Extremophilic actinomycetes isolated from soil in Kazakhstan: Classification and antimicrobial activities

Extremophilic actinomycetes species are capable of surviving in extreme environment and producing antibiotics. In this study, we hypothesize that extremophiles produce antimicrobial compounds that are potentially novel agent(s) effective against drug resistant pathogens. The goal of this study is to test inhibitory activity of the extracts derived from extremophilic actinomycetes species against the most prevalent drug-resistant bacteria in Kazakhstani hospitals, and preliminarily analyze chemical composition of the active extracts. Actinomycetes species isolated from the soil of Kazakhstan were cultured in modified media mimicking extreme environment the species were isolated from. Antimicrobial compound(s) extracted with organic solvent were tested against conditionally pathogenic and multi-drug resistant pathogens Acinetobacter baumanni and Pseudomonas aeruginosa. Our study generated promising results regarding the potential discovery of novel components effective against drug resistant pathogens. Future studies will focus on further chemical analysis to identify the active component within these extremophilic extracts.

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A Simple Assay to Screen Antimicrobial Compounds Potentiating the Activity of Current Antibiotics

BioMed Research International ◽

10.1155/2013/927323 ◽

2013 ◽

Vol 2013 ◽

pp. 1-4 ◽

Cited By ~ 10

Author(s):

Junaid Iqbal ◽

Ruqaiyyah Siddiqui ◽

Shahana Urooj Kazmi ◽

Naveed Ahmed Khan

Keyword(s):

Aqueous Extract ◽

Bacterial Infections ◽

Juglans Regia ◽

Tree Bark ◽

Resistant Bacteria ◽

Multiple Drug ◽

Drug Resistant ◽

Antimicrobial Compounds ◽

Drug Resistant Bacteria ◽

Multiple Drug Resistant

Antibiotic resistance continues to pose a significant problem in the management of bacterial infections, despite advances in antimicrobial chemotherapy and supportive care. Here, we suggest a simple, inexpensive, and easy-to-perform assay to screen antimicrobial compounds from natural products or synthetic chemical libraries for their potential to work in tandem with the available antibiotics against multiple drug-resistant bacteria. The aqueous extract ofJuglans regiatree bark was tested against representative multiple drug-resistant bacteria in the aforementioned assay to determine whether it potentiates the activity of selected antibiotics. The aqueous extract ofJ. regiabark was added to Mueller-Hinton agar, followed by a lawn of multiple drug-resistant bacteria,Salmonella typhior enteropathogenicE. coli. Next, filter paper discs impregnated with different classes of antibiotics were placed on the agar surface. Bacteria incubated with extract or antibiotics alone were used as controls. The results showed a significant increase (>30%) in the zone of inhibition around the aztreonam, cefuroxime, and ampicillin discs compared with bacteria incubated with the antibiotics/extract alone. In conclusion, our assay is able to detect either synergistic or additive action ofJ. regiaextract against multiple drug-resistant bacteria when tested with a range of antibiotics.

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The Quest for Novel Antimicrobials from Bacteria

10.33178/boolean.2012.14 ◽

2012 ◽

pp. 63-66

Author(s):

Alan James Marsh

Keyword(s):

Methicillin Resistant Staphylococcus Aureus ◽

Resistant Bacteria ◽

Drug Resistant ◽

Antimicrobial Compounds ◽

Resistant Tuberculosis ◽

Life Threatening Illness ◽

Drug Resistant Bacteria ◽

Multi Drug Resistant Tuberculosis ◽

Life Threatening ◽

Tuberculosis Meningitis

Imagine a world without antibiotics. A world where diseases such as syphilis, tuberculosis, meningitis were still commonplace, where a scrape on a leg could develop into life-threatening illness and the plague was still to be feared. Such was life before 1928, the year Alexander Fleming revolutionised the field of medicine by accidentally discovering penicillin, a mould which could kill bacteria. This drug became the world’s first antibiotic and it spurred scientists to discover other classes of antimicrobial compounds, which together dramatically reduced the spread of disease. However, this golden era of medicine will not last forever. After only a few years of use, disease-causing bacteria had emerged which were resistant to antibiotics. The most common of these so-called “superbugs”, methicillin-resistant Staphylococcus aureus (MRSA), is now responsible for an increasing number of deaths, and is practically untreatable. Similarly, incidents of multi- drug-resistant tuberculosis are on the rise. Other drug-resistant bacteria are ...

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Tackling Antibiotic Resistance with Compounds of Natural Origin: A Comprehensive Review

Biomedicines ◽

10.3390/biomedicines8100405 ◽

2020 ◽

Vol 8 (10) ◽

pp. 405 ◽

Cited By ~ 1

Author(s):

Francisco Javier Álvarez-Martínez ◽

Enrique Barrajón-Catalán ◽

Vicente Micol

Keyword(s):

Antimicrobial Agents ◽

New Technologies ◽

Protein Biosynthesis ◽

Natural Compounds ◽

Network Pharmacology ◽

Resistant Bacteria ◽

Drug Resistant ◽

Antimicrobial Compounds ◽

Natural Antimicrobial ◽

Drug Resistant Bacteria

Drug-resistant bacteria pose a serious threat to human health worldwide. Current antibiotics are losing efficacy and new antimicrobial agents are urgently needed. Living organisms are an invaluable source of antimicrobial compounds. The antimicrobial activity of the most representative natural products of animal, bacterial, fungal and plant origin are reviewed in this paper. Their activity against drug-resistant bacteria, their mechanisms of action, the possible development of resistance against them, their role in current medicine and their future perspectives are discussed. Electronic databases such as PubMed, Scopus and ScienceDirect were used to search scientific contributions until September 2020, using relevant keywords. Natural compounds of heterogeneous origins have been shown to possess antimicrobial capabilities, including against antibiotic-resistant bacteria. The most commonly found mechanisms of antimicrobial action are related to protein biosynthesis and alteration of cell walls and membranes. Various natural compounds, especially phytochemicals, have shown synergistic capacity with antibiotics. There is little literature on the development of specific resistance mechanisms against natural antimicrobial compounds. New technologies such as -omics, network pharmacology and informatics have the potential to identify and characterize new natural antimicrobial compounds in the future. This knowledge may be useful for the development of future therapeutic strategies.

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Potential of Novel Antimicrobial Peptide P3 from Bovine Erythrocytes and Its Analogs To Disrupt Bacterial MembranesIn Vitroand Display Activity against Drug-Resistant Bacteria in a Mouse Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04932-14 ◽

2015 ◽

Vol 59 (5) ◽

pp. 2835-2841 ◽

Cited By ~ 25

Author(s):

Qinghua Zhang ◽

Yanzhao Xu ◽

Qing Wang ◽

Bolin Hang ◽

Yawei Sun ◽

...

Keyword(s):

Antimicrobial Activity ◽

Body Weight ◽

Mouse Model ◽

Antimicrobial Activities ◽

Resistant Bacteria ◽

Drug Resistant ◽

Drug Resistant Bacteria ◽

Resistant Strains ◽

Bovine Erythrocytes

ABSTRACTWith the emergence of many antibiotic-resistant strains worldwide, antimicrobial peptides (AMPs) are being evaluated as promising alternatives to conventional antibiotics. P3, a novel hemoglobin peptide derived from bovine erythrocytes, exhibited modest antimicrobial activityin vitro. We evaluated the antimicrobial activities of P3 and an analog, JH-3, bothin vitroandin vivo. The MICs of P3 and JH-3 ranged from 3.125 μg/ml to 50 μg/ml when a wide spectrum of bacteria was tested, including multidrug-resistant strains. P3 killed bacteria within 30 min by disrupting the bacterial cytoplasmic membrane and disturbing the intracellular calcium balance. Circular dichroism (CD) spectrometry showed that P3 assumed an α-helical conformation in bacterial lipid membranes, which was indispensable for antimicrobial activity. Importantly, the 50% lethal dose (LD50) of JH-3 was 180 mg/kg of mouse body weight after intraperitoneal (i.p.) injection, and no death was observed at any dose up to 240 mg/kg body weight following subcutaneous (s.c.) injection. Furthermore, JH-3 significantly decreased the bacterial count and rescued infected mice in a model of mouse bacteremia. In conclusion, P3 and an analog exhibited potent antimicrobial activities and relatively low toxicities in a mouse model, indicating that they may be useful for treating infections caused by drug-resistant bacteria.

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