title: Microbial population profiles of the microflora associated with pre- and postharvest tomatoes contaminated with Salmonella typhimurium or Salmonella montevideo.
abstract: OBJECTIVE
  To determine the microflora profiles of pre- and postharvest tomatoes contaminated with Salmonella montevideo or S. typhimurium DT104.
  
  
  RESULTS
  Salmonella montevideo or S. typhimurium was inoculated onto the flowers of tomato plants with the microflora of the subsequent fruit examined using a combination of Source Carbon Utilization and 16S rDNA-PCR profiling. From 16S rDNA profiles it was evident that tomatoes derived from Salmonella inoculated plants harboured a different microbial population compared to nontreated controls. The same result was observed for tomatoes inoculated at postharvest and subsequently stored for 14 days at 15 degrees C. From sequencing analysis it was found that tomatoes derived from Salmonella inoculated plants but testing negative for the enteric pathogen, frequently harboured Enterobacter and Bacillus spp. In contrast, both bacterial types were not found associated with tomatoes testing positive for Salmonella.
  
  
  CONCLUSIONS
  Salmonella introduced onto tomatoes at pre- or postharvest alters the composition of the microbial community. The presence of Enterobacter and Bacillus spp negatively affects the persistence of Salmonella on preharvest tomatoes.
  
  
  CONCLUSIONS
  Salmonella appears to modify rather than become integrated into the microbial communities associated with tomatoes. Yet, the presence of antagonistic bacteria appears to reduce the persistence of the enteric pathogen.
authors.affiliation: Department of Food Science, University of Guelph, Guelph, ON, Canada.
authors.forename: X
authors.initials: X
authors.lastname: Shi
authors.forename: Z
authors.initials: Z
authors.lastname: Wu
authors.forename: A
authors.initials: A
authors.lastname: Namvar
authors.forename: M
authors.initials: M
authors.lastname: Kostrzynska
authors.forename: K
authors.initials: K
authors.lastname: Dunfield
authors.forename: K
authors.initials: K
authors.lastname: Warriner
mesh_terms: D002244:Carbon / Q000378:metabolism; D015169:Colony Count, Microbial; D015180:Electrophoresis, Gel, Two-Dimensional; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D018551:Solanum lycopersicum / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D012336:RNA, Ribosomal, 16S; D002244:Carbon