Exposure of Escherichia coli ATCC 12806 to Sublethal Concentrations of Food-Grade Biocides Influences Its Ability To Form Biofilm, Resistance to Antimicrobials, and Ultrastructure

Abstract

b Escherichia coli ATCC 12806 was exposed to increasing subinhibitory concentrations of three biocides widely used in food industry facilities: trisodium phosphate (TSP), sodium nitrite (SNI), and sodium hypochlorite (SHY). The cultures exhibited an acquired tolerance to biocides (especially to SNI and SHY) after exposure to such compounds. E. coli produced biofilms (as observed by confocal laser scanning microscopy) on polystyrene microtiter plates. Previous adaptation to SNI or SHY enhanced the formation of biofilms (with an increase in biovolume and surface coverage) both in the absence and in the presence (MIC/2) of such compounds. TSP reduced the ability of E. coli to produce biofilms. The concentration of suspended cells in the culture broth in contact with the polystyrene surfaces did not influence the biofilm structure. The increase in cell surface hydrophobicity (assessed by a test of microbial adhesion to solvents) after contact with SNI or SHY appeared to be associated with a strong capacity to form biofilms. Cultures exposed to biocides displayed a stable reduced susceptibility to a range of antibiotics (mainly aminoglycosides, cephalosporins, and quinolones) compared with cultures that were not exposed. SNI caused the greatest increase in resistances (14 antibiotics [48.3% of the total tested]) compared with TSP (1 antibiotic [3.4%]) and SHY (3 antibiotics [10.3%]). Adaptation to SHY involved changes in cell morphology (as observed by scanning electron microscopy) and ultrastructure (as observed by transmission electron microscopy) which allowed this bacterium to persist in the presence of severe SHY challenges. The findings of the present study suggest that the use of biocides at subinhibitory concentrations could represent a public health risk.

Disinfectant and Antimicrobial Susceptibility Profiles of Campylobacter coli Isolated in 1998 to 1999 and 2015 from Swine and Commercial Pork Chops

“…During application of disinfectants, the resultant concentrations used may be lower than required to kill the targeted bacteria (Chapman, ). These lower levels of disinfectants can result in the formation of biofilms and antimicrobial resistance (AMR) (Capita, Riesco‐Paláez, Alonso‐Hernando, & Alonso‐Calleja, ). The emergence of multidrug‐resistant pathogens worldwide as well as a lack of new drug development is a concern in both human and veterinary medicine (CDC, ; Ventola, ).…”

Characterization of antibiotic and disinfectant susceptibility profiles amongPseudomonas aeruginosaveterinary isolates recovered during 1994-2003

“…Reports also have suggested increasing resistance of bacteria to biocides (McDonnell and Russell ; Russell ), that sublethal concentrations of food‐grade biocides influenced formation of biofilms and antimicrobial resistance (Capita et al . ) and that biocide use resulted in cross‐resistance to antibiotics (Maris ; Sidhu et al . ; Braoudaki and Hilton ; Beier et al .…”

“…Ciprofloxacin is a very potent antimicrobial used in human medicine (Bergan et al 1988), and increased multidrug-resistant pathogens are a concern in both human and veterinary medicine (Cohen et al 1991;Hartmann et al 1997). Reports also have suggested increasing resistance of bacteria to biocides (McDonnell and Russell 1999;Russell 2002), that sublethal concentrations of food-grade biocides influenced formation of biofilms and antimicrobial resistance (Capita et al 2014) and that biocide use resulted in cross-resistance to antibiotics (Maris 1991;Sidhu et al 2002a;Braoudaki and Hilton 2004;Beier et al 2005;Al-Jailawi et al 2013). This study was designed to characterize the antibiotic and disinfectant susceptibility profiles among Ps.…”

Antibiotic effectiveness: Balancing conservation against innovation

“…The widespread use of biocides coselects for antibiotic resistance genes and could promote the spread of multidrug resistance plasmids (26).…”