Modelling of bacterial growth with shifts in temperature using automated methodswith Listeria monocytogenes and Pseudomonas aeruginosa as examples

摘要

Time to detection (TTD) measurements using turbidometry allow a straightforwardmethod for the measurement of bacterial growth rates under isothermalconditions. Growth rate measurements were carried out for Listeria monocytogenesat 25, 30 and 37°C and for Pseudomonas aeruginosa over the temperature range 25to 45°C. The classical three-parameter logistic model was rearranged to providethe theoretical foundation for the observed TTD. A model was subsequentlydeveloped for the analysis of TTD data from non-isothermal studies based on theMalthusian approximation of the logistic model. The model was able to predictthe TTD for cultures of L. monocytogenes or P. aeruginosa undergoing simpletemperature shunts (e.g. 25 to 37°C and vice versa), and for a multipletemperature shunt for L. monocytogenes (25-37-25-37°C and 37-25-37-25°C) over aperiod of 24h. In no case did a temperature shunt induce a