Mutant frequency of deletions was unchanged by H. pylori infection. H. pylori infection did not alter the levels of deletions detected by the Spi− assay in uninfected mice (white bars; 6 MPI, n = 12; 12 MPI, n = 16), H. pylori-infected males (light gray bars; 6 MPI, n = 3; 12 MPI, n = 5) and H. pylori-infected females (dark gray bars; 6 MPI, n = 9; 12 MPI, n = 12). Control mice of both sexes were grouped for this analysis. Data are mean (SEM) of mutant frequency of mice in different treatment groups.