Foods introduced into Brazil through the border with Argentina and Uruguay: Pathogen detection and evaluation of hygienic-sanitary quality

Abstract

This study aimed to evaluate the presence of pathogens in, and the hygienic-sanitary quality of, commercialized foods of animal origin at the international border region of Rio Grande do Sul, Brazil. In total, 270 samples of raw and processed foods of animal origin were collected in Paso de los Libres, Argentina (n = 65 raw meat, n = 47 dairy products, n = 28 processed meat) and Rivera, Uruguay (n = 60 raw meat, n = 31 dairy products, n = 29 processed meat), or were seized by the Brazilian International Agricultural Surveillance System (Brazil-Argentina border) (n = 9 raw meat, n = 1 bush meat). The samples were subjected to the enumeration of aerobic mesophilic bacteria, enterobacteria, and coagulase-positive staphylococci, and were tested for Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7. The virulence genes for Salmonella spp. (hilA, invA, spvC, pefA, and sefA), L. monocytogenes (prs, inlA, inlC, and inlJ) and E. coli O157:H7 (uspA, eae, rfbO157, fliCH7, stx1, stx2, and hlyA) were investigated using PCR assays. Raw products showed higher counts of aerobic mesophiles and enterobacteria compared to processed products (P < 0.05). There were no significant differences in aerobic mesophile or in enterobacterial counts between identical products according to origin (Argentina vs. Uruguay, P > 0.05). Escherichia coli O157:H7 was not detected in any of the samples tested. Salmonella spp. was detected in six (8%) raw products from Argentina. Listeria monocytogenes was isolated from five (6.66%) raw products originating in Argentina and 20 (16.66%) raw products from Uruguay. All 52 E. coli isolates carried the uspA gene, but only one carried the eae gene. The rfbO157, fliCH7, stx1, stx2, and hlyA genes were not detected. All Salmonella spp. isolates carried hilA and invA genes, but spvC, pefA, and sefA were not found. All L. monocytogenes isolates carried the prs gene; however, inlA, inlC, and inlJ genes were found in 20% of the isolates from Argentina and 95% of those from Uruguay. To our knowledge, this is the first microbiological study into the hygienic-sanitary quality of animal products in Brazil's land border region. Salmonella spp. and L. monocytogenes were detected in products of animal origin, constituting a public health concern and emphasizing the need for an active surveillance system to reduce the risk of foodborne pathogen introduction into Brazil.