Affiliation:
1. Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305
2. Departments of Microbiology and Medicine, University of Washington, Seattle, Washington 98195
Abstract
ABSTRACT
It was previously demonstrated that the
mig
-
14
gene of
Salmonella enterica
serovar Typhimurium is necessary for bacterial proliferation in the liver and spleen of mice following intragastric inoculation and that
mig
-
14
expression, which is induced within macrophages, is under the control of the global regulator PhoP. Here we demonstrate that the
mig
-
14
promoter is induced by growth in minimal medium containing low magnesium or acidic pH, consistent with regulation by PhoP. In addition,
mig
-
14
is strongly induced by polymyxin B, protamine, and the mammalian antimicrobial peptide protegrin-1. While
phoP
is necessary for the induction of
mig
-
14
in response to protamine and protegrin,
mig
-
14
is still induced by polymyxin B in a
phoP
background. We also demonstrate that
mig
-
14
is necessary for resistance of
S. enterica
serovar Typhimurium to both polymyxin B and protegrin-1. Gram-negative resistance to a variety of antimicrobial peptides has been correlated with modifications of lipopolysaccharide structure. However, we show that
mig
-
14
is not required for one of these modifications, the addition of 4-aminoarabinose to lipid A. Additionally, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of wild-type and
mig
-
14
lipopolysaccharide also shows no detectable differences between the two strains. Therefore,
mig
-
14
contributes to
Salmonella
resistance to antimicrobial peptides by a mechanism that is not yet fully understood.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
70 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献