827| International Journal of Pharmaceutical Research | October- December 2018 | Vol 10 | Issue 4 Research Article Antimicrobial metabolite producing Streptomyces from the fertile soil of Gujarat active against multidrug resistant clinical pathogen BINA AGHERA*, SAISIVAM SRINIVASAN N.R. Vekaria Institute of Pharmacy, Junagadh, Gujarat, India Affiliated to Gujarat Technological University, Ahmedabad E-mail: beenaaghera@gmail.com. (m) : +91- 9016133643 Received: 30.10.18, Revised: 30.11.18, Accepted: 30.12.18 ABSTRACT Pathogenic organisms are acquiring resistance worldwide against existing antibiotics due to the indiscriminate use and associated toxicities leading to the necessity of new antimicrobial substances from natural resources. As soil is one of the potential resources and most of the fertile land soil of Gujarat has not been explored so far, the present work was undertaken to find the suitable antimicrobial producing Streptomyces active against multidrug resistant clinical strains. Streak plate purified soil isolates were tested against test strains of MTCC, Chandigarh by cross streak technique. The potential ones were subjected to shake flask fermentation using suitable media and supernatants were tested against the multidrug resistant clinical strains. The soil isolate GSB11 was found to be more active against Klebsiella species (KPR-45) which was found to be resistant to most of the commonly used antibiotics. Hence, efforts were made to identify and characterize GSB11 based on physiological, biochemical parameters including 16s ribosomal analysis which confirmed that GSB11 is a type strain of Streptomyces enissocaesilis. Active metabolite got extracted in ethyl acetate from shake flask fermented broth culture. Further, ongoing studies will yield a useful characterized metabolite active against various clinical pathogens. Key Words: Soil Screening, Streptomyces, Fermentation, Antibacterial activity, Multidrug resistant strain. INTRODUCTION Antibiotic resistance to human pathogenic bacteria is the global health hazard of epidemic proportion. [1] Many pathogenic bacteria are acquiring resistance to at least one of the currently available antibiotics. The so called ‘super bugs’ (organisms that are resistant to most of the clinically used antibiotic) are emerging at a rapid rate. [2] Examples include Methicillin-resistant staphylococci, Penicillin and Macrolides resistant Pneumococci, Vancomycin- resistant enterococci as well as multidrug resistant gram-negative organisms. [3] The global emergence of multidrug resistant bacterial strains is increasingly limiting the effectiveness of current drugs and significantly causing treatment failure of infections. [4] The drug resistant pathogens have further complicated the treatment of infectious diseases in immune compromised AIDS and cancer patients. [5,6] Moreover, many potentially important antibiotics have associated toxicities that limit their use. In the present global scenario, the emergence of drug and multidrug resistance pathogens, evolution of novel diseases and toxicity of currently used drug necessitate a continuous search for new antimicrobial compound with novel mechanism of action. Soil is a repository of microorganisms capable of producing antimicrobial substances. The species belong to the genus Streptomyces constitute 50% of the total population of soil Actinomycetes and are of commercial interest due to their unique ability to produce variety of bioactive secondary metabolites including antibiotics, immune modulators, anticancer drugs, antiviral drugs, herbicides, and insecticides. [7,8,9] Even though much work on the terrestrial Streptomyces is done, still soil remains the richest versatile reservoir for novel and clinically important antibiotics. Moreover, the soil samples of Gujarat have not been explored so far in search of secondary metabolites. Therefore, the present work was undertaken to isolate and characterize the potent Streptomyces from diverse source of soil to elucidate their activity against various test and multidrug resistant clinical strains. MATERIALS AND METHODS Materials: The bacterial test strains Bacillus subtilis (MTCC 441), Staphylococcus aureus (MTCC 96), Pseudomonas auregenosa (MTCC 1688), Escherichia coli (MTCC 443) and Klebsiella pneumoniae (MTCC 3384) were obtained from Microbial Type Culture Collection Center (MTCC), Chandigarh, India. The multidrug resistant clinical pathogens Klebsiella species (KPR-45), Pseudomonas species (PAR) and Escherichia coli (EC-1) isolated from the urine sample of patients were obtained from the diagnostic Laboratories, Junagadh, Gujarat. Antibiotic discs (OD270R and OD053R), Nystatin and other medium ingredients were purchased from Hi-media, Mumbai. Isolation and purification of soil isolates Soil samples were collected aseptically in the sterile tubes from top 5-10 cm depth considering difference in physiological and chemical characteristics of soil