Meeting Abstract
Being able to accurately measure the immunocompetence of free living, non-model animals would be of great value; making it possible to make comparisons across species, niche, sex, and life-history stage. However, currently it is very difficult to measure even just one aspect of immunocompetence. The methods currently used for determining innate immune capacity (phytohemagglutinin assay (PHA) and bacteria killing assays (BKA)) are problematic and often don’t work for non-model species (Martin et. al., 2004). We have developed a variation on a traditional BKA technique that can accurately and efficiently assess immune capabilities of birds by exposing static bacteria to the antibodies and complement contained in small volumes of blood plasma by observing bacterial growth using a spectrophotometer. In principle, the greater the cell death caused by plasma, the lower the final bacterial cell number will be following exposure to complement in bird plasma. Our variation on the traditional BKA takes a relatively short amount of time to conduct, is cost effective compared to plate count assays, and utilizes a minimal amount of plasma making it useful for small vertebrates and potentially even invertebrates. Here we present results utilizing this technique to determine complement-mediated killing in various passerine groups, in comparison with heterophil:lymphocyte ratio. The heterophil:lymphocyte ratio technique and traditional bacterial plate counts were used to validate the data observed in the use of our novel BKA.
