Screening Of Novel Antibiotic From Streptomyces Griseus To Control Pyogenic Infection Causing Multidrug Resistant Staphylococcus Aureus

摘要

Recent studies by epidemiology surveys on acquiring the potential of drug resistance among Staphylococcus aureus delineated that drugresistance is tremendously increasing due to the high rate of mutation in virulence genes of pathogens. Apart from the emergence of Methicillin resistantStaphylococcus aureus (MRSA), Vancomycin resistant cases also increased 170% within last one decade, indicating a need for continued surveillanceand to search and develop prospective agent to treat drug resistant pathogens. Present study aimed to screen for novel antibiotic from Streptomycessp., isolated from undisturbed areas. Alkaline to acidic range of soil samples from different part of Western Ghats regions in and around Coimbatoredistrict of Tamil Nadu were collected and upon processing thirty different Streptomyces species with unique morphological features were identified.Antibiotic production against pathogenic, multidrug resistant Staphylococcus aureus (AR, CR, ChR, CdS, ER, GR, MR, OR, VR) isolated from suppurativewound swab used in the study along with a reference strain S. aureus MTCC740 (AR, CS, ChR, CdR, ER, GS, MR, OR, VS). By the primary screening forantibiotic production from thirty Streptomyces sp., maximum zone of inhibition of 27mm showing organism belonging to Streptomyces griseus, wasidentified and confirmed by 16S rDNA sequencing. Antibiotic was partially purified from the S. griseus and minimal bacteriocidal concentration (MBC) ofantibiotic against test pathogens S. aureus MTCC740 and clinical pathogen recorded as 128μg/ml and 256μg/ml respectively. Minimal inhibitoryconcentration (MIC) for S. aureus MTCC740 was confirmed as 8μg/ml and against the clinical isolate as 32μg/ml. Recorded MIC and MBCconcentrations of novel antibiotics required to control the pathogens were comparatively lower than the antibiotics used in treatment at present. Therebythe study recommends the potential use of novel antibiotic purified from new strain of Streptomyces griseus as drug, after complete purification,characterization and toxicity assay as drug to treat emerging pan drug resistant clinical pathogens of S. aureus.