Antibiotic resistance among enterococci isolated from clinical specimens between 1953 and 1954.

Two hundred twenty group D streptococci isolated from 1953 to 1954 from patients in the Washington, D.C., area were characterized.

Identification of plasmids in Actinobacillus actinomycetemcomitans and construction of intergeneric shuttle plasmids.

A collection of 39 isolates of Actinobacillus actinomycetemcomitans, obtained from laboratories located in 5 different geographical regions of the United States, was examined for the presence of plasmid DNA. Only 2 of the strains examined, designated VT736 and VT745, harbored detectable plasmids. Strain VT736 contained a 1.

Molecular, genetic, and functional analysis of the basic replicon of pVA380-1, a plasmid of oral streptococcal origin.

The 4.2-kb cryptic plasmid pVA380-1 has been used as a vector for the cloning of antibiotic resistance genes directly in streptococci, and in the construction of Escherichia coli/Streptococcus shuttle vectors. The results of subcloning experiments located the basic replicon of pVA380-1 within a 2.