Marine Sediment-Derived Streptomyces Strain Produces Angucycline Antibiotics against Multidrug-Resistant Staphylococcus aureus Harboring SCCmec Type 1 Gene

• Published in: Journal of marine science and engineering Vol. 8; no. 10; p. 734
• Main Authors: Sabido, Edna M., Tenebro, Chuckcris P., Suarez, Angelica Faith L., Ong, Sarah Diane C., Trono, Dana Joanne Von L., Amago, Diana S., Evangelista, Jose E., Reynoso, Ann Marielle Q., Villalobos, Ivy Grace M., Alit, Luigi Dan D., Surigao, Cherryl F., Villanueva, Christelle A., Saludes, Jonel P., Dalisay, Doralyn S.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2020
• Subjects: Actinomycetes; Antibacterial activity; antibiotic angucycline glycosides; Antibiotics; Archipelagoes; Aromatic compounds; Biodiversity; Biomarkers; Biosynthesis; Cancer; Chromosomes; Drug resistance; Gene amplification; Genomes; Glycosides; Harbors; Islands; Laboratories; Liquid chromatography; Marine sediments; Mass spectrometry; Mass spectroscopy; Maximum likelihood method; Metabolism; Metabolites; Minimum inhibitory concentration; Multidrug resistance; Multidrug resistant organisms; multidrug-resistant Staphylococcus aureus; Natural products; New species; Phylogenetics; Polyketide synthase; RecA protein; RNA polymerase; RpoB protein; rRNA 16S; Salinity tolerance; SCCmec gene; Sediment; Sediments; Social organization; Spectroscopy; Staphylococcus aureus; Staphylococcus infections; Streptomyces; Tropical environments; type II polyketide synthase; United States > US; Germany; Singapore
• ISSN: 2077-1312; 2077-1312
• DOI: 10.3390/jmse8100734

The Philippine archipelago is geographically positioned in the tropics with rich areas of marine biodiversity. Its marine sediments harbor actinomycetes that exhibit antibacterial activity. Screening of actinomycetes isolated from marine sediments collected near the coast of Islas de Gigantes, Iloilo showed one isolate that exhibited high activity against the multidrug-resistant Staphylococcus aureus (MRSA) strain carrying the Staphylococcal Cassette Chromosome mec (SCCmec) type 1 gene, a biomarker for drug resistance. The isolate was identified as Streptomyces sp. strain DSD011 based on its 16s rRNA and protein-coding genes (atpD, recA, rpoB, and trpB) sequences, and was found to be a new species of salt-tolerant marine Streptomyces. Further, the strain harbors both non-ribosomal peptide synthetase (NRPS) and type II polyketide synthase (PKS) in its genome. The targeted chromatographic isolation and chemical investigations by Liquid Chromatography Mass Spectrometry-Time of Flight (LCMS-TOF), tandem mass spectrometry (MS/MS), and Global Natural Product Social molecular networking (GNPS) of the antibiotics produced by the strain afforded the two polycyclic aromatic polyketide angucycline glycosides, fridamycin A (1) and fridamycin D (2), which are products of type II PKS biosynthesis. Compounds 1 and 2 displayed antibacterial activity against MRSA with minimum inhibitory concentration (MIC) of 500 μg/mL and 62.5 μg/mL, respectively. These results suggest that the underexplored marine sediments near the coast of Islas de Gigantes, Iloilo offer access to undiscovered Streptomyces species that are invaluable sources of antibiotic leads.