title: Differences in susceptibility of Listeria monocytogenes strains to sakacin P, sakacin A, pediocin PA-1, and nisin.
abstract: Two hundred strains of Listeria monocytogenes collected from food and the food industry were analyzed for susceptibility to the class IIa bacteriocins sakacin P, sakacin A, and pediocin PA-1 and the class I bacteriocin nisin. The individual 50% inhibitory concentrations (IC(50)) were determined in a microtiter assay and expressed in nanograms per milliliter. The IC(50) of sakacin P ranged from 0.01 to 0.61 ng ml(-1). The corresponding values for pediocin PA-1, sakacin A, and nisin were 0.10 to 7.34, 0.16 to 44.2, and 2.2 to 781 ng ml(-1), respectively. The use of a large number of strains and the accuracy of the IC(50) determination revealed patterns not previously described, and for the first time it was shown that the IC(50) of sakacin P divided the L. monocytogenes strains into two distinct groups. Ten strains from each group were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins and amplified fragment length polymorphism. The results from these studies essentially confirmed the grouping based on the IC(50) of sakacin P. A high correlation was found between the IC(50) of sakacin P and that of pediocin PA-1 for the 200 strains. Surprisingly, the correlation between the IC(50) of the two class IIa bacteriocins sakacin A and sakacin P was lower than the correlation between the IC(50) of sakacin A and the class I bacteriocin nisin.
authors.affiliation: Matforsk, Norwegian Food Research Institute, N-1430 s., Norway.
authors.forename: T
authors.initials: T
authors.lastname: Katla
authors.forename: K
authors.initials: K
authors.lastname: Naterstad
authors.forename: M
authors.initials: M
authors.lastname: Vancanneyt
authors.forename: J
authors.initials: J
authors.lastname: Swings
authors.forename: L
authors.initials: L
authors.lastname: Axelsson
mesh_terms: D001430:Bacteriocins / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects*; D009561:Nisin / Q000494:pharmacology*; D000070017:Pediocins
chemical_list: D001430:Bacteriocins; D000070017:Pediocins; C071456:sakacin A; C074288:pediocin PA-1; D009561:Nisin; C087217:sakacin P protein, Lactobacillus