Modelling and the induced resistance of inactivation of Staphylococcus aureus to high hydrostatic pressure incubated at different culture temperatures

The resistance models of Staphylococcus aureus( ATCC6538) were established in order to investigate the development of resistance responses to high hydrostatic pressure( HHP) treatment in S.aureus cultured at different temperatures. The resistance data for S. aureus incubated at different temperatures were obtained under the conditions of the pressures from 100 to 500 MPa. Then Linear,Weibull,and Gompertz models were selected to fit the curves of resistance to HHP of S. aureus. Regression coefficients( R2),root mean square error( RMSE),accuracy factor( Af) and bias factor( Bf) were used to evaluate the goodness of fit for the three models. Results showed that the Linear model provided a poor fit for the data,which has minimum R2( 0.8870),and Weibull model and Gompertz model showed suitable goodness- of- fit at five pressure levels between 100 to 500 MPa( R2≥0.9467).The Weibull model,which had maximum R2( 0.9956) and minimum RMSE( 0.0312),could be fitted perfectly to the curves of resistance to HHP in the three models.In conclusion,Weibull model showed ideal goodness- of- fit to the curves of resistance to HHP inactivation of Staphylococcus aureus. Moreover,with increasing incubation temperatures,the pressure resistance of S.aureus increased.