A method for improving the original Galton microtechnique for detecting leptospiral antibodies has been developed. Simultaneous titrations were performed on 281 animal and human sera and 17 hyperimmune sera with the microscopic agglutination (MA) test and the improved microtechnique. Reproducibility of the improved microtechnique was determined independently on 65 animal sera by two laboratory sections. The results obtained by comparing positive test data from human and animal sera indicated that agreement between the original MA test and this new method exceeded 94%, whereas the original Galton microtechnique and the original MA test agreed in a maximum of 77% of the tests. This study indicates that the results obtained with the improved microtechnique are much more comparable to results obtained with the original MA test than are those obtained with the original Galton microtechnique.

A method for improving the original Galton microtechnique for detecting leptospiral antibodies has been developed. Simultaneous titrations were performed on 281 animal and human sera and 17 hyperimmune sera with the microscopic agglutination (MA) test and the improved microtechnique. Reproducibility of the improved microtechnique was determined independently on 65 animal sera by two laboratory sections. The results obtained by comparing positive test data from human and animal sera indicated that agreement between the original MA test and this new method exceeded 94%, whereas the original Galton microtechnique and the original MA test agreed in a maximum of 77% of the tests. This study indicates that the results obtained with the improved microtechnique are much more comparable to results obtained with the original MA test than are those obtained with the original Galton microtechnique.

INE R. SULZER, C. A. SANTA ROSA, AND MICHAEL J. FIELDS. Application of a microtechnique to the agglutination test for leptospiral antibodies. Appl. Microbiol. 13:81-85. 1965.-A microtechnique has been developed and adapted successfully to the microscopic agglutination test with live antigens for detection of leptospiral antibodies. Simultaneous titrations were performed by the conventional microscopic agglutination test and the microtechnique. When the microtechnique was used to screen 50 unknown leptospiral strains with a battery of hyperimmune sera, 98% agreement was obtained with the conventional procedure. Conmparative data on 635 tests on these 50 cultures established the reliability of the microtechnique. Results with the two tests on 46 human sera revealed 93% agreement in the detection of leptospiral antibodies. The validity and reliability of the microtechnique obtained in these comparative studies suggests that it can be used as a valuable screening procedure for the microscopic agglutination test for preliminary cross agglutination studies on unknown strains and for the detection of leptospiral antibodies in human and animal sera.

Forty-two of 46 sera (91%) from turtles (Pseudenzys scripta-elegans) in Georgia had microscopic agglutination titers of 200 or greater to Leptospira serotype tarassovi. Leptospires were isolated from eight of ten hamsters (80%) inoculated with surface water collected from the settling ponds of the untreated sewage disposal system in which the turtles lived. Leptospires were also isolated from 12 of 20 hamsters (60%) inoculated with turtle kidney suspensions and six of 20 hamsters (30%) inoculated with turtle cloacal suspension. Hamster brain appeared to be the best tissue for recovering leptospires since 24 of the 41 isolates (59%) from the 26 culture-positive hamsters were from the brain and 17 (41%) were from the kidney. Six of the 41 isolates from hamsters that had been injected with surface water and turtle kidney and cloacal tissue were identified as being identical to serotype tarassovi.