title: Characterization of Listeria monocytogenes isolated from a fresh mixed sausage processing line in Pelotas-RS by PFGE.
abstract: Listeria monocytogenes is a bacterium capable to adhere to the surfaces of equipment and utensils and subsequently form biofilms. It can to persist in the food processing environmental for extended periods of time being able to contaminate the final product. The aim of this study was to trace the contamination route of L. monocytogenes on a fresh mixed sausage processing line, from raw material to the final product. The isolates obtained were characterized by serotyping and molecular typing by pulsed-field gel electrophoresis (PFGE) using the restriction enzymes ApaI and AscI. L. monocytogenes was detected in 25% of the samples. The samples of raw material were not contaminated, however, the microorganism was detected in 21% of the environmental samples (food contact and non-food contact), 20.8% of the equipments, 20% of the food worker's hands, 40% of the mass ready to packaging and in all the final products samples, demonstrating that the contamination of final product occurred during the processing and the importance of cross contamination. PFGE yielded 22 pulsotypes wich formed 7 clusters, and serotyping yielded 3 serotypes and 1 serogroup, however, the presence of serotypes 4b and 1/2b in the final product is of great concern for public health. The tracing of contamination showed that some strains are adapted and persisted in the processing environment in this industry.
authors.affiliation: Laboratório de Microbiologia de Alimentos, Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas , Pelotas, RS , Brasil.
authors.forename: Ana Eucares
authors.initials: AE
authors.lastname: von Laer
authors.forename: Andréia Saldanha
authors.initials: AS
authors.lastname: de Lima
authors.forename: Paula Dos Santos
authors.initials: Pdos S
authors.lastname: Trindade
authors.forename: Cristiano
authors.initials: C
authors.lastname: Andriguetto
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Destro
authors.forename: Wladimir Padilha
authors.initials: WP
authors.lastname: da Silva
keywords: Listeria monocytogenes; PFGE; persistent strains; serotyping
references.citation: Int J Food Microbiol. 2001 Apr 11;65(1-2):55-62
references.pmid: 11322701
references.citation: Mem Inst Oswaldo Cruz. 2000 Sep-Oct;95(5):615-20
references.pmid: 10998209
references.citation: Int J Food Microbiol. 1999 Dec 15;53(2-3):127-40
references.pmid: 10634704
references.citation: Int J Food Microbiol. 2006 Nov 1;112(2):153-61
references.pmid: 16843563
references.citation: Mol Biol Evol. 1987 Jul;4(4):406-25
references.pmid: 3447015
references.citation: Appl Environ Microbiol. 1996 Feb;62(2):705-11
references.pmid: 8593073
references.citation: Braz J Microbiol. 2008 Apr;39(2):375-83
references.pmid: 24031233
references.citation: J Food Prot. 2002 Jul;65(7):1129-33
references.pmid: 12117246
references.citation: Int J Food Microbiol. 2000 Dec 5;62(1-2):155-9
references.pmid: 11139016
references.citation: J Appl Microbiol. 2001 Nov;91(5):888-99
references.pmid: 11722667
references.citation: J Food Prot. 2000 Sep;63(9):1204-7
references.pmid: 10983793
references.citation: Int J Food Microbiol. 2003 Aug 1;84(3):285-97
references.pmid: 12810292
references.citation: J Appl Microbiol. 2006 Jul;101(1):7-17
references.pmid: 16834586
references.citation: Appl Environ Microbiol. 1999 Jan;65(1):150-5
references.pmid: 9872773
references.citation: Syst Appl Microbiol. 2008 Oct;31(5):387-92
references.pmid: 18835121
references.citation: Int J Food Microbiol. 2001 Feb 28;64(1-2):51-61
references.pmid: 11252511
references.citation: J Food Prot. 2005 May;68(5):980-5
references.pmid: 15895730
references.citation: J Food Prot. 2002 Nov;65(11):1811-29
references.pmid: 12430709
references.citation: Int J Food Microbiol. 2005 Jun 25;102(1):85-94
references.pmid: 15925005
references.citation: Meat Sci. 2008 Jan;78(1-2):130-4
references.pmid: 22062102
references.citation: J Food Prot. 2003 Nov;66(11):2062-9
references.pmid: 14627284