Recombinant DNA risk assessment studies in humans: Efficacy of poorly mobilizable plasmids in biologic containment

M. M. Levine, J. B. Kaper, H. Lockman, R. E. Black, M. L. Clements, S. Falkow

Research output: Contribution to journalArticlepeer-review

Abstract

Recombinant DNA risk assessment studies quantitated the mobilizability of 'safe' plasmid pBR325, in comparison with readily mobilizable plasmid pJBK5 (chloramphenicol and tetracycline resistant). Of 15 volunteers who became colonized after ingestion of 5 x 1010 Escherichia coli HS-4, a normal human flora strain containing pJBK5 and daily oral tetracycline, nine manifested transfer of pJBK5 to normal flora by means of triparental mating. In contrast, none of 12 other volunteers cocolonized with HS-4 bearing 'safe' pBR325 and normal flora showed transfer (P = 0.001), despite ingestion of tetracycline. To accomplish transfer directly, E coli HS-4 containing both pBR325 and a derepressed, conjugative plasmid (F-amp) was fed to two groups of volunteers. Transfer of pBR325 to normal flora occurred in 13 of 18 volunteers taking daily tetracycline but in none of eight who did not (P<0.002). Nor were transconjugants detected, despite tetracycline ingestion, in five volunteers who ingested and excreted E coli K12 (pBR325 plus F-amp).

Original languageEnglish (US)
Pages (from-to)699-705
Number of pages7
JournalUnknown Journal
Volume148
Issue number4
DOIs
StatePublished - 1983
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Infectious Diseases

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