INVESTIGATION INTO THE EXPRESSION OF VIRU LENCE-ASSOCIATED CHARACTERISTICS OF STRAINS OF PLESIOMONAS-SHIGELLOIDES

Plesiomonas (PI.) shigelloides (shig.), a gram-negative facultative an aerobically growing and oxidase-positive rod-shaped bacterium is an im portant pathogen causing enteritis in regions of warmer climate: Possi bly, it is also responsible for foodborne infections. Previous investi gations concerning virulence factors and pathogenic mechanisms produce d partly divergent results. As regard virulence-associated characteris tics of PI. shig, strains only a few facts are known. In pattern inves tigations the cytotoxicity in various cell cultures, the presence of p lasmids as well as the expression of properties which could possibly r epresent virulence markers were examined using 11 strains of different origins. The main marker which was regularly to be found was the upta ke of congo red, whereas autoagglutination, haemagglutination and seru m resistance did not appear at all or occured just sporadically, havin g no connection with the cytotoxicity which become apparent in Bat- an d chickenembryofibroblast-cultures but not in Vero-cell-cultures. Plas mid-DNA was found merely in two strains.