Antimicrobial activity of some actinomycetes from Western Ghats of Tamil Nadu, India

Abstract

Introduction: Microbial diseases are increasing year by year and they are becoming a big threat to public health. There are more than 200 known diseases transmitted by bacteria, fungi, viruses, prions, rickettsia and other microbes to humans. The emergence of drug resistance to chemical drugs is the biggest threat in controlling human pathogens. Hence novel antimicrobial agents from actinomycetes are timely needed for the control of several human pathogens. Aim: The aim was to find some actinomycetes with antimicrobial metabolites. Methods: Soil samples were collected from Nilgiris district in Western Ghats of Tamil Nadu, India. Actinomycetes were isolated using serial dilution and plating techniques on actinomycetes isolation agar. Streptomycin and ketoconazole (25 lg/disc) were used as reference controls. The active strains were identified by 16S rRNA and phylogenetic tree was constructed; the sequences were submitted in the GenBank. Results: Totally 106 actinomycete strains were isolated and cross streaked against various human microbial pathogens. Only 44 (41.50%) exhibited good antimicrobial activity against different pathogenic microbes. Five isolates (FMS-20, TGH-30, TGH-31, TGH-31-1 and IS-4) were chosen for secondary screening using filtrate. Among them FMS-20 filtrate showed good inhibition on the 16th day against all tested microbial pathogens. Further the intracellular methanol extract of FMS-20 showed maximum zone of inhibition against A. brasiliensis (22 mm) at 5 mg/disc. Similarly the extracellular ethyl acetate extract of FMS-20 showed maximum zone of inhibition against B. subtilis (25 mm).

Antagonistic activity of terrestrial <i>Streptomyces</i> sp. VITNK9 against Gram negative bacterial pathogens affecting the fish and shellfish in aquaculture

“…The antibacterial activities of the isolated actinomycetes were examined by cross streak method (Ganesan et al 2016). The Muller Hinton Agar (MHA) plates were prepared.…”

Isolation, Identification and Antibiosis Efficacy of Marine Thermophilic Actinomycetes

“…The emergence of drug resistance to chemical drugs is the biggest threat in controlling human pathogens; current research objectives was designated in accordance with several studies based on this aim (Messaoudi et al, 2015;Ibrahim &Abd El-Salam, 2016 andGanesan et al, 2017). In present work, 135 isolates of actinomycetes were isolated from marine sediment soil habitat; and screened for their antibiosis activity against variable human pathogenic bacterial and fungal strains; 20 isolates registered detectable bioactivity.…”

“…Discovering new natural therapeutic agents is driven by the need to combat the increase in the incidence of infection due to antibiotic resistant pathogens coupled with the search for antitumor and antiviral compounds (Eccleston et al, 2008). In spite of the heavily studied concerning pharmaceutically relevant microorganisms, actinomycetes continue to prove themselves as reliable sources of novel bioactive compounds; they remain one of major sources of novel therapeutically relevant natural products (Messaoudi et al, 2015;Trabelsi et al, 2016 andGanesan et al, 2017). The taxonomic and ecological positions of antibiotic producing actinomycetes are well recognized for their metabolic flexibility, commonly accompanied by the production of primary and secondary metabolites of economic significance (Sharma et al, 2014).…”

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“…The six antagonists of Streptomyces and Trichoderma se ha propuesto como un agente potencial de control biológico de Colletotrichum spp., debido a su rápido crecimiento y a la actividad de sus enzimas líticas como quitinasas, endoglucanasas y exoglucanasas (Hoyos et al, 2008;Rodríguez & Veneros 2011;Sanmartín et al, 2012;Vargas et al, 2012). Peláez et al (2016) Streptomyces strains could be due to the production of some fungistatic compound (De Lima et al, 2012;Atta, 2015;Pathalam et al, 2017). In this regard, Srividya et al en la reducción de la severidad de C. gloeosporioides (Santamaría et al, 2011).…”