Gebreselema Gebreyohannes

Dr. Gebreselema Gebreyohannes


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2019 in Heliyon
Verified
Journal Article
Open access
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
ANAndrew Nyerere
Andrew Nyerere
CBChristine Bii
Christine Bii
DSDesta B. Sbhatu
Desta B. Sbhatu
Biofilms are multicellular communities of microorganisms held together by a self-produced extracellular matrix. The ability of microbes to form biofilm is a universal, ubiquitous, and dynamic process. This dynamic process of biofilms establishes an important strategy to withstand and survive harsh environmental conditions and antimicrobial agents. This review paper aims to give an overview of antibiotic resistance, intervention, and treatment of infections caused by biofilm-forming organisms. Moreover, it can also help to motivate scholars to search for new anti-biofilm strategies and most appropriate methods to tackle the effect of biofilm infections on healthcare services. This paper was written by reviewing recent research and review articles which are reporting about the antibiotic resistance, prevention, and treatment of biofilm-producing organisms. Bioprospecting for quorum quenching compounds can be an appropriate solution for controlling biofilm infections.

1 June 2013 in Asian Pacific Journal of Tropical Biomedicine
Verified
Journal Article
Closed access
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
FMFeleke Moges
Feleke Moges
SSSamuel Sahile
Samuel Sahile
NRNagappan Raja
Nagappan Raja
To isolate, evaluate and characterize potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia. A total of 31 strains of actinomycetes were isolated and tested against Gram positive and Gram negative bacterial strains by primary screening. In the primary screening, 11 promising isolates were identified and subjected to solid state and submerged state fermentation methods to produce crude extracts. The fermented biomass was extracted by organic solvent extraction method and tested against bacterial strains by disc and agar well diffusion methods. The isolates were characterized by using morphological, physiological and biochemical methods. The result obtained from agar well diffusion method was better than disc diffusion method. The crude extract showed higher inhibition zone against Gram positive bacteria than Gram negative bacteria. One-way analysis of variance confirmed most of the crude extracts were statistically significant at 95% confidence interval. The minimum inhibitory concentration and minimum bactericidal concentration of crude extracts were 1.65 mg/mL and 3.30 mg/mL against Staphylococcus aureus, and 1.84 mg/mL and 3.80 mg/mL against Escherichia coli respectively. The growth of aerial and substrate mycelium varied in different culture media used. Most of the isolates were able to hydrolysis starch and urea; able to survive at 5% concentration of sodium chloride; optimum temperature for their growth was 30 °C. The results of the present study revealed that freshwater actinomycetes of Lake Tana appear to have immense potential as a source of antibacterial compounds.

18 February 2019 in Evidence-Based Complementary and Alternative Medicine
Verified
Journal Article
Open access
PDF file
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
ANAndrew Nyerere
Andrew Nyerere
CBChristine Bii
Christine Bii
DSDesta B. Sbhatu
Desta B. Sbhatu
Objective. This study has investigated the antimicrobial activity of extracts of indigenous wild mushrooms against selected organisms. Methods. Thirty-five (35) indigenous wild mushrooms were collected from Arabuko-Sokoke and Kakamega National Reserve Forests, Kenya. All mushrooms were identified and their contents were extracted and screened for their antimicrobial activities against Escherichia coli (clinical isolate), Klebsiella pneumoniae (ATCC 13883), Pseudomonas aeruginosa (clinical isolate), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), MRSA (ATCC 33591), Candida albicans (clinical isolate), and Candida parapsilosis (ATCC 90018) using tetrazolium microtiter plate bioassay method. Results. Of the 35 tested mushroom extracts, extracts of three (3) mushrooms, namely, Trametes spp. (Arabuko-Sokoke forest), Trametes, and Microporus spp. (Kakamega forest), have shown promising antimicrobial activities against the tested organisms. The S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), and Methicillin-Resistant Staphylococcus aureus (MRSA) (ATCC 33591) were the most susceptible to chloroform extract of Trametes spp. collected from Arabuko-Sokoke forest. Of the tested organisms, S. aureus (ATCC 25923) was the most susceptible whereas E. coli was the most resistant organism to the hot water extract of Trametes spp. collected from Arabuko-Sokoke forest. Chloroform extract of Microporus spp. has shown the highest antibacterial activity against S. aureus (ATCC 25923), MRSA (ATCC 33591), and K. pneumoniae (ATCC 13883) but limited activity against E.coli. All extracts of the three wild mushrooms have shown the most antibacterial activities against S. aureus (ATCC 25923). Conclusion. The present study has shown that the extracts of the three wild mushrooms have shown promising antimicrobial activities against the tested organisms.

24 July 2019 in The Scientific World Journal
Verified
Journal Article
Open access
PDF file
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
ANAndrew Nyerere
Andrew Nyerere
CBChristine Bii
Christine Bii
DSDesta B. Sbhatu
Desta B. Sbhatu
Mushrooms produce a variety of bioactive compounds that are known to have a potential source of antioxidant and antimicrobial properties. Natural antioxidants can protect against free radicals without any side effects. The purpose of this study was to evaluate the antioxidant and antimicrobial activities of Auricularia and Termitomyces extracts. Specimens of Auricularia and Termitomyces spp. were collected from Kakamega National Reserve Forest in Kenya. Specimens were identified, extracted, and screened for their antioxidant and antimicrobial activities using stable free radical DPPH and colorimetric bioassay methods, respectively. The antimicrobial activity of the extracts was tested against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, MRSA, Candida albicans, and Candida parapsilosis. The maximum scavenging activity of hot water extract of Auricularia spp. was observed at 70.4% with the IC50 value of 40 μg/mL. Of the three extracts of Termitomyces spp., 70% ethanol extract has shown the highest scavenging activity (63%) with the IC50 value of 50 μg/mL. Chloroform and hot water extracts of Auricularia have shown statistically significantly different antifungal activities against C. parapsilosis (df = 2, F = 22.49, p ≤ 0.05). Of all the organisms, S. aureus was highly susceptible to 70% ethanol and hot water extracts of Termitomyces spp. with minimum inhibitory concentration values of 0.67±0.29 mg/mL. S. aureus and E. coli were the most susceptible and resistant bacteria to the hot water extract, respectively. In conclusion, the extracts of Auricularia spp. and Termitomyces spp. have shown promising antimicrobial and antioxidant activities.

22 September 2023 in International Journal of Analytical Chemistry
Verified
Journal Article
Open access
PDF file
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
DSDesta B. Sbhatu
Desta B. Sbhatu
Secondary metabolites are hidden gems in mushrooms. Understanding these secondary metabolites biological and pharmacological effects can be aided by identifying them. The purpose of this work was to profile the mycochemical components of the extracts of Auricularia auricula judae, Microporus xanthopus, Termitomyces umkowaani, Trametes elegans, and Trametes versicolor to comprehend their biological and pharmacological capabilities. Mushroom samples were collected from Kenyas ArabukoSokoke and Kakamega National Reserved Forests and identified using morphological and molecular techniques. Chloroform, 70 ethanol, and hot water solvents were used to extract the mycochemical components. Gas chromatography mass spectrometry (GC-MS) was used to analyze the chloroform, 70 ethanol, and hot water extracts of all the species examined. A total of 51 compounds were isolated from all extracts and classified as carboxylic acids, esters, phenols, fatty acids, alcohol, epoxides, aldehydes, fatty aldehydes, isoprenoid lipids, and steroids. Tetracosamethyl-cyclododecasiloxane (18.90), oleic acid (72.90), phenol, 2, 6-bis (1, 1-dimethylethyl)-4-methyl-, and methylcarbamate (26.56) were all found in high concentrations in A. auricular judae, M. xanthopus, T. umkowaani, T. elegans, and T. versicolor, respectively. Fatty acids make up the majority of the compounds isolated from the T. elegans chloroform extract and the T. umkowaani 70 ethanol extract, respectively. Particularly, these fatty acids play crucial roles in the anti-inflammatory, hypocholesterolemic, anticancer, and antibiofilm formation activities. These bioactive elements indicate that the extracts of five wild mushrooms may be reliable sources of secondary metabolites for therapeutic development. Therefore, additional research is required to comprehend the usefulness of these chemicals in many functional areas and to improve the present understanding of macrofungi.

15 July 2025 in Food Science & Nutrition
Verified
Journal Article
Open access
SFSolomon Fitsum
Solomon Fitsum
DSDesta Berhe Sbhatu
Desta Berhe Sbhatu
GGGebreselema Gebreyohannes
Gebreselema Gebreyohannes
Mushrooms have been valued for their unique flavor and medicinal properties since ancient times. As a nutrient‐dense superfood, they provide essential nutrients, including dietary fiber, high‐quality protein, and key vitamins (especially D and B), along with minerals. They are naturally low in fat, sugar, and calories, and cholesterol, making them a beneficial addition to a balanced diet. Increasingly, mushrooms are incorporated into functional foods, cosmetics, and even used as meat substitutes, enhancing nutritional value and offering significant health benefits. They contain a variety of bioactive compounds—such as terpenoids, flavonoids, tannins, alkaloids, polyphenols, and polysaccharides—which contribute to their therapeutic properties. These include antioxidant, anticancer, antimicrobial, immunomodulatory, anti‐inflammatory, anti‐tyrosinase, immune‐boosting, and antihyperglycemic effects, all of which support human health and medical applications. Additionally, mushrooms promote heart health, help reduce cholesterol, and assist in managing chronic conditions like hypertension, obesity, and diabetes. Ongoing research continues to uncover new bioactive compounds that may be effective in treating neurological and cardiovascular diseases. With advancements in science and technology, mushrooms are becoming increasingly valuable in medicine, pharmaceuticals, food production, cosmetics, and environmental bioremediation, creating potential opportunities across various industries. This review aims to explore the nutritional value and bioactive compounds of mushrooms, along with their health benefits, therapeutic properties, and applications in functional foods, cosmetics, and pharmaceuticals. It highlights their potential as sustainable medicinal resources and a rich source of novel bioactive compounds for managing chronic diseases and other health conditions.