Gentamicin

Gold acid chloride trihydrate (HAuCl₄·3H₂O) was obtained from Aladdin Bio-Chem Technology Co., Ltd. (Shanghai, China). Polyethyleneimine (PEI, Mw = 1800) was purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). Three fluorescent signal molecules (BSA–FITC, PNA–RhB and β–Lac–Cy5) were synthesized by Bersee Science and Technology Co., Ltd. (Beijing, China) and Fubo Biotechnology Co., Ltd. (Beijing, China). Ibuprofen and diclofenac sodium were supplied by Aladdin Co., Ltd. (Shanghai, China). Omeprazole, lansoprazole, esOmeprazole, pantoprazole, gentamicin, tobramycin and neomycin were provided by Yuanye Biotechnology Co., Ltd. (Shanghai, China). Naproxen was supplied from Solarbio Life Sciences Co., Ltd. (Beijing, China). Ultrapure water was prepared by using the Millipore Simplicity System (Millipore, Bedford, MA, USA) with a resistivity of 18.2 MΩ·cm⁻¹.

Two tmexCD1-toprJ1 positive K. pneumoniae (RGT9-1, RGF15-2-1) and one tet(A) mutant positive K. pneumoniae RGF131 were isolated from swine faeces in 2020 by our lab. All the isolates mediate high level resistance to tigecycline (TIG) with the MIC value over than 16 µg/mL. The TIG, ciprofloxacin, meropenem, gentamicin, and metformin were purchased from Yuanye Biological Technology Company (Shanghai, China). Other fluorescence probes and reagents were purchased from Sigma-Aldrich (Saint Louis, MO, USA).