Expression levels of selected genes related to membrane (pspD, pspG), heat (ibpB), and oxidative (grxA, soxS) stress responses and iron uptake (ECs0632, feoA), in E. coli O157:H7 nonadapted (control) or adapted to a sublethal concentration of thymol (1/2T), carvacrol (1/2C), or trans-cinnamaldehyde (1/2TC), determined by RT-qPCR.