[Use of the coagglutination reaction for typing Leptospira cultures]

The coagglutination test has been employed for the serologic typing of Leptospira cultures. A set of diagnostic agents with a maximum kit of anti-Leptospira sera of various serogroups has been prepared on the basis of a 10% suspension of formalin-treated Cowan 1 staphylococcus strain. To prepare the diagnostic agent, 0.1 portion of the serum and 9 portions of phosphate buffer solution, pH 7.2 should be added to 1 portion of a 10% staphylococcal suspension. 1% staphylococcal suspension has been prepared for control. The diagnosticum and the culture to type (0.01 ml each) have been mixed on the slides; the control test has been carried out with 1% non-sensitized staphylococcal suspension. The test has been read by microscopy in the dark visual field after the slides' 15 min exposure in a humid chamber. Typing of 17 Leptospira cultures of known serologic groups has yielded positive responses with the homologous diagnosticums only; no cross reactions have been recorded. The coagglutination test may be used for the rapid differentiation of mixed Leptospira cultures belonging to different serologic groups.