Simple solutions to false-positive staphylococcal enterotoxin assays with seafood tested with an enzyme-linked immunosorbent assay kit (TECRA).
AUTOR(ES)
Park, C E
RESUMO
The TECRA kit, a commercial staphylococcal enterotoxin visual immunoassay kit, is an enzyme-linked immunosorbent assay system which utilizes polyvalent antisera against staphylococcal enterotoxin types A to E. The test is simple and rapid to perform (4 h) and has therefore been widely used for screening purposes. In this study, the TECRA kit produced a number of false-positive reactions with seafood; 25% of 218 samples of seven types of seafood gave false-positive results, particularly shellfish such as mussels (85%), clams (32%), oysters (23%), winkles (20%), and squid (13%). Some nonshellfish samples also gave false-positive results with the TECRA kit (smelt [20%] and trout [10%]). The substance contributing to the false-positive results differed from true staphylococcal enterotoxins in that it was: (i) heat labile, being completely inactivated by heating for 3 min at 70 degrees C, compared with 5% inactivation of true staphylococcal enterotoxins by the same heat treatment, (ii) in a selective reaction with normal rabbit or calf serum (nonspecific reactions were completely abolished by these sera, whereas staphylococcal enterotoxins were not affected), and (iii) incapable of binding to a copper-chelate Sepharose gel (all of the substance remained in the unbound wash fraction, whereas staphylococcal enterotoxins were quantitatively bound to the gel). The false-positive reactions occurring with seafood were not associated with substances produced by microorganisms, since the bacterial isolates from the samples did not give positive results with the TECRA kit.(ABSTRACT TRUNCATED AT 250 WORDS)
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=182259Documentos Relacionados
- Serum albumin treatment to eliminate false-positive results with laboratory rodent specimens tested by rotazyme enzyme-linked immunosorbent assay.
- False-Positive Aspergillus Galactomannan Enzyme-Linked Immunosorbent Assay Results In Vivo during Amoxicillin-Clavulanic Acid Treatment
- Heterophile Antibodies to Bovine and Caprine Proteins Causing False-Positive Human Immunodeficiency Virus Type 1 and Other Enzyme-Linked Immunosorbent Assay Results
- Method for avoiding false-positive results occurring in immunoglobulin M enzyme-linked immunosorbent assays due to presence of both rheumatoid factor and antinuclear antibodies.
- Nonspecific reactions of a commercial enzyme-linked immunosorbent assay kit (TECRA) for detection of staphylococcal enterotoxins in foods.