Microbiological quality of marketed ricotta cheese and disease risks associated with Listeria monocytogenes contamination

• Main Author: Esper, Luciana Maria Ramires
• Publication Date: 2011
• Other Authors: Kabuki, Dirce Yorika, Kuaye, Arnaldo Yoshiteru
• Format: Article
• Language: por
• Source: Revista do Instituto Adolfo Lutz (Online)
• Download full: https://periodicos.saude.sp.gov.br/RIAL/article/view/32514
• topic: ricotta cheese; Microbiological quality; Listeria monocytogenes; Virulence genes; PCR; ricota; qualidade microbiológica; Listeria monocytogenes; genes de virulência e PCR

The present study aimed at evaluating the quality of ricotta cheeses marketed in the region of Campinas, SP, and to characterize the pathogenic potential of the isolated Listeria monocytogenes strains. Of 45 analyzed samples, 46.7% (21/45) did not comply with the Brazilian microbiological standard established. Most of the evaluated samples showed the microorganisms counts above those established by the regulation, that is, 46.7% for thermotolerant coliforms, 2.2% for coagulase-positive staphylococci, and 6.7% for Listeria monocytogenes. No Salmonella was isolated from these samples. It was evidenced the ocurrence of Listeria monocytogenes strains, with virulence genes acta type 4 and hly type 1, and classified as lineage I, which indicate the pathogenic potential for human. This study evidenced that this class of product deserves more attention from the scientific community, and also from manufacturing sector and sanitary surveillance bureau, improving the products quality, and consequently the consumer safety.