TY - JOUR
T1 - Influence of lipopolysaccharide outer-core in the intrinsic resistance to antimicrobial peptides and virulence in Edwardsiella ictaluri
AU - Martin, Taylor
AU - Diaz, Ignacia
AU - Kilbourne, Jacquelyn
AU - Almarza, Oscar
AU - Segovia, Cristopher
AU - Curtiss, Roy
AU - Santander, Javier
N1 - Funding Information:
This work was supported by USDA grant CRIS-ARZR-2009-01801 , SoLARA Fellowship (School of Life Sciences, Arizona State University) , Comisión Nacional de Investigación Científica y Tecnológica , Gestión Propia Fellowship 12864830-5 , grant FONDECY Regular competition 1140330 , grant FIC BIP30170275-0 , Chile and grant COPEC-UC 2014.J0.71 . We thank to Erika Arch, Paul Hartig, Tina Hartig (Arizona State University) and Francisca Rodriguez (Universidad Mayor) for their logistic support.
Publisher Copyright:
© 2016 Elsevier Ltd.
PY - 2016/4/1
Y1 - 2016/4/1
N2 - The genus Edwardsiella consists of bacteria with an intrinsic resistance to cyclic cationic antimicrobial peptides (CAMPs). Edwardsiella ictaluri, a pathogen of the catfish (Ictalurus punctatus) and the causative agent of a systemic infection, is highly resistant to CAMPs. Previously, we determined that the oligo-polysaccharide (O-PS) of the lipopolysaccharide (LPS) does not play a role in the E. ictaluri CAMP resistance and an intact core-lipid A structure is necessary for CAMPs resistance. Here, we evaluated the influence of the outer-core in the CAMPs resistance and fish virulence. E. ictaluri wabG, a gene that encodes for the UDP-glucuronic acid transferase that links the lipid A-inner-core to the outer-core-oligopolysaccharides, was deleted. Deletion of δwabG caused a pleiotropic effect, influencing LPS synthesis, CAMPs resistance, growth, and biofilm formation. E. ictaluri δwabG was attenuated in zebrafish indicating the important role of LPS during fish pathogenesis. Also, we evaluated the inflammatory effects of wabG LPS in catfish ligated loop model, showing a decreased inflammatory effect at the gut level respects to the E. ictaluri wild type. We conclude that E. ictaluri CAMPs resistance is related to the molecules present in the LPS outer-core and that fish gut inflammation triggered by E. ictaluri is LPS dependent, reinforcing the hypothesis that fish gut recognizes LPS in an O-PS dependent fashion.
AB - The genus Edwardsiella consists of bacteria with an intrinsic resistance to cyclic cationic antimicrobial peptides (CAMPs). Edwardsiella ictaluri, a pathogen of the catfish (Ictalurus punctatus) and the causative agent of a systemic infection, is highly resistant to CAMPs. Previously, we determined that the oligo-polysaccharide (O-PS) of the lipopolysaccharide (LPS) does not play a role in the E. ictaluri CAMP resistance and an intact core-lipid A structure is necessary for CAMPs resistance. Here, we evaluated the influence of the outer-core in the CAMPs resistance and fish virulence. E. ictaluri wabG, a gene that encodes for the UDP-glucuronic acid transferase that links the lipid A-inner-core to the outer-core-oligopolysaccharides, was deleted. Deletion of δwabG caused a pleiotropic effect, influencing LPS synthesis, CAMPs resistance, growth, and biofilm formation. E. ictaluri δwabG was attenuated in zebrafish indicating the important role of LPS during fish pathogenesis. Also, we evaluated the inflammatory effects of wabG LPS in catfish ligated loop model, showing a decreased inflammatory effect at the gut level respects to the E. ictaluri wild type. We conclude that E. ictaluri CAMPs resistance is related to the molecules present in the LPS outer-core and that fish gut inflammation triggered by E. ictaluri is LPS dependent, reinforcing the hypothesis that fish gut recognizes LPS in an O-PS dependent fashion.
KW - Edwardsiella
KW - Fish virulence
KW - Glucuronic acid transferase
KW - O-polysaccharide
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U2 - 10.1016/j.micpath.2016.02.020
DO - 10.1016/j.micpath.2016.02.020
M3 - Article
AN - SCOPUS:84960107985
SN - 0882-4010
VL - 93
SP - 204
EP - 212
JO - Microbial Pathogenesis
JF - Microbial Pathogenesis
ER -