Culham and Wood [15] suggested that the 2.1-kb insertion upstream of rpoS arrived earlier than certain virulence determinants linked with urinary tract infections, such as genes for P-fimbriae (pap), S-fimbriae (sfa), a polyketide synthetase (pks), and α-hemolysin (hly) during the evolution of group B2. The gene discussed is ARAF; the disease is urinary tract infection.