A Multi-resistance Plasmid Isolated from Commensal Neisseria Species is Closely Related to the Enterobacterial Plasmid RSF1010 (original) (raw)
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Microbiology, 1988
~~ We have previously shown that some strains of Neisseria cinereu can serve as recipients in conjugation (Con+) with Neisseria gonorrhoeae while others cannot (Con-). To determine if a replication defect contributes to the inability of certain strains of N. cinerea to serve as recipients in conjugation, we attempted to introduce a naturally occurring gonococcal #l-lactamase plasmid into N. cinerea by transformation. Various methods were employed, and all proved unsuccessful. Since specific sequences are required for DNA uptake in transformation of N. gonomhoeae, we constructed a number of hybrid plasmids containing N. cinerea chromosomal DNA inserted into the N. gonotrkae/Esckerichia coli Plactamase shuttle vector, pLES2. When nine randomly selected plasmids with inserts were used to transform an N. cinerea strain which did not accept the gonococcal fl-lactamase plasmid by conjugation, transformants were observed with four of the hybrid plasmids. The presence of one of the hybrid plasmids, pCAG9, in transformants was confitmed by agarose gel electrophoresis, Southern hybridization, and /I-lactamase production. When an N. gonorrhue donor strain containing pCAG9 was used in conjugation with several N. cmerea strains, only those strains that were previously shown to act as recipients could accept and maintain pCAG9. The ability of pCAG9 and the other three hybrid plasmids to transform Constrains demonstrates that the Plactamase plasmid can replicate in Constrains , and, therefore, the Con-phenotype is due to a block in some other stage of the conjugation process.
Journal of Bacteriology, 1975
Strains of Streptococcus faecalis var. zymogenes, designated JH1 and JH3, produced a hemolysin and a bacteriocin. Hemolytic activity was lost from a low percentage of cells grown in broth at either 37 or 45 C. All nonhemolytic (Hly-) variants had lost bacteriocin activity (Ben-), and those from strain JH3 had also lost resistance to the bacteriocin (Bnr-). The majority of Hly-, Ben- variants from JH1 retained bacteriocin resistance (Bnrplus). Strains JH1 and JH3 contained a plasmid deoxyribonucleic acid species of molecular weight 38 times 10-6 (plasmids pJH2 and pJH3, respectively), and strain JH1 also contained a 50 times 10-6 molecular weight plasmid (pJH1) which has previously been shown to carry the genes determining resistance to the antibiotics kanamycin, neomycin, streptomycin, erythromycin, and tetracycline. Hly-, Bcn-, Bnr- variants of strain JH3 had completely lost plasmid pJH3. Hly-, Bcn-, Bnr- variants of strain JH1 had completely lost plasmid pJH2 and retained plasmid ...
Conjugal transfer and characterization of bacteriocin plasmids in group N (lactic acid) streptococci
Journal of Bacteriology, 1984
Thirteen bacteriocin-producing strains of group N (lactic acid) streptococci were screened for their potential to transfer this property by conjugation to Streptococcus lactis subsp. diacetylactis Bu2-60. Bacteriocin production in three strains was plasmid encoded as shown by conjugal transfer and by analysis of cured, bacteriocin-tiegative derivatives of the donor strains and the transconjugants. With Streptococcus cremoris strains 9B4 and 4G6 and S. lactis subsp. diacetylactis 6F7 as donors, bacteriocin-producing transconjugants were isolated with frequencies ranging from ca. 2 x 10-2 to 2 x 10-1 per recipient cell. Bacteriocin-producing transconjugants had acquired a 39.6-megadalton plasmid from the donor strains 9B4 and 4G6, and a 75-megadalton plasmid from the donor strain 6F7. As shown by restriction endonuclease analysis, the plasmids from strains 9B4 and 4G6 were almost identical. The plasmid from strain 6F7 yielded some additional fragments not present in the two other plasmids. In hybridization experiments any of the three plasmids strongly hybridized with each other and with some other bacteriocin but nontransmissible plasmids from other S. cremoris strains. Homology was also detected to a variety of cryptic plasmids in lactic acid streptococci.
Journal of general microbiology, 1970
Plasmids containing the genetic determinants for resistance to tetracyclines (Tc), streptomycin (Sm) and sulphonamide (Su), colicine production (Col) and a-haemolysin production (Hly) were transferred from four wild strains of Escherichia coli to E. coli K 12 by conjugation brought about by F factor. Linkage was demonstrated between F and Tc and between Sm and Su. No linkage was noted between Col, Hly, F and Tc, and Sm and Su, which were transmitted as four independent units in no predetermined order. F and Tc were eliminated together during acridine orange and sodium lauryl sulphate treatment ; the other characters were not eliminated. After mating for prolonged periods, F and Tc were most frequently found in the recipients. Recipients of other characters in the absence of F and Tc did not transmit them.
Species differences in plasmid carriage in the Enterobacteriaceae
Plasmid, 2003
Modern concerns about the spread of antibiotic resistance raise questions about the effect of bacterial species on plasmid evolution and maintenance. We studied 223 Enterobacteriaceae isolated from wild mammals and determined the number of plasmids per isolate, the size of those plasmids, and the distribution of plasmid incompatibility groups N, P, W, FII, and A/C. All of these variables were non-randomly distributed with respect to bacterial species, suggesting that host-cell factors constrain the plasmids that a strain will carry. The implication for the evolution of multiple-resistance plasmids in a clinical setting is that although inter-generic plasmid transfer may introduce a novel resistance plasmid into a bacterial genus, it is likely to be modified to suit the requirements of the new host cell. This then further suggests that resistance plasmids will evolve independent lineages within bacterial species although the genes incorporated in them may have come from the same original source.