Open AccessSodium chloride‐induced filamentation and alternative gene expression of fts , murZ, and gnd in L isteria monocytogenes 08‐5923 on vacuum‐packaged ham
Author(s) -
Liu Xiaoji,
Miller Petr,
Basu Urmila,
McMullen Lynn M.
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12599
Subject(s) - listeria monocytogenes , filamentation , flow cytometry , food science , protein filament , gene , gene expression , microbiology and biotechnology , biology , chemistry , bacteria , biochemistry , genetics , physics , optics , laser
The aim of this study was to examine the filament formation and differential gene expression of L isteria monocytogenes 08‐5923 grown on refrigerated vacuum‐packaged ham products with various NaCl concentrations. Filament formation of L . monocytogenes was observed on ham products with 1.35% and 2.35% NaCl, which was monitored using flow cytometry by measuring forward light scatter. Quantitative real‐time PCR was used to study the differential expression of genes in filamented cells of L . monocytogenes grown on hams following 2 or 3 months of storage at 4 °C. The genes involved in cell division ( ftsX / lmo2506 ), cell wall synthesis ( murZ / lmo2552 ), and NADPH production ( gnd / lmo1376 ) were significantly downregulated in filamented cells of L . monocytogenes grown on ham with 2.35% NaCl stored at 4 °C. To our knowledge, this study reports the first evidence of filament formation of L isteria grown on meat products, which could impact the food safety risk and tolerance levels of L . monocytogenes set by regulatory agencies.