AUTHOR=Kasthuri Thirupathi , Barath Sivaraj , Nandhakumar Muruganandam , Karutha Pandian Shunmugiah 

TITLE=Proteomic profiling spotlights the molecular targets and the impact of the natural antivirulent umbelliferone on stress response, virulence factors, and the quorum sensing network of Pseudomonas aeruginosa

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 12 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.998540

DOI=10.3389/fcimb.2022.998540

ISSN=2235-2988

ABSTRACT=Pseudomonas aeruginosa easily adapts to newer environments and acquires several genome flexibilities to overcome the effect of antibiotics during therapeutics, especially in cystic fibrosis patients. During adaptation to the host system, the bacteria employ various tactics including virulence factors production and biofilm formation for escaping the host immune system and resisting the antibiotics. Hence, identifying alternative strategies to combat recalcitrant pathogens is imperative for the successful elimination of drug-resistant microbes. In this context, this study portrays the anti-virulence efficacy of umbelliferone (UMB) against P. aeruginosa. Umbelliferone (7-hydroxy coumarin) is pervasively found among the plant family of Umbelliferae & Asteraceae. The UMB impeded biofilm formation in the P. aeruginosa reference strain and clinical isolates on polystyrene and glass surfaces at the concentration of 125 µg/ mL. Global proteomic analysis of UMB-treated cells revealed the downregulation of major virulence-associated proteins such as RhlR, LasA, AlgL, FliD, Tpx, HtpG, KatA, FusA1, Tsf, PhzM, PhzB2, CarB, DctP, MtnA & MscL. Functional interaction study, gene ontology & KEGG pathway analysis unveiled that UMB could modulate the global regulators, enzymes, co-factors, and transcription factors related to quorum sensing, stress tolerance, siderophore production, motility, and microcolony formation. In vitro biochemical assays further affirmed the anti-virulence efficacy of UMB by reducing the pyocyanin, protease, elastase, and catalase production in various strains of P. aeruginosa. Besides the antibiofilm activity, UMB-treated cells exhibited enhanced antibiotic susceptibility to various antibiotics including amikacin, kanamycin, tobramycin, ciprofloxacin and cefotaxime. Furthermore, ex vivo cytotoxicity analysis revealed the biocompatibility of UMB and the IC50 value was determined to be 249.85 µg/ mL on the HepG2 cell line. Altogether, the study substantiates the anti-virulence efficacy of UMB against P. aeruginosa and the proteomic analysis reveals the differential expression of the regulators related to the QS, stress response & motility factors.