In vitro resistance of Staphylococcus aureus to thrombin-induced platelet microbicidal protein is associated with alterations in cytoplasmic membrane fluidity
| Autor: | Jyotsna Chandra, Nevillem Firth, Archana Varma, S.-P. Koo, Rajendra Prasad, Ronald A. Skurray, M. Smriti, Arnold S. Bayer, Michael R. Yeaman, Melissa H. Brown, Anjni Koul |
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| Rok vydání: | 2000 |
| Předmět: |
Staphylococcus aureus
Membrane Fluidity Membrane lipids Immunology Biology medicine.disease_cause Microbiology Cell membrane Plasmid Species Specificity Serial passage Membrane fluidity medicine Amino Acids Phospholipids Cell Membrane Fatty Acids Biological Transport Drug Resistance Microbial Blood Proteins beta-Thromboglobulin In vitro Anti-Bacterial Agents Mutagenesis Insertional Infectious Diseases medicine.anatomical_structure Phenotype DNA Transposable Elements Molecular and Cellular Pathogenesis Parasitology Transposon mutagenesis Chemokines |
| Zdroj: | Infection and immunity. 68(6) |
| ISSN: | 0019-9567 |
| Popis: | Platelet microbicidal proteins (PMPs) are small, cationic peptides which possess potent microbicidal activities against common bloodstream pathogens, such as Staphylococcus aureus . We previously showed that S. aureus strains exhibiting resistance to thrombin-induced PMP (tPMP-1) in vitro have an enhanced capacity to cause human and experimental endocarditis (T. Wu, M. R. Yeaman, and A. S. Bayer, Antimicrob. Agents Chemother. 38:729–732, 1994; A. S. Bayer et al., Antimicrob. Agents Chemother. 42:3169–3172, 1998; V. K. Dhawan et al., Infect. Immun. 65:3293–3299, 1997). However, the mechanisms mediating tPMP-1 resistance in S. aureus are not fully delineated. The S. aureus cell membrane appears to be a principal target for the action of tPMP-1. To gain insight into the basis of tPMP-1 resistance, we compared several parameters of membrane structure and function in three tPMP-1-resistant (tPMP-1 r ) strains and their genetically related, tPMP-1-susceptible (tPMP-1 s ) counterpart strains. The tPMP-1 r strains were derived by three distinct methods: transposon mutagenesis, serial passage in the presence of tPMP-1 in vitro, or carriage of a naturally occurring multiresistance plasmid (pSK1). All tPMP-1 r strains were found to possess elevated levels of longer-chain, unsaturated membrane lipids, in comparison to their tPMP-1 s counterparts. This was reflected in corresponding differences in cell membrane fluidity in the strain pairs, with tPMP-1 r strains exhibiting significantly higher degrees of fluidity as assessed by fluorescence polarization. These data provide further support for the concept that specific alterations in the cytoplasmic membrane of S. aureus strains are associated with tPMP-1 resistance in vitro. |
| Databáze: | OpenAIRE |
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