Genotyping of Helicobacter pylori in paraffin-embedded gastric biopsy specimens: relation to histological parameters and effects on therapy.
OBJECTIVE
Colonization with Helicobacterpylori can lead to GI disease. Bacterial genotypes and host factors, such as acid production, can influence the progress of disease. We investigated H. pylori genotypes and histological parameters in the same paraffin-embedded gastric biopsy specimens.


METHODS
Paraffin-embedded antrum and corpus biopsy samples from 75 gastroesophageal reflux disease patients were histologically examined and tested for H. pylori vacA (s and m regions), cagA, and iceA genotypes. Patients were investigated at baseline (58 H. pylori positive and 17 H. pylori negative) and after treatment with omeprazole with or without additional antibiotic therapy.


RESULTS
Genotyping at baseline was complete in 52 (90%) of the 58 H. pylori positive patients. Multiple genotypes were detected in eight (14%) of these. Genotypes were highly consistent between antrum and corpus biopsy specimens at baseline and in follow-up samples. Genotypes from paraffin sections matched those from corresponding cultured strains in 10 selected cases. In the antrum, the degree of inflammation was associated with vacA s1 and cagA+ genotypes, and the degree of neutrophil activity was associated with the cagA+ genotype. In the corpus, the degree of inflammation was significantly associated with vacA s1, cagA+, and iceA1 genotypes and the degree of atrophy was associated with vacA s1, m1, and cagA+ genotypes, whereas the degree of neutrophil activity was associated with vacA s1 and cagA+ genotypes. vacA s2 and cagA-strains appeared more resistant to antibiotic therapy, irrespective of resistance to clarithromycin.


CONCLUSIONS
Our findings confirm the relevance of the H. pylori genotypes for the severity of gastric disease and the efficacy of antibiotic therapy.
Department of Pathology, Slotervaart Hospital, Amsterdam, The Netherlands.
Ger H A
GH
Scholte
Leen-Jan
LJ
van Doorn
Annemieke
A
Cats
Elisabeth
E
Bloemena
Jan
J
Lindeman
Wim G V
WG
Quint
Stefan G M
SG
Meuwissen
Ernst J
EJ
Kuipers
D000658:Amoxicillin / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001706:Biopsy; D017291:Clarithromycin / Q000627:therapeutic use*; D005764:Gastroesophageal Reflux / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D005838:Genotype; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000145:classification* / Q000235:genetics*; D006801:Humans; D009853:Omeprazole / Q000627:therapeutic use*; D016612:Paraffin Embedding; D013270:Stomach / Q000382:microbiology* / Q000473:pathology*
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C063113:ice nucleation protein; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole