NUTRIENT SUBSTRATES USED BY BACTERIAL ISOLATES FROM THE POULTRY PROCESSING ENVIRONMENT

Authors: Boothe, Dorothy; Arnold, Judy

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2002
Publication Date: 9/11/2002
Citation: BOOTHE, D.D., ARNOLD, J.W. NUTRIENT SUBSTRATES USED BY BACTERIAL ISOLATES FROM THE POULTRY PROCESSING ENVIRONMENT. JOURNAL OF POULTRY SCIENCE. 2002.

Interpretive Summary: Bacteria causing human illness may grow on solid surfaces in communities called biofilms. To prevent biofilms from contaminating products, knowledge of the sources and characteristics of bacteria from these environments is needed. Bacteria were obtained from cut-up meat samples (breast with or without skin, wings, and thighs), either fresh or stored at two temperatures relevant to poultry processing. Profiles of the usage of 95 nutrients were determined for individual bacterial species having either a gram-positive or a gram-negative cell wall type. Utilization of specific nutrients was determined by the development of a purple color, resulting from a chemical change in an indicator dye, on experimental plates containing the test bacterium and nutrients. Of the 62 nutrients tested for use by both gram-positive and gram-negative bacteria, one-third were utilized by 50% or more of all bacterial isolates. One-fourth of the nutrients were also only used by a single isolate in the respective Gram type category. For the remaining nutrients tested for use only by gram-negative or by gram-positive bacteria, a higher percentage were used by gram-negative than by gram- positive isolates. The nutrient usage profiles of bacteria obtained from the poultry processing environment are a useful reference for selecting nutrients for the growth or control of these bacteria, especially those which may potentially cause human illness.

Technical Abstract: In order to successfully prevent pathogens found in biofilms in poultry processing facilities from contaminating products, knowledge of the sources and properties of the bacteria from these environments is needed. Bacteria were isolated from cut-up meat samples (breast with or without skin, wings, and thighs), either fresh or stored at 4C or 13C (temperatures relevant to poultry processing facilities). Profiles of the nutrient substrates utilized by individual bacterial species were determined using Biolog microtiter plates with different substrates in 95 wells of each plate. Pure cultures of bacterial isolates were inoculated onto either Gram positive (GP) or Gram negative (GN) Biolog plates, and transformation of specific substrates was determined by reduction (indicated by a purple color) of the tetrazolium violet included in each well. Of the 62 substrates common to GP and GN microtiter plates, one-third were utilized by 50% or more of all bacterial isolates. Similarly, approximately one-third of the substrates were used by gram-negative bacteria but not by gram-positive bacteria. One-fourth of the substrates were also only used by a single isolate in the respective Gram type category. For the remaining 33 substrates on each of the GP and GN plates, a higher percentage of substrates on GN than on GP plates were utilized by the respective isolates. These substrate utilization profiles of bacteria isolated from the poultry processing environment are a useful reference for selecting nutrients for the growth or control of these bacteria, especially pathogens.