Global analysis of the impact of linezolid onto virulence factor production in S. aureus USA300

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• 作者：Florian Bonn^a ; Jan Pané ; -Farré ; ^a ; Rabea Schlü ; ter^a ; Marc Schaffer^b ; Stephan Fuchs^a ; ¹ ; Jö ; rg Bernhardt^a ; Katharina Riedel^a ; Andreas Otto^a ; Uwe Vö ; lker^b ; Jan Maarten van Dijl^c ; Michael Hecker^a ; Ulrike M&auml ; der^b ; Dö ; rte Becher^a ; ^{dbecher@uni-greifswald.de" class="auth_mail" title="E-mail the corresponding author}
• 关键词：LZD ; linezolid ; GeLC-MS ; one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by liquid chromatography mass spectrometry ; EMF ; enriched membrane fraction ; TEAB ; triethylammonium bicarbonate buffer ; SEM ; scanning electron microscopy ; TEM ; transmission electron microscopy ; TBS ; tris-buffered saline ; Hi3 quantification ; absolute protein quantification by the average signal intensity of the three most intense peptides per protein compared to an internally digested stand
• 刊名：International Journal of Medical Microbiology
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：306
• 期：3
• 页码：131-140
• 全文大小：3322 K

文摘

The translation inhibitor linezolid is an antibiotic of last resort against Gram-positive pathogens including methicillin resistant strains of the nosocomial pathogen Staphylococcus aureus. Linezolid is reported to inhibit production of extracellular virulence factors, but the molecular cause is unknown. To elucidate the physiological response of S. aureus to linezolid in general and the inhibition of virulence factor synthesis in particular a holistic study was performed.

spar0010">Linezolid was added to exponentially growing S. aureus cells and the linezolid stress response was analyzed with transcriptomics and quantitative proteomics methods. In addition, scanning and transmission electron microscopy experiments as well as fluorescence microscopy analyses of the cellular DNA and membrane were performed.

spar0015">As previously observed in studies on other translation inhibitors, S. aureus adapts its protein biosynthesis machinery to the reduced translation efficiency. For example the synthesis of ribosomal proteins was induced. Also unexpected results like a decline in the amount of extracellular and membrane proteins were obtained. In addition, cell shape and size changed after linezolid stress and cell division was diminished. Finally, the chromosome was condensed after linezolid stress and lost contact to the membrane. These morphological changes cannot be explained by established theories. A new hypothesis is discussed, which suggests that the reduced amount of membrane and extracellular proteins and observed defects in cell division are due to the disintegration of transertion complexes by linezolid.