Disinfectant Resistance Profiles and Biofilm Formation Capacity of Escherichia coli Isolated from Retail Chicken.

Abstract

Disinfectant resistance and biofilm formation capacity are two important characteristics that contribute to the persistence of microorganisms in food processing environments and contamination of food products. This study investigated the susceptibility of 510 Escherichia coli isolates against 5 disinfectants and the prevalence of 10 disinfectant-resistant genes in these isolates. The biofilm formation capacity of 194 isolates was determined, and the correlation between disinfectant resistance and biofilm formation was analyzed. The minimal inhibitory concentrations (MICs) of cetyltrimethylammonium bromide (CTAB), benzalkonium chloride (BC), cetylpyridinium chloride, and chlorhexidine (CHX) against isolates were 32-512, 16-256, 32-256, and 2-32 mg/L, respectively. The MICs of triclosan against 88.43% of isolates were 8-1,024 mg/L, while the MICs for the rest of isolates exceed 2,048 mg/L. The presence of ydgE, ydgF, and qacF genes was significantly correlated with the CHX resistance of E. coli isolates, while the presence of qacF and qacEΔ1 genes was significantly correlated with CTAB and BC resistance, respectively. The biofilm formation capacity (adjusted optical density value) was positively correlated with BC resistance (r = 0.201, p < 0.01) and showed no correlation with other disinfectants. The presence of sugE(p) was positively correlated with biofilm formation, while four genes were negatively correlated with biofilm formation. This study provides useful data on disinfectant resistance and biofilm formation capacity of E. coli contaminating poultry products, which could be helpful in guiding proper disinfectant usage and establishing effective biofilm eradication strategy in food industry.