Staphylococcus aureus isolados de Merluccius merluccius durante o processamento do pescado salgado: caracterização fenotípica e genotípica

Abstract

Salting is one of the oldest techniques and used worldwide to prolong the shelf life of fish.Staphylococcus aureus is a microorganism capable of growing in the presence of salt and may be a source of contamination during handling and processing of salted fish.The objective of this study was to identify the presence of S. aureus in different stages of the production of salted fish in a canning factory, evaluating the enterotoxigenicity, biofilm production capacity, salt tolerance and the profile of resistance to sanitizers and antimicrobials in the isolated by phenotypic and genotypic tests.A total of 18 S. aureus isolates were obtained on different days of collection and processing steps. All isolates were resistant to the action of the chlorhexidine sanitizer (4 μg/mL<MIC<16 μg/mL), while 83% were resistant to benzalkonium chloride (2 μg/mL<MIC<8 μg/mL).The mepA gene was identified in 22% of the isolates. A multidrug resistance profile was identified in isolated and verified the presence of genes ereb (67%), tetM (50%),blaZ (50%), Tn916-1545 (44%), tetL (33%) and tetB (17%).The presence of the genes eea, eeb, icaA and icaD was verified in 78%, 11%, 89% and 89% of the isolates, respectively.In addition to tolerating high salt concentrations (30%), S. aureus isolates showed a strong adaptation to 10% NaCl, concentration at which biofilm production was better induced and expression of enterotoxin A, most commonly involved in outbreaks of staphylococcal food poisoning.The results found highlight the importance of adopting correct hygienic-sanitary practices during the processing and handling of salted fish, avoiding the persistence and dissemination of S. aureus in the environment and reducing the health risks of the population.