{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T04:28:17Z","timestamp":1778128097853,"version":"3.51.4"},"reference-count":13,"publisher":"Microbiology Society","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2008,4,1]]},"abstract":"<jats:p>The virulence potential of 51 <jats:italic>Listeria monocytogenes<\/jats:italic> isolates, including strains from cheese, cheese production environments and from human cases of listeriosis, was evaluated in this study. The isolates were used to infect HT-29 cell monolayers in an <jats:italic>in vitro<\/jats:italic> test of virulence, based on a plaque-forming assay (PFA). Fifteen selected isolates were used for subcutaneous footpad inoculation in mice and subsequent recovery of the bacterium from the spleen 3\u2005days after inoculation. In the PFA, two isolates from milk (serovar 1\/2a) were not significantly different (<jats:italic>P<\/jats:italic>&lt;0.05) from the low-virulence strain (442) used as reference. Thirty-three isolates were not significantly different (<jats:italic>P<\/jats:italic>&lt;0.05) from the virulent strain (EGDe) used as reference. Nine isolates were significantly more virulent (highly virulent) than the EGDe strain and seven isolates were significantly less virulent. The nine highly virulent isolates were either from humans (four), from cheese dairy environments (two isolates of a strain were found persistently in two dairies), from cheese (one), from milk (one) and the reference strain for serovar 1\/2b (CECT 936). The two milk isolates with low virulence in the PFA were found to be virulent in mice. In conclusion, all the isolates from food and food-related environments were potentially virulent or highly virulent. These results stress the risk of listeriosis associated with the consumption of cheese contaminated with <jats:italic>L. monocytogenes<\/jats:italic>, and once more emphasize the importance of good manufacturing practices (GMPs) together with sanitation standard operating procedures (SSOPs) throughout the food chain.<\/jats:p>","DOI":"10.1099\/jmm.0.47672-0","type":"journal-article","created":{"date-parts":[[2008,3,18]],"date-time":"2008-03-18T19:20:00Z","timestamp":1205868000000},"page":"411-415","source":"Crossref","is-referenced-by-count":25,"title":["Virulence of Listeria monocytogenes isolated from the cheese dairy environment, other foods and clinical cases"],"prefix":"10.1099","volume":"57","author":[{"given":"Elsa","family":"Neves","sequence":"first","affiliation":[{"name":"Instituto Superior de Estudos Interculturais e Transdisciplinares (ISEIT), Campus Universit\u00e1rio de Almada, Instituto Piaget, Quinta da Arreinela de Cima, 2800-305 Almada, Portugal"},{"name":"Laborat\u00f3rio de Microbiologia, CBAA\/DBEB, Instituto Superior de Agronomia, Technical University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal"}]},{"given":"Ana Carla","family":"Silva","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Microbiologia, CBAA\/DBEB, Instituto Superior de Agronomia, Technical University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal"}]},{"given":"Sylvie M.","family":"Roche","sequence":"additional","affiliation":[{"name":"Institut National de la Recherche Agronomique, Infectiologie Animale et Sant\u00e9 Publique, UR1282, F-37380 Nouzilly, France"}]},{"given":"Philippe","family":"Velge","sequence":"additional","affiliation":[{"name":"Institut National de la Recherche Agronomique, Infectiologie Animale et Sant\u00e9 Publique, UR1282, F-37380 Nouzilly, France"}]},{"given":"Luisa","family":"Brito","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Microbiologia, CBAA\/DBEB, Instituto Superior de Agronomia, Technical University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal"}]}],"member":"345","reference":[{"key":"R1","first-page":"47","article-title":"Experimental infection of mice with Listeria monocytogenes and L. innocua","volume":"131B","author":"Audurier","year":"1980","journal-title":"Ann Microbiol (Paris)"},{"key":"R2","doi-asserted-by":"crossref","first-page":"296","DOI":"10.4315\/0362-028X-56.4.297","article-title":"Virulence heterogeneity of Listeria monocytogenes strains from various sources (food, human, animal) in immunocompetent mice and its associated typing characteristics","volume":"56","author":"Brosch","year":"1993","journal-title":"J Food Prot"},{"key":"R3","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1078\/0723202041438518","article-title":"Genetic characterization of Listeria monocytogenes food isolates and pathogenic potential within serovars 1\/2a and 1\/2b","volume":"27","author":"Cabrita","year":"2004","journal-title":"Syst Appl Microbiol"},{"key":"R4","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/S0168-1605(00)00501-8","article-title":"PulseNet standardized protocol for subtyping Listeria monocytogenes by macrorestriction and pulsed-field gel electrophoresis","volume":"65","author":"Graves","year":"2001","journal-title":"Int J Food Microbiol"},{"key":"R5","doi-asserted-by":"crossref","first-page":"2157","DOI":"10.4315\/0362-028X-69.9.2157","article-title":"Virulence of Listeria monocytogenes from humans and smoked salmon, peeled shrimp, and their processing environments","volume":"69","author":"Gudmundsd\u00f3ttir","year":"2006","journal-title":"J Food Prot"},{"key":"R6","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.ijfoodmicro.2005.05.017","article-title":"Comparative characterization of Listeria monocytogenes isolated from Portuguese farmhouse ewe's cheese and from humans","volume":"106","author":"Leite","year":"2006","journal-title":"Int J Food Microbiol"},{"key":"R7","doi-asserted-by":"crossref","first-page":"1065","DOI":"10.1099\/jmm.0.05358-0","article-title":"Characterization of virulent and avirulent Listeria monocytogenes strains by PCR amplification of putative transcriptional regulator and internalin genes","volume":"52","author":"Liu","year":"2003","journal-title":"J Med Microbiol"},{"key":"R8","doi-asserted-by":"crossref","first-page":"2247","DOI":"10.1128\/JCM.25.11.2247-2251.1987","article-title":"Listeria monocytogenes ATCC 35152 and NCTC 7973 contain a nonhemolytic, nonvirulent variant","volume":"25","author":"Pine","year":"1987","journal-title":"J Clin Microbiol"},{"key":"R9","doi-asserted-by":"crossref","first-page":"3900","DOI":"10.1128\/AEM.71.7.3900-3910.2005","article-title":"Definition of genetically distinct attenuation mechanisms in naturally virulence-attenuated Listeria monocytogenes by comparative cell culture and molecular characterization","volume":"71","author":"Roberts","year":"2005","journal-title":"Appl Environ Microbiol"},{"key":"R10","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/S0168-1605(01)00460-3","article-title":"Assessment of the virulence of Listeria monocytogenes : agreement between a plaque-forming assay with HT-29 cells and infection of immunocompetent mice","volume":"68","author":"Roche","year":"2001","journal-title":"Int J Food Microbiol"},{"key":"R11","doi-asserted-by":"crossref","first-page":"6039","DOI":"10.1128\/AEM.71.10.6039-6048.2005","article-title":"Investigation of specific substitutions in virulence genes characterizing phenotypic groups of low-virulence field strains of Listeria monocytogenes","volume":"71","author":"Roche","year":"2005","journal-title":"Appl Environ Microbiol"},{"key":"R12","doi-asserted-by":"crossref","first-page":"584","DOI":"10.1128\/CMR.14.3.584-640.2001","article-title":"Listeria pathogenesis and molecular virulence determinants","volume":"14","author":"V\u00e1zquez-Boland","year":"2001","journal-title":"Clin Microbiol Rev"},{"key":"R13","doi-asserted-by":"crossref","first-page":"2707","DOI":"10.1128\/IAI.65.7.2707-2716.1997","article-title":"Ribotypes and virulence gene polymorphisms suggest three distinct Listeria monocytogenes lineages with differences in pathogenic potential","volume":"65","author":"Wiedmann","year":"1997","journal-title":"Infect Immun"}],"container-title":["Journal of Medical Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.microbiologyresearch.org\/content\/journal\/jmm\/10.1099\/jmm.0.47672-0?crawler=true","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,9,28]],"date-time":"2020-09-28T05:15:08Z","timestamp":1601270108000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.microbiologyresearch.org\/content\/journal\/jmm\/10.1099\/jmm.0.47672-0"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,1]]},"references-count":13,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2008,4,1]]}},"URL":"https:\/\/doi.org\/10.1099\/jmm.0.47672-0","relation":{},"ISSN":["0022-2615","1473-5644"],"issn-type":[{"value":"0022-2615","type":"print"},{"value":"1473-5644","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,1]]}}}