Open AccessHeterogeneity of Helicobacter pylori cag genotypes in experimentally infected mice
Author(s) -
Sozzi Michele,
Crosatti Marialuisa,
Kim SungKook,
Romero Judith,
Blaser Martin J.
Publication year - 2001
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2001.tb10828.x
Subject(s) - caga , biology , helicobacter pylori , genotype , population , polymerase chain reaction , microbiology and biotechnology , gene , southern blot , strain (injury) , spirillaceae , virology , genetics , gastritis , virulence , medicine , anatomy , environmental health
Our aim was to assess whether the Helicobacter pylori population recovered from experimentally infected mice show heterogeneity in cag genotypes. Wild‐type FVB/N mice were challenged with strain Hp1 and sacrificed 8 weeks later. Direct PCR on gastric tissue was performed using primers for glmM and cagA , and for these two genes and for cagE and virB11 using DNA from the infecting and the emerging strains. The gastric tissues of two of five mice were PCR+ for glmM but not cagA . For the infecting strain, the PCRs for all four genes studied were strongly positive, but the sweeps from the emerging strains from both mice gave weaker signals for cagA and cagE . Examination of single colonies showed reduced or absent signals for cagA and cagE in relation to glmM and virB11 . Serial dilution PCR of sweep isolates from the mice showed a 10‐ to 100‐fold decrease in cagA signal compared to the infecting strain. The decrease of cagA and cagE , but not virB11 , amplification and lack of cagA hybridization in Southern blots indicates a selective loss of the right half of the cag island during murine infection. This phenomenon is consistent with host‐induced adaptive changes of cag genotype in the population of colonizing H. pylori cells.