Disinfectant and antimicrobial susceptibility profiles of Salmonella strains from feedlot water-sprinkled cattle: Hides and feces

Authors: BEIER, ROSS; CALLAWAY, TODD; Andrews, Kathleen - Kate; Poole, Toni; Crippen, Tawni - Tc; Anderson, Robin; NISBET, DAVID

Submitted to: Journal of Food Chemistry & Nanotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2017
Publication Date: 5/5/2017
Citation: Beier, R.C., Callaway, T.R., Andrews, K., Poole, T.L., Crippen, T.L., Anderson, R.C., Nisbet, D.J. 2017. Disinfectant and antimicrobial susceptibility profiles of Salmonella strains from feedlot water-sprinkled cattle: Hides and feces. Journal of Food Chemistry & Nanotechnology. 3(2):50-59. https://doi.org/10.17756/jfcn.2017-037.
DOI: https://doi.org/10.17756/jfcn.2017-037

Interpretive Summary: Many different kinds of disinfectants are used in animal production, in food processing plants, in hospitals, and in homes. In each of these places there is also widespread use of a variety of antibiotics. Little is known about the impact of disinfectants on the spread of antibiotic resistance. Here we evaluate the disinfectant and antimicrobial susceptibility profiles of Salmonella strains from feedlot water-sprinkled cattle. A low prevalence of antimicrobial resistance (AMR) was observed; resistance was primarily observed to streptomycin (29.7%) and sulfamethoxazole (8.3%). All strains were susceptible to the 8 fluoroquinolones tested. There was no observed correlation between disinfectant resistance and antibiotic resistance. All strains were susceptible to triclosan, and all strains were resistant to chlorhexidine. Nearly 1/3 of the strains had low level resistance to benzalkonium chloride. Benzyl ammonium chlorides C12, C14, and C16 (BACs) were the most active ingredients in the disinfectant DC&R. C14BAC and C16BAC were shown to be more active as a disinfectant than was C12BAC. Dimethyl ammonium chloride C10 was the most active ingredient in the disinfectant P-128, and the most active ammonium chloride in this work and in all of our previous studies. All manufacturer recommended application levels were above the observed MICs. However, observed MICs for DC&R and Tek-Trol were close to the suggested application rates, and a small change in the disinfectant dilution could easily render these disinfects non-functional. The continued use of THN and formaldehyde in DC&R is questionable because these components are not effective, and their inclusion only results in additional unwanted chemicals in the environment.

Technical Abstract: The disinfectant and antimicrobial susceptibility profiles of 145 Salmonella strains obtained from feedlot water sprinkled cattle were determined. A low prevalence of antimicrobial resistance (AMR) was observed; resistance was primarily observed to streptomycin (29.7%) and sulfamethoxazole (8.3%). All strains were susceptible to the 8 fluoroquinolones tested. The most common AMR traits was streptomycin resistance in serovar Kentucky, sulfamethoxazole resistance in Muenster and Cerro, and amoxicillin/clavulonic acid–ceftiofur resistance in Meleagridis. Salmonella were more resistant to the disinfectants P-I, DC&R, and Tek-Trol and disinfectant component THN than to other disinfectants. All strains were susceptible to triclosan, and all strains were resistant to chlorhexidine. Nearly 1/3 of the strains had low level resistance to benzalkonium chloride. The BACs, or benzyl ammonium chlorides, C12, C14, and C16 were the most active ingredient in the disinfectant DC&R. C14BAC and C16BAC were shown to be more active as a disinfectant than was C12BAC. Dimethyl ammonium chloride C10 (C10AC) was the most active ingredient in the disinfectant P-128, and the most active ammonium chloride in this work and in all of our previous studies. All manufacturer recommended application levels were above the observed MICs. However, observed MICs for DC&R and Tek-Trol were close to the suggested application rates, and a small change in the disinfectant dilution could easily render these disinfects non-functional. The continued use of THN and formaldehyde in DC&R is questionable because these components are not effective, and their inclusion only results in additional unwanted chemicals in the environment.