title: Claritromycin resistance and Helicobacter pylori genotypes in Italy.
abstract: The relationship between H. pylori clarithromycin resistance and genetic pattern distribution has been differently explained from different geographic areas. Therefore, we aimed to assess the clarithromycin resistance rate, to evaluate the bacterial genetic pattern, and to search for a possible association between clarithromycin resistance and cagA or vacA genes. This prospective study enrolled 62 consecutive H. pylori infected patients. The infection was established by histology and rapid urease test. Clarithromycin resistance, cagA and vacA status, including s/m subtypes, were assessed on paraffin-embedded antral biopsy specimens by TaqMan real time polymerase chain reaction (PCR). Primary clarithromycin resistance was detected in 24.1 % of cases. The prevalence of cagA was 69.3 %, and a single vacA mosaicism was observed in 95.1 % cases. In detail, the s1m1 was observed in 23 (38.9 %) patients, the s1m2 in 22 (37.2 %), and the s2m2 in 14 (23.7 %), whereas the s2m1 combination was never found. The prevalence of cagA and the vacA alleles distribution did not significantly differ between susceptible and resistant strains. Primary clarithromycin resistance is high in our area. The s1m1 and s1m2 are the most frequent vacA mosaicisms. There is no a relationship between clarithromycin resistance and bacterial genotypic pattern and/or cagA positivity.
authors.affiliation: Gastroenterology Unit, Riuniti Hospital, Foggia, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Francesco
authors.forename: Marcella
authors.initials: M
authors.lastname: Margiotta
authors.forename: Angelo
authors.initials: A
authors.lastname: Zullo
authors.forename: Cesare
authors.initials: C
authors.lastname: Hassan
authors.forename: Nicola Della
authors.initials: ND
authors.lastname: Valle
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Burattini
authors.forename: Roberto
authors.initials: R
authors.lastname: D'Angelo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Stoppino
authors.forename: Ugo
authors.initials: U
authors.lastname: Cea
authors.forename: Floriana
authors.initials: F
authors.lastname: Giorgio
authors.forename: Rosa
authors.initials: R
authors.lastname: Monno
authors.forename: Sergio
authors.initials: S
authors.lastname: Morini
authors.forename: Carmine
authors.initials: C
authors.lastname: Panella
authors.forename: Enzo
authors.initials: E
authors.lastname: Ierardi
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; D017291:Clarithromycin