Virulence genes and sanitizers resistance in Salmonella isolates from eggs in southern Brazil

Salmonella spp. causes foodborne diseases related to the consumption of contaminated foods, especially poultry products. This study aimed to investigate the occurrence of Salmonella spp. serovars in raw eggs from supermarkets and street food markets in southern Brazil, to analyze virulence genes, resistance profiling to antimicrobials and sanitizers, and to determine the susceptibility of the isolates to Butia odorata extract. Among 160 samples analyzed, just two (1.25%) were positive for Salmonella spp.. One positive sample was from egg yolk (S. enterica serovar Gallinarum, isolate S28), and another one was from eggshell (S. enterica serovar Panama, isolate S37). Regarding the virulence genes, the isolate S37 harbored all the genes evaluated (hilA, invA, spvC, sefA, and pefA), while the isolate S28 did not harbor the pefA gene. The isolate S28 was resistant to tobramycin, azithromycin, and trimethoprim, while the isolate S37 showed resistance profile just to nalidixic acid. However, none of the resistance genes evaluated were identified. Both isolates showed resistance to benzalkonium chloride, chlorhexidine digluconate, sodium hypochlorite, and peracetic acid, presenting high MIC values for these sanitizers. In contrast, B. odorata extract showed antimicrobial activity against the isolates S28 and S37, however, more studies are needed to prove its potential as a natural antimicrobial compound.