title: Fate of Listeria spp. on parsley leaves grown in laboratory and field cultures.
abstract: OBJECTIVE
  To investigate the population dynamics of Listeria monocytogenes and Listeria innocua on the aerial surfaces of parsley.
  
  
  RESULTS
  Under 100% relative humidity (RH) in laboratory and regardless of the inoculum tested (10(3)-10(8) CFU per leaf), counts of L. monocytogenes EGDe, LO28, LmP60 and L. innocua CIP 80-12 tended towards approx. 10(5) CFU per leaf. Under low RH, Listeria spp. populations declined regardless to the inoculum size (10(4)-10(8) CFU per leaf). L. innocua CIP 80-12 survived slightly better than L. monocytogenes in the laboratory and was used in field cultures. Under field cultures, counts of L. innocua decreased more rapidly than in the laboratory, representing a decrease of 9 log(10) in 2 days in field conditions compared to a decrease of 4.5 log(10) in 8 days in the laboratory. Counts of L. innocua on tunnel parsley cultures were always higher (at least by 100 times) than those on unprotected parsley culture.
  
  
  CONCLUSIONS
  Even with a high inoculum and under protected conditions (i.e. plastic tunnels), population of L. monocytogenes on the surface of parsley on the field would decrease by several log(10) scales within 2 days.
  
  
  CONCLUSIONS
  Direct contamination of aerial surfaces of parsley with L. monocytogenes (i.e. through contaminated irrigation water) will not lead to contaminated produce unless it occurs very shortly before harvest.
authors.affiliation: UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, F-84000 Avignon, France. ndreux@avignon.inra.fr
authors.forename: N
authors.initials: N
authors.lastname: Dreux
authors.forename: C
authors.initials: C
authors.lastname: Albagnac
authors.forename: F
authors.initials: F
authors.lastname: Carlin
authors.forename: C E
authors.initials: CE
authors.lastname: Morris
authors.forename: C
authors.initials: C
authors.lastname: Nguyen-The
mesh_terms: D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D005516:Food Microbiology; D006813:Humidity; D008087:Listeria / Q000254:growth & development*; D008089:Listeria monocytogenes / Q000254:growth & development; D050296:Microbial Viability; D028528:Petroselinum / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology*; D013997:Time Factors; D014871:Water Microbiology