[Strains of Salmonella with atypical biochemical activity found in diagnostic material]

Biochemically atypical strains belonging to 11 genera of Salmonella subspecies I in the number of 200 were collected in Poland in the years 1980-1991 were tested by means of 22 biochemical tests. Atypical property stability was detected in 164 strains. Most stable properties were following: ability to ferment lactose, lack of ability of dulcitol fermentation, lack of hydrosulfide production and lack of lysine decarboxylation. Atypical properties were occurring singularly or clusters numbering two or three. Identification procedure for Salmonella accepted in this country enables proper diagnosis of an atypical strain, however it requires application of supplemental biochemical tests. These strains were tested for susceptibility of 15 antimicrobial agents and no correlation between antibiotic resistance and occurrence of one or several atypical properties has been found.