Fig 1.

Phenotypic analyses of representative B. cereus strains. (A) Quantitative mean values ± standard deviations for motility, epithelial cell adhesion, cytotoxicity, biofilm formation, polymyxin B resistance, and virulence in the model insect G. mellonella for each group of strains. NP, nonpathogenic strains; FP, food poisoning strains; C, clinical strains. Bars with different letters (a, b, c) indicate significant differences in their mean values (P < 0.005). Results are the means of results of at least three independent experiments. (B) Frequencies of strains positive for each of the tested phenotypes in the various B. cereus groups. NP, nonpathogenic strains; FP, food poisoning strains; C, clinical strains. Frequencies were calculated relative to a threshold value defined for each phenotype as the median value for all strains.