Transfer of plasmid-mediated antibiotic resistance from streptococci to lactobacilli

Abstract
The transmissible plasmid pAM.beta.1, which codes for erythromycin and lincomycin resistance, was conjugally transferred from a Lancefield group F Streptococcus to a strain of S. avium. Both organisms served as pAM.beta.1 donors for 3 strains of Lactobacillus casei. Introduction of pAM.beta.1 into 1 of the L. casei strains caused the organism to lose its native 6.7 .times. 106-dalton plasmid. Loss of the native plasmid produced no alterations in the organism''s growth characteristics or [carbohydrate] fermentation pattern.