title: Rapid Salmonella detection in experimentally inoculated equine faecal and veterinary hospital environmental samples using commercially available lateral flow immunoassays.
abstract: BACKGROUND
  Salmonella enterica is the most commonly reported cause of outbreaks of nosocomial infections in large animal veterinary teaching hospitals and the closure of equine hospitals. Rapid detection may facilitate effective control practices in equine populations. Shipping and laboratory testing typically require ≥48 h to obtain results. Lateral flow immunoassays developed for use in food-safety microbiology provide an alternative that has not been evaluated for use with faeces or environmental samples.
  
  
  OBJECTIVE
  We aimed to identify enrichment methods that would allow commercially available rapid Salmonella detection systems (lateral flow immunoassays) to be used in clinical practice with equine faecal and environmental samples, providing test results in 18-24 h.
  
  
  METHODS
  In vitro experiment.
  
  
  METHODS
  Equine faecal and environmental samples were inoculated with known quantities of S. enterica serotype Typhimurium and cultured using 2 different enrichment techniques for faeces and 4 enrichment techniques for environmental samples. Samples were tested blindly using 2 different lateral flow immunoassays and plated on agar media for confirmatory testing.
  
  
  RESULTS
  In general, commercial lateral flow immunoassays resulted in fewer false-negative test results with enrichment of 1 g faecal samples in tetrathionate for 18 h, while all environmental sample enrichment techniques resulted in similar detection rates. The limit of detection from spiked samples, ∼4 colony-forming units/g, was similar for all methods evaluated.
  
  
  CONCLUSIONS
  The lateral flow immunoassays evaluated could reliably detect S. enterica within 18 h, indicating that they may be useful for rapid point-of-care testing in equine practice applications. Additional evaluation is needed using samples from naturally infected cases and the environment to gain an accurate estimate of test sensitivity and specificity and to substantiate further the true value of these tests in clinical practice.
authors: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, USA.
authors: B A
authors: BA
authors: Burgess
authors: N R
authors: NR
authors: Noyes
authors: D S
authors: DS
authors: Bolte
authors: D R
authors: DR
authors: Hyatt
authors: D C
authors: DC
authors: van Metre
authors: P S
authors: PS
authors: Morley
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods / Q000662:veterinary*; D004783:Environmental Microbiology; D005243:Feces / Q000382:microbiology*; D006736:Horses; D006762:Hospitals, Animal; D012475:Salmonella / Q000302:isolation & purification*
keywords: Salmonella; culture; faeces; horse; lateral flow immunoassay