Conjugal transfer of penicillin resistance plasmids to proline-citrulline-uracil dependent strains of Neisseria gonorrhoeae.

Proline-, citrulline-, uracil (PCU)-dependent Neisseria gonorrhoeae represented only 2% of all Neisseria gonorrhoeae isolated in Greece during 1984-1987. We investigated whether these strains could be recipients of gonococcal plasmids. We carried out bacterial conjugation experiments and obtained the transfer of the African (3.2 Mdal) and of the Asian (4.5 Mdal) penicillin resistance plasmid from clinical penicillinase producing N. gonorrhoeae (PPNG) isolates to PCU gonococcal strains. The transfer frequency was very low, which suggests an explanation of the fact that the wild type PCU strains do not harbour either of these two plasmids. The conjugative plasmid of 24.5 Mdal was not transferred to any of the transconjugants carrying either the African or the Asian type plasmids.