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Updated: Jul 31, 2026

Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
Published on: August 9, 2011
An improved selective isolation medium for the recovery of Listeria monocytogenes from smoked fish
A A N Neamatallah1, S J Dewar, B Austin
1School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh, UK.
Aims:
The aim of this study was to improve the selective isolation of Listeria monocytogenes from smoked haddock fillets.
Methods And Results:
Listeria selective agar (LSA)--Oxford formulation was supplemented with 25 microg x ml(-1) of colistin sulphate and 30 microg x ml(-1) of nalidixic acid. Inocula from four smoked haddock fillets produced colonies (approx. 2-13 bacteria x g(-1)), identified as L. monocytogenes, on LSA supplemented with antimicrobial compounds (MLSA). Moreover, there was only negligible evidence of bacteria which were not L. monocytogenes on MLSA. In contrast, LSA supported dense bacterial growth, which was not equated with L. monocytogenes.
Significance And Impact Of The Study:
The modified medium permitted the recovery of L. monocytogenes from smoked haddock fillets and reduced the growth of contaminating bacteria.

