Identification of genetic determinants for the hemolytic activity of Streptococcus agalactiae by ISS1 transposition.

ABSTRACT: Streptococcus agalactiae is a poorly transformable bacterium and studies of molecular mechanisms are difficult due to the limitations of genetic tools. Employing the novel pGh9:ISS1 transposition vector we generated plasmid-based mutant libraries of S. agalactiae strains O90R and AC475 by random chromosomal integration. A screen for mutants with a nonhemolytic phenotype on sheep blood agar led to the identification of a genetic locus harboring several genes that are essential for the hemolytic function and pigment production of S. agalactiae. Nucleotide sequence analysis of nonhemolytic mutants revealed that four mutants had distinct insertion sites in a single genetic locus of 7 kb that was subsequently designated cyl. Eight different open reading frames were identified: cylX, cylD, cylG,

SUBMITTER: Spellerberg B 

PROVIDER: S-EPMC93778 | biostudies-literature | 1999 May

REPOSITORIES: biostudies-literature