Investigation article published in Zentralblatt für Veterinarmedizin. Reihe B. Journal of Veterinary Medicine. Series B

September 1^st, 1992

Twenty-two silage samples were analyzed for the presence of L. monocytogenes using five Listeria selective plating media, with and without previous selective enrichment step. L. monocytogenes was recovered from 3 samples by both procedures, but direct plating allowed the quantification of Listeria population. Two of these positive samples were implicated in outbreaks of listeriosis in sheep; the L. monocytogenes population in these samples was about 10(6) cells/g. The L. monocytogenes population in the other positive sample was 10(3) cells/g. Direct isolation of L. monocytogenes was only possible from LPM, PALCAM and LSAMm media. MOX and LSM media were not selective enough to allow direct Listeria isolation. In our hands, LSAMm was the most suitable plating medium for the direct isolation and specific quantification of L. monocytogenes from silage employing a red blood cells overlay technique

Fernandez-Garayzabal JF., Blanco MM., Vazquez-Boland JA., Briones V., Garcia JA., Delgado C., Domingo M., Marco J. and Dominguez L..

A Direct Plating Method for Monitoring the Contamination of Listeria monocytogenes in silage

A Direct Plating Method for Monitoring the Contamination of Listeria monocytogenes in silage

	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Servicio de Identificación y Caracterización Microbiana (ICM). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).