[Virulence of plasmids of diarrhea-causing strains of Salmonellae wien and Escherichia coli].

Use of molecular genetic methods in the study of sources and ways of spreading the infection provides precise data on the mutual clonal origin of the strains, on the basis of the determination of plasmid DNK maps. Results of the investigation of Salmonellae Wien strain show the same type of resistance to antimicrobial drugs and the impact of resistotypization as an epidemiologic marker. The analysis of the plasmid profile in these strains has confirmed the presence of FIme virulence plasmid of 80 megadalton in size and resistance plasmid of 60 megadalton which was by conjugation transferred to the recipient strain (in vitro experiment). The presence of antigen factors of colonization in escherichial coli, a cause of diarrhea, was confirmed: CFA-I in the serogroup 078, and CFA-II in the serogroup 06.