Separation of Listeria monocytogenes and Salmonella berta from a complex food matrix by aqueous polymer two-phase partitioning

Lett Appl Microbiol. 1998 Jan;26(1):47-50. doi: 10.1046/j.1472-765x.1998.00275.x.

Abstract

In the present study, the use of aqueous polymer two-phase systems for separation of pathogenic bacteria from a complex food sample was investigated. Three different two-phase systems, a polyethylene glycol 3350/dextran T 500, a methoxy polyethylene glycol 5000/dextran T 500 and a polyethylene glycol 3350/hydroxypropyl starch system, were compared at pH 3 and pH 6 for their capacity to separate the pathogenic bacteria Listeria monocytogenes and Salmonella berta from a Cumberland sausage. In all three phase systems, the food particles partitioned to the lower phase. Best performance was obtained by the polymer combinations, polyethylene glycol 3350/dextran T 500 and polyethylene glycol 3350/hydroxypropyl starch. In these systems, Salmonella berta partitioned to the hydrophobic upper phase both at pH 3 and pH 6 with an average partitioning ratio of 80% and a recovery of 56%. Listeria monocytogenes partitioned to the upper phase at pH 3 only with an average partitioning ratio of 72% and a recovery of 45%. This method may become a valuable tool for separation of bacteria from complex food matrices.

MeSH terms

  • Bacteriological Techniques*
  • Dextrans
  • Listeria monocytogenes / isolation & purification*
  • Meat Products / microbiology*
  • Methods
  • Polyethylene Glycols
  • Polymers
  • Salmonella / isolation & purification*
  • Starch / analogs & derivatives

Substances

  • Dextrans
  • Polymers
  • Polyethylene Glycols
  • Starch