{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T01:25:14Z","timestamp":1783560314553,"version":"3.55.0"},"reference-count":24,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2018,2,1]],"date-time":"2018-02-01T00:00:00Z","timestamp":1517443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Listeria monocytogenes has been extensively studied as a model facultative intracellular pathogen. While the roles of major virulence factors in host-pathogen interactions have been extensively characterized, recent work suggests that some of these factors can also contribute to environmental proliferation of this pathogen. In this study, we characterized two non-hemolytic transposon mutants of strain 2011L-2858 (serotype 1\/2b), implicated in the 2011 listeriosis outbreak via whole cantaloupe, for their capacity to form biofilms on polystyrene, aggregate, and colonize cantaloupe rind. One mutant harbored a single mariner-based transposon insertion in hly, encoding the hemolysin Listeriolysin O, while the other harbored a single insertion in prfA, encoding PrfA, a master regulator for hly and numerous other virulence genes. Biofilm formation was significantly reduced in the prfA mutant, and to a lesser extent, in the hly mutant. Inactivation of either hly or prfA significantly reduced L. monocytogenes aggregation. However, both mutants adhered similarly to the wildtype parental strain on cantaloupe rind at either 25 or 37\u00b0C. Furthermore, growth and competitive fitness of the mutants on cantaloupe rind was not significantly impacted at either temperature. The findings suggest that, in spite of their involvement in biofilm formation and aggregation, these key virulence determinants may not be required for the ability of L. monocytogenes to colonize fresh produce.<\/jats:p>","DOI":"10.3390\/pathogens7010018","type":"journal-article","created":{"date-parts":[[2018,2,2]],"date-time":"2018-02-02T04:20:50Z","timestamp":1517545250000},"page":"18","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["The Listeria monocytogenes Key Virulence Determinants hly and prfA are involved in Biofilm Formation and Aggregation but not Colonization of Fresh Produce"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0204-9305","authenticated-orcid":false,"given":"Robert","family":"Price","sequence":"first","affiliation":[{"name":"Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27604, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victor","family":"Jayeola","sequence":"additional","affiliation":[{"name":"Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27604, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffrey","family":"Niedermeyer","sequence":"additional","affiliation":[{"name":"Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27604, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5307-2222","authenticated-orcid":false,"given":"Cameron","family":"Parsons","sequence":"additional","affiliation":[{"name":"Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27604, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophia","family":"Kathariou","sequence":"additional","affiliation":[{"name":"Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27604, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,2,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1201\/9781420015188.ch4","article-title":"Listeriosis in humans","volume":"Volume 30","author":"Painter","year":"2007","journal-title":"Listeria, Listeriosis and Food Safety"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3201\/eid1701.P11101","article-title":"Foodborne illness acquired in the United States-major pathogens","volume":"17","author":"Scallan","year":"2011","journal-title":"Emerg. Infect. Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1811","DOI":"10.4315\/0362-028X-65.11.1811","article-title":"Listeria monocytogenes virulence and pathogenicity, a food safety perspective","volume":"65","author":"Kathariou","year":"2002","journal-title":"J. Food Prot."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1236","DOI":"10.1016\/j.micinf.2007.05.011","article-title":"The epidemiology of human listeriosis","volume":"9","author":"Swaminathan","year":"2007","journal-title":"Microbes Infect."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"337","DOI":"10.4315\/0362-028X.JFP-15-387","article-title":"Fresh produce-associated listeriosis outbreaks, sources of concern, teachable moments, and insights","volume":"79","author":"Garner","year":"2016","journal-title":"J. Food Prot."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3201\/eid1901.120393","article-title":"Listeriosis outbreaks and associated food vehicles, United States, 1998\u20132008","volume":"19","author":"Cartwright","year":"2013","journal-title":"Emerg. Infect. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"944","DOI":"10.1056\/NEJMoa1215837","article-title":"Multistate outbreak of listeriosis associated with cantaloupe","volume":"369","author":"McCollum","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2506","DOI":"10.1128\/IAI.74.5.2505-2512.2006","article-title":"How the bacterial pathogen Listeria monocytogenes mediates the switch from environmental Dr. Jekyll to pathogenic Mr. Hyde","volume":"74","author":"Gray","year":"2006","journal-title":"Infect. Immun."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"623","DOI":"10.1038\/nrmicro2171","article-title":"Listeria monocytogenes\u2014From saprophyte to intracellular pathogen","volume":"7","author":"Freitag","year":"2009","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.mib.2011.01.005","article-title":"Regulation of Listeria virulence: PrfA master and commander","volume":"14","author":"Cain","year":"2011","journal-title":"Curr. Opin. Microbiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/j.tim.2012.04.006","article-title":"Listeriolysin O: The Swiss army knife of Listeria","volume":"20","author":"Hamon","year":"2012","journal-title":"Trends Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3969","DOI":"10.1128\/JB.00179-10","article-title":"The virulence regulator PrfA promotes biofilm formation by Listeria monocytogenes","volume":"192","author":"Lemon","year":"2010","journal-title":"J. Bacteriol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Travier, L., Guadagnini, S., Gouin, E., Dufour, A., Chenal-Francisque, V., Cossart, P., Olivo-Marin, J.C., Ghigo, J.M., Disson, O., and Lecuit, M. (2013). ActA promotes Listeria monocytogenes aggregation, intestinal colonization and carriage. PLoS Pathog., 9.","DOI":"10.1371\/journal.ppat.1003131"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"839","DOI":"10.2217\/fmb.12.57","article-title":"Optimizing the balance between host and environmental survival skills: Lessons learned from Listeria monocytogenes","volume":"7","author":"Xayarath","year":"2012","journal-title":"Future Microbiol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Maury, M.M., Tsai, Y.-H., Charlier, C., Touchon, M., Chenal-Francisque, V., Leclercq, A., Criscuolo, A., Gaultier, C., Roussel, S., and Brisabois, A. (2016). Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity. Nat. Genet.","DOI":"10.1038\/ng.3501"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3770","DOI":"10.1128\/JCM.01874-13","article-title":"\u201cEpidemic clones\u201d of Listeria monocytogenes are widespread and ancient clonal groups","volume":"51","author":"Cantinelli","year":"2013","journal-title":"J. Clin. Microbiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1468","DOI":"10.1093\/infdis\/jix118","article-title":"Listeria monocytogenes CadC regulates cadmium efflux and fine-tunes lipoprotein localization to escape the host immune response and promote infection","volume":"215","author":"Pombinho","year":"2017","journal-title":"J. Infect. Dis."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.micinf.2016.10.009","article-title":"1926\u20132016: 90 Years of listeriology","volume":"18","author":"Lebreton","year":"2016","journal-title":"Microbes Infect."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e02580-16","DOI":"10.1128\/AEM.02580-16","article-title":"Novel cadmium resistance determinant in Listeria monocytogenes","volume":"83","author":"Parsons","year":"2017","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1016\/S0092-8674(02)00905-4","article-title":"An RNA thermosensor controls expression of virulence genes in Listeria monocytogenes","volume":"110","author":"Johansson","year":"2002","journal-title":"Cell"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"6855","DOI":"10.1128\/AEM.01006-13","article-title":"Characterization of a potential Listeria monocytogenes virulence factor associated with attachment to fresh produce","volume":"79","author":"Bae","year":"2013","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Parsons, C., Costolo, B., Brown, P., and Kathariou, S. (2017). Penicillin-binding protein encoded by pbp4 is involved in mediating copper stress in Listeria monocytogenes. FEMS Microbiol. Lett., 364.","DOI":"10.1093\/femsle\/fnx207"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"757","DOI":"10.4315\/0362-028X.JFP-15-498","article-title":"Capacity of Listeria monocytogenes strains from the 2011 cantaloupe outbreak to adhere, survive, and grow on cantaloupe","volume":"79","author":"Osborne","year":"2016","journal-title":"J. Food Prot."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2758","DOI":"10.1128\/AEM.02844-06","article-title":"A mariner-based transposition system for Listeria monocytogenes","volume":"73","author":"Cao","year":"2007","journal-title":"Appl. Environ. Microbiol."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/7\/1\/18\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:53:23Z","timestamp":1760194403000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/7\/1\/18"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,2,1]]},"references-count":24,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2018,3]]}},"alternative-id":["pathogens7010018"],"URL":"https:\/\/doi.org\/10.3390\/pathogens7010018","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,2,1]]}}}