title: A novel gene, lstC, of Listeria monocytogenes is implicated in high salt tolerance.
abstract: Listeria monocytogenes, causative agent of human listeriosis, has been isolated from a wide variety of foods including deli meats, soft cheeses, cantaloupes, sprouts and canned mushrooms. Standard control measures for restricting microbial growth such as refrigeration and high salt are often inadequate as L. monocytogenes grows quite well in these environments. In an effort to better understand the genetic and physiological basis by which L. monocytogenes circumvents these controls, a transposon library of L. monocytogenes was screened for changes in their ability to grow in 7% NaCl and/ or at 5 °C. This work identified a transposon insertion upstream of an operon, here named lstABC, that led to a reduction in growth in 7% NaCl. In-frame deletion studies identified lstC which codes for a GNAT-acetyltransferase being responsible for the phenotype. Transcriptomic and RT-PCR analyses identified nine genes that were upregulated in the presence of high salt in the ΔlstC mutant. Further analysis of lstC and the genes affected by ΔlstC is needed to understand LstC's role in salt tolerance.
authors: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA.
authors: Laurel S
authors: LS
authors: Burall
authors: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA.
authors: Alexandra C
authors: AC
authors: Simpson
authors: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA.
authors: Luoth
authors: L
authors: Chou
authors: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA.
authors: Pongpan
authors: P
authors: Laksanalamai
authors: Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD 20708, USA. Electronic address: atin.datta@fda.hhs.gov.
authors: Atin R
authors: AR
authors: Datta
mesh_terms: D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008089:Listeria monocytogenes / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D009876:Operon; D017434:Protein Structure, Tertiary; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012965:Sodium Chloride; D000123:Acetyltransferases
keywords: Food preservation; Listeria monocytogenes; Salt growth; Stress adaptation