scholarly journals Molecular profiling and anti-infective potency of endophytic actinomycetes inhabiting Madhuca insignis Radlk., from Western Ghats of India

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Soma Mondal ◽  
V. Ravishankar Rai
Keyword(s):  
Cell Line ◽  
Inhibition Zone ◽  
Ethyl Acetate Fraction ◽  
Multidrug Resistant ◽  
Bioactive Metabolites ◽  
Rrna Gene ◽  
Microbial Metabolites ◽  
Endophytic Actinomycetes ◽  
Western Ghats Of India ◽  
Drug Development Research

Abstract Background Endophytic actinomycetes are well known for their diverse bioactive entities and considered as an important source for drug development research. Results We isolated and identified four potential endophytic Streptomyces species, i.e., Streptomyces misionensis MI22, Streptomyces roietensis MI24, Streptomyces glaucescens MI29, and Streptomyces sp. MI04 inhabiting Madhuca insignis by its characteristic morphological features and 16S rRNA gene sequence analysis. S. misionensis MI22 exhibits a broad spectrum of anti-microbial activity against methicillin-resistant Staphylococcus aureus (25.00 ± 1.00 mm) followed by Bacillus subtilis (23.66 ± 0.57 mm), Escherichia coli (22.00 ± 0.00 mm), and Candida albicans (18.00 ± 0.00 mm). Minimum inhibitory concentrations of the ethyl acetate fraction of S. misionensis MI22 against test pathogens were ranged from 25 to 100 μg/mL. Indeed, strain MI22 also exhibited significant anti-proliferative activity against HeLa cell line with IC50 value 98 μg/mL and showed no cytotoxicity effect to the normal human embryonic kidney cell line in the MTT assay. The anti-microbial metabolites from strain MI22 were detected at Rf 0.55 as depicted by the inhibition zone on the intensive band in TLC-bioautography assay. Conclusion The study indicates that, anti-microbial metabolites of these endophytic Streptomyces species, especially S. misionensis MI22 as a prolific source to discover novel bioactive metabolites to combat multidrug-resistant pathogens.

scholarly journals Biosynthesis and Characterization of Silver Nanoparticles produced by Phormidium ambiguum and Desertifilum tharense

2021 ◽  
Author(s):  
Amira Lotfy Hanna ◽  
Hayam Hamouda ◽  
Hanan Goda ◽  
Tarek Elsayed ◽  
Mahmoud Sadik
Keyword(s):  
Silver Nanoparticles ◽  
Micrococcus Luteus ◽  
16S Rrna Gene Sequencing ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Face Centered Cubic ◽  
Ag Nps ◽  
Rrna Gene Sequencing

Abstract The world faces a challenge with pervasion of multidrug resistant bacteria which encouraged the scientists to develop and discover alternative ecofriendly and easy to produce new antibacterial agents. Two Egyptian cyanobacteria were isolated and identified according to 16S rRNA gene sequencing as Phormidium ambiguum and Desertifilum tharense . The sequences were deposited in the GenBank with accession numbers of MW762709 and MW762710 for Desertifilum tharense and Phormidium ambiguum, respectively. These isolates have the ability to produce silver nanoparticles (Ag-NPs) extra- and intracellularly under light and dark conditions. The results of UV-Vis analysis showed promising extracellular Ag-NPs synthesis by Desertifilum tharense and Phormidium ambiguum under light conditions. Therefore, these Ag-NPs were characterized and evaluated for antibacterial and antioxidant activity. TEM, SEM and XRD analyses revealed the spherical crystals with face-centered cubic structures and size range of 6.24–11.4 nm and 6.46–12.2 nm for Ag-NPs of Desertifilum tharense and Phormidium ambiguum , respectively. XRD and EDX results clearly confirmed the successful synthesis of Ag-NPs in its oxide form or chloride form. The FTIR spectrum data confirmed the presence of hydroxyl and amide groups. Desertifilum tharense Ag-NPs displayed the largest inhibition zone ranged from 9 mm against Micrococcus luteus ATCC 10240 to 25 mm against methicillin resistant S. aureus (MRSA) ATCC 43300. For Phormidium ambiguum Ag-NPs, the inhibition zone diameter was in a range of 9–18 mm. The Ag-NPs of Phormidium ambiguum exhibited the highest scavenging activity of 48.7% comparing with that of Desertifilum tharense which displayed 43.753%.

scholarly journals Isolation and Characterization of Novel Marine-Derived Actinomycete Taxa Rich in Bioactive Metabolites

2004 ◽  
Vol 70 (12) ◽  
pp. 7520-7529 ◽  
Author(s):  
Nathan A. Magarvey ◽  
Jessica M. Keller ◽  
Valerie Bernan ◽  
Martin Dworkin ◽  
David H. Sherman
Keyword(s):  
16S Rrna ◽  
Multidrug Resistant ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bioactive Metabolites ◽  
Rrna Gene ◽  
New Genera ◽  
Isolation And Identification ◽  
Fermentation Products ◽  
Isolation And Characterization

ABSTRACT A unique selective enrichment procedure has resulted in the isolation and identification of two new genera of marine-derived actinobacteria. Approximately 90% of the microorganisms cultured by using the presented method were from the prospective new genera, a result indicative of its high selectivity. In this study, 102 actinomycetes were isolated from subtidal marine sediments collected from the Bismarck Sea and the Solomon Sea off the coast of Papua New Guinea. A combination of physiological parameters, chemotaxonomic characteristics, distinguishing 16S rRNA gene sequences, and phylogenetic analysis based on 16S rRNA genes provided strong evidence for the two new genera (represented by strains of the PNG1 clade and strain UMM518) within the family Micromonosporaceae. Biological activity testing of fermentation products from the new marine-derived actinomycetes revealed that several had activities against multidrug-resistant gram-positive pathogens, malignant cells, and vaccinia virus replication.

Modulation of the drug resistance by Platonia insignis Mart. extract, ethyl acetate fraction and Morelloflavone/Volkensiflavone (biflavonoids) in Staphylococcus aureus strains overexpressing efflux pump genes

2020 ◽  
Vol 21 ◽  
Author(s):  
Andressa Kelly Ferreira e Silva ◽  
Antonielly Campinho dos Reis ◽  
Emanuelly Elanny Andrade Pinheiroc ◽  
Jonas Nascimento de Sousa ◽  
Felipe Araújo de Alcântara Oliveira ◽  
...  
Keyword(s):  
Natural Products ◽  
Ethyl Acetate ◽  
Native Species ◽  
Efflux Pump ◽  
Public Health Problem ◽  
Ethyl Acetate Fraction ◽  
Multidrug Resistant ◽  
Global Public Health ◽  
Minimal Inhibitory Concentrations ◽  
Subinhibitory Concentrations

Background: Microbial resistance to antibiotics is a global public health problem, which requires urgent attention. Platonia insignis is a native species from the eastern Brazilian Amazon, used in the treatment of burns and wounds. Objectives: To evaluate the antimicrobial activity of the hydroalcoholic extract of P. insignis (PIHA), the ethyl acetate fraction (PIAE), and its subfraction containing a mixture of biflavonoids (BF). Moreover, the effect of these natural products on the antibiotic activity against S. aureus strains overexpressing efflux pump genes was also evaluated. Methods: Minimal inhibitory concentrations were determined against different species of microorganisms. To evaluate the modulatory effect on the Norfloxacin-resistance, the MIC of this antibiotic was determined in the absence and presence of the natural products at subinhibitory concentrations. Inhibition of the EtBr efflux assays were conducted in the absence or presence of the natural products. Results: PIHA showed a microbicidal effect against S. aureus and C. albicans, while PIAE was bacteriosctatic for S. aureus. PIAE and BF at subinhibitory concentrations were able to reduce the MIC of Norfloxacin acting as modulating agents. BF was able to inhibit the efflux of EtBr efflux in S. aureus strains overexpressing specific efflux pump genes. Conclusion: P. inignisis a source of efflux pump inhibitors, including volkensiflavone and morelloflavone which were able to potentiate the Norfloxacin activity by NorA inhibition, being also able to inhibit QacA/B, TetK and MsrA. Volkensiflavone and morelloflavone could be used as adjuvant in the antibiotic therapy of multidrug resistant S. aureus strains overexpressing efflux pumps.

scholarly journals Antimicrobial Activities of Marine Sponge-Associated Bacteria

2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco
Keyword(s):  
Pathogenic Bacteria ◽  
South Australia ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Marine Sponges ◽  
Bioactive Metabolites ◽  
Human Pathogens ◽  
Sponge Associated Bacteria ◽  
Microbial Symbionts ◽  
Bacteria And Fungi

The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.

A novel myeloma cell line identified for multidrug resistant study

2009 ◽  
Vol 8 (5) ◽  
pp. 296-299
Author(s):  
Hui Xiao ◽  
Qi Xiao ◽  
Kejian Zhang ◽  
Xuelan Zuo
Keyword(s):  
Cell Line ◽  
Myeloma Cell ◽  
Multidrug Resistant ◽  
Myeloma Cell Line

Healthcare microenvironments define multidrug-resistant organism persistence

2021 ◽  
pp. 1-7
Author(s):  
Brendan J. Kelly ◽  
Selamawit Bekele ◽  
Sean Loughrey ◽  
Elizabeth Huang ◽  
Pam Tolomeo ◽  
...  
Keyword(s):  
16S Rrna ◽  
Hot Spots ◽  
Multidrug Resistant ◽  
Systematic Sampling ◽  
Resistant Organism ◽  
Rrna Gene ◽  
Environmental Cleaning ◽  
Healthcare Environment ◽  
Clostridioides Difficile ◽  
Modifiable Factors

Abstract Background: Multidrug-resistant organisms (MDROs) colonizing the healthcare environment have been shown to contribute to risk for healthcare-associated infections (HAIs), with adverse effects on patient morbidity and mortality. We sought to determine how bacterial contamination and persistent MDRO colonization of the healthcare environment are related to the position of patients and wastewater sites. Methods: We performed a prospective cohort study, enrolling 51 hospital rooms at the time of admitting a patient with an eligible MDRO in the prior 30 days. We performed systematic sampling and MDRO culture of rooms, as well as 16S rRNA sequencing to define the environmental microbiome in a subset of samples. Results: The probability of detecting resistant gram-negative organisms, including Enterobacterales, Acinetobacter spp, and Pseudomonas spp, increased with distance from the patient. In contrast, Clostridioides difficile and methicillin-resistant Staphylococcus aureus were more likely to be detected close to the patient. Resistant Pseudomonas spp and S. aureus were enriched in these hot spots despite broad deposition of 16S rRNA gene sequences assigned to the same genera, suggesting modifiable factors that permit the persistence of these MDROs. Conclusions: MDRO hot spots can be defined by distance from the patient and from wastewater reservoirs. Evaluating how MDROs are enriched relative to bacterial DNA deposition helps to identify healthcare micro-environments and suggests how targeted environmental cleaning or design approaches could prevent MDRO persistence and reduce infection risk.

Efficacy of Chemotherapeutic Agents Under Hypoxic Conditions in Pulmonary Adenocarcinoma Multidrug Resistant Cell Line

2007 ◽  
Vol 19 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Shicang Yu ◽  
Guijun Huang ◽  
Guisheng Qian ◽  
Yuying Li ◽  
Guoming Wu ◽  
...  
Keyword(s):  
Cell Line ◽  
Multidrug Resistant ◽  
Resistant Cell ◽  
Chemotherapeutic Agents ◽  
Resistant Cell Line ◽  
Pulmonary Adenocarcinoma ◽  
Hypoxic Conditions

PHYTOCHEMICAL INVESTIGATION AND ANTIMICROBIAL PROPERTIES OF DIOSCOREA BULBIFERA TUBER

2017 ◽  
Vol 10 (12) ◽  
pp. 317
Author(s):  
Dahiya P
Keyword(s):  
Antimicrobial Properties ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Phytochemical Analysis ◽  
Phytochemical Investigation ◽  
Dioscorea Bulbifera ◽  
Acinetobacter Sp ◽  
Almost All

  Objective: The inhibitory properties of successive extracts from Dioscorea bulbifera (Dioscoreaceae) tubers have been evaluated for the presence of phytochemical constituents and antimicrobial efficacy against multidrug-resistant (MDR) clinical isolates was evaluated.Methods: The tuber of D. bulbifera was oven dried and extracted successively with n-hexane, chloroform, methanol, ethanol, and water. The antimicrobial potential of successive extracts against MDR isolates was studied by agar well-diffusion method. Qualitative phytochemical analysis was performed.Results: Qualitative phytochemical analysis demonstrated the presence of steroids, flavonoids, cardiac glycosides, saponins, and reducing sugars in almost all the extracts tested. Anthraquinones, phlobatanins, and tannins were not reported in any extracts tested. The in vitro antimicrobial activity of various solvents and water extracts of D. bulbifera was further investigated against ten MDR bacteria and three fungi, respectively. Aqueous and chloroform extracts were found to be more potent being capable of exerting significant inhibitory activities against the majority of the isolates such as Escherichia coli, Acinetobacter sp., Salmonella paratyphi, Klebsiella pneumoniae, and Candida albicans. The highest inhibitory activity was observed for K. pneumoniae with wide inhibition zone diameters (17 ± 0.15 mm), followed by E. coli 1(13 ± 0.11) mm, and Acinetobacter sp. (11 ± 0.12).Conclusion: Based on the present study, the extracts of D. bulbifera tubers have shown excellent activity against MDR microbial cultures tested. Further study is recommended for clinical evaluation, of the efficacy of crude extract in herbal medicine that can serve as a base for the development of novel potent drugs and phytomedicines.

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