Antibiotic treatment modulates protein components of cytotoxic outer membrane vesicles of multidrug-resistant clinical strain, Acinetobacter baumannii DU202

Abstract

BackgroundOuter membrane vesicles (OMVs) of Acinetobacter baumannii are cytotoxic and elicit a potent innate immune response. OMVs were first identified in A. baumannii DU202, an extensively drug-resistant clinical strain. Herein, we investigated protein components of A. baumannii DU202 OMVs following antibiotic treatment by proteogenomic analysis.MethodsPurified OMVs from A. baumannii DU202 grown in different antibiotic culture conditions were screened for pathogenic and immunogenic effects, and subjected to quantitative proteomic analysis by one-dimensional electrophoresis and liquid chromatography combined with tandem mass spectrometry (1DE-LC-MS/MS). Protein components modulated by imipenem were identified and discussed.ResultsOMV secretion was increased > twofold following imipenem treatment, and cytotoxicity toward A549 human lung carcinoma cells was elevated. A total of 277 proteins were identified as components of OMVs by imipenem treatment, among which β-lactamase OXA-23, various proteases, outer membrane proteins, β-barrel assembly machine proteins, peptidyl-prolyl cis–trans isomerases and inherent prophage head subunit proteins were significantly upregulated.ConclusionIn vitro stress such as antibiotic treatment can modulate proteome components in A. baumannii OMVs and thereby influence pathogenicity.Electronic supplementary materialThe online version of this article (10.1186/s12014-018-9204-2) contains supplementary material, which is available to authorized users.

Integrative analysis of outer membrane vesicles proteomics and whole-cell transcriptome analysis of eravacycline induced Acinetobacter baumannii strains

“…The low correlation of the mRNA and protein components based on the log 2 -fold change comparison suggests that proteins in OMVs are selectively enriched, transported from the bacterial cell and/or due to wide range of regulatory mechanisms involved in the posttranscriptional level [66]. A poor correlation of similar comparison was reported by Yun et al (2018) in their study of proteins in OMVs and protein fractions from bacterial cell membranes. They have mentioned the reason to be that proteins in the OMVs are differentially selected and sorted from the host bacteria.…”

The Cytotoxicity Effects of Outer Membrane Vesicles Isolated From Hospital and Laboratory Strains of Pseudomonas Aeruginosa on Human Keratinocyte Cell Line

“…Other studies tested polymyxin and hydrogen peroxide as stress molecules resulting in similar increase in OMV release, which indicate that weakening the integrity of the bacterial cell wall stimulates OMV production. In contrast, tetracycline, a protein synthesis inhibitor targeting ribosome, had no effect on OMV production (MacDonald & Kuehn, 2013;Yahya, Alhawari, Amhimmid, AbuAeshah, & Saada, 2018;Yun et al, 2018). Viable bacterial count (VBC) was slightly different among the two strains and this might be due to the difference in OMV production.…”

Toll-Like Receptors 2 and 4 Modulate Pulmonary Inflammation and Host Factors Mediated by Outer Membrane Vesicles Derived from Acinetobacter baumannii

“…Moreover, antibiotic treatments can result in OMV secretion and modulate OMV protein components. Additional research is needed to determine the implications of these OMVs in clinical infection (41).…”