The study of Salmonellaenteritidis growth kinetics using Rapid Automated Bacterial Impedance Technique

Abstract

In order to study strain-specific differences in their growth behaviour at different, and particularly lower, temperatures, generation times for 45 strains of Salmonella enteritidis isolated from food were determined impedimetrically over a temperature range from 7 to 42 °C. In practical terms, 7 °C is the minimum requirement for Salm. enteritidis growth, and generation time variability increases markedly as this temperature is reached. Reports in the literature describing psychrotrophic behaviour and multiplication at lower temperatures cannot be confirmed. Generation time variability increased as temperature moved away from the optimal range with variation coefficients tending to rise as temperature fell. The great variability of multiplication parameters near the growth limit found in Salm. enteritidis may also be a characteristic of other bacterial species. It is therefore imperative to commence studies on larger numbers of strains to allow prediction of their behaviour at lower temperatures.