Salmonella enteritidis phage type 4 isolates more tolerant of heat, acid, or hydrogen peroxide also survive longer on surfaces

Abstract

In a comparative study of different Salmonella enteritidis phage type 4 isolates we found that those isolates with enhanced heat tolerance also survived better than isolates that were heat sensitive either at pH 2.6, in 10 mM H 2 O 2 , or on surfaces. Culture to the stationary phase increased the heat tolerance of all isolates and the acid and H 2 O 2 tolerance of heat-tolerant isolates. With heat-sensitive isolates, however, extended culture had no impact on survival in H 2 O 2 and only a marginal impact on acid tolerance. The growth phase had no appreciable impact on the surface survival of any of the isolates.

Variation in resistance of natural isolates of Staphylococcus aureus to heat, pulsed electric field and ultrasound under pressure

“…Cluster analysis distinguished two main groups according to their heat resistance, a group including three heat-resistant strains (strain SA11, SA12 and SA87) and a second group including the remaining 12 strains. Some researchers have reported that natural isolates tend to be fairly resistant to environmental stresses (Shah et al 1991;Humphrey et al 1995). However, in this investigation, we have observed that the majority of the strains tested were very heat sensitive, showing D 58values between 0AE09 and 0AE2 min, which are even lower than those reported for many gram-negative bacteria (Shah et al 1991;Pagán et al 1999).…”

“…It is generally acknowledged that the most resistant strains to a given stressing agent, e.g. heat, are also more tolerant to a variety of different stresses (Humphrey et al 1995;Benito et al 1999). However, some investigations seem to disagree with this general observation.…”

Biofilm building capacity ofSalmonella entericastrains from the poultry farm environment

“…For S. Typhimurium, evidence exists that strains from the same Salmonella phage type have different survival profiles on identical surfaces (Humphrey et al, 1995).…”

The chicken, the egg and Salmonella enteritidis

“…It has therefore not been obvious how S. enteritidis is especially able to follow the human infection route described and, above all, at a critical step, how it so successfully contaminates and grows in egg contents. S. enteritidis has been shown by a number of investigators to generate a striking degree of strain heterogeneity (Ward et al, 1987;Petter, 1993;Gast and Benson, 1995;Humphrey et al, 1995;Guard-Petter et al, 1999;Lu et al, 1999;Liebana et al, 2001;Parker et al 2001b), suggesting that a complex network of characteristics may underlie its diverse behaviour. I describe here some emerging characteristics that correlate with infection and that may be central to the impact of this pathogen.…”