A time-series transcriptomic changes of Streptococcus mutans in response to heat stress. Streptococcus mutans UA159

Dental caries are closely associated with the virulence of Streptococcus mutans. The virulence expression of S. mutans is linked to its stress adaptation to the changes in the oral environment. In this work we used whole-genome microarrays to profile the dynamic transcriptomic responses of S. mutans during physiological heat stress. In addition, we evaluated the phenotypic changes, including initial biofilm formation, acid production and ATP turnover of S. mutans during heat stress. There were distinct patterns observed in the way that S. mutans responded to heat stress that included 66 transcription factors for the expression of functional genes being differentially expressed. Especially, response regulators of two component systems (TCSs), the repressors of heat shock proteins and regulators involved in sugar transporting and metabolism co-ordinated to enhance the cell’s survival and energy generation against heat stress in S. mutans. Overall design: S. mutans UA159 whole-genome arrays (8 x 15 K) were obtained from Agilent and included 1997 probes for S. mutans transcripts. We used time series microarrays to detect the dynamic changes of S. mutans under heat stress. For the exposure to heat stress, cultures of S. mutans (OD600nm=0.5) were transferred from 37℃ to a 45℃ water bath, the temperature of each culture was raised to 42℃ in < 4 min. Then the cultures were transferred to a 42℃ water bath for 5 min, 10 min, 15 min, 30 min, 45 min and 60 min. The control was a cell culture grown at 37℃ and collected before transferred to 45℃ water bath.