Background
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.
Methods
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.
Results
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
hpy
IIIR-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
hpy
IIIR 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).
Conclusions
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
...