Study of simultaneous experimental colonization of Meriones unguiculatus (Mongolian gerbils) by cagPAI+ and cagPAI- strains of Helicobacter pylori.
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+.
Ortiz-Herrera
Maribel
M
Laboratorio de Bacteriología Experimental, Instituto Nacional de Pediatría, México DF, Mexico.
Camorlinga-Ponce
Margarita
M
López-Corella
Eduardo
E
Romero-Olvera
Javier
J
Gerónimo-Gallegos
Armando
A
Soria-Hernández
Alejandra
A
Coria-Jiménez
Rafael
R
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
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori