title: [Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis].
abstract: OBJECTIVE
  To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE).
  
  
  METHODS
  Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound.
  
  
  RESULTS
  Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85% for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99% similarity with the marine species Streptomyces erythrogriseus.
  
  
  CONCLUSIONS
  Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drug-resistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.
authors.affiliation: Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú. jorgeleonq@yahoo.com
authors.forename: Jorge
authors.initials: J
authors.lastname: León
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Aponte
authors.forename: Rosario
authors.initials: R
authors.lastname: Rojas
authors.forename: D'Lourdes
authors.initials: D
authors.lastname: Cuadra
authors.forename: Nathaly
authors.initials: N
authors.lastname: Ayala
authors.forename: Gloria
authors.initials: G
authors.lastname: Tomás
authors.forename: Marco
authors.initials: M
authors.lastname: Guerrero
mesh_terms: D039903:Actinobacteria / Q000302:isolation & purification / Q000502:physiology*; D000898:Antibiosis; D013293:Enterococcus faecalis / Q000187:drug effects; D019015:Geologic Sediments / Q000382:microbiology; D055624:Methicillin-Resistant Staphylococcus aureus; D010568:Peru; D012623:Seawater / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology; D014871:Water Microbiology
chemical_list: D014640:Vancomycin