Is Listeria innocua 2030c, a tetracycline-resistant strain, a suitable marker for replacing L-monocytogenes in challenge studies with cold-smoked fish?

The suitability of Listeria innocua 2030c, a tetracycline-resistant strain, to be used as an indicator for replacing Listeria monocytogenes in challen ge studies with cold-smoked fish was ascertained. L. innocua 2030c was comp ared to serovars 4b and 1/2c of L. monocytogenes, the major types isolated from Portuguese cold-smoked fish products. Growth curves at 30 degreesC, gr owth/survival patterns at 30 degreesC under exposure to different times and concentrations of ozone and sensitivity to Carnobacterium divergens V41 an d C piscicola V1 and their bacteriocins V41 and V1, were determined. No imp ortant differences between L. innocua 2030c and L. monocytogenes 4b and 1/2 c were found, therefore L. innocua 2030c can be considered a suitable indic ator for replacing those L. monocytogenes strains in challenge studies. (C) 2001 Elsevier Science Ltd. All rights reserved.