Assessment of survival during starvation ofEscherichia coli andKlebsiella pneumoniae in artificial urine: analysis of the kinetics of colony formation

Abstract

A kinetic model of colony formation was proposed by Hattori, based on a count of the colonies that appear on a plate in successive short intervals of time. In this model, three parameters (lambda, tr and N infinity) are defined, which reflect the ability of a bacterium to yield colonies and allow us to described the dynamics of bacterial populations in soil and of E. coli at different growth phases. In this paper we report a reparametrization of the kinetic model of colony formation, with the aim of facilitating more accurate calculation of lambda and tr. Moreover, we observed that during the starvation of E. coli and K. pneumoniae in urine, lambda can be used to assess survival, since this parameter clearly decreases during starvation. Retardation time values (tr) were similar in E. coli and K. pneumoniae throughout the starvation experimental period.