Novel antimicrobial peptides showed promising activity against multidrug resistant Salmonella enterica serovar Choleraesuis and its stress response mechanism revealed.
J Appl Microbiol. 2016 Jun 9;
Authors: Tsai WC, Zhuang ZJ, Lin CY, Chen WJ
AIMS: To evaluate the antibacterial efficacy of novel antimicrobial peptides (AMPs) against multidrug-resistant (MDR) Salmonella enterica serovar Choleraesuis (S. Choleraesuis) and to delineate the AMP-responsive mechanisms of wild-type (WT) and MDR strains.
METHODS AND RESULTS: We performed proteomic approaches based on two-dimensional gel electrophoresis (2-DE) and liquid chromatography-electrospray ionization-quadrupole- time-of-flight tandem mass spectrometry (LC-ESI-Q-TOF MS/MS) to analyze the protein profiles of these two strains upon exposure to AMP GW-Q6. Quantitative real-time PCR was conducted to determine the mRNA expression level of the target genes. Furthermore, lipopolysaccharide (LPS) competition analysis was applied to verify whether LPS may serve as the potential binding target when AMP approach and adhere to the bacterial surface.
CONCLUSIONS: The minimal inhibitory concentration (MIC) assay revealed that our AMPs are even more effective against the MDR strains (4-32 μg/mL), as compared to those for WT (8-64 μg/mL). LPS dose-dependently suppresses GW-Q6 antimicrobial activity. Clusters of orthologous groups (COGs) analysis showed that the majority of the AMP-responsive proteins were involved in cell envelope biogenesis and outer membrane, translation and chaperones.
SIGNIFICANCE AND IMPACT OF STUDY: These results indicated that the novel AMP GW-Q6 serves as a potential candidate for antimicrobial drug development against MDR strains. These findings will also be helpful for expanding our knowledge on the molecular mechanisms of AMP-microbe interaction and pathogenicity of salmonellosis caused by MDR strains of S. Choleraesuis. This article is protected by copyright. All rights reserved.
PMID: 27280957 [PubMed - as supplied by publisher]