Microbial ecology and dynamics of Escherichia coli, Staphylococcus aureus, and lactic acid bacteria in Serrano Artisanal Cheese from Santa Catarina, Brazil, during ripening.

This study evaluated the dynamics of lactic acid bacteria (LAB), Escherichia coli, and Staphylococcus aureus, the occurrence of Salmonella spp. and Listeria monocytogenes, and characterized the bacterial community composition of Serrano Artisanal Cheese (SAC) during a 63-day ripening period through sequencing of the V3/V4 region of the 16S rRNA gene. A total of 120 cheese samples were collected from certified artisanal cheese dairies in Santa Catarina, Brazil. Neither Salmonella spp. nor L. monocytogenes was detected. Counts of S. aureus and E. coli exceeding the legal limits were observed in 40.8% and 16.6% of the samples, respectively, with a marked reduction after 35 days of ripening. The presence of the enterotoxin genes sea, sec, and see was evaluated in S. aureus isolates. LAB was detected in 90.8% of the samples, while 56% of the S. aureus isolates carried enterotoxin genes. Sequencing revealed marked shifts in bacterial community composition throughout ripening. At day 0, the microbial community was dominated by Citrobacter, Enterobacter, and Lactococcus, whereas by day 63, Enterococcus and Enterobacter became predominant. Ripening reshaped the microbial community but was insufficient to ensure the microbiological safety of SAC, reinforcing the importance of Good Manufacturing Practices.