Distribution of Helicobacter pylori cagA, cagE and vacA in different ethnic groups in Kuala Lumpur, Malaysia.
OBJECTIVE
There is a geographic variation in Helicobacter pylori (HP) genotypes and virulence factors. Cytotoxin associated genes A (cagA) and E (cagE), and certain vacuolating cytotoxin (vacA) genotypes are associated with peptic ulcer disease (PUD). There is also a different prevalence of PUD among different ethnic groups in Malaysia. The present study compared the distribution of vacA alleles and cagA and cagE status in three ethnic groups residing in Kuala Lumpur, Malaysia, and their association with clinical outcome.


METHODS
All patients with cultured positive HP were recruited prospectively. DNA was extracted and polymerase chain reaction was carried out to determine the cagA and cagE status and vacA alleles.


RESULTS
The results of 127 patients (72 men and 55 women) were included. The mean age was 55.53 +/- 12.52 years. The ethnic distribution was 59 Chinese, 38 Indian and 30 Malay patients. The predominant genotype was s1a among the Malay (76.6%) and Indian patients (71.0%), and s1c among the Chinese patients (66.1%). The vacA middle region sequence m1 was detected in 66.7% of Malay, 54.2% of Chinese and 76.3% of Indian patients. Of the Malay, Chinese and Indian patients, 76.6%, 86.4% and 86.8%, respectively, were cagA positive, and 70.0%, 39.0% and 81.6%, respectively, were cagE positve. HP cagA, cagE and vacA were not associated with PUD.


CONCLUSIONS
There is a distinctive difference in the HP strains among the three ethnic groups in Malaysia. There was no association between cagA, cagE or vacA genotypes and clinical outcome in the patients. None of these markers are helpful in predicting the clinical presentation of a HP infection.
Tan
Huck Joo
HJ
Department of Gastroenterology, Sunway Medical Center, Selangor, Malaysia. hucktan@hotmail.com
Rizal
Abdul Manaf
AM
Rosmadi
Mohamed-Yusoff
MY
Goh
Khean-Lee
KL
D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D002681:China / Q000208:ethnology; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics*; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000208:ethnology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000382:microbiology; D011446:Prospective Studies; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori