Figure 3. Lewis antigen expression in clinical H. pylori isolates shows large intra-individual diversity.

Western blots detecting Le^x and Le^y antigens. Fifteen single-colony isolates were analyzed from each individual and time point. (A) High variability of Lewis antigen pattern was usually observed among intra-individual isolates, e.g. in single-colony isolates from Kx345 where large variation in sizes of Le^x and Le^y fucosylated O-antigen chains were detected. Here all the four different Lewis antigen phenotypes are represented: those expressing both Le^x and Le^y, isolates that only expressed Le^x or Le^y and strains that lacked expression of both these Lewis antigens. (B) Kx438 isolates simultaneously expressed both Le^x and Le^y at both time points, except two isolates at year 0 (isolate 3 and 9) that only expressed Le^y, but with comparably higher intensities. (C) The Kx1379 isolates show how the amount of Lewis antigen expression can vary in expression intensities, e.g. at year 4, where low amounts of Le^y were expressed in isolates 2, 3, 4, 5 and 7 as compared to isolates 1, 6 and 8–15, where more pronounced Le^y expression was observed.