Helicobacter pylori genotypes in Israeli children: the significance of geography

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.

Unique constellations of five polymorphic sites of Helicobacter pylori vacA and cagA status associated with risk of gastric cancer

Helicobacter pylori possesses virulence genes that are involved in the pathogenesis of the bacterium. There are little data regarding all constellations of five polymorphic sites of H. pylori vacA and cagA status. We therefore aimed to i) find any associations between H. pylori vacA alleles (s1/s2, m1/m2, i1/i2, d1/d2, and c1/c2) and cagA status and ii) determine the frequency of all five-genotype combinations of the vacA alleles with and without cagA gene, and their associations with risk of gastric cancer (GC). A total of 290 Iranian H. pylori isolates from gastrointestinal patients were obtained successfully by the cultivation of biopsies and genotyped. The patients included 144/290 with non-atrophic gastritis (NAG), 57/290 with peptic ulcer disease (PUD), and 89/290 with GC. We found that each of the vacA m1-, i1-, d1-, and c1-genotypes was significantly associated with cagA⁺ status. The odds ratio(OR) and 95% confidence interval (95% CI) was 2.316 (1.241-4.301) for cagA⁺/vacA m1, 2.764 (1.540-4.960) for cagA⁺/vacA i1, 4.288 (2.305-7.977) for cagA⁺/vacA d1, and 2.639 (1.488-4.680) for cagA⁺/vacA c1, respectively. In this study, 43 five- and six-genotype combinations were found among 224 strains. The highest frequencies were observed for vacA s1m2i2d2c2 (85/224, 37.9%), s1m2i2d2c2/cagA (48/222, 21.6%), s1m1i1d1c1 (40/224, 17.9%) and s1m1i1d1c1/cagA (35/222, 15.8%). Logistic regression analysis showed that vacA s1m1i1d1c1, s1m2i1d2c1, s1m2i2d2c1, and s1m2i2d2c1/cagA had a high prevalence in GC patients compared to non-atrophic gastritis patients (p < .05). The ORs and 95% CI were 2.433 (1.070-5.531), 11.524 (1.253-106.023), 4.200 (1.261-13.993), and 6.263 (1.494-26.256), respectively. These results were also confirmed when the controls were non-tumors (NAG/PUD). We found novel five- and six-genotype combinations associated with the risk of GC. These associations seem to be strongly dependent on the presence of c1-type of vacA. Therefore, analysis of all combined genotypes of the vacA alleles and cagA status may play a significant role in determining H. pylori-related clinical outcomes.

Gene polymorphisms of pathogenic Helicobacter pylori in patients with different types of gastrointestinal diseases

Helicobacter pylori (H. pylori) is a kind of chronic infectious pathogen which can cause chronic gastritis, peptic ulcer, gastric cancer and other diseases. The genetic structure of the pathogenic genes of H. pylori varies largely, which contributes to the differences in virulence among various strains, and in clinical symptoms. Virulence genes of H. pylori can be categorized into three main classes: those related to adhesion and colonization, those related to gastric mucosal injury, and others. This review focuses on the relationship between genetic polymorphisms of the three classes of virulence genes of H. pylori and diseases. Most of the genetic polymorphisms of the main virulence factors of H. pylori are summarized in this paper.

Prevalence of infection with cagA-positive Helicobacter pylori strains among children and adolescents in southern Brazil

CONTEXT

Helicobacter pylori (H. pylori) has a worldwide distribution, but the prevalence of infection, virulence factors, and clinical presentation vary widely according to the studied population. In Brazil, a continental country composed of several ethnicities and cultural habits, the behavior of infection also appears to vary, as many other studies have shown.

OBJECTIVES

Describe the prevalence of infection with cagA-positive H. pylori strains in a group of children and adolescents who underwent esophagogastroduodenoscopy in Porto Alegre, Rio Grande do Sul.

METHODS

Fifty-four gastric biopsy specimens of children and adolescents with H. pylori infection demonstrated by histology, urease test and molecular analysis were tested for the presence of cagA positive H. pylori strains by the polymerase chain reaction method.

RESULTS

The prevalence of cagA-positive H. pylori was 29.6% (95% confidence interval, 18 to 43.6%). There were no statistically significant differences in clinical or demographic characteristics or in the endoscopic and histological features of patients infected with cagA-positive strains as compared with those infected by cagA-negative strains.

CONCLUSIONS

he study showed a low prevalence of infection with cagA-positive H. pylori strains among children and adolescents who underwent EGD in southern Brazil, in comparison to studies conducted with children from other regions of Brazil. There was no association between the presence of cagA-positive strains and more severe clinical presentations in the studied sample.

cagE as a biomarker of the pathogenicity of Helicobacter pylori

INTRODUCTION

Helicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses.

METHODS

Were collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR.

RESULTS

Of the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested. Conclusions Thus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.

Prevalence and distribution of Helicobacter pylori cagA and vacA genotypes in the Moroccan population with gastric disease

Helicobacter pylori infection is the etiologic agent of various gastric pathologies. The severity of disease outcome has been attributed to some H. pylori genotypes, which varies geographically. In Morocco, there are no data regarding the pattern of H. pylori genotypes; therefore, this is the first prospective study conducted in our country to investigate the genotype profiles (vacA and cagA) of H. pylori in patients with gastric pain. Endoscopic biopsies were obtained in patients attending the gastroenterology department of the Hospital University Hassan II of Fez for gastric pain and were directly used for H. pylori detection and genotyping by polymerase chain reaction (PCR). The SPSS software program was used to study the genotype correlation to different clinical outcomes. A total of 429 patients were included in this study, with an infection rate of 69.9%. cagA was detected in 42.3% of cases. However, vacA genotyping reveal a large predominance of s2m2. Infection with multiple strains was detected in 10.8% of cases and incomplete vacA was observed in 31.5%. In Morocco, vacA s1m1 was significantly associated to peptic ulcer diseases, while s2m2 was associated to gastritis. Moroccan H. pylori vacA genotype profiles differ from the Latin American, European, and South African profiles, with more similarities to the North African profile. Because of the small number of cases with gastric cancer, no correlations with H. pylori have been studied, so, further studies will be required in order to highlight the effects of those genes on this disease.

Interaction among ethnicity, socioeconomic status, and Helicobacter pylori seroprevalence in Israeli children and adolescents

OBJECTIVES

The aim of the study was to examine the prevalence of Helicobacter pylori infection among Israeli children from different backgrounds and to assess potential interactions between ethnicity, socioeconomic status (SES), and H pylori seroprevalence.

PATIENTS AND METHODS

The present sero-epidemiologic study was conducted among 0- to 20-year-old children seeking medical attention, not specifically gastrointestinal symptoms, using sera collected between 2000 and 2001 from 575 Israeli Arab children, 584 Jewish children from the general population, and sera that were obtained between 1997 and 2007 from 464 children of an ultraorthodox Jewish community. An enzyme-linked immunosorbent assay was used to measure H pylori serum immunoglobulin G antibodies and seropositivity to H pylori CagA strains.

RESULTS

H pylori seropositivity was 22.9% (95% confidence interval [CI] 19.7-26.5) among Jewish children from the general population, 25.2% (95% CI 21.5-29.4) among ultraorthodox Jewish children, and 45.6% (95% CI 41.5-49.7) among Arab children. H pylori seroprevalence increased significantly with age in the 3 study groups, but it was consistently higher in Arab children. Compared with Jewish participants from high SES and controlling for age and sex, the odds ratio for H pylori seropositivity was 2.03 (95% CI 1.31-3.12) in Jewish children from intermediate SES, 2.42 (95% CI 1.29-4.53) in Arab children from intermediate SES, 2.26 (95% CI 1.52-3.36) in Jewish children from low SES, and 5.72 (95% CI 3.89-8.42) in Arab children from low SES. CagA seropositivity was 40.8% and 45.0% among Jewish and Arab children, respectively (P =0.59), and it was highest among subjects of lower SES.

CONCLUSIONS

Socioeconomic factors may not totally explain the ethnic differences in H pylori prevalence.

Helicobacter pylori genotypes and types of gastritis in first-degree relatives of gastric cancer patients

The frequency of Helicobacter pylori vacA alleles, cagA, and jhp0947 and their association with types and advanced forms of gastritis in 143 first-degree relatives of gastric cancer (GC) patients was assessed. The subjects included 64/143 with antral-predominant gastritis, 68/143 with pangastritis, and 11/143 with corpus-predominant gastritis, with or without atrophy or intestinal metaplasia (IM). Further classification included the severity of atrophy or IM. Group I (40/143) included the subjects with moderate-marked atrophy or IM, group II (58/143) those with no atrophy or IM, and group III (45/143) with mild atrophy or IM. The frequency of vacA s1 was 79.7%, vacA s2 20.3%, m1 49.7%, m2 50.3%, cagA 76.2%, and jhp0947 58%. The most prevalent combination was vacAs1 cagA (+) (65.7%) (P=0.001). Of the 143 subjects, 85 (59.4%) showed atrophy or IM, and 40/85 (47%) developed the moderate-marked atrophy or IM. No significant correlation was found between genotypes and the types of gastritis, non-atrophy, atrophy, or IM and severe forms of atrophy or IM (P>0.05). It is proposed that H. pylori genotype status might not be considered as an important determinant of the types and advanced forms of gastritis in the first-degree relatives of GC patients.

Molecular Basis of pathogenicity in Helicobacter pylori clinical isolates

This study identified pathogenicity genes in 40 Helicobacter pylori clinical isolates. The cagA, vacA, and iceA genes were detected in 65%, 97.5%, and 97.5% of the isolates, respectively. The cagA, iceA1, and vacAs1a/m1 genes were related to erosive gastritis, whereas the vacAs2/m2 and iceA2 genes were associated with enanthematous gastritis.

Helicobacter pylori and gastric cancer in the Middle East: A new enigma?

The Middle East is the home of ethnic groups from three main backgrounds: Semitic (Arabs and Jews), Indo-European (Persians and Kurdish) and Turkic (Turkish and Turkmens). Its geographic location, which has been under continuous influences from Asia, Europe and Africa, has made it an ideal site for epidemiological studies on Helicobacter pylori (H. pylori) infection and genotyping. The gastric cancer rate differs in this region from very high in Iran (26.1/10⁵) to low in Israel (12.5/10⁵) and very low in Egypt (3.4/10⁵). Epidemiological studies showed that the prevalence of H. pylori is almost similar in those countries with a high level of infection in childhood. Importantly, the frequency of vacA s1 and m1 regions and cagA+ genotypes were higher in non Semitic populations who inhabit the North than Semitic populations, the inhabitants of Southern parts of the Middle East. H. pylori infection prevalence, distribution pattern of virulence factors, diet and smoking could not have explained the difference in cancer rate. This reflects the multifactorial aetiology of gastric cancer and suggests that H. pylori infection does not always directly correlate with the risk for gastrointestinal disease, such as gastric cancer. Further detailed investigations and international comparative studies of each risk factor need to be performed to investigate whether this represents a true enigma.

Prevalence and clinical relevance of cagA, vacA, and iceA genotypes of Helicobacter pylori isolated from Slovenian children

BACKGROUND

Although infection with Helicobacter pylori in children mostly induces asymptomatic chronic gastritis, the clinical outcome of H pylori infection is generally unpredictable. To identify the risk subgroup of infected children who can progress toward serious gastrointestinal disease, we assessed the prevalence of H pylori virulence genes cagA, vacA, and iceA in children from southeastern Europe and correlated their presence with the severity of histological changes in the stomach.

MATERIALS AND METHODS

A total of 165 children (age range 4-18 years, mean 13 years) with H pylori infection were studied for a 6-year period. Virulence genes were determined by polymerase chain reaction from biopsy samples.

RESULTS

The cagA gene was present in 61.2% of patients. The predominant vacA genotype was s1m1 (42%), followed by s1m2 (28%), and s2m2 (24%). IceA genotypes iceA1 and iceA2 were detected in 62% and 31% of the samples, respectively. Multiple genotypes were found in 11.5% of isolates. The H pylori density score, the degree of chronic and acute inflammation, correlated with a cagA-positive status (P < 0.01, P < 0.01, P = 0.01, respectively). Higher bacterial infiltration (P < 0.01) and degree of chronic inflammation (P = 0.03) were detected in vacA s1-positive samples.

CONCLUSION

CagA, vacA s1m1, and iceA1 genotypes are the predominant genotypes of H pylori isolated from the southeastern European pediatric population. CagA and vacA s1 are important virulence determinants of H pylori in children, but were not found associated with an increased incidence of precancerous gastric lesions.

The association of vacA genotypes and Helicobacter pylori-related gastroduodenal diseases in the Middle East

The variations in the three regions of the Helicobacter pylori vacA gene, the signal (s1 and s2), intermediate (i1 and i2) and middle regions (m1 and m2), are known to cause the differences in vacuolating activities. However, it was unclear whether these vacA genotypes are associated with the development of gastric cancer and peptic ulcer in the Middle East. The aim was to identify the prevalence of vacA genotypes in the Middle East and the association with gastroduodenal diseases. We investigated the relationship of vacA genotypes to H. pylori-related disease development by meta-analysis using previous reports of 1,646 patients from the Middle East. The frequency of the vacA s1, m1 and i1 genotypes in the Middle Eastern strains was 71.5% (1,007/1,409), 32.8% (427/1,300) and 40.7% (59/145), respectively. Importantly, the frequency of vacA s- and m-region genotypes significantly differed between the north and south parts of the Middle East countries (P < 0.001). The vacA genotypes significantly increased the risk of gastric cancer (odds ratio [OR]: 4.02, 95% confidence interval [CI]: 1.98-8.14 for the s1 genotype; 2.50, 1.62-3.85 for m1; 5.27, 1.97-14.1 for s1m1; 15.03, 4.69-48.17 for i1) and peptic ulcers (OR: 3.07, 95% CI: 2.08-4.52 for s1; 1.81, 1.36-2.42 for m1). The cagA-positive genotype frequently coincided with the s1, m1 and i1 genotypes. The vacA s- and m-region genotypes may be useful risk factors for gastrointestinal diseases in the Middle East, similar to European and American countries. Further studies will be required to evaluate the effects of the i-region genotype.

Prevalence of cagA in relation to clinical presentation of Helicobacter pylori infection in Egypt

Helicobacter pylori infection, peptic ulcer and gastric cancer are common problems in Egypt. We investigated the prevalence of cagA-positive Helicobacter pylori infections among Egyptian adults in relation to presentation (e.g. dyspepsia vs asymptomatic controls) in Minofyia, Egypt. Patients included men or women seeking care for at least 3 months of upper gastrointestinal symptoms. Helicobacter pylori status was determined by rapid urease test and gastric histopathology in patients and by anti-Helicobacter pylori IgG antibodies in controls. CagA status was determined using an anti-cag A ELISA. 99 Helicobacter pylori infected patients were entered including 90 dyspeptic patients (30 each with gastric cancer, peptic ulcer, and non-ulcer dyspepsia) and 9 non-dyspeptic healthy controls. Age ranged from 27 to 78 y (mean 49.5 y); 50% were men. Anti-cagA antibodies were present in 62.2% of dyspeptic patients compared with 11% of asymptomatic controls (p = 0.004). Anti-cagA antibodies were more prevalent among dyspeptic patients with gastric cancer or peptic ulcer (73.3%) compared to those with non-ulcer dyspepsia (40%) (p = 0.004). The prevalence of cagA in Egypt was related to the clinical presentation of Helicobacter pylori infection being lowest in asymptomatic controls (11.1%) and increasingly prevalent in non-ulcer dyspepsia (40%), peptic ulcer (66.7%), and gastric cancer (89%).

Prevalence of Helicobacter pylori pathogenicity-associated cagA and vacA genotypes among Pakistani dyspeptic patients

The cytotoxin-associated gene A (cagA), and the vacuolating cytotoxin gene A (vacA) products are considered the most important pathogenic determinants of Helicobacter pylori, a gram-negative bacterium causing gastrointestinal disorders such as duodenal ulcers, gastritis and mucosa-associated lymphoid tissue disease. A higher prevalence of H. pylori has been reported in various regions in the Pakistani population; however, no data are available about the virulence-associated genetic determinants. The objective of this study was to determine the prevalence of virulence-associated genes, cagA, vacA and particularly vacA allelic variants among dyspeptic patients from Pakistan. Gastric biopsy samples were obtained from 78 adult patients presenting dyspepsia symptoms. DNA was isolated and analyzed for the presence of H. pylori and its genotypes by PCR. Genus-specific PCR involving 16S rRNA gene revealed that 66 of the 78 patients were positive for H. pylori, an overall prevalence of 84.6% for this particular study. The most common vacA genotype was s1b/m2 (54.5%) followed by s1a/m1 (19.7%). cagA was positive in 24.2% of the cases and strongly associated with s1a/m1, vacA. The prevalence of virulent cagA, and vacA allelic form s1a/m1 was lower than that reported from neighboring countries.

cagA, vacA, and iceA genotypes of Helicobacter pylori in Korean children

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.

cagA gene and protein status among Iranian Helicobacter pylori strains

The wide geographic genetic diversity of Helicobacter pylori (Hp) and, in particular, the varying prevalence of cagA in different countries has been documented repeatedly. This study was designed to determine the frequency of cagA in Iranian Hp strains by means of genotyping and assessment of host antibodies. Helicobacter pylori strains from 235 patients, including 174 non-ulcer dyspepsia, 25 peptic ulcer and 36 gastric cancer patients, were studied. The frequencies of the 5', middle and 3' terminal regions of the cagA gene were 90.6, 57.6, 89%, respectively, with no correlation to the clinical outcomes. Antibodies against the CagA protein were present in 90.7% of patients. Multiple biopsy sampling in 97 cases revealed multiple infection in 16.5% of the patients. Sequencing of the seven variants of the 3' end of the cagA gene revealed no clustering and the distribution of the Iranian strains among those of other countries. Our results from the genotyping and serology analyses confirm that the majority of Iranian Hp strains are cagA-positive.

Combination of Helicobacter pylori strain and tumor necrosis factor-alpha polymorphism of the host increases the risk of peptic ulcer disease in children

BACKGROUND

Helicobacter pylori infection is probably acquired in childhood and causes a vigorous immune response. It is unclear why only a subgroup of infected children develops peptic ulcer disease. We have previously reported that iceA1 strains tend to be associated with duodenal disease in children. However, the pathogenesis probably does not depend solely on the H pylori strain but also on the variability of the host response.

OBJECTIVES

The aim of this study was to assess the significance of tumor necrosis factor-alpha (TNF-alpha) promoter polymorphism in relation to infection with H pylori strains in children.

METHODS

A total of 113 antral biopsies of H pylori-positive children (ages 2-18 years) were analyzed. Of these, 23 had duodenal disease, including erosive duodenitis and/or duodenal ulceration, and 90 had gastritis only. H pylori infection was diagnosed by bacterial culture and histology. Patient genomic DNA extracted from the antral biopsy was used to characterize the genetic polymorphism of TNF-alpha promoter at nucleotide positions -308 and -238 by polymerase chain reaction-based restriction fragment-length polymorphism. All H pylori strains were examined for cytotoxin-associated gene A and induced-by-contact-with-epithelium gene (iceA1).

RESULTS

A total of 31% of children with duodenal disease were infected with iceA1 positive strains and had the -238 G to A polymorphism in the TNF-alpha gene vs only 1.6% of children with gastritis alone (P < 0.0005).

CONCLUSIONS

The combination of bacterial iceA1 and TNF-alpha 238 G to A polymorphism may be a risk factor for peptic ulcer disease in children infected with H pylori. Larger studies are needed to confirm this association.

Helicobacter pylori genotypes identified in gastric biopsy specimens from Jordanian patients

BACKGROUND

The genetic diversity of Helicobacter pylori can be analyzed at two different levels: the genomic variation between strains originating from different individuals, and the variation in bacterial populations within an individual host. We reported for the first time the H. pylori genotypes in Jordanian patients with gastrointestinal diseases.

METHODS

Upper endoscopy was performed on 250 patients with symptoms of gastrointestinal diseases. Multiple gastric biopsy specimens were taken from the antrum. All the biopsies were tested by PCR for the H. pylori virulence genes vacA, cagA, and iceA, and 151 were tested by histology.

RESULTS

The biopsies positive for H. pylori by PCR were 110/250 (44%), and by histology 117/151 (77.5%), and these results were highly associated (P < 0.02). Analyses of virulence genes revealed that iceA2 (73.6%) was the predominant genotype, the vacAs2 allele was more frequently identified than the vacAs1 allele, while the cagA genotype was low (26.4%). The presence of certain genotypes might be associated with each other, but the presence of certain genotypes was not significantly associated with the age, or gender of the patient.

CONCLUSION

The results illustrate the geographic nature of the genetic diversity of H. pylori, as the identified genotypes are similar to those reported in neighboring countries. This study provides a baseline data of H. pylori genotypes identified in gastric biopsy specimens from Jordan, serving as a powerful epidemiological tool for prospective investigations to better understand the genetic diversity of this pathogen.

Treatment regimens for Helicobacter pylori infection in children: is in vitro susceptibility testing helpful?

BACKGROUND

Treatment regimens for Helicobacter pylori have variable success rates, and data comparing effectiveness with respect to strain sensitivity are relatively scarce.

OBJECTIVE

To evaluate the efficacy of two treatment regimens for eradication of H. pylori and the impact of bacterial susceptibility testing.

STUDY DESIGN

265 children endoscopically diagnosed with H. pylori infection were randomly assigned to receive omeprazole + amoxicillin with clarithromycin or omeprazole + amoxicillin with metronidazole. Bacterial culture and susceptibility was performed in a subgroup. Eradication was assessed by C-urea breath test.

RESULTS

Eradication was achieved in 73.4% by omeprazole + amoxicillin with metronidazole and in 62.6% by omeprazole + amoxicillin with clarithromycin (P = 0.078). H. pylori was cultured successfully in 105 patients. Resistance to metronidazole was detected in 31.4% of the isolates and resistance to clarithromycin in 15%. Eradication rate by omeprazole + amoxicillin with metronidazole for metronidazole-susceptible bacteria (N = 38) was 90%, and for resistant bacteria (N = 19) it was 42%. Only 75% of clarithromycin-sensitive strains were successfully treated by omeprazole + amoxicillin with clarithromycin, and none of the cases with clarithromycin-resistant strains responded to omeprazole + amoxicillin with clarithromycin treatment.

CONCLUSION

There is a trend of greater efficacy of eradication with omeprazole + amoxicillin with metronidazole versus omeprazole + amoxicillin with clarithromycin therapy. Although resistance negatively influences eradication, first-line sensitivity-based treatment would be expected to improve this rate only slightly. Susceptibility testing should probably be reserved only for treatment failures.

Genotypes of the Helicobacter pylori vacA signal sequence differ with age in Korea

BACKGROUND

Studies on Helicobacter pylori genotypes have focused on adults in developed countries, and data on the genotypes of Helicobacter pylori recovered from the children are rare.

MATERIALS AND METHODS

One hundred and twenty-eight biopsy samples from patients with H. pylori infection were studied. The patients' ages ranged from 9 to 83 years. PCR analysis for vacA genotypes was performed using DNA extracted from biopsy specimens.

RESULTS

Genotyping of the s-region showed s1a in 33 (25.8%) samples and s1c in 82 (64.1%) samples. When the specimens were grouped by age, the distribution of s-region genotype was found to be significantly different between groups (p = .002). The prevalence of s1a was 45.2% in patients < 20 years old, but 14.9% in patients > or = 50 years old. On the other hand, the prevalence of s1c or recombinant s1a-s1c was higher in those > or = 50 years old. The distribution of the m-region did not differ significantly with age (p = .110).

CONCLUSIONS

Strain populations infecting Korean adults and children differ.