100%, and 6.9%, respectively. There was no significant association between these genes and different disease types. The dominant hpyIIIR-positive genotype was detected in 83.1% of the strains, making it significantly more prevalent than the hrgA-positive genotype (P<0.001). Surprisingly, the mixed genotype of hrgA and hpyIIIR was common and accounted for 41.3%. The hrgA-positive strains were more common in GC patients (71.1%) compared to CG patients (50.7%, P<0.05). The mixed genotype was prevalent and accounted for 55.3% and 31.2% of strains from GC and CG patients, respectively. Multivariate analysis showed that the hrgA gene exhibited a positive correlation with GC and increased the risk of GC [odds ratio (OR) =3.606, P<0.05]. In contrast, the presence of hrgA exhibited a negative correlation with CG (OR =0.499, P<0.05). These results suggested that the universal presence of cagA, cagE, vacA s1, jhp0562, homB, and hopQI made it impossible to examine disease-specific associations with any of these virulence factors. In addition, they may synergistically contribute to more virulent strains and severe diseases in China. Furthermore, there was a strong association between the hrgA gene and progression to GC, indicating the potential application of other virulence factors in clinical detection.

Pattern and trends of Helicobacter pylori genotypes in gastric cancer: A Kenyan 8-year study.

Notable geographic and temporal variations in the prevalence and genotypes of Helicobacter pylori, in relation to gastric pathologies, have been observed; however, their significance and trends in African populations is scarcely described. The aim of this study, was to investigate the association of H. pylori and its respective CagA and vacuolating cytotoxin A (VacA) genotypes with gastric adenocarcinoma, and to describe the trends of H. pylori genotypes over an 8-year period (2012-2019). A total of 286 samples of gastric cancer cases and benign controls (one-to-one matching), from three main cities in Kenya, between 2012 and 2019 were included. Histologic evaluation, and CagA and VacA genotyping using PCR, was performed. Distribution of H. pylori genotypes was presented in proportions. To determine association, a univariate analysis was conducted using a Wilcoxon rank sum test for continuous variables, and a Chi-squared test or Fisher's exact test for categorical data. The VacA s1m1 genotype was associated with gastric adenocarcinoma, {odds ratio (OR) = 2.68 [confidence interval (CI) of 95%: 0.83-8.65]; p = 0.108}, whilst VacA s2m2 was associated with a reduced probability of gastric adenocarcinoma [OR = 0.23 (CI 95%: 0.07-0.78); p = 0.031]. No association between cytotoxin associated gene A (CagA) and gastric adenocarcinoma was observed. Over the study period, an increase in all genotypes of H. pylori was seen, and although no predominant genotype was noted, there was significant year-to-year variation, with VacA s1 and VacA s2 showing the greatest variation. VacA s1m1 and VacA s2m2 were associated with increased, and reduced risk of gastric cancer, respectively. Intestinal metaplasia and atrophic gastritis did not appear to be significant in this population.

Helicobacter pylori Virulence Factors and Clarithromycin Resistance-Associated Mutations in Mexican Patients.

Persistent infection with Helicobacter pylori (H. pylori) is an important factor in gastric diseases. The vacA and cagA virulence factors of H. pylori contribute to the development of these diseases. Triple therapy containing clarithromycin has been used to eradicate this infection. Unfortunately, resistance to this antibiotic is the primary cause of treatment failure. This study aimed to determine the prevalence of clarithromycin resistance-associated mutations and to assess the relationship between virulence factors and Mexican patients infected with H. pylori. The cagA and vacA genotypes were determined by multiplex PCR. Furthermore, a qPCR was used to identify mutations of the 23S rRNA gene. This study reported a prevalence of 84.3% of H. pylori among patients with gastric diseases, and the vacA s1m1/cagA+ genotype was the most frequent (44.8%) in antrum and corpus. Analysis of the 23S rRNA gene revealed a 19.8% prevalence of clarithromycin resistance-associated mutations. The most prevalent mutations were A2143G (56%) and A2142C (25%). A significant association (p < 0.05) between the A2142G and the vacA s1m1/cagA+ genotype was detected. In conclusion, we report a high prevalence (>15%) of clarithromycin resistance-associated mutations, and we found an association between the genotypes of virulence factors and a mutation in the 23S rRNA gene.

Immunological Study of Gastroduodenal Disorders Patients Infected with H. Pylori in Basrah Province-Iraq

The purpose of the current study was to investigate the immunological finding of the most important Helicobacter pylori virulence factors CagA, VacA, DupA, HopQ, and IceA genotypes in gastric biopsies of gastroduodenal diseases patients infected with H. pylori, and to determine the concentrations of CagA, VacA, DupA, HopQ, and IceA in the sera of the patients infected with H. pylori in Iraq-Basrah, by using ELISA technique, to give acknowledge about the role of these virulence factors in patients with the gastroduodenal disorder. A case-control study included 112 confirmed gastroduodenal patients and 112 healthy individuals as a control group. Data about age, gender, smoking, alcohol abuse, family history, occupation, residence, and clinical findings for all study populations were collected. Blood samples have been gathered from each patient as well as the control group. Each individual in this study was examined under the supervision of a gastroenterologist and was subjected to a urea breath test (UBT) for definitive confirmation of H. pylori infection. The finding of this study show a significant effect of these factors with an increased risk of gastroduodenal disorder. Conclusion: The study show a significant effect of the studied virulence factors (CagA, VacA, DupA, HopQ, and IceA) with an increased risk of gastroduodenal disorder of Iraqi population in Basrah province. Keywords: Immunological factors, gastroduodenal disorder, Helicobacter pylori, ELISA, CagA, VacA, DupA, HopQ, and IceA.