title: Study of simultaneous experimental colonization of Meriones unguiculatus (Mongolian gerbils) by cagPAI+ and cagPAI- strains of Helicobacter pylori.
abstract: Helicobacter pylori has a chromosomal pathogenicity island (cagPAI), and the presence or absence of this Island places the microorganism into two types of strains: cagPAI+ which is associated to serious infectious processes, and cagPAI- related to mild to moderate infectious events. Simultaneous colonization by cagPAI+ and cagPAI- strains is frequent and these bacteria can interact among themselves. The aim of this project was to analyze the interaction between cagPAI+ and cagPAI- strains of H. pylori in experimental infection, using the Mongolian gerbil as an experimental animal model. We employed J99 (cagPAI+) and 251F (cagPAI-) strains, and obtained 3 derivate strains in successive isolation from experimentally infected gerbils. By RAPD-PCR we found that cagPAI+ and cagPAI- underwent genetic rearrangement during the gerbil-adaptation process. We identified individual isolates from gerbils, and by in situ hybridization we established that both type of strains were able to colonize the same regions of the host's stomach, and induce a mild to moderate inflammatory process. We studied the competence between cagPAI+ and cagPAI- strains by simultaneous and sequential infections. The study shows that in both colonization experiments, the cagPAI- strains were more efficient than cagPAI+ strains in colonizing the infected host by displacing cagPAI+.
authors.affiliation: Laboratorio de Bacteriología Experimental, Instituto Nacional de Pediatría, México DF, Mexico.
authors.forename: Maribel
authors.initials: M
authors.lastname: Ortiz-Herrera
authors.forename: Margarita
authors.initials: M
authors.lastname: Camorlinga-Ponce
authors.forename: Eduardo
authors.initials: E
authors.lastname: López-Corella
authors.forename: Javier
authors.initials: J
authors.lastname: Romero-Olvera
authors.forename: Armando
authors.initials: A
authors.lastname: Gerónimo-Gallegos
authors.forename: Alejandra
authors.initials: A
authors.lastname: Soria-Hernández
authors.forename: Rafael
authors.initials: R
authors.lastname: Coria-Jiménez
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D044404:Genomic Islands; D005849:Gerbillinae / Q000382:microbiology; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology*; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D008297:Male; D019105:Random Amplified Polymorphic DNA Technique; D011995:Recombination, Genetic; D012720:Severity of Illness Index; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori