Abstract:Multidrug-resistant and drug-sensitive strains of Escherichia coli were inoculated separately into fresh beef, and cultured at 10 ℃, 20 ℃, 30 ℃, and 40 ℃. The growth data at 25 ℃ and 35 ℃ were used for validation. The primary and secondary models were set up using Origin 8.0 in order to obtain the maximum specific growth rate and lag phase of the two strains at different temperatures. The results showed that the modified Gompertz and Logistic models fit well with the growth parameters of the two multidrug-resistant and drug-sensitive strains in beef (R2＞0.95). The lag phase of drug-sensitive E. coli was shorter than that of the drug-resistant strain. The functional relationship between the parameter values (U and LPD) and temperature was explained by a Belehvadek model. The experimental results showed that the temperature and maximum specific growth rate presented a linear relationship. The maximum specific growth rates at 25 ℃ and 35 ℃ were computed by the secondary growth kinetic model. The deviation value was relatively small when compared with the predicted values and actual values, indicating that the growth model was reliable. These experimental results provide a theoretical basis for the control of E. coli in beef.
