Isolation and characterization of coaggregation-defective (Cog-) mutants of Streptococcus gordonii DL1 (Challis)

J Ind Microbiol. 1995 Sep;15(3):193-7. doi: 10.1007/BF01569825.


Streptococcus gordonii DL1 (Challis) bears coaggregation-mediating surface adhesins which recognize galactoside-containing surface polysaccharides on Streptococcus oralis 34, Streptococcus oralis C104, and Streptococcus SM PK509. Fifty-nine spontaneously-occurring coaggregation-defective (Cog-) mutants of S. gordonii DL1 unable to coaggregate with partner streptococci were isolated. Six representative Cog- mutants were characterized by their coaggregation properties with four Actinomyces naeslundii strains (T14V, PK947, PK606, PK984), Veillonella atypica PK1910, and Propionibacterium acnes PK93. The six representative Cog- mutants showed altered coaggregation with their streptococcal partners, A. naeslundii PK947, and P. acnes PK93. Based on the coaggregation phenotypes of these mutants, a model for the lactose-inhibitable coaggregation between S. gordonii DL1 and its partner bacteria is proposed. The potential use of these mutants in studies of oral biofilms is discussed.

MeSH terms

  • Adhesins, Bacterial / genetics
  • Adhesins, Bacterial / metabolism
  • Bacterial Adhesion / genetics*
  • Bacterial Adhesion / physiology
  • Biofilms / growth & development*
  • Humans
  • Models, Biological
  • Mutation*
  • Polysaccharides, Bacterial / metabolism
  • Streptococcus / genetics*
  • Streptococcus / isolation & purification
  • Streptococcus / physiology*


  • Adhesins, Bacterial
  • Polysaccharides, Bacterial