Phage receptor binding protein-based magnetic enrichment method as an aid for real time PCR detection of foodborne bacteria

Analyst. 2013 Oct 7;138(19):5619-26. doi: 10.1039/c3an01100c.

Abstract

We present a novel phage receptor binding protein-based magnetic separation and pre-enrichment method as an alternative to the immunomagnetic separation methods by replacing antibodies with bacteriophage receptor binding proteins (RBPs). We couple the proposed RBP-based magnetic separation with real time PCR for rapid, sensitive and specific detection of Campylobacter jejuni cells in artificially contaminated skim milk, milk with 2% fat and chicken broth. Recovery rates, assessed by real time PCR, were greater than 80% for the samples spiked with as low as 100 cfu mL(-1) of C. jejuni cells. The specificity of capture was confirmed using Salmonella Typhimurium as a negative control where no bacteria were captured on the RBP-derivatized magnetic beads. The combination of RBP-based magnetic separation and real time PCR improved PCR sensitivity and allowed the detection of C. jejuni cells in milk and chicken broth samples without a time consuming pre-enrichment step through culturing. The total sample preparation and analysis time in the proposed RBP-based enrichment method coupled with real time PCR was less than 3 h.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Campylobacter jejuni / isolation & purification*
  • Campylobacter jejuni / metabolism
  • Cattle
  • Chickens
  • Food Microbiology / methods*
  • Magnetic Fields*
  • Milk / microbiology*
  • Protein Binding / physiology
  • Real-Time Polymerase Chain Reaction / methods*
  • Receptors, Virus / analysis*
  • Receptors, Virus / metabolism

Substances

  • Receptors, Virus