Recovery of Listeria monocytogenes on selective agar media in a collaborative study using reference samples.
Sixteen laboratories compared counts of Listeria monocytogenes in reference samples using Blood agar, Palcam(y) agar and Oxford agar. Significant differences were found between laboratories. The mean counts on Blood agar were significantly higher than on Palcam(y) or Oxford agar. The mean counts on Palcamy agar were somewhat higher than on Oxford agar (only after 48 h incubation), but no significant difference was found. Addition of egg yolk to Palcam agar seems to be beneficial for the recovery of sublethally injured cells. Recovery of L. monocytogenes was higher after 48 h incubation for all media tested.
in 't Veld
P H
PH
Laboratory for Water and Food Microbiology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
de Boer
E
E
D000362:Agar; D000704:Analysis of Variance; D015169:Colony Count, Microbial; D003470:Culture Media; D008089:Listeria monocytogenes / Q000254:growth & development / Q000302:isolation & purification*
D003470:Culture Media; D000362:Agar