Purpose: This study aimed to determine the incidence and concentration of Listeria monocytogenes and Salmonella in Brazilian AC.
Methods: We analyzed 582 samples of Brazilian AC, divided according to their production region: North (Marajó; n=8); Northeast (Curd cheese; n=78) and (Butter cheese; n=23); Central (Caipira cheese; n=108); Southeast (Araxá; n = 56), (Campo das Vertentes; n = 54), (Cerrado; n = 54), (Serra da Canastra; n = 48) and (Serro; n = 50) and South cheeses (Colonial; n = 55) and (Serrano; n = 48). Detection and enumeration of L. monocytogenes was performed according to ISO 11290-1 and ISO 11290-2. Identification of L. monocytogenes was performed by biochemical tests and real-time PCR (RT-PCR) with amplification of listeriolysin gene (hlyA). Detection of Salmonella based on ISO 6579: 2002, while for enumeration ISO 6579-2: 2012 was used.
Results: Presumptive colonies of L. monocytogenes were found in 11% of samples. From 266 presumptive colonies of L. monocytogenes, seven were recovered from Butter (n=5 isolates), Serro (n=1 isolate) and Curd (n=1 isolate) cheeses and confirmed by RT-PCR. Salmonella was not detected in any of the 582 AC samples analyzed. Populations of L. monocytogenes and Salmonella were always below the limit of quantification of methods used (1 log CFU/g).
Significance: The prevalence of L. monocytogenes was very low (0.005), while Salmonella was not detected in any of 582 AC samples analyzed, indicating that practices used to produce them are adequate from hygienic point of view.