title: The killing effect of cryptolepine on Staphylococcus aureus.
abstract: OBJECTIVE
  This study was undertaken to further examine the antimicrobial actions of the alkaloid cryptolepine.
  
  
  RESULTS
  The minimum inhibitory concentration (MIC) of cryptolepine against Staphylococcus aureus was determined using the broth dilution method. Time-kill kinetics and scanning electron microscopy (SEM) techniques were employed to monitor the survival characteristics and the changes in morphologies respectively of staphylococci in the presence of cryptolepine. A notable antistaphylococcal activity was recorded for cryptolepine (MIC against S. aureus NCTC 10788=5 microg ml(-1)). Cryptolepine appears to have a lytic effect on S. aureus as seen in SEM photomicrographs following 3, 6 or 24 h treatment with 4X MIC, i.e. 20 microg ml(-1) of cryptolepine. The surface morphological appearance of the staphylococcal cells was also altered. The lytic effect appeared to coincide with low viable counts recorded in survival curves following treatment with cryptolepine.
  
  
  CONCLUSIONS
  These findings demonstrate that lysis occurs when susceptible organisms are exposed to cryptolepine.
authors.affiliation: Faculty of Pharmacy, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: I K
authors.initials: IK
authors.lastname: Sawer
authors.forename: M I
authors.initials: MI
authors.lastname: Berry
authors.forename: J L
authors.initials: JL
authors.lastname: Ford
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D026121:Indole Alkaloids; D007211:Indoles / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D011804:Quinolines / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D000470:Alkaloids; D026121:Indole Alkaloids; D007211:Indoles; D011804:Quinolines; C024015:cryptolepine