In vitro and in vivo exploration of palmitic acid from Synechococcus elongatus as an antibiofilm agent on the survival of Artemia franciscana against virulent vibrios

• Published in: Journal of invertebrate pathology 2017-11, Vol.150, p.21-31
• Main Authors: Santhakumari, Sivasubramanian, Nilofernisha, Nizam Mohamed, Ponraj, Jeyaraj Godfred, Pandian, Shunmugiah Karutha, Ravi, Arumugam Veera
• Format: Article
• Language: English
• Subjects: Animals; Aquaculture; Artemia - microbiology; Biofilm; Biofilms - drug effects; Brine shrimp; Palmitic acid; Palmitic Acid - pharmacology; Palmitic Acid - therapeutic use; Quorum sensing; Synechococcus; Synechococcus elongatus; Vibrio - drug effects; Vibrio Infections - drug therapy; Vibrio Infections - veterinary; Vibriosis
• ISSN: 0022-2011; 1096-0805
• DOI: 10.1016/j.jip.2017.09.001

[Display omitted] •Palmitic acid (PA) effectively promotes the loosening of biofilm architecture of vibrios.•Anti-biofilm potential of PA can be related to Quorum Sensing interruption.•PA enhanced the survival rate of vibrios challenged Artemia franciscana larvae.•PA could be exploited as anti-biofilm agent against seafood borne pathogens in aquaculture. Biofilm formation of Vibrio spp. has been demonstrated as a potentially important mechanism contributing antibiotic treatment failure in aquaculture. In the present study, the effect of palmitic acid (PA) identified from Synechococcus elongatus was assessed for the inhibition of quorum sensing (QS) regulated biofilm formation in aquatic bacterial pathogens. The biofilm inhibitory concentration (BIC) of PA against Vibrio spp. was found to be 100µgml−1. In this concentration, PA exhibited a significant inhibition in biofilm biomass of Vibrio harveyi MTCC 3438, V. parahaemolyticus ATCC 17802, V. vulnificus MTCC 1145 and V. alginolyticus ATCC 17749 without hindering their planktonic growth. Also, PA displayed gradual decrease in bioluminescence production of V. harveyi. The results of extracellular polymeric substances quantification, microbial adhesion to hydrocarbons and Fourier transform infrared spectroscopic (FT-IR) analyses suggested that PA positively interferes with the initial adhesion stages of biofilm formation. In addition, confocal and scanning electron microscopic analysis substantiates the antibiofilm efficacy of the PA. The transcriptomic analysis revealed the down-regulation of QS mediated response regulator genes expression in V. harveyi. Concomitantly, PA reduced the intestinal colonization of vibrios in brine shrimp larvae and thereby attenuates the biofilm assemblage and its associated virulence. In vivo studies using brine shrimp larvae manifested the reduction in adherence and virulence, which prompts further investigation about the potential of PA for the treatment of vibriosis.