title: Physiological effect of the alterations of plasmids derived from Neisseria gonorrhoeae.
abstract: Transfer of plasmid DNA from penicillinase-producing Neisseria gonorrhoeae to Escherichia coli produced relatively small colonies that became pigmented in the presence of the dye, congo red. Mutations to large, non-pigmented colonies were frequent, and were the result of a variety of alterations in these plasmids. Miniplasmid formation was the major alteration that led to non-pigmented colonies. However, deletions in any of three putative replication regions resulted in non-pigmented colonies. These altered plasmids mediated significantly less beta-lactamase production than that of the parent plasmid. A new origin of replication was discovered and mapped within the miniplasmid. This origin was responsible for: 1) high plasmid copy number, 2) stability of inheritance, and 3) the majority of beta-lactamase produced in culture. The evolution of gonococcal plasmids may be followed in E. coli, since less defective plasmids produce nonpigmented colonies on congo red agar medium.
authors.affiliation: Infectious Disease Division, Winthrop-University Hospital, Mineola, New York 11501.
authors.forename: P
authors.initials: P
authors.lastname: Domenico
authors.forename: E C
authors.initials: EC
authors.lastname: Gotschlich
authors.forename: B A
authors.initials: BA
authors.lastname: Cunha
mesh_terms: D003224:Congo Red; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D009344:Neisseria gonorrhoeae / Q000235:genetics*; D010405:Penicillinase / Q000096:biosynthesis; D010858:Pigmentation / Q000235:genetics; D010957:Plasmids / Q000235:genetics*; D013489:Suppression, Genetic / Q000235:genetics
chemical_list: D003224:Congo Red; D010405:Penicillinase