Antiviral activities of extremophilic actinomycetes extracts from Kazakhstan's unique ecosystems against influenza viruses and paramyxoviruses.

BACKGROUND: Commercially available antiviral drugs, when used in the treatment of viral infections, do not always result in success. This is an urgent problem currently that needs to be addressed because several viruses including influenza and paramyxoviruses are acquiring multi-drug resistance. A potential solution for this emerging issue is to create new antiviral drugs from available compounds of natural products. It is known that the majority of drugs have been developed using compounds derived from actinomycetes, which are naturally occurring gram-positive bacteria. The purpose of this study was to investigate the antiviral properties of extremophilic actinomycetes extracts from strains that were isolated from extreme environments in Kazakhstan. METHODS: Five strains of extremophilic actinomycetes isolated from the unique ecosystems of Kazakhstan were extracted and tested for antiviral activity against influenza viruses (strains H7N1, H5N3, H1N1 and H3N2) and paramyxoviruses (Sendai Virus and Newcastle Disease Virus). The antiviral activity of these selected extracts was tested by checking their effect on hemagglutination and neuraminidase activities of the studied viruses. Additionally, actinomycetes extracts were compared with commercially available antiviral drugs and some plant preparations that have been shown to exhibit antiviral properties. RESULTS: The main findings show that extracts from strains K-192, K-340, K-362, K-522 and K525 showed antiviral activities when tested using influenza viruses, Sendai Virus, and Newcastle Disease Virus. These activities were comparable to those shown by Rimantadine and Tamiflu drugs, and "Virospan" and "Flavovir" plant preparations. CONCLUSIONS: We identified several extracts with antiviral activities against several strains of influenza viruses and paramyxoviruses. Our research findings can be applied towards characterization and development of new antiviral drugs from the active actinomycetes extracts.

Characterization of the antibiotic compound no. 70 produced by Streptomyces sp. IMV-70.

We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified as Streptomyces sp. IMV-70. In the process of fermentation, the strain Streptomyces spp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics.

Characterizationharacterization of Extremophilic Actinomycetes Strains as Sources of Antimicrobial Agents.

Extremophilic actinomycetes strains can survive extreme saline and alkaline environments and produce antimicrobial agents. In this chapter, we discuss laboratory methods that can be used to isolate and characterize actinomycetes strains capable of potentially producing novel antimicrobial agent(s) when cultured in conditions that mimic the environments from which they were isolated. Methods used to screen for antibacterial and antiviral activities from these producer strains, and microbiological and molecular approaches used to identify these strains are described. Here we describe three methods. Method 1 focuses on the strategy to select optimal conditions to synthesize and accumulate the antibiotics from the studied actinomycetes strains by preparing crude extracts. In Method 2, we describe the screening strategies used to test the actinomycetes strains against gram-negative and gram-positive bacteria, antifungal agents, multidrug-resistant pathogens (MDR), and viral pathogens. Thus, the specific techniques to test for MDR pathogens such as the disk diffusion assay and wells assay are outlined. We also describe the antiviral activity screening of the selected actinomycetes extracts in Method 2 of this chapter. Specifically, we concentrate on methods used to test for antiviral activities such as primary hemolytic, hemagglutination, neuraminidase, and specific virus-inhibitory activities. Finally, the Method 3 section reveals the microbiological techniques used to morphologically characterize the actinomycetes strains that depend on the culture medium utilized for growth. Additionally, the method used to perform a detailed characterization of the morphology that actinomycetes strains possess is specified by the protocol for sample preparation and visualization using the scanning electron microscopy (SEM). Finally, we summarize the molecular approaches used to characterize actinomycetes strains, focusing specifically on the PCR and sequencing techniques.

Discovery of Actinomycetes from Extreme Environments with Potential to Produce Novel Antibiotics.

INTRODUCTION: Antimicrobial-resistant pathogens pose serious challenges to healthcare institutions and health of the public. Thus, there is an urgent need for the discovery of new and effective antimicrobial agents. Microorganisms that exist in extreme environments such as those with high salinity or alkalinity, are known as extremophiles, and include various species of actinomycetes. The goal of this study is to discover novel antibiotics from extremophiles found in Kazakhstan that are effective against drug resistant pathogens. METHODS: Soil from extreme environments of Kazakhstan was collected, and pure cultures of actinomycetes were isolated and cultured in modified Bennett's broth with either high concentrations of salt or high pH to mimic extreme environments. Extracts obtained from selected actinomycetes strains were used to test for antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger. RESULTS: A total of 5936 strains of extremophile actinomycetes were isolated; from these, 2019 strains were further isolated into pure cultures. Of these, 415 actinomycetes strains that demonstrated antagonistic antibacterial activities were selected. These actinomycetes were further classified into groups and subgroups based on their responses to different culture conditions. Antimicrobial antagonism activity for some of the actinomycetes strains was dependent on culture conditions and development of aerial mycelia under extreme conditions. CONCLUSION: We identified several interesting candidate extracts with putative antimicrobial activities against several strains of drug resistant pathogens. Our research of the actinomycetes' ability to produce antibiotics in the near-natural conditions provides a great opportunity to assess their biodiversity and distribution in the Central Asian region and to develop new methodological approaches to the screening of new antimicrobial agents.