Fig. 8

Induction of arnT mRNA expression in the presence of CST in ECC. A arnT mRNA induction by CST in various species found in ECC clinical isolates. The y axis shows relative mRNA expression levels following culture in the presence of 16 mg/L CST for 120 min. The values were normalized by those in the absence of CST in each strain (set to 1.0). CST-heteroresistant and -susceptible isolates are indicated by red and black circles, respectively. Isolates of E. hormaechei subsp. hoffmannii, E. hormaechei subsp. oharae, and E. hormaechei subsp. xiangfangensis, which lack the arn operon, were not examined. ^a, E. cloacae subsp. cloacae (n = 1) and E. cloacae subsp. dissolvens (n = 2). B Comparison of arnT mRNA induction by CST between CST-susceptible and -heteroresistant ECC clinical isolates. The y axis shows relative mRNA expression levels in ECC clinical isolates cultured in the presence of 16 mg/L CST for 120 min. Number in parentheses indicates the number of ECC isolates. The values were normalized by those in the absence of CST in each strain (set to 1.0). *p < 0.001. C arnT mRNA induction by CST in ECC clinical isolates with low, moderate, and high CST MICs. The y axis shows relative mRNA expression levels in the presence of 16 mg/L CST normalized by those in the absence of CST in each strain (set to 1.0). Number in parentheses indicates the number of ECC isolates. *p < 0.05 and **p < 0.001