In vitro and in vivo efficacy of rosmarinic acid on quorum sensing mediated biofilm formation and virulence factor production inAeromonas hydrophila

Abstract

Rosmarinic acid (RA) was assessed for its quorum sensing inhibitory (QSI) potential against Aeromonas hydrophila strains AH 1, AH 12 and MTCC 1739. The pathogenic strains of A. hydrophila were isolated from infected zebrafish and identified through biochemical analysis and amplification of a species-specific gene (rpsL). The biofilm inhibitory concentration (BIC) of RA against A. hydrophila strains was found to be 750 μg ml. At this concentration, RA reduced the QS mediated hemolysin, lipase and elastase production in A. hydrophila. In FT-IR analysis, RA treated A. hydrophila cells showed a reduction in cellular components. Gene expression analysis confirmed the down-regulation of virulence genes such as ahh1, aerA, lip and ahyB. A. hydrophila infected zebrafish upon treatment with RA showed increased survival rates. Thus, the present study demonstrates the use of RA as a plausible phytotherapeutic compound to control QS mediated biofilm formation and virulence factor production in A. hydrophila.

Niclosamide Blocks Rice Leaf Blight by Inhibiting Biofilm Formation of Xanthomonas oryzae

“…The cell pellets were freeze-dried for 16 h under vacuum (Sentry 2.0, SP Scientific, United States). The disks for FTIR analysis were prepared by pressing a mixture of 1 mg freeze-dried bacterial powder along with 100 mg of potassium bromide (KBr) powder in a hydraulic press ( Rama Devi et al, 2016 ). The FT-IR spectra of niclosamide treated and untreated samples were recorded at the range of 4,000–400 cm -1 using Nicolet 6700 Thermo Scientific spectrophotometer, and the variations in the components of cell membrane were determined using OMNIC software 8.2 (Thermo Fisher Scientific Inc.) were analyzed by subtracting the spectrum of pure KBr.…”

Indigenous AHL‐degrading bacteriumBacillus firmussw40 affects virulence of pathogenicAeromonas hydrophilaand disease resistance of gibel carp

“…In Gram‐negative bacteria, AHLs are the common quorum sensing signalling molecules, which regulate diverse biological functions including the release of virulence factors and biofilm formation of pathogens (Khajanchi et al, ; Ponnusamy, Paul, & Kweon, ; Rama Devi et al, ; Swift et al, ; Zhang, Cao, Yao, Bai, & Zhou, ; Zhao, Chen, Quan, & Fan, ). Degradation of AHLs has been proven as an efficient approach to control bacterial infections and identified in many species of Bacillus , like Bacillus subtilis , Bacillus cereus and Bacillus thuringiensis (Torabi Delshad, Soltanian, Sharifiyazdi, & Bossier, ).…”

"Jack of all trades" spotted in the Clinical Centre of Vojvodina - first detection of Aeromonas hydrophila from urinary tract infection samples

“…Regarding the wide presence and pathogenicity of Aeromonas spp. strains, extensive and protracted use of antibiotics in treatment and prevention finally resulted in evolution of antimicrobial resistant strains, mainly in aquatic microbial pathogen group [2,5,10,11]. Furthermore, Daood [12] reported a possible link between rising antibiotic resistance of aquatic strains and decreasing effect of antimicrobials in patients with Aeromonas hydrophila infections.…”

“…The tested substance showed larger inhibition zone compared to chloramphenicol (23.2 mm vs. 17.3 mm), as well as impressive biofilm inhibition activity against Aeromonas hydrophila [11]. Considering the treatment of aquatic organisms, as well as human patients, Rama Devi et al [10] conducted an experiment with approach to target the quorum sensing system of Aeromonas hydrophila by introducing rosmarinic acid. They reported effect that includes significant inhibition of biofilm formation and production of virulence factors in three Aeromonas hydrophila isolates (AH 1, AH 12, and MTCC 1739) [10].…”

“…Considering the treatment of aquatic organisms, as well as human patients, Rama Devi et al [10] conducted an experiment with approach to target the quorum sensing system of Aeromonas hydrophila by introducing rosmarinic acid. They reported effect that includes significant inhibition of biofilm formation and production of virulence factors in three Aeromonas hydrophila isolates (AH 1, AH 12, and MTCC 1739) [10]. Stanković et al [15] introduced millipede Pachyiuli hungaricus defensive secretion compounds as potential antimicrobial agents.…”