title: The antimicrobial effects of ketamine combined with propofol: An in vitro study.
abstract: OBJECTIVE
  Ketamine and propofol are the general anesthetics that also have antimicrobial and microbial growth-promoting effects, respectively. Although these agents are frequently applied together during clinical use, there is no data about their total effect on microbial growth when combined. In this study, we investigated some organisms' growth in a ketamine and propofol mixture.
  
  
  METHODS
  We used standard strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in this study. Time-growth analysis was performed to assess microbial growth rates in 1% propofol. Antimicrobial activity of ketamine, alone and in propofol was studied with microdilution method.
  
  
  RESULTS
  In propofol, studied strains grew from 10(3)-10(4) cfu/mL to ≥10(5) cfu/mL concentrations within 8-16 hours depending on the type of organism. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) (for candida, minimal fungicidal concentration) of ketamine were determined as follows (MIC, MBC): E.coli 312.5, 312.5 μg/mL; S.aureus 19.5, 156 μg/mL; P.aeruginosa 312.5, 625 μg/mL; and C.albicans 156, 156 μg/ml. In ketamine+propofol mixture, ketamine exhibited antimicrobial activity to E.coli, P.aeruginosa and C.albicans as MBCs at 1250, 625 and 625 μg/mL, respectively. Growth of S. aureus was not inhibited in this mixture (ketamine concentration=1250 μg/mL).
  
  
  CONCLUSIONS
  Ketamine has sustained its antimicrobial activity in a dose-dependent manner against some organisms in propofol, which is a strong microbial growth-promoting solution. Combined use of ketamine and propofol in routine clinical application may reduce the risk of infection caused by accidental contamination. However, one must keep in mind that ketamine cannot reduce all pathogenic threats in propofol mixture.
authors.affiliation: Department of Anesthesiology and Reanimation, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Zekine
authors.initials: Z
authors.lastname: Begec
authors.affiliation: Department of Anesthesiology and Reanimation, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Aytac
authors.initials: A
authors.lastname: Yucel
authors.affiliation: Department of Clinical Microbiology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Yakupogullari
authors.affiliation: Department of Anesthesiology and Reanimation, School of Medicine, Inonu University, Malatya, Turkey. Electronic address: drmalierdogan@gmail.com.
authors.forename: Mehmet Ali
authors.initials: MA
authors.lastname: Erdogan
authors.affiliation: Department of Clinical Microbiology, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Yucel
authors.initials: Y
authors.lastname: Duman
authors.affiliation: Department of Anesthesiology and Reanimation, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Durmus
authors.affiliation: Department of Anesthesiology and Reanimation, School of Medicine, Inonu University, Malatya, Turkey.
authors.forename: M Ozcan
authors.initials: MO
authors.lastname: Ersoy
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D007649:Ketamine / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015742:Propofol / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D007649:Ketamine; D015742:Propofol
keywords: Antimicrobial activity; Benzethonium chloride; Ketamine; Ketofol; Propofol