Of the 3 cases not amplifiable for vacA s, one (Italy 23) showed the vacA m2 genotype (cagA-positive); another (Italy 24, cagA-positive) contained two different vacA m1 sequences, suggesting double infection; the third (Italy 36), undetermined for vacA s and m, harbored different cagA genotypes, also pointing to mixed infection. Here, S100A8 is linked to infection.