Biofilms enable food-borne pathogens to resist removal from surfaces and survive disinfection. Biofilms of pathogens [e.g., S. enterica Serovar Typhimurium DT104 (STDT104)] formed on various surface types were probed with Calcofluor (b-D-glucan-specific ) and lectins…
Contents
Chapter 1: FOOD-BORNE PATHOGENS AND BIOFILMS
The problem of food-borne pathogens
National Food Safety Initiative
PulseNet
FoodNet
Summary of the Pathogen Reduction and Hazard Analysis and Critical Control Points (HACCP) Systems
Significance of organisms included in this study
Escherichia coli
Salmonella
Aeromonas
Vibrio
An overview of biofilms
Capsular polysaccharides (CP)
Exopolysaccharides (ES)
Biofilms and their advantage to bacteria
Biofilm formation occurs in three main stages
Stage 1
Stage 2
Stage
Objectives of this research
Summary of procedures for all four objectives
Chapter 2: CALCOFLUOR AND LECTINS AS FLUORESCENT PROBES TO DETECT BIOFILMS OF FOOD-BORNE PATHOGENS
Rationale
Materials and Methods
Bacterial strains, media and culture conditions
Calcofluor preparation and biofilm staining
Labeling of biofilms and planktonic cells with Calcofluor
Probing biofilm-covered surfaces with Calcofluor
Labeling biofilms with lectins
Results and Discussion
Chapter 3: A CAPSULAR POLYSACCHARIDE SURROUNDS SMOOTH AND RUGOSE VARIANT CELLS OF SALMONELLA ENTERICA SEROVAR
TYPHIMURIUM DT104
Rationale
Materials and Methods
Bacterial strains, media and culture conditions
Screening Rv and Stv for production of EPS
Adhesion assay
Purification of CP
Measurement of carbohydrate content
Measurement of protein content
Measurement of Lipopolysaccharide (LPS) content
FACE monosaccharide composition analysis of CP
Production of anti-CP polyclonal antibodies
SDS-PAGE gel electrophoresis of CP
Electroblotting, protein staining and eastern blot
Immunoelectron microscopy
Lectin-gold labeling of cells
Scanning Confocal Laser Microscopy (SCLM)
Results
Screening for CP production by Rv/25, Rv/37 and Stv
Adherence assay….
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Author: Eriksson de Rezende, Christian Luiz
Source: University of Maryland