Test sensitivity of a commercial serine protease digestion kit for the detection of Trichinella spiralis and Trichinella pseudospiralis larvae in pig muscle

Food Microbiol. 2019 Apr:78:99-103. doi: 10.1016/j.fm.2018.10.012. Epub 2018 Oct 22.

Abstract

The reference method for Trichinella detection at meat inspection is the magnetic stirrer method (MSM) utilising HCl-pepsin for pooled sample digestion. Due to availability and quality issues with pepsin, alternative digestion methods are being offered, such as the Priocheck Trichinella AAD kit (T-AAD), based on serine endopeptidase digestion. In this study the T-AAD kit was compared to the reference method. Minced pork samples were spiked with T. spiralis muscle larvae (ML) with- and without capsule or T. pseudospiralis ML, and analysed with both tests. Test results of individually spiked test samples were analysed by generalised linear modelling. The T-AAD test kit was comparable to the reference method for the qualitative detection of T. spiralis in pigs, but not quantitatively. Overall, 94% of spiked T. spiralis were recovered using MSM against 75.2% when using T-AAD (p < 0.0001). Using the MSM 80.0% of spiked T. pseudospiralis were recovered against 20% with the T-AAD (p < 0.0001). Based on our experience with the T-AAD kit, we strongly recommend validating the method on site prior to introduction into routine diagnostic laboratories, but this will not alleviate the poor test sensitivity of the T-AAD for the detection of T. pseudospiralis.

Keywords: Meat inspection; Pepsin; Serine endopeptidase; Trichinella.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Food Inspection
  • Larva / physiology*
  • Magnetic Fields
  • Male
  • Meat / parasitology*
  • Muscles / parasitology*
  • Reagent Kits, Diagnostic
  • Sensitivity and Specificity
  • Serine Endopeptidases / metabolism
  • Serine Proteases / metabolism*
  • Swine
  • Swine Diseases / diagnosis*
  • Swine Diseases / parasitology
  • Trichinella / isolation & purification*
  • Trichinella spiralis / isolation & purification*
  • Trichinellosis / diagnosis
  • Trichinellosis / parasitology
  • Trichinellosis / veterinary

Substances

  • Reagent Kits, Diagnostic
  • Serine Proteases
  • Serine Endopeptidases