Fig 5. Virulence assessed in a mouse model of necrotizing myositis.

(A) Virulence of 9T, 10T, and 11T isogenic strains in a mouse model of necrotizing myositis (n = 40 mice per strain). The treatment groups’ size was based on a power calculation from results of a pilot study. Significantly increased near-mortality was observed for the 10T and 11T strains compared with the 9T strain. Significance was determined using the log-rank test. (B) Representative gross and microscopic pathology images of the hindlimb lesions from mice (n = 5 mice per strain). Boxed areas demarcate areas with major lesions.