A coagglutination test with antibody-sensitized staphylococci for rapid and simple diagnosis of bacterial and viral diseases of fish.

Abstract

The application of a coagglutination test for the diagnosis of diseases in fish was studied using staphylococci specifically sensitized with antibodies against the bacteria causing bacterial kidney disease (BKD), furunculosis, vibriosis and goldfish ulcer disease, and also against the virus causing infectious pancreatic necrosis (IPN). This method proved to be a simple, rapid and reliable diagnostic test suitable for use in the laboratory or field and requires no special apparatus.Procedures for this method are summarized as follows : 1. The kidney or affected tissue samples from the diseased fish are homogenized in four to nine times their volume of PBS or HANKS' BSS. If the antigen is heat stable, it is also heated in a boiling water bath for 30 min.2. The supernatant material is collected after centrifugation at 4000 rpm for 20 min. This may be omitted if a centrifuge is unavailable.3. One drop of the supernatant material and one drop of antibody-sensitized staphylococci suspension are mixed on a glass slide and incubated in a wet chamber at room temperature. The slide is examined after 30, 60 and 90 min.4. If coagglutination is observed, the infected fish should be examined using another method to confirm the diagnostic results.