Application of sialidase antibodies for the diagnosis of clostridial infections.

Two immunological methods, a sialidase-inhibition test and an ELISA, had been developed for a species-specific detection of sialidases (EC 3.2.1.18) secreted by growing cells of Clostridium perfringens, C. septicum, and C. sordellii. These assays were applied to samples from the infected tissues and cotton wool plugs soaked with wound exudate from patients suspected to be suffering from gas gangrene. The results from 72 patients were compared with bacteriological investigations of 67 homologous samples. From these, 35 patients were found to be infected with one or two of the clostridial species: thirty patients contained C. perfringens, six samples showed an immunologically positive reaction for C. septicum and eight for C. sordellii. In the case of C. perfringens, a high degree of coincidence between the immunological and the bacteriological analyses was obtained. However, in infections with C. septicum or C. sordellii the bacteriological and immunological tests did not agree well. The simple and rapid sialidase inhibition test or the slightly more time-consuming ELISA, which even detects low quantities of sialidase, can be applied for the specific diagnosis of infections caused by C. perfringens, thus allowing a species-specific detection of this bacterial species in two or six hours, respectively, even at an early stage of infection. This early diagnosis is a prerequisite for a specific and life-saving therapy of this severe disease.