The use of a rapid Salmonella latex serogrouping test (Spectate) to assist in the confirmation of ELISA-based rapid Salmonella screening tests.
Spectate, a 10 min, simple, latex-based agglutination test for serogrouping of salmonellae, has been investigated as a tool to assist in the confirmation of ELISA presumptive positive broth samples when screening for salmonellae in foods. When obtaining a combined ELISA and Spectate positive result, there was a 90% (27/30) confidence limit of a genuine positive result, some one or two working days quicker than the traditional methods. Of the 10% (3/30) that were not confirmed as salmonellas, two gave a Spectate result which is advised as being a possible Citrobacter spp. and one sample gave a positive confirmation by Spectate only, which suggested a failure of the traditional confirmation process, a finding confirmed at other sites. Extensive studies performed at several food company microbiology laboratories showed Spectate to be a useful additional tool in the confirmation process of ELISA screening techniques for salmonellae in food. Additionally the concept of a "false positive' may need to be refined to that of a "not culturally' positive, given the apparent possible failure of the traditional confirmation methods.
Cheesbrough
S
S
Rhône-Poulenc Diagnostics Ltd, West of Scotland Science Park, Glasgow, UK.
Donnelly
C
C
D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005516:Food Microbiology; D007841:Latex Fixation Tests / Q000379:methods*; D008863:Microspheres; D011237:Predictive Value of Tests; D012475:Salmonella / Q000145:classification / Q000302:isolation & purification*