If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Sodium Chloride Enhances Adherence and Aggregation and Strain Variation Influences Invasiveness of Listeria monocytogenes Strains

$37.00 plus tax (Refund Policy)

Buy Article:

Abstract:

Some subtypes of Listeria monocytogenes can persist in the food-processing industry, but the reasons for such persistence are not known. In the present study, 10 strains of L. monocytogenes representing known persistent randomly amplified polymorphic DNA (RAPD) types from fish processing plants were compared to eight strains of different RAPD type and origin (clinical, food, and animal). All 18 strains of L. monocytogenes had similar growth patterns at different temperatures (5 or 37°C) or different salinities (0.5 or 5% NaCl), and all strains formed a thin layer of adhered cells on a plastic surface when cultured in tryptone soya broth (TSB) with a total of 1% glucose. Many ready-to-eat foods, such as cold-smoked fish, contain NaCl at concentrations of 2 to 5%, and NaCl is present in the processing environment. Adding NaCl to TSB changed the adhesion patterns of all strains, and all adhered better when NaCl was added. Also, the addition of NaCl caused a marked aggregation of 13 of the strains; however, 5 of the 18 strains did not aggregate in the presence of up to 5% NaCl. The aggregates stuck to the plastic surface, and this occurred in all but one of the persistent RAPD types. Four strains represented one particular RAPD type that has been isolated as a persistent RAPD type in several fish processing plants for up to 10 years. Because this RAPD type often can contaminate fish products, it is important to address its potential virulence. The 18 strains differed markedly in their ability to invade Caco-2 cells, and the four strains representing the universal persistent RAPD type were the least invasive (102 to 103 CFU/ml), whereas other strains invaded Caco-2 cells at levels of 104 to 105 CFU/ml. Five of the 18 strains belonged to the genetic lineage 1 and were the most invasive. Although the most commonly isolated persistent RAPD type was low invasive, it is important to understand why moderate salinity facilitates aggregation and biofilm formation, for this understanding can be beneficial in developing procedures to reduce processing plant contamination.

Document Type: Research Article

Affiliations: 1: Danish Institute for Fisheries Research, Department of Seafood Research, Søltofts Plads, DTU bldg. 221, DK-2800 Kgs. Lyngby, Denmark 2: Department of Veterinary Pathobiology, The Royal Veterinary and Agricultural University, Stigbøjlen 8, DK-1870 Frederiksberg C, Denmark

Publication date: March 1, 2007

More about this publication?
  • IAFP members must first sign in on the right to access full text articles of JFP

    First published in 1937, the Journal of Food Protection®, is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection® is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.

    Print and online subscriptions are available to Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: info@foodprotection.org or Web site: www.foodprotection.org
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Membership Information
  • Information for Advertisers
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more