Association of Helicobacter pylori restriction endonuclease-replacing gene, hrgA with overt gastrointestinal diseases.
OBJECTIVE
Helicobacter pylori has been proven to be responsible for causing various gastrointestinal disorders including gastric adenocarcinoma. Several genes of pathogen (the genes of the cag-PAI, vacA, iceA, and babA) either in combination or independently have been reported to significantly increase the risk of ulceration/gastric carcinoma, with the cagA gene having the strongest predictive value. Pursuit to identify new genes which could serve as a marker of overt disease progression, lead to the discovery of hrgA gene.


METHODS
Fifty-six indigenous strains of H. pylori from subjects with various gastric disorder were screened to assess the status of hrgA gene along with the cagA gene using simple polymerase chain reaction using specific oligonucleotide primers. Post-amplification, amplicons were subjected for sequencing to identify any strain specific variations in sequences from the H. pylori isolated from different disease manifestations. Histopathological analysis was done to ascertain any significant change in the histological scores of subjects infected with cagA+/hrgA+ and cagA-/hrg+ strains.


RESULTS
All the 56 (100%) subjects amplified with the oligonucleotide primers specific to hrgA gene, whereas 81.71% subjects showed the presence of cagA gene. Sequencing of the amplimers showed 99% homology. Histology of the cagA+/hrgA+ and cagA-/hrg+ subjects did not show any significant difference.


CONCLUSIONS
hrgA gene of Helicobacter pylori is not a ideal surrogate marker for identifying individuals with higher risk of developing overt gastro-duodenal diseases such as neoplasia of the stomach.
Center for Liver Research and Diagnostics, Deccan College of Medical Sciences and Allied Hospitals, Kanchanbagh, Hyderabad, Andhra Pradesh, India.
Manoj
M
G
Santosh K
SK
Tiwari
Vishwas
V
Sharma
Mohammed Aejaz
MA
Habeeb
Aleem A
AA
Khan
Habibullah
H
Cm
D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D015415:Biomarkers / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D004415:Dyspepsia / Q000382:microbiology; D005260:Female; D005767:Gastrointestinal Diseases / Q000382:microbiology*; D016481:Helicobacter Infections / Q000235:genetics / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D055815:Young Adult
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; D004269:DNA, Bacterial; C080866:cagA protein, Helicobacter pylori; D015252:Deoxyribonucleases, Type II Site-Specific; C470753:HrgA protein, Helicobacter pylori