Table 2.

Frequencies of mobilization of pBHR1 into different bacteriaa

RecipientTransfer frequencyb:
Per donorPer recipient
Escherichia coliXA106F 3 × 10−2 1 × 10−1
Ralstonia eutrophaAE1102 × 10−1 3 × 10−1
Erwinia chrysanthemi A12401 × 10−2 1 × 10−1
Klebsiella pneumoniae KAY2026 Nalr 2 × 10−3 1 × 10−1
Agrobacterium tumefaciens C58 Nalr 3 × 10−2 2 × 10−2
Salmonella enterica serovar Typhimurium MA767 Nalr 2 × 10−2 1 × 10−2
Pseudomonas stutzeri ATCC 17588 Nalr 4 × 10−2 9 × 10−3
Pseudomonas aeruginosa PAO362 Nalr 9 × 10−3 7 × 10−3
Azospirullum brasilense 7000 Nalr 2 × 10−3 6 × 10−3
Pseudomonas aeruginosa PAO5318 × 10−3 4 × 10−3
Serratia marcescens HY(yΨ) Nalr 2 × 10−3 1 × 10−3
Erwinia herbicola RH6101 Nalr 4 × 10−4 5 × 10−6
Acinetobacter sp. strain AC58 Nalr ≤2 × 10−6 ≤9 × 10−7
Proteus mirabilis NCTC5887 Nalr ≤4 × 10−7 ≤6 × 10−7
Proteus vulgaris OX19 Nalr ≤8 × 10−6 ≤8 × 10−7
  • a The Nals E. colistrain S17-1 containing an integrated RP4 plasmid and the Kanr pBHR1 plasmid was mated at 30°C on LB plates with various Nalr Kans bacteria as described by Lejeune et al. (26). After overnight incubation, the recipient, donor, and transconjugants were titrated at 30°C on LB medium supplemented with the appropriate antibiotics (nalidixic acid at 20 μg/ml; kanamycin at 50 or 1,000 μg/ml according to the recipient used).

  • b Mobilization frequencies were determined by dividing the number of transconjugants (KanrNalr) by the number of recipients (Nalr) or donors (Kanr − Kanr Nalr).