Membranes of class IIa bacteriocin-resistant Listeria monocytogenes cells contain increased levels of desaturated and short-acyl-chain phosphatidylglycerols

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dc.contributor.authorVadyvaloo, Viveka
dc.contributor.authorHastings J.W.
dc.contributor.authorVan der Merwe M.J.
dc.contributor.authorRautenbach, Marina
dc.date.accessioned2011-05-15T15:56:33Z
dc.date.available2011-05-15T15:56:33Z
dc.date.issued2002
dc.description.abstractA major concern in the use of class IIa bacteriocins as food preservatives is the well-documented resistance development in target Listeria strains. We studied the relationship between leucocin A, a class IIa bacteriocin, and the composition of the major phospholipid, phosphatidylglycerol (PG), in membranes of both sensitive and resistant L. monocytogenes strains. Two wild-type strains, L. monocytogenes B73 and 412, two spontaneous mutants of L. monocytogenes B73 with intermediate resistance to leucocin A (±2.4 and ±4 times the 50% inhibitory concentrations [IC50] for sensitive strains), and two highly resistant mutants of each of the wild-type strains (<500 times the IC50 for sensitive strains) were analyzed. Electrospray mass spectrometry analysis showed an increase in the ratios of unsaturated to saturated and short- to long-acyl-chain species of PG in all the resistant L. monocytogenes strains in our study, although their sensitivities to leucocin A were significantly different. This alteration in membrane phospholipids toward PGs containing shorter, unsaturated acyl chains suggests that resistant strains have cells with a more fluid membrane. The presence of this phenomenon in a strain (L. monocytogenes 412P) which is resistant to both leucocin A and pediocin PA-1 may indicate a link between membrane composition and class IIa bacteriocin resistance in some L. monocytogenes strains. Treatment of strains with sterculic acid methyl ester (SME), a desaturase inhibitor, resulted in significant changes in the leucocin A sensitivity of the intermediate-resistance strains but no changes in the sensitivity of highly resistant strains. There was, however, a decrease in the amount of unsaturated and short-acyl-chain PGs after treatment with SME in one of the intermediate and both of the highly resistant strains, but the opposite effect was observed for the sensitive strains. It appears, therefore, that membrane adaptation may be part of a resistance mechanism but that several resistance mechanisms may contribute to a resistance phenotype and that levels of resistance vary according to the type of mechanisms present.
dc.description.versionArticle
dc.identifier.citationApplied and Environmental Microbiology
dc.identifier.citation68
dc.identifier.citation11
dc.identifier.issn992240
dc.identifier.urihttp://hdl.handle.net/10019.1/9913
dc.subjectBiological membranes
dc.subjectCells
dc.subjectEsters
dc.subjectFatty acids
dc.subjectMass spectrometry
dc.subjectMutagenesis
dc.subjectPhospholipids
dc.subjectWild type strains
dc.subjectBacteria
dc.subjectacyl coenzyme A desaturase
dc.subjectbacteriocin
dc.subjectfatty acid derivative
dc.subjectfood preservative
dc.subjectleucocin a
dc.subjectmembrane phospholipid
dc.subjectpediocin
dc.subjectpediocin pa 1
dc.subjectphosphatidylglycerol
dc.subjectsterculic acid methyl ester
dc.subjectunclassified drug
dc.subjectmicrobiology
dc.subjectadaptation
dc.subjectantibacterial activity
dc.subjectantibiotic resistance
dc.subjectarticle
dc.subjectbacterial membrane
dc.subjectcontrolled study
dc.subjectfatty acid desaturation
dc.subjectfood preservation
dc.subjectlipid composition
dc.subjectListeria monocytogenes
dc.subjectmass spectrometry
dc.subjectnonhuman
dc.subjectBacteriocins
dc.subjectCell Membrane
dc.subjectDrug Resistance, Bacterial
dc.subjectFatty Acids, Monounsaturated
dc.subjectInhibitory Concentration 50
dc.subjectListeria monocytogenes
dc.subjectMicrobial Sensitivity Tests
dc.subjectPhosphatidylglycerols
dc.subjectPhospholipids
dc.subjectSpectrometry, Mass, Electrospray Ionization
dc.subjectBacteria (microorganisms)
dc.subjectListeria
dc.subjectListeria monocytogenes
dc.subjectPosibacteria
dc.titleMembranes of class IIa bacteriocin-resistant Listeria monocytogenes cells contain increased levels of desaturated and short-acyl-chain phosphatidylglycerols
dc.typeArticle
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