Phadebact coagglutination test for the rapid identification of pneumococci

Conventional tests for the presumptive identification of Streptococcus pneumoniae from culturally similar non-pneumococcal alpha hemolytic streptococci include optochin sensitivity, bile solubility and inulin fermentation. These tests require up to 24 h for completion. In this paper we report the evaluation of a simple and rapid coagglutination procedure that requires less than 5 min. Of the 150 clinical isolates of pneumococci that were identified by conventional methods, all were correctly recognized by the Phadebact coagglutination technique within one minute. Forty strains of non-pneumococcal alpha hemolytic streptococci were also tested to determine the specificity of the method. Of these, 32 (80%) did not react in either the typing or control reagents, whereas 8 (20%) showed coagglutination in the control. The Phadebact coagglutination test for the definitive identification of pneumococci is simple, rapid, and easy to perform and interpret.