[Presence of Listeria monocytogenes and Listeria sp. in fresh and cured sausages. Use of different conditions of time and temperature for incubation].

Abstract

Two different temperatures for enrichment of Listeria monocytogenes and related species have been studied (1) cold enrichment at 4 degrees C (2) enrichment at 30 degrees C (FDA method). Also, two selective media for isolation were tested: Acriflavine-Ceftazidime agar (A.C.) and Palcam agar. We have studied 72 samples of dry-cured sausage (called 'longaniza') at different stages of maturation: fresh, semi-cured and cured samples. The most efficient method was cold enrichment at 4 degrees C during 5 days followed by isolation in Palcam agar, but results were only significant for fresh sausages (P < 0.05).