Hemolytic properties of strains of the genus Yersinia. II. Evaluation on liquid media
Zaremba, M.; Jaworowska, J.; Sacha, P.
Medycyna Doswiadczalna i Mikrobiologia 37(2): 74-81
1985
ISSN/ISBN: 0025-8601 PMID: 4033297 Document Number: 261151
Hemolytic activity of Y. entercolitica was tested in the supernatants of liquid cultures (trypticase soy broth, TSB). Quantitative method of evaluation of the activity was standardized, the error being calculated as 4%. Of the 10 Y. enterocolitica strains producing direct hemolysins in TSA (trypticasase soy agar) medium, 8 showed hemolytic activity in supernatants of 48-h cultures at 22.degree. C, and 3 in cultures at 37.degree. C. Hemolytic activity ranged from 5.2-33.3% at 22.degree. C, and from 5.8-18.6% at 37.degree. C. In the supernatants of liquid cultures of 21 Y. enterocolitica strains, hemolytic activity after contact with erythrocytes and lecithin ranged from 4.2-32.5% at 22.degree. C and from 6.2-17.6% at 37.degree. C. Coincident results of the hemolytic reaction upon growth on TSA solid medium and in liquid TSB culture supernatants at 22 and 37.degree. C was observed in 2 strains for direct hemolysins and in 6 strains for indirect hemolysins. In other strains hemolytic reactions were variable. One strain of Y. pseudotuberculosis, producing indirect hemolysin on TSA with 5% sheep blood and 0.01% lecithin at 22.degree. C, was found to show hemolytic activity in liquid culture supernatant under the same conditions. Previous studies on hemolytic activity on solid media (TSA), and the present results obtained in liquid media (TSB), with rabbit, sheep, and human blood, point to the production of different hemolysins by Yersinia.