RESUMO
Due to specific bacterial microbiota, raw milk cheeses have appreciated sensory properties. However, they may pose a threat to consumer safety due to potential pathogens presence. This study evaluated the microbiological contamination of 98 raw milk cheeses from Beira Baixa, Portugal. Presence and enumeration of Coagulase Positive Staphylococci (CPS), Listeria monocytogenes, Salmonella spp., pathogenic Escherichia coli, and indicator microorganisms (non-pathogenic E. coli and Listeria spp.) was attained. E. coli antimicrobial resistance (AMR) was also evaluated. PCR and/or Whole genome sequencing (WGS) was used to characterize E. coli, Salmonella spp. and L. monocytogenes isolates. Sixteen cheeses (16.3%) were classified as Satisfactory, 59 (60.2%) as Borderline and 23 (23.5%) as Unsatisfactory/Potential Injurious to Health. L. monocytogenes, CPS > 104 cfu g-1, Extraintestinal pathogenic E. coli (ExPEC) and Salmonella spp. were detected in 4.1%, 6.1%, 3.1% and 1.0% of the samples, respectively. Listeria innocua (4.1%) and E. coli > 104 cfu g-1 (16.3%) were also detected. AMR E. coli was detected in 23/98 (23.5%) of the cheese samples, of which two were multidrug resistant. WGS identified genotypes already associated to human disease and Listeria spp. cluster analysis indicated that cheese contamination might be related with noncompliance with Good Hygiene Practices during cheese production.
Assuntos
Queijo , Microbiologia de Alimentos , Leite , Queijo/microbiologia , Portugal , Animais , Leite/microbiologia , Inocuidade dos Alimentos , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , Listeria monocytogenes/classificação , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Higiene , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Contaminação de Alimentos/análise , Farmacorresistência Bacteriana , HumanosRESUMO
Salmonella enterica serovars Heidelberg and Minnesota frequently display several genetic mobile elements making them potential spreaders of resistance genes. Here, we phenotypically determined the antibiotic resistance profile and subsequently performed whole-genome sequencing on 36 isolates recovered from samples of fresh poultry meat, within the Portuguese Official Inspection Plan for Imported Foodstuffs. Several isolates of both serovars showed high genetic relatedness either with isolates from raw poultry meat imported to the Netherlands from Brazil or with isolates from samples from the broiler production chain in Brazil. The multidrug-resistant (MDR) character was common to the vast majority (94.4%) of isolates from both serovars, and several isolates carried the plasmid IncA/C2 containing the ß-lactamase gene blaCMY-2 and IncX1 containing a type IV secretion system. These results somehow mirror the scenario observed in the Netherlands, showing the introduction, through fresh imported poultry meat in compliance with European legislation, of MDR Salmonella enterica serovars Heidelberg and Minnesota in Europe, with the potential spread of resistance markers. These data suggest the need to revise the hygiene criteria for foodstuffs monitoring before its placement on the market, with the determination of the resistome being an invaluable contribute to limit the dissemination of resistance markers.