title: A model of Helicobacter pylori persistence in a case of gastric cancer.
abstract: The aim of this work was to analyze several clones of Helicobacter pylori isolated from a patient with gastric cancer, to evaluate i) genetic variability ii) virulence factors profile and iii) antimicrobial susceptibility against the drugs commonly used in the H. pylori therapy. A total of 32 H. pylori clones isolated from a biopsy sample coming from a patient with gastric cancer previously treated for H. pylori infection, were analyzed for: the genetic variability by amplified fragment polymorphism analysis; the vacA, cagA virulence status by PCR; the antimicrobial susceptibility by minimum inhibitory concentrations with the agar dilution method towards amoxicillin, clarithromycin, levofloxacin and tinidazole. The patient showed a mixed infection with the presence of at least 3 different strains. The clones isolated possessed the vacA, cagA virulence factors with a different allelic combination (vacA s1/i1/m1; s1/i1i2/m1; s2/i2/m2; s2/i1i2/m2) together with repeated cagA EPIYA motif pattern P1P2P3P3P3. Moreover, a pattern of multi-drug resistance was disclosed in the different clones. The presence of multiple H. pylori strains colonizing the same patient, with the main virulence factors displaying a different allelic combination and a different multi-drug resistance among isolates, point out the role of genetic variability generating, in time, more virulent and adapted strains.
authors.affiliation: Department of Drug Sciences, "G. d'Annunzio" University, Chieti-Pescara, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Grande
authors.forename: Mara
authors.initials: M
authors.lastname: Di Giulio
authors.forename: Emanuela
authors.initials: E
authors.lastname: Di Campli
authors.forename: Soraya
authors.initials: S
authors.lastname: Di Bartolomeo
authors.forename: Luigina
authors.initials: L
authors.lastname: Cellini
mesh_terms: D000368:Aged; D000483:Alleles; D054458:Amplified Fragment Length Polymorphism Analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D011110:Polymorphism, Genetic; D013274:Stomach Neoplasms / Q000150:complications / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori