Plasmid transfer and behaviour in Acinetobacter calcoaceticus EBF65/65.

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Bacterial conjugation is a key mechanism for horizontal gene transfer.
• Understanding plasmid transfer between different bacterial species is crucial for tracking antibiotic resistance.
• Acinetobacter calcoaceticus is an important opportunistic pathogen, and its genetic manipulation is of interest.

Purpose of the Study:

• To investigate the transferability of plasmids from Escherichia coli K12 to Acinetobacter calcoaceticus EBF65/65.
• To assess the influence of recipient strain factors and plasmid incompatibility groups on transfer efficiency.
• To evaluate the stability and re-transfer capability of plasmids in Acinetobacter calcoaceticus.

Main Methods:

• Conjugation experiments were performed to transfer plasmids from E. coli K12 to A. calcoaceticus EBF65/65.
• Plasmids from multiple incompatibility groups (B, C, FIV, H2/S, Iα, Iδ, P, W, X) were tested.
• The effect of the pAV2 plasmid in the recipient strain was examined, along with the transfer of trimethoprim resistance plasmids.

Main Results:

• Plasmids from all tested incompatibility groups were capable of transfer to A. calcoaceticus EBF65/65.
• The presence of pAV2 in the recipient influenced transfer, but not uniformly across all plasmids.
• 31 out of 40 trimethoprim resistance plasmids successfully transferred, with 17 requiring a mobilizing plasmid for re-transfer.

Conclusions:

• Plasmids exhibit broad transferability from E. coli to A. calcoaceticus, irrespective of incompatibility group.
• Plasmid stability in A. calcoaceticus varies, but re-transfer to E. coli is possible.
• This study highlights the potential for interspecies plasmid transfer, including clinically relevant resistance genes.