title: Antimicrobial activity of some Alnus species.
abstract: OBJECTIVE
  The increasing prevalence of resistant microorganisms forced scientists to find new antimicrobial substances from different sources like medicinal plants. The aim of this study was to determine the antimicrobial activities of leaf extracts of some Alnus sp. against some bacteria and a yeast.
  
  
  METHODS
  Aqueous and ethanolic leaf extracts of A. glutinosa subsp. glutinosa, A. orientalis var. orientalis, A. orientalis var. pubescens were screened for their antimicrobial activities against Staphylococcus aureus ATCC 25923, S. aureus ATCC 43300 (MRSA), Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231. Broth dilution method was used to determine the antimicrobial activities of plant extracts.
  
  
  RESULTS
  Ethanolic extracts of tested species exhibited better antimicrobial activity than aqueous extracts. Ethanolic extracts of tested species possessed activity having MIC values of 0.125-0.250 mg/ml against the tested microorganisms. No antibacterial activity was observed against B. subtilis, E. coli, P. aeruginosa for all the aqueous extracts. Except these aqueous extracts, the others possessed activity having MIC value of 1.000 mg/ml against the tested microorganisms.
  
  
  CONCLUSIONS
  To our knowledge, this is the first investigation on the evaluation of antimicrobial activities on aqueous and ethanolic leaf extracts of these species. This study provides significant information about antimicrobial activities of leaf extracts of A. glutinosa subsp. glutinosa, A. orientalis var. orientalis, A. orientalis var. pubescens. It is conceivable that one of the reason for the usage of Alnus glutinosa, in treatment of wound healing in folk medicine, is because of its antimicrobial activity.
authors.affiliation: The Ministry of Health of Turkey, Turkish Medicines and Medical Devices Agency, Ankara, Turkey.  meryilmaz@ankara.edu.tr.
authors.forename: Ç
authors.initials: Ç
authors.lastname: Altınyay
authors.forename: M
authors.initials: M
authors.lastname: Eryılmaz
authors.forename: A N
authors.initials: AN
authors.lastname: Yazgan
authors.forename: B
authors.initials: B
authors.lastname: Sever Yılmaz
authors.forename: M L
authors.initials: ML
authors.lastname: Altun
mesh_terms: D029661:Alnus / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D008519:Medicine, Traditional / Q000379:methods; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000890:Anti-Infective Agents; D010936:Plant Extracts