Osmotic stress relief antibiotic tolerance of 1, 8-cineole in biofilm persister cells of Escherichia coli O157:H7 and expression of toxin-antitoxin system genes. (December 2022)

• Record Type: Journal Article
• Authors: Addo, Keren Agyekumwaa; Li, Linying; Li, Hui; Yu, Yigang; Xiao, Xinglong
• Is Part Of: Microbial pathogenesis. Volume 173(2022)Part B
• Publication Date: 2022-12
• Subjects: Cineole -- Osmotic stress -- Biofilm matrix -- E. coli -- Persister cells -- Fresh cucumber; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2022.105883
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: The control of E. coli activity from forming biofilm and persister cells is an essential factor in both the health and food industries. The efficacy of antimicrobial treatment is often limited due to their low penetrability as biofilm formation protect cells within from physical or chemical threats. Among other factors, osmotic stress has shown to have a high capacity to enhance the antimicrobial activities against various pathogens. Thus, this study aimed to test the hypothesis that the antimicrobial activity of cineole (CN) could be enhanced under osmotic stress to inhibit biofilm and persister cells. Time-kill analysis revealed that CN under NaCl-induced osmotic stress (CN–S) had better inhibitory effect on E. coli biofilm. 5% CN–S altered the integrity, hydration, motilities and exopolysaccharide production of E. coli cells. Also, the outer membrane permeability, surface roughness and hydrophobicity which determine initial cell adhesion, aggregation and colony assembly were significantly perturbed. Furthermore, the expression levels of virulence genes stx 1, stx 2, eae, flh D, and the TA system antitoxin genes maz E, hip B were downregulated. When applied to cucumber, the rate of increase in internalized bacterial cells significantly reduced after storage at 4 °C for 48 h. Thus, the results suggested that the application of osmotic stress could minimize the working concentration of antimicrobials in real food systems, which could be helpful in counteracting the growing concern of microbial resistance. Highlights: NaCl-induced osmotic stress has appreciable impact on E. coli biofilm formation. NaCl-induced osmotic stress enhances the bactericidal effect of CN on E. coli biofilm. Osmotic stress enhances the anti- E. coli adhesion ability of CN. CN–S significantly reduces the rate of internalized E. coli cells in cucumber tissues. CN–S significantly distort cell membrane and reduces persister cells in E. coli biofilm.