title: Detection of Salmonella spp. survival and virulence in poultry feed by targeting the hilA gene.
abstract: OBJECTIVE
  The objectives of this work were to evaluate immunomagnetic beads and a reverse transcriptase (RT)-PCR method for the detection of Salmonella inoculated into feed. In addition, a reverse transcriptase (RT)-PCR method was evaluated for quantifying virulence gene hilA expression of Salmonella ssp. in poultry feed matrices and utilized to determine the influence of poultry feed environmental factors on Salmonella hilA expression.
  
  
  RESULTS
  An immunomagnetic separation technique was evaluated for increased recovery of Salmonella from feed. Salmonella cultures were inoculated into feed samples and exposed to heat treatments of 70°C and sampled periodically. From these samples, RNA was collected and hilA gene expression was measured relative to the housekeeping 16S rRNA gene. The immunomagnetic bead protocol increased recovery by 1 log. The up-regulation of hilA was demonstrated after 5 and 10 min of inoculated feed samples being exposed to heat treatment.
  
  
  CONCLUSIONS
  From this work, the data indicate that the ability to detect live Salmonella cells in feed samples may be increased by targeting the hilA gene.
  
  
  CONCLUSIONS
  Foodborne salmonellosis originating from poultry is a major problem, and feed is a leading source of contamination in poultry, but detection in feed is complicated by low concentrations. The assays and experiments in this study examine possible improvements to recovery and detection of Salmonella in feed.
authors.affiliation: Center for Food Safety - Department of Food Science, University of Arkansas, Fayetteville, AR, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Park
authors.forename: R
authors.initials: R
authors.lastname: Jarquin
authors.forename: I
authors.initials: I
authors.lastname: Hanning
authors.forename: G
authors.initials: G
authors.lastname: Almeida
authors.forename: S C
authors.initials: SC
authors.lastname: Ricke
mesh_terms: D000821:Animal Feed / Q000382:microbiology*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D005506:Food Contamination; D005798:Genes, Bacterial; D018189:Immunomagnetic Separation / Q000379:methods / Q000662:veterinary; D057230:Limit of Detection; D011200:Poultry; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D015534:Trans-Activators / Q000235:genetics*; D015854:Up-Regulation; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C102236:HilA protein, Salmonella; D015534:Trans-Activators