Heat acclimation and the role of RpoS in prolonged heat shock of Escherichia coli O157.

Escherichia coli, a commensal mesophile that primarily inhabits the gastro-intestinal tract, responds to temperature up-shifts with transient expression of stress-response proteins. The goal of this study was to identify adaptive proteins of E. coli O157 crucial for growth resumption of this human pathogen after heat shock, with specific focus on the role of the RpoS sigma factor.

Prolonged cold stress response of Escherichia coli O157 and the role of rpoS.

Phenotypic analyses were performed using an enterohemorrhagic Escherichia coli O157 (EHEC) strain (B-1) and a commensal E. coli K-12 strain, exposed to prolonged cold stress. The EHEC E.

Dynamics of antimicrobial resistance and virulence genes in Enterococcus faecalis during swine manure storage.

In this study we used 2 experimental approaches to evaluate the stability of antimicrobial resistance (AMR) phenotypes, selected AMR genes, and selected virulence genes in Enterococcus faecalis during manure storage on a commercial swine farm. Isolates of E. faecalis were obtained directly from fresh fecal material (n = 120) and from the manure storage facility (n = 85) and compared.

Cells in shearable and nonshearable regions of Salmonella enterica serovar Enteritidis biofilms are morphologically and physiologically distinct.

Cellular morphology, exopolymer chemistry, and protein expression of shearable and nonshearable fractions of Salmonella enterica serovar Enteritidis biofilms were examined. Biofilms were grown at a laminar flow velocity of 0.07 cm.

Differential adaptive response and survival of Salmonella enterica serovar enteritidis planktonic and biofilm cells exposed to benzalkonium chloride.

This study examined the adaptive response and survival of planktonic and biofilm phenotypes of Salmonella enterica serovar Enteritidis adapted to benzalkonium chloride (BC). Planktonic cells and biofilms were continuously exposed to 1 microg ml(-1) of BC for 144 h. The proportion of BC-adapted biofilm cells able to survive a lethal BC treatment (30 microg ml(-1)) was significantly higher (4.

Architectural adaptation and protein expression patterns of Salmonella enterica serovar Enteritidis biofilms under laminar flow conditions.

Salmonella enterica serovar Enteritidis is a significant biofilm-forming pathogen. The influence of a 10-fold difference in nutrient laminar flow velocity on the dynamics of Salmonella Enteritidis biofilm formation and protein expression profiles were compared in order to ascertain how flow velocity influenced biofilm structure and function. Low-flow (0.

Adaptive resistance and differential protein expression of Salmonella enterica serovar Enteritidis biofilms exposed to benzalkonium chloride.

The development of adaptive resistance of Salmonella enterica serovar Enteritidis ATCC 4931 biofilms following exposure to benzalkonium chloride (BC) either continuously (1 microg ml(-1)) or intermittently (10 microg ml(-1) for 10 min daily) was examined. Biofilms adapted to BC over a 144-h period could survive a normally lethal BC challenge (500 microg ml(-1) for 10 min) and then regrow, as determined by increases in biofilm thickness, total biomass, and the ratio of the viable biomass to the nonviable biomass. Exposure of untreated control biofilms to the lethal BC challenge resulted in biofilm erosion and cell death.