title: In vitro and in vivo activity of EDTA and antibacterial agents against the biofilm of mucoid Pseudomonas aeruginosa.
abstract: OBJECTIVE
  Refractory infection caused by bacterial biofilm is an important clinical problem. Pseudomonas aeruginosa is a common pathogen responsible for persistent and chronic biofilm infections. We aimed to explore the in vitro and in vivo activity of ethylenediamine tetraacetic acid (EDTA) in combination with antibacterial agents against mucoid P. aeruginosa biofilm.
  
  
  METHODS
  The minimal inhibitory concentration (MIC) and minimal bactericidal concentration of ciprofloxacin, gentamicin, and ampicillin alone or with EDTA against P. aeruginosa were determined in vitro. Extracellular polysaccharides (EPS) and structural parameters of the biofilm were monitored. P. aeruginosa was aerosolized and delivered into the lungs of guinea pigs, which were treated with ciprofloxacin with or without EDTA. The colony-forming units (CFUs) of P. aeruginosa were determined from the lungs.
  
  
  RESULTS
  EDTA reduced the MIC of ciprofloxacin and ampicillin by about 30-fold and that of gentamicin by twofold. EDTA reduced the biofilm EPS and the proportion of viable bacteria. The thickness, average diffusion distance, and textural entropy of EDTA-treated biofilm were significantly decreased. EDTA plus antibiotics reduced the colony counting from 107to 103CFU/mL. In vivo, EDTA plus ciprofloxacin had a significantly lower mean CFU/g of lung tissue (EDTA + ciprofloxacin 1.3 ± 0.19; EDTA 4.4 ± 0.57; ciprofloxacin 4.2 ± 0.47), and lung lesions were less severe compared with the single treatment groups.
  
  
  CONCLUSIONS
  EDTA can destroy the biofilm structures of mucoid P. aeruginosa in vitro. Moreover, EDTA and ciprofloxacin had a significant bactericidal effect against biofilm in vivo.
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Zhenqiu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Neonatology, Maternal and Child Health Hospital of Xiamen City, Xiamen, Fujian, China.
authors.forename: Yaying
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China. yujialin486@126.com.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China. yujialin486@126.com.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China. yujialin486@126.com.
authors.forename: Jialin
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Zhengli
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Neonatology, Children's Hospital, Chongqing Medical University, Chongqing, China.|Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.|Key Laboratory of Pediatrics in Chongqing and Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Song
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018441:Biofilms / Q000187:drug effects*; D004195:Disease Models, Animal; D004492:Edetic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D006168:Guinea Pigs; D018410:Pneumonia, Bacterial / Q000188:drug therapy; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D004492:Edetic Acid
keywords: Antibacterial agents; Biofilm; Ethylenediamine tetraacetic acid; Pseudomonas aeruginosa