Modification of enrichment protocols for TECRA Listeria Visual Immunoassay method 995.22: collaborative study.
A collaborative study was conducted to validate new enrichment methods for the TECRA Listeria Visual Immunoassay (TLVIA). These new methods incorporate a newly formulated medium, TECRA Listeria Enrichrment Broth, which does not contain the highly toxic antifungal agent, cycloheximide. The new procedures will provide an alternative to the enrichment procedures described in AOAC Method 995.22. Three food types (raw ground beef, lettuce, and ice cream) were analyzed in the United States, and 2 food types (cooked turkey and cooked fish fillets) were analyzed in Australasia. Thirty collaborators participated in the study, 16 in Australasia and 14 in the United States. With the exception of one batch of ground beef, comparison of the proportion of positive test portions (p > or = 0.05) showed no significant difference between the TLVIA and the reference method for the 5 foods at 3 inoculation levels. For the one batch of naturally contaminated raw ground beef, the TLVIA gave significantly more confirmed positive results than the reference method.
Hughes
Denise
D
TECRA International, 13 Rodborough Rd, French's Forest, NSW 2086, Australia. denise.hughes@tecra.net
Dailianis
Angela
A
Duncan
Louise
L
Briggs
Julie
J
McKintyre
Deborah A
DA
Silbernagel
Karen
K
D000818:Animals; D002417:Cattle; D003470:Culture Media; D003611:Dairy Products / Q000382:microbiology; D005399:Fishes; D007118:Immunoassay; D007124:Immunoenzyme Techniques; D018545:Lactuca / Q000382:microbiology; D008087:Listeria / Q000737:chemistry*; D008460:Meat / Q000382:microbiology; D008892:Milk / Q000382:microbiology; D011202:Poultry Products / Q000382:microbiology; D012015:Reference Standards; D014422:Turkeys
D003470:Culture Media