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.


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.


CONCLUSIONS
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.
Homan
Matjaz
M
Department of Gastroenterology, University Medical Center Ljubljana, Slovenia. matjaz.homan@guest.arnes.si
Luzar
Bostjan
B
Kocjan
Bostjan J
BJ
Orel
Rok
R
Mocilnik
Tina
T
Shrestha
Maja
M
Kveder
Maja
M
Poljak
Mario
M
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005798:Genes, Bacterial; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007249:Inflammation / Q000382:microbiology; D008297:Male; D017524:Slovenia; D013270:Stomach / Q000382:microbiology / Q000473:pathology*; D037521:Virulence Factors / Q000235:genetics* / Q000302:isolation & purification
D037521:Virulence Factors