Nonhemolytic Listeria monocytogenes mutants that are also noninvasive for mammalian cells in culture: evidence for coordinate regulation of virulence.
We identified nonhemolytic mutants of Listeria monocytogenes that were severely deficient in their ability to invade mammalian nonprofessional phagocytes. These mutants were generated spontaneously or by means of transposon Tn916 mutagenesis. In terms of their extracellular proteins, the noninvasive mutants were deficient not only in the sulfhydryl-activated hemolysin (listeriolysin) but also in an antigenically unrelated extracellular protein with an apparent molecular weight of 32,000 which could induce opacity in egg yolk and is considered to be a phospholipase. Our results suggest the existence of a common genetic control between the expression of listeriolysin and that of other determinants, including a phospholipase and determinants involved in the ability of L. monocytogenes to enter mammalian cells.
Kathariou
S
S
Division of Bacterial Diseases, Center for Infectious Diseases, Centers for Disease Control, Atlanta, Georgia 30333.
Pine
L
L
George
V
V
Carlone
G M
GM
Holloway
B P
BP
D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics; D006460:Hemolysin Proteins; D006461:Hemolysis; D008089:Listeria monocytogenes / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D051379:Mice; D008813:Mice, Inbred ICR; D009154:Mutation; D010740:Phospholipases / Q000502:physiology; D014774:Virulence
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D010740:Phospholipases; C038705:hlyA protein, Listeria monocytogenes