Psychrobacter immobilis isolated from foods: characteristics and identification

A total of 15 strains of Psychrobacter immobilis isolated from animal sourc es, e.g. cheese, fish and poultry, were tested. A commercial diagnostic kit NEFERMtest 24, conventional tests and determination of fatty acids were us ed for identification. By using the results of NEFERMtest 24 and numerical identification system TNW version 6.0 the identification was successful on the species level (46.7%) while the correct species identification by using conventional tests increased up to 86.7%. All 9 saccharolytic strains incl uding 7 Czech isolates were identified in most cases on an excellent or ver y good level by both methods based on biochemical reactions. On the other h and, the identification of 6 asaccharolytic strains was unsuccessful especi ally by NEFERMtest 24. While 4 asaccharolytic strains were identified corre ctly on the basis of conventional tests on species or genus level, incorrec t identification on species level, for example Ralstonia paucula, Comamonas terrigena, Oligella ureolytica, Moraxella lincolnii and Psychrobacter phen ylpyruvicus, was found by using NEFERMtest 24. Determination of fatty acid composition by MIDI System confirmed the species identification of 9 out of the 10 tested strains of P. immobilis and 1 tested strain of Psychrobacter sp.