title: The antimicrobial potential of algicolous marine fungi for counteracting multidrug-resistant bacteria: phylogenetic diversity and chemical profiling.
abstract: Marine fungi represent an important but still largely unexplored source of novel and potentially bioactive secondary metabolites. The antimicrobial activity of nine sterile mycelia isolated from the green alga Flabellia petiolata collected from the Mediterranean Sea was tested on four antibiotic-resistant bacterial strains using extracellular and intracellular extracts obtained from each fungal strain. The isolated fungi were identified at the molecular level and assigned to one of the Dothideomycetes, Sordariomycetes or Eurotiomycetes classes. Following assessment of inhibition of bacterial growth (IC50), all crude extracts were subjected to preliminary (1)H NMR and TLC analysis. According to preliminary pharmacologic and spectroscopic/chromatographic results, extracts of fungal strains MUT 4865, classified as Beauveria bassiana, and MUT 4861, classified as Microascacea sp.2, were selected for LC-HRMS analysis. Chemical profiling of antibacterial extracts from MUT 4861 and MUT 4865 by LC HRMS allowed identification of the main components of the crude extracts. Several sphingosine bases were identified, including a compound previously unreported from natural sources, which gave a rationale to the broad spectrum of antibacterial activity exhibited.
authors.affiliation: Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, I-10125 Turin, Italy. Electronic address: giorgio.gnavi@unito.it.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gnavi
authors.affiliation: Institute of Protein Biochemistry, National Research Council, I-80131 Naples, Italy. Electronic address: f.palma@ibp.cnr.it.
authors.forename: Fortunato
authors.initials: F
authors.lastname: Palma Esposito
authors.affiliation: Department of Pharmacy, University of Naples "Federico II", I-80131 Naples, Italy. Electronic address: carmen.festa@unina.it.
authors.forename: Carmen
authors.initials: C
authors.lastname: Festa
authors.affiliation: Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, I-10125 Turin, Italy. Electronic address: anna.poli@unito.it.
authors.forename: Anna
authors.initials: A
authors.lastname: Poli
authors.affiliation: Institute of Protein Biochemistry, National Research Council, I-80131 Naples, Italy. Electronic address: p.tedesco@ibp.cnr.it.
authors.forename: Pietro
authors.initials: P
authors.lastname: Tedesco
authors.affiliation: Laboratory of Microbial and Molecular Evolution, Department of Biology, University of Florence, I-50019 Sesto Fiorentino, Florence, Italy. Electronic address: renato.fani@unifi.it.
authors.forename: Renato
authors.initials: R
authors.lastname: Fani
authors.affiliation: Department of Pharmacy, University of Salerno, I-84084 Fisciano, SA, Italy. Electronic address: mcmonti@unisa.it.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Monti
authors.affiliation: Institute of Protein Biochemistry, National Research Council, I-80131 Naples, Italy. Electronic address: d.depascale@ibp.cnr.it.
authors.forename: Donatella
authors.initials: D
authors.lastname: de Pascale
authors.affiliation: Department of Pharmacy, University of Naples "Federico II", I-80131 Naples, Italy. Electronic address: madauria@unina.it.
authors.forename: Maria Valeria
authors.initials: MV
authors.lastname: D'Auria
authors.affiliation: Mycotheca Universitatis Taurinensis (MUT), Department of Life Sciences and Systems Biology, University of Turin, I-10125 Turin, Italy. Electronic address: cristina.varese@unito.it.
authors.forename: Giovanna Cristina
authors.initials: GC
authors.lastname: Varese
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001688:Biological Products / Q000302:isolation & purification / Q000494:pharmacology*; D000460:Chlorophyta / Q000382:microbiology; D002855:Chromatography, Thin Layer; D005658:Fungi / Q000737:chemistry* / Q000145:classification* / Q000302:isolation & purification; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D008522:Mediterranean Sea
chemical_list: D000900:Anti-Bacterial Agents; D001688:Biological Products
keywords: Antimicrobial compounds; Bioactive fungal compounds; Marine fungi; Marine natural products; Multidrug-resistant bacteria; Sphingosine bases