CsrS and CsrR mutation frequency and positions.
(a) The CsrS and CsrR mutation frequency in S. dysgalactiae subsp. equisimilis isolates from 79 STSS and 34 non-invasive infections. STSS isolates (19.0%: CsrS, 12.7%; CsrR, 6.3%) carried CsrS/CsrR mutations, whereas non-invasive isolates did not harbour any mutations in these genes. WT indicated intact CsrS/CsrR. Numbers above bars indicate the percentages, and number in the boxes indicate the number of isolates. (b) CsrS/CsrR amino acid sequence variations. Labels refer to amino acid positions, and numbers above boxes indicate amino acid number. 1 is the start codon and 228 and 499 are penultimate amino acids to the stop codons of CsrR and CsrS, respectively.