VIRULENCE AND PATHOGENICITY OF YERSINIA-ENTEROCOLITICA UNDER DIFFERENT TEST SYSTEMS

Eight clinical isolates of Y. enterocolitica were tested for various p athogenicity and virulence markers. Seven of the eight strains gave po sitive results for Congo red magnesium oxalate (CRMOX) agar test and a utoagglutination test at 37 degrees C. Seven strains bound crystal vio let (CV) completely at 37 degrees C but not at 25 degrees C. One strai n (Y-1) bound CV partially. None of the strains showed pyrazimamidase activity indicating these strains to be virulent. Cells of all but one strains were aggregated by 1.8 M and 3.2 M concentration of ammonium sulphate. A good correlation between these tests and virulence was obs erved.