title: [Antimicrobial effects of qingkailing injection extract and combination therapy of qingkailing injection and antibiotics on bacteria carrying blaNDM-1 resistance gene].
abstract: OBJECTIVE
  To research the bacteriostatic effects of Qingkailing Injection Extract (QKLIE) and combination therapy of Qingkailing Injection (QKLI) and antibiotics on bacteria carrying New Delhi metallo-3-lactamase 1 (NDM-1) blaNDM-1 resistance gene, and to determine their minimal inhibitory concentrations (MIC).
  
  
  METHODS
  The antimicrobial experiments of QKLIE (Radix Isatidis, baicalin, gardenia, honeysuckle) and combination therapy of QKLI and antibiotics were performed by using the agar dilution method and K-B method. The MIC was determined from each extract.
  
  
  RESULTS
  There were different degrees of inhibitory effects on resistant bacteria carrying blaNDM-1 by extracts from main components of QKLI. Of them, the inhibitory effect of baicalin was the best and the MIC of the resistant bacteria was 0.015 g/mL to WD, 0.020 g/mL to WX, 0. 005 g/mL to WJ, and more than 0.020 g/mL to pGEX-4T-NDM-1/DH5alpha (GST-NDM-1), respectively. The MIC value of each extract was sequenced from high to low as baicalin, honeysuckle, gardenia, and Radix Isatidis. Furthermore, combination therapy of QKLI and antibiotics greatly enhanced the antimicrobial activity of each antibiotics when used alone, showing very obvious antibacterial effects on multidrug resistant bacteria carrying blaNDM-1 gene. Of them, the optimal effects were obtained when combined with penicillins (penicillin G, mezlocillin, piperacillin/ tazobactam, ampicillin/sulbactam), with the antibacterial effects improved by 10 folds. The antibacterial effects of other kinds of antibiotics were improved to some extent. Conclusions QKLIE and combination therapy of QKLI and antibiotics showed better bacteriostatic effects on resistant bacteria carrying blaNDM-1 gene. This study provided theoretical bases for drug development, medication and treatment for super-resistant bacteria carrying blaNDM-1.
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shang
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Wang
authors.forename: Da-Yang
authors.initials: DY
authors.lastname: Zou
authors.forename: Zhuang-Nian
authors.initials: ZN
authors.lastname: Zhang
authors.forename: Xiang-Ru
authors.initials: XR
authors.lastname: Liao
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics; D004359:Drug Therapy, Combination; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D004365:Drugs, Chinese Herbal; C504928:Qingkailing; D001618:beta-Lactamases