Role of ISKpn23 in bla_BKC-1 Expression and Mobilization

This study aimed to verify the role of ISKpn23 in the expression and mobilization of bla_BKC-1 and aph(3')-VIi. Five constructs related to the natural bla_BKC-1 genetic background in plasmid p60136 were made and submitted for antimicrobial susceptibility testing and quantitative reverse transcription-PCR. Transposition of ISKpn23-bla_BKC-1 was investigated using transposition assays involving a 9.7-kb nonconjugative plasmid carrying bla_BKC-1 (p60136) and a transfer-proficient plasmid (pOX38-Gen). The presence of ISKpn23 had a crucial role in bla_BKC-1 expression, resulting in increased β-lactam MICs. While we detected mobilization of p60136 by the pOX38-Gen plasmid, transposition of ISKpn23-bla_BKC-1 was not observed.