<i>In vivo </i> evaluation of anti-MRSA compound from <i>Streptomyces collinus </i> ICN1 in zebrafish embryos

Abstract

<i>Streptomyces collinus </i> ICN1, an endosymbiotic actinomycete, isolated from the marine sponge <i>Echinodictyum gorgonoides</i> collected from Kanyakumari coast was studied for its antagonistic activity against the clinical pathogen Methicillin-resistant <i>Staphylococcus aureus </i> (MRSA). 16S rRNA gene sequencing confirmed the strain was related to <i>Streptomyces collinus </i> and spore morphology showed smooth surface in scanning electron microscopy. Media optimization for anti MRSA compound production was carried out in solid state fermentation using defined parameters, followed by extraction in methanol. Antagonistic anti-MRSA compound showed 0.91 R<i>f</i> value in the Thin layer chromatography analysis and 1.53 min retention time in the high performance liquid chromatography analysis at the wavelength of 236 nm. Antagonistic activity of purified compound was studied against MRSA in both <i>in vitro</i> antibacterial assays and <i>in vivo</i> biocompatibility studies in zebrafish embryos. Minimum inhibitory concentration of the compound was found to be 2 µg/ ml by <i>in vitro</i> broth micro dilution method and 4X MIC dose of the compound effective enough to inhibit the pathogenicity of MRSA in <i>in vivo </i> zebrafish infection assay and for the survival of embryos.