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Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
12:50

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes

Published on: August 9, 2011

Growth of Listeria monocytogenes on vacuum-packaged horsemeat for human consumption

P Bonilauri1, G Liuzzo, G Merialdi

  • 1Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione di Reggio Emilia, Via Pitagora 2, 42100 Reggio Emilia, Italy.

Meat Science
|November 9, 2011
PubMed

Insights

Vacuum-packaged horsemeat stored at refrigeration temperatures showed significant Listeria monocytogenes growth. This study tracked bacterial levels over 42 days, indicating potential food safety risks from this pathogen in processed meat products.

Area of Science:

  • Food Microbiology
  • Food Safety
  • Meat Science

Background:

  • Listeria monocytogenes is a significant foodborne pathogen.
  • Vacuum packaging is a common meat preservation method.
  • Refrigeration is critical for controlling microbial growth in meat.

Purpose of the Study:

  • To determine the growth potential of Listeria monocytogenes (serotype 4b) in vacuum-packaged horsemeat under refrigeration.
  • To assess the microbial dynamics and safety of horsemeat during cold storage.

Main Methods:

  • Horsemeat samples were inoculated with Listeria monocytogenes.
  • Samples were vacuum-packaged and stored at 4±1 °C for 42 days.
  • Listeria monocytogenes counts and pH were monitored periodically.

Main Results:

  • A 7-day lag phase for Listeria monocytogenes growth was observed.
  • Bacterial levels increased to 5.78 log(10) CFU/g by day 42.
  • No significant variations in surface pH were detected during storage.

Conclusions:

  • Listeria monocytogenes can grow in vacuum-packaged horsemeat at refrigeration temperatures.
  • Extended storage periods increase the risk of pathogen proliferation.
  • This highlights the need for strict temperature control and monitoring in horsemeat processing and storage.

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