Application of an automated immunomagnetic separation–enzyme immunoassay for the detection of Salmonella enterica subspecies enterica from poultry environmental swabs

An automated immunomagnetic separation (IMS) and enzyme immunoassay (EIA) was applied to the detection of Salmonella enterica subspecies enterica serotypes from poultry environmental samples. The analytical sensitivity and specificity of the IMS–EIA for 46 S. enterica serotypes and 33 non-salmonellae isolates belonging to 21 different genera were 91.3% and 90.9%, respectively. From post enrichment S. enterica cultures, the limit of detection of the assay was estimated at 104–106 CFU/mL. Application of IMS–EIA on 850 naturally contaminated poultry environmental samples achieved 98.4% sensitivity and 96.8% specificity, as compared with a standard culture reference method performed concurrently on the same set of samples. The IMS–EIA described, allows for the identification of suspect positive samples within 48 h of testing versus 4–6 days required by standard culture methods while significantly reducing the materials and labour required for the detection of S. enterica serotypes in poultry environmental samples.