Early diagnosis of clostridial gas gangrene using sialidase antibodies

In order to improve the diagnosis of gas gangrene, especially at an early stage of infection, new ways for the detection of the responsible Clostridia were investigated. Sialidase, known to be excreted in large amounts by the most frequently occurring myonecrotizing clostridial species, Clostridium perfringens, Clostridium septicum, and Clostridium sordellii, was isolated. With polyclonal antibodies raised against these enzymes, two immunological assays were established, which are directed against the sialidase activity (sialidase inhibition test) and the enzyme protein ('sandwich'-ELISA), respectively. Using these assays, species-specific information about the presence of clostridial sialidase was obtained within 50 min or 6 h. Animal tests revealed that both assays are applicable 8-12 h after clostridial infection, using resected tissues or wound fluids for estimations. The assays allow specific, sensitive, and quantitative measurement of clostridial sialidases, and no significant interference by sialidases from other microbes or from host tissues occurred. The applicability of the new assays for an early diagnosis of gas gangrene in human patients is discussed.