Research Institute of Epidemiology and Microbiology, Research Institute of Veterinary in Non-Chernozem Region, Nizhny Nov-gorod, Russia
Presence of plasmid-contained strains in probiotics prepared on the basis of Bacillus bacteria was assessed. Plasmid analysis was performed by the method based on neutralization of bacterial suspension after alkaline treatment with lithium chloride. Presence of 4 — 6 plasmids with molecular weight from 1 to 75 MDa was revealed in 4 commercially available probiotics. Since plasmids can facilitate transfer of genes of the antimicrobial resis-tance to pathogenic microorganisms it was recommended to perform thorough search of probiotic microorgan-isms without plasmids or ensure the elimination of R-plasmids in start cultures for the most promising bioprepara-tions.
Zh. Microbiol. (Moscow), 2007, No. 5, P. 77—79