Diagnosis and genotyping of Helicobacter pylori by polymerase chain reaction of bacterial DNA from gastric juice.
BACKGROUND
Efficient and accurate detection of Helicobacter pylori infection as well as identification of virulence-associated alleles are important for the treatment of gastroduodenal diseases caused by this gastric pathogen. The present study was performed to test the efficiency of gastric juice polymerase chain reaction (PCR) method for the rapid detection of H. pylori infection and to determine the bacterial genotypes without the need for culture, which is often not feasible especially in developing countries.


METHODS
DNA was extracted from gastric juice samples collected from 45 subjects and was used to amplify urease B gene (ureB) for H. pylori. Results obtained from this method were further confirmed by rapid urease test (RUT), histology and culture. Genotypes of the infected strains predicted from gastric juice PCR were compared to the genotype data obtained from the isolated strains.


RESULTS
Among 45 cases, 32 were positive by RUT, 37 by histological examination, 25 by gastric juice PCR method, while culture yielded positive results for 19 samples. Except for one case, all the 19 culture-positive strains gave the same genotype with the gastric juice PCR result. It was found that the gastric juice PCR is more efficient for detection of multiple-strain infection as compared to genotype data obtained from strains isolated as pooled culture.


CONCLUSIONS
This moderately sensitive technique could be employed with good efficiency, particularly in cases where it is difficult to obtain biopsy. Moreover, with this method bacterial genotype could be obtained.
Datta
Simanti
S
National Institute of Cholera and Enteric Diseases, Calcutta 700 010, India.
Chattopadhyay
Santanu
S
Chowdhury
Abhijit
A
Santra
Amal
A
Saha
Dhira Rani
DR
Ramamurthy
T
T
Bhattacharya
Sujit Kumar
SK
Berg
Douglas E
DE
Nair
G Balakrish
GB
Mukhopadhyay
Asish Kumar
AK
D001459:Bangladesh / Q000208:ethnology; D004269:DNA, Bacterial / Q000032:analysis* / Q000737:chemistry; D005260:Female; D005750:Gastric Juice / Q000382:microbiology*; D005756:Gastritis / Q000382:microbiology / Q000473:pathology; D005838:Genotype; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000208:ethnology / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
D004269:DNA, Bacterial