Early detection of streptococcal group antigens in skin samples by latex particle agglutination

The streptococcal group antigens (A to G) were researched in skin biopsy specimens by a latex agglutination technique using commercial (Slidex Streptokit bio-Mérieux and Streptex Wellcome) and experimental reagents. Twenty-seven patients with obvious cutaneous infections (12 cases of erysipelas, nine cases of cellulitis, and six cases of necrotizing fasciitis) and 27 age- and sex-matched controls were studied. Our preliminary data demonstrated the possibility of an early diagnosis of streptococcal cutaneous infections involving the deep dermis and/or hypodermis. We used a latex agglutination technique that is quite specific and gives a better sensitivity (0.63) than either conventional bacteriologic cultures on needle aspiration or skin biopsy specimens.