Antimicrobial and disinfectant resistance of Salmonella Heidelberg from Brazilian flocks did not increase for ten years (2006-2016)

Abstract

Salmonella is a major cause of foodborne illness worldwide, and poultry and its derived products are the most common food products associated with salmonellosis outbreaks. Some countries, including Brazil, have experienced an increased prevalence of Salmonella Heidelberg among their poultry flocks. Some isolates have also presented high resistance to antimicrobial agents and persist in the poultry farm environment. This study aimed to compare the susceptibility of S. Heidelberg strains isolated in 2006 with those isolated in 2016 against disinfectants and antimicrobial agents. The results showed that all the strains were highly susceptible to sodium hypochlorite, regardless of the conditions and year of isolation. Resistance to benzalkonium chloride varied according to the conditions applied, but not to the year of isolation. Increased antimicrobial resistance from 2006-2016 was observed only for tetracycline. The results suggest that the antimicrobial and disinfectant resistance of S. Heidelberg did not increase for ten years (2006-2016). However, further analysis should include a larger number of S. Heidelberg isolates from poultry origin and additional antimicrobial agents for more precise conclusions about the increasing in antimicrobial resistance in the last years.