Vancomycin hydrochloride

The AMPs used in this study included IP (GFGCPFNQGACHRHCRSIGRRGGYCAGLFKQTCTCYSR [19 (link)]), bLfinB (FKCRRWQWRMKKLGAPSITCVRRAF [22 (link)]), which was derived from pepsin-digested bovine lactoferrin, the lantibiotic peptide nisin (MP Biomedicals, Santa Ana, CA, USA) and the lipopeptide daptomycin (Tokyo Chemical Industry, Tokyo, Japan). IP and bLfinB were chemically synthesized by Scrum Inc. (Tokyo, Japan) and GL Biochem Co., Ltd. (Shanghai, China), respectively. The antimicrobial agents used in this study included vancomycin hydrochloride (FUJIFILM Wako Pure Chemical Corp., Osaka, Japan) and cephazolin sodium salt (Tokyo Chemical Industry). IP was dissolved in dimethyl sulfoxide (DMSO) (FUJIFILM Wako Pure Chemical Corp.) to a concentration of 5 mg/mL and then diluted to a concentration of 160 µg/mL with sterile water. The formation of disulfide bridge was accomplished by air oxidation, as previously described [18 (link)]. Thereafter, the products were analyzed by electrospray ionization mass spectrometry using a micrOTOF-Q-II mass spectrometer (Bruker Daltonic, Bremen, Germany).

P. aeruginosa (NBRC 13275 and PAO1) was purchased from Biological Resource Center in the National Institute of Technology and Evaluation, Chiba, Japan. A. baumannii (JCM 6841) was purchased from RIKEN BioResource Research Center, Ibaraki, Japan. MRSA (IID 1677) was purchased from the Institute of Medical Science in the University of Tokyo, Japan. Lysozyme (Lysozyme BIO; purified from fresh chicken egg white) was purchased from Biocon Japan Ltd., Aichi, Japan. Chitosan oligosaccharide (COS) (made from shells of the crab) was purchased from Kimika Co., Aichi, Japan. COS presented a deacetylation degree of over 98% and a molecular weight (MW) of 5 kDa. Galactomannan was purchased from Taiyo Kagaku, Tokyo, Japan. Galactomannan presented an MW of 15 kDa. Precast sodium dodecyl sulfate (SDS) gel (SuperSep Ace 10–20%), the Wako Silver Stain II kit, colistin sulfate, vancomycin hydrochloride, N-phenyl-1-naphthylamine (NPN), 2-nitrophenyl β-D-galactopyranoside (ONPG), and Micrococcus luteus were purchased from FUJIFILM Wako Pure Chemical Corporation, Osaka, Japan. Defibrinated rabbit blood was purchased from Cosmo Bio Co., Tokyo, Japan. The LIVE/DEAD BacLight Bacterial Viability Kit (L7012) was purchased from Thermo Fisher Scientific Corporation, Massachusetts, USA.

Vancomycin hydrochloride, polymyxin B sulfate, lithocholic acid, sodium deoxycholate, sodium taurocholate, and lysyl endopeptidase were purchased from Wako Pure Chemical Industries (Osaka, Japan). QIAamp Fast DNA Stool Mini Kit was from Qiagen (Hilden, Germany). Taq DNA polymerase containing 10 × Standard buffer (Taq) and dNTPs were obtained from BioAcademia (Osaka, Japan) and synthesised PCR primers were obtained from FASMAC (Kanagawa, Japan). Sodium taurolithocholate and sodium taurochenodeoxycholate were purchased from Sigma-Aldrich (St. Louis, MO, USA). Taurodeoxycholic acid sodium salt was purchased from Nacalai Tesque (Kyoto, Japan). Tauro β-muricholic acid sodium salt was purchased from Steraloids (Newport, RI, USA). Taurocholic acid-d5 (TCA-d5) sodium salt was purchased from Toronto Research Chemicals (Toronto, Ontario, Canada). Triglyceride Quantification Assay kit was purchased from Abcam (Cambridge, UK). Plasma Membrane Protein Extraction Kit was obtained from BioVision (Milpitas, CA, USA). Pierce BCA Protein Assay Kit was obtained from Thermo Fisher Scientific (Waltham, MA, USA). Sequencing-grade modified trypsin (frozen) was obtained from Promega (Madison, WI, USA). Synthesised isotope-labelled peptides were obtained from Sigma-Aldrich. Other reagents were commercially available products of reagent or analytical grade.