Development and evaluation of an immunomagnetic separation-ELISA for the detection of Staphylococcus aureus thermostable nuclease in composite milk.
An ELISA method based on monodisperse magnetic beads was developed for the detection of Staphylococcus aureus thermostable nuclease (TNase) in composite milk, wherein S. aureus TNase is captured by magnetic beads coated with monoclonal antibodies directed against TNase and subsequently detected by an enzyme-labelled MAb against the same antigen. Sensitivity of the test was approximately 1 ng TNase, which corresponds to the amount of TNase produced and secreted by approximately 10(5) S. aureus per ml. The Immuno Magnetic Separation (IMS)-ELISA detected TNase in samples from which no S. aureus could be demonstrated on culture. The total test time is 3 h and can be performed either on preserved or fresh milk. The method may be automated.
Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine, Oslo. siamak.p.yazdankhah@veths.no
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Sølverød
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Simonsen
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Olsen
D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D004396:Coloring Agents / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D005260:Female; D018189:Immunomagnetic Separation / Q000379:methods / Q000662:veterinary; D008414:Mastitis, Bovine / Q000175:diagnosis* / Q000276:immunology; D008836:Micrococcal Nuclease / Q000032:analysis / Q000737:chemistry; D008863:Microspheres; D008892:Milk / Q000382:microbiology; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000276:immunology / Q000302:isolation & purification*; D014048:Tolonium Chloride / Q000737:chemistry
D000911:Antibodies, Monoclonal; D004396:Coloring Agents; D014048:Tolonium Chloride; D008836:Micrococcal Nuclease