Synergistic Inhibitory Effect of Polymyxin B in Combination with Ceftazidime against Robust Biofilm Formed by Acinetobacter baumannii with Genetic Deficiency in AbaI/AbaR Quorum Sensing

Abstract

Deeper explorations of molecular correlation among antibiotic resistance, biofilm formation, and pathogenicity could provide novel insights that would facilitate the development of therapeutics and prevention against A. baumannii biofilm-related infections. The major finding that polymyxin B in combination with ceftazidime displayed a synergistic antibiofilm effect against robust biofilm formed by an A. baumannii strain with genetic deficiency in AbaI/AbaR quorum sensing further provides a theoretical basis for clinical applications of antibiotics in combination with quorum quenching in antibiofilm therapy.

Virtual Screening and In Vitro Experimental Verification of LuxS Inhibitors for Escherichia coli O157:H7

“…Therefore, new targets are needed to treat these bacterial infections. The QS system is a bacterial communication mechanism that can regulate the formation of bacterial resistance ( 28 , 29 ), biofilm formation ( 26 , 27 ), and virulence factors ( 22 , 23 , 52 ). In addition, biofilms formed by many pathogens also lead to strong bacterial resistance ( 53 ).…”

“…Quorum sensing (QS) is a cellular mechanism mediated by autoinducers that allows bacteria to organize their behavior depending on their density ( 21 ). QS regulates different pathogenic processes like secretion of virulence factors ( 22 – 24 ), biofilm formation ( 25 – 27 ), and antibiotic sensitivity ( 28 , 29 ), but it does not result in the development of resistance ( 30 – 32 ). It has been reported that autoinducer-2 (AI-2) is the only QS molecule produced by E. coli .…”

Synthesized 3-(2-isocyano-6-methylbenzyl)-1H-indole Enhanced Susceptibility of Serratia marcescens to Kanamycinby Occluding Quorum Sensing

“…The QS system is a bacterial communication mechanism that can regulate the formation of bacterial resistance (Liu et al 2022), biofilm formation (Li et al 2022), and virulence factors (Defoirdt 2018). In addition, biofilms formed by many pathogens also lead to strong bacterial resistance (Rajput et al 2018).…”

“…To date, a number of natural products, such as alkaloids, phenols, and cinnamic acids, and their synthetic analogous have been reported as QS inhibitors (QSIs) and antibiofilm agents (Zhou et al 2018;Xu et al 2022), for example, norharmane (Luo et al 2021) and hordenine (Zhou et al 2019) can QS-mediate virulence factors and biofilm formation against S. marcescens NJ01. VAN isolated from kiwifruit can significant decrease the pathogenicity of S. marcescens through QS inhibiting (Sethupathy et al 2017).…”

Global Downregulation of Penicillin Resistance and Biofilm Formation by MRSA Is Associated with the Interaction between Kaempferol Rhamnosides and Quercetin

“… S. aureus strains ATCC 43300, BWSA11, and BWSA15 were chosen to investigate the antibacterial activities of CAEs and their representative compounds in combination with ceftazidime, erythromycin, levofloxacin, penicillin G, and vancomycin. A broth microdilution checkerboard procedure ( 54 ) with slight modification was used to determine the inhibitory effect of drug combinations on the growth of bacterial cells. Each drug was 2-fold diluted with TSB at six concentrations to create a 6-by-6 matrix in a 96-well plate.…”