The Effect of Antimicrobial Resistance Plasmids Carrying blaCMY-2 on Biofilm Formation by Escherichia coli from the Broiler Production Chain

Abstract

Extended-spectrum cephalosporin-resistant Escherichia coli (ESCR E. coli) with plasmids carrying the blaCMY-2 resistance gene have been isolated from the Norwegian broiler production chain through the Norwegian monitoring program for antimicrobial resistance in animals, food and feed, NORM-VET. The aim of the present study was to investigate the biofilm forming abilities of these strains, and in particular to see whether these might be influenced by the carriage of blaCMY-2 plasmids. The ESCR E. coli from the broiler production chain displayed relatively low biofilm forming abilities in the crystal violet biofilm assay as compared to quinolone-resistant E. coli (QREC) from the same population (mean ± SD = 0.686 ± 0.686 vs. 1.439 ± 0.933, respectively). Acquisition of two different blaCMY-2 plasmids by QREC strains reduced their biofilm production in microtiter plates, but not their biofilm production on Congo Red agar plates. Furthermore, motility was reduced, but not planktonic growth. We hypothesize that genes carried by these plasmids may have caused the observed reduction in biofilm formation, possibly mediated through changes in flagellar expression or function. Furthermore, this may help explain the different biofilm forming abilities observed between ESCR E. coli and QREC. The results also indicate that the risk of biofilm reservoirs of antimicrobial resistant E. coli on in the broiler production is lower for ESCR E. coli than for QREC.

Plasmid carriage and the natural complexity of bacterial populations contributes to plasmid persistence

“…E. coli cells showed low formation of biofilm in a crystal violet biofilm assay versus in quinolone-resistance E. coli found in the same population [21]. Acquiring the two different plasmids of the E. coli QREC virulent strain lowered the production of biofilm in the microtiter plates [21]. The rates of motility were reduced, but planktonic growth continued to increase [21].…”

“…One of the plasmids showed dominance over the other plasmid where one of the plasmids directed the increase of biofilm formation. E. coli cells showed low formation of biofilm in a crystal violet biofilm assay versus in quinolone-resistance E. coli found in the same population [21]. Acquiring the two different plasmids of the E. coli QREC virulent strain lowered the production of biofilm in the microtiter plates [21].…”

“…Acquiring the two different plasmids of the E. coli QREC virulent strain lowered the production of biofilm in the microtiter plates [21]. The rates of motility were reduced, but planktonic growth continued to increase [21]. Therefore, Nesse et al hypothesized that plasmids carrying antibiotic resistance genes may have reduced the formation of biofilm dependent upon the fluxes of flagellar protein expression [21].…”

Role played by the environment in the emergence and spread of antimicrobial resistance (AMR) through the food chain

“…Biofilm formation and the degree of relevant gene expression may also be important for persistence of Salmonella within the host and in the environment, including for certain strains of MDR S. Typhimurium and S. Heidelberg (Hoffmann et al, 2014;Shi et al, 2019). Biofilms also reduce the effectiveness of antimicrobials, which may lead to greater selection of resistance (Penesyan et al, 2020) and reduce the activity of disinfectants (Nesse et al, 2021).…”

“…Heidelberg (Hoffmann et al., 2014; Shi et al., 2019). Biofilms also reduce the effectiveness of antimicrobials, which may lead to greater selection of resistance (Penesyan et al., 2020) and reduce the activity of disinfectants (Nesse et al., 2021).…”