Characterization of a Potential β-Lactamase Inhibitory Metabolite from a Marine Streptomyces sp. PM49 Active Against Multidrug-Resistant Pathogens

• Published in: Applied biochemistry and biotechnology 2015-04, Vol.175 (8), p.3696-3708
• Main Authors: Shanthi, J, Senthil, A, Gopikrishnan, V, Balagurunathan, R
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii; Actinobacteria; agricultural wastes; antibacterial properties; Aquatic Organisms - chemistry; beta-lactamase; beta-Lactamases - drug effects; beta-Lactamases - metabolism; Biochemistry; Biotechnology; Chemistry; Chemistry and Materials Science; chloroform; coasts; Drug Resistance, Multiple - drug effects; electrospray ionization mass spectrometry; ethyl acetate; genes; Humans; India; Klebsiella pneumoniae; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - pathogenicity; Microbial Sensitivity Tests; molecular weight; multiple drug resistance; mycelium; nuclear magnetic resonance spectroscopy; pathogens; polymerase chain reaction; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - pathogenicity; ribosomal RNA; RNA, Ribosomal, 16S - genetics; secondary metabolites; spectral analysis; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - pathogenicity; Streptomyces; Streptomyces - chemistry; Streptomyces - genetics; Streptomyces rochei
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-015-1538-x

Actinobacteria is a prolific producer of complex natural products; we isolated a potential marine Streptomyces sp. PM49 strain from Bay of Bengal coastal area of India. The strain PM49 exhibited highly efficient antibacterial properties on multidrug-resistant pathogens with a zone of inhibition of 14–17 mm. SSF was adopted for the production of the secondary metabolites from PM49 with ISP2; utilizing agricultural wastes for compound extraction was also attempted. Bioactive fraction of Rf value 0.69 resolved using chloroform and ethyl acetate (1:1, v/v) was obtained and subjected to further analysis. Based on UV, IR, ESI-MS, and¹H and¹³C NMR spectral analysis, it was revealed that the compound is closely similar to cyslabdan with a molecular mass of 467.66 corresponding to the molecular formula C₂₅H₄₁NO₅S. ESBL and MBL production was screened in the hospital test isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Staphylococcus aureus. PCR amplification in the phenotypically positive strains was positive for blaIMP, blaSHV, blaCTX₋M, and mec genes. The β-lactamase enzyme from tested strains had cephalosporinase activity with a 31-kDa protein and isolated compound from the strain possessing β-lactamase inhibitory potential. MIC of the active fraction was 16–32 μg/ml on ATCC strains; the ceftazidime and meropenem sensitive and resistant test strains showed MIC of 64–256 μg/ml. The Streptomyces sp. PM49 aerial mycelium was rectiflexibile; the 16S rRNA showed 99 % identity with Streptomyces rochei and submitted at Genbank with accession no JX904061.1.