THE GENETIC-CONTROL OF VIRULENCE IN GROUP-A STREPTOCOCCI .1. CONJUGAL TRANSFER OF PLASMIDS AND THEIR EFFECT ON EXPRESSION OF SOME HOST-CELL PROPERTIES

  • 1 January 1983
    • journal article
    • research article
    • Vol. 91  (1) , 55-60
Abstract
Transfer of 5 plasmids was studied in 30 different mating systems involving streptococci of groups A, D and H. The erythromycin resistance marker (Emr) of all 5 plasmids was transferable at frequencies ranging from 8 .times. 10-7-2 .times. 10-4. All original donor strains except SM60 (pERL1) contained phage activity, but evidence was obtained favoring conjugation over transduction as the mechanism of transfer. The process was rec-independent. The transconjugants served as donors of the Emr-marker in secondary matings. A shortened derivate (pSM10) of the plasmid pSM10419 could also be transferred. The presence of the plasmid pSM15346 influenced the expression of the capacity to adhere to human epithelial cells and the resistance to UV-light of the host; anti-phagocytic activity, production NAD glycohydrolase and opacity factor were unaffected by the plasmid.

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