Protein characteristics of leptospiras after in vitro subcultivation

Abstract

Leptospirosis is a zoonosis of worldwide distribution. Current methods for the direct detection of leptospires are either slow or of limited reliability so
that serology is often the most appropriate diagnostic method. The microscopic agglutination test (MAT) using live bacteria is the reference serological test. For longterm preservation leptospiras are usually maintained by periodic subculture into fresh media because the conventional methods such as freeze-drying have reported inconsistent results for storing leptospiras. Although this technique is very simple the question is to which extent such procedure affects the protein structure of the outer membrane with its key antigens. The aim of the study was to identify potential protein variations of serovars Hardjo and Grippotyphosa after thirty consecutive subcultivations by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS). The overall analysis of the leptospiral proteins by SDS-PAGE demonstrated minor differences in the intensities of some bands, while changes in protein expression were not detected.