TY - JOUR
T1 - Comparative Analysis of Listeria monocytogenes Plasmids and Expression Levels of Plasmid-Encoded Genes during Growth under Salt and Acid Stress Condition
AU - Hingston, Patricia
AU - Brenner, Thomas
AU - Hansen, Lisbeth Truelstrup
AU - Wang, Siyun
PY - 2019
Y1 - 2019
N2 - Listeria monocytogenes strains are known to harbour plasmids that confer resistance to sanitizers, heavy metals, and antibiotics; however, very little research has been conducted into how plasmids may influence L. monocytogenes’ ability to tolerate food-related stresses. To investigate this, a library (n = 93) of L. monocytogenes plasmid sequences were compared. Plasmid sequences were divided into two groups (G1 and G2) based on a repA phylogeny. Twenty-six unique plasmid types were observed, with 13 belonging to each of the two repA-based groups. G1 plasmids were significantly (p < 0.05) smaller than G2 plasmids but contained a larger diversity of genes. The most prevalent G1 plasmid (57,083 bp) was observed in 26 strains from both Switzerland and Canada and a variety of serotypes. Quantitative PCR (qPCR) revealed a >2-fold induction of plasmid-contained genes encoding an NADH peroxidase, cadmium ATPase, multicopper oxidase, and a ClpL chaperone protein during growth under salt (6% NaCl) and acid conditions (pH 5) and ProW, an osmolyte transporter, under salt stress conditions. No differences in salt and acid tolerance were observed between plasmid-cured and wildtype strains. This work highlights the abundance of specific plasmid types among food-related L. monocytogenes strains, the unique characteristics of G1 and G2 plasmids, and the possible contributions of plasmids to L. monocytogenes tolerance to food-related stresses
AB - Listeria monocytogenes strains are known to harbour plasmids that confer resistance to sanitizers, heavy metals, and antibiotics; however, very little research has been conducted into how plasmids may influence L. monocytogenes’ ability to tolerate food-related stresses. To investigate this, a library (n = 93) of L. monocytogenes plasmid sequences were compared. Plasmid sequences were divided into two groups (G1 and G2) based on a repA phylogeny. Twenty-six unique plasmid types were observed, with 13 belonging to each of the two repA-based groups. G1 plasmids were significantly (p < 0.05) smaller than G2 plasmids but contained a larger diversity of genes. The most prevalent G1 plasmid (57,083 bp) was observed in 26 strains from both Switzerland and Canada and a variety of serotypes. Quantitative PCR (qPCR) revealed a >2-fold induction of plasmid-contained genes encoding an NADH peroxidase, cadmium ATPase, multicopper oxidase, and a ClpL chaperone protein during growth under salt (6% NaCl) and acid conditions (pH 5) and ProW, an osmolyte transporter, under salt stress conditions. No differences in salt and acid tolerance were observed between plasmid-cured and wildtype strains. This work highlights the abundance of specific plasmid types among food-related L. monocytogenes strains, the unique characteristics of G1 and G2 plasmids, and the possible contributions of plasmids to L. monocytogenes tolerance to food-related stresses
U2 - 10.3390/toxins11070426
DO - 10.3390/toxins11070426
M3 - Journal article
C2 - 31330827
VL - 11
JO - Toxins
JF - Toxins
SN - 2072-6651
IS - 7
M1 - 426
ER -