Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.14/14334
Título: Foci of contamination of Listeria monocytogenes in different cheese processing plants
Autor: Almeida, Gonçalo
Magalhães, R.
Carneiro, L.
Santos, I.
Silva, Joana
Hogg, T.
Teixeira, Paula
Palavras-chave: Listeria monocytogenes
Cheese
Sources of contamination
Typing
PFGE
Persistence
Data: 2013
Editora: Elsevier
Citação: ALMEIDA, Gonçalo ...[et al.] - Foci of contamination of Listeria monocytogenes in different cheese processing plants. International Journal of Food Microbiology. ISSN 0168-1605. Vol. 167 (2013), p. 303–309
Resumo: Listeria monocytogenes is a ubiquitous bacterium widely distributed in the environment that can cause a severe disease in humans when contaminated foods are ingested. Cheese has been implicated in sporadic cases and in outbreaks of listeriosis worldwide. Environmental contamination, in several occasions by persistent strains, has been considered an important source of !nished product contamination. The objectives of this research were to (i) evaluate the presence of L. monocytogenes within the factory environments and cheeses of three processing plants, artisanal producer of raw ewe's milk cheeses (APC), small-scale industrial cheese producer (SSI) and industrial cheese producer (ICP) each producing a distinct style of cheese, all with history of contamination by L. monocytogenes (ii) and identify possible sources of contamination using different typing methods (arsenic and cadmium susceptibility, geno-serotyping, PFGE). The presence of markers speci!c for 3 epidemic clones (ECI– ECIII) of L. monocytogenes was also investigated. Samples were collected from raw milk (n = 179), whey (n = 3), cheese brining solution (n = 7), cheese brine sludge (n = 505), !nished product (n = 3016), and environment (n = 2560) during, at least, a four-year period. Listeriamonocytogeneswas detected in environmental, raw milk and cheese samples, respectively, at 15.4%, 1.1% and 13.6% in APC; at 8.9%, 2.9% and 3.4% in SSI; and at 0%, 21.1% and 0.2% in ICP. Typing of isolates revealed that raw ewe's milk and the dairy plant environment are important sources of contamination, and that some strains persisted for at least four years in the environment. Although cheeses produced in the three plants investigated were never associated with any case or outbreak of listeriosis, some L.monocytogenes belonging to speci!c PFGE types that caused disease (including putative epidemic clone strains isolated from !nal products) were found in this study.
Peer review: yes
URI: http://hdl.handle.net/10400.14/14334
Aparece nas colecções:CBQF - Artigos em revistas internacionais com Arbitragem / Papers in international journals with Peer-review



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