Novel antimicrobial peptides with promising activity against multidrug resistant Salmonella enterica serovar Choleraesuis and its stress response mechanism.
OBJECTIVE
To evaluate the antibacterial efficacy of novel antimicrobial peptides (AMPs) against multidrug-resistant (MDR) Salmonella enterica serovar Choleraesuis (Salm. Choleraesuis) and to delineate the AMP-responsive mechanisms of wild-type (WT) and MDR strains.


RESULTS
Proteomic approaches were performed based on two-dimensional gel electrophoresis and liquid chromatography-electrospray ionization-quadrupole- time-of-flight tandem mass spectrometry to analyse 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 used 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 assay revealed that our AMPs were even more effective against the MDR strains (4-32 μg ml(-1) ), compared with those for the WT (8-64 μg ml(-1) ). LPS dose-dependently suppressed the GW-Q6 antimicrobial activity. Clusters of orthologous groups analysis showed that the majority of the AMP-responsive proteins were involved in cell envelope biogenesis and outer membrane, translation and chaperones.


CONCLUSIONS
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 the pathogenicity of salmonellosis caused by MDR strains of Salm. Choleraesuis.
Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan.
W-C
WC
Tsai
Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan.
Z-J
ZJ
Zhuang
School of Medical Laboratory Science and Biotechnology, Taipei Medical University, Taipei, Taiwan.
C-Y
CY
Lin
Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan. wjchen@niu.edu.tw.
W-J
WJ
Chen
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis; D024901:Drug Resistance, Multiple, Bacterial; D015180:Electrophoresis, Gel, Two-Dimensional; D008826:Microbial Sensitivity Tests; D040901:Proteomics; D060888:Real-Time Polymerase Chain Reaction; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D065288:Serogroup
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins
Salmonella enterica serovar Choleraesuis (Salm. Choleraesuis); antimicrobial peptides; multidrug resistance; proteomics; stress response mechanism