Antioksidacijska i antimikrobna aktivnost etil-acetatnog ekstrakta kvasca Saccharomyces cerevisiae

Research background. Antioxidants are important compounds present at low concentrations that inhibit oxidation processes. Due to the side effects of synthetic antioxidants, research interest has increased considerably towards finding natural sources of antioxidants that can replace the synthetic ones. The emergence and spread of antibiotic resistance require the development of new drugs or some potential sources of novel medicine. This work aims to extract the secondary metabolites of Saccharomyces cerevisiae using ethyl acetate as a solvent and to determine the antioxidant and antimicrobial activities of these extracted metabolites. Experimental approach. The antioxidant activity of the secondary metabolites of S. cerevisiae were determined using DPPH, ABTS and FRAP assays. Furthermore, the antimicrobial potential of the ethyl acetate extract of S. cerevisiae against Cutibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis was assessed. Results and conclusion. Five out of 13 of the extracted secondary metabolites were identified as antioxidants. The antioxidant activity of the S. cerevisiae extract exhibited relatively high IC50 of 455.26 and 294.51 μg/mL for DPPH and ABTS respectively, while the obtained FRAP value, expressed as ascorbic acid equivalents, was 44.40 μg/mL. Moreover, the extract had a significant antibacterial activity (p<0.05) against Staphylococcus aureus and Staphylococcus epidermidis at the concentrations of 100 and 200 mg/mL, respectively. However, no inhibitory effect was observed against Cutibacterium acnes as the extract was only effective against the bacterium at the concentrations of 300 and 400 mg/mL (inhibition zones ranging from 9.0±0.0 to 9.3±0.6) respectively (p<0.05). Staphylococcus aureus was highly sensitive to the extract, with a MIC value of 18.75 mg/mL. Novelty and scientific contribution. This report confirmed the efficacy of the secondary metabolites of S. cerevisiae as a natural source of antioxidants and antimicrobials and suggested the possibility of employing them in drugs for the treatment of infectious diseases caused by the tested microorganisms.Pozadina istraživanja. Antioksidansi su važni spojevi koji već pri niskim koncentracijama inhibiraju oksidacijske procese. Zbog štetnih nuspojava primjene sintetskih antioksidanasa porastao je interes za istraživanjem prirodnih izvora antioksidansa. Pojava i proširenost antibiotske rezistencije potakli su interes za razvojem novih lijekova ili mogućih izvora novih lijekova. Svrha je ovoga rada bila ekstrahirati sekundarne metabolite kvasca Saccharomyces cerevisiae pomoću etil-acetata kao otapala, te odrediti antioksidacijsku i antimikrobnu aktivnost dobivenih metabolita. Eksperimentalni pristup. Antioksidacijska aktivnost sekundarnih metabolita kvasca S. cerevisiae određena je pomoću metoda DPPH, ABTS i FRAP. Osim toga, ispitan je antimikrobni učinak etil-acetatnog ekstrakta kvasca S. cerevisiae na bakterije Cutibacterium acnes, Staphylococcus aureus i Staphylococcus epidermidis. Rezultati i zaključci. Od 13 izdvojenih sekundarnih metabolita, identificirano je njih pet s antioksidacijskim učinkom. Ekstrakt S. cerevisiae imao je relativno veliku IC50 vrijednost, i to 455,27 μg/mL utvrđenu DPPH metodom i 294,51 μg/mL dobivenu ABTS metodom, te FRAP vrijednost, izraženu u ekvivalentima askorbinske kiseline, od 44,40 μg/mL. Osim toga, ekstrakt je imao izraženi antibakterijski učinak (p<0,05) na Staphylococcus aureus pri koncentraciji od 100 mg/mL i Staphylococcus epidermidis pri koncentraciji od 200 mg/mL. Međutim, nije opažena inhibicija bakterije Cutibacterium acnes, budući da je ekstrakt učinkovito (p<0.05) inhibirao tu bakteriju samo pri koncentracijama od 300 i 400 mg/mL (sa zonama inhibicije od 9,0±0,0 do 9,3±0,6). Bakterija Staphylococcus aureus bila je vrlo osjetjiva na djelovanje ekstrakta, s minimalnom inhibicijskom koncentracijom od 18,75 mg/mL. Novina i znanstveni doprinos. U ovom je radu potvrđena učinkovitost sekundarnih metabolita kvasca S. cerevisiae kao prirodnih antioksidacijskih i antimikrobnih spojeva, te je dokazana mogućnost njihove primjene u lijekovima protiv zaraznih bolesti uzrokovanih ispitanim bakterijama

Observations on the Pearl Oyster Fishery of Kuwait

The pearl oyster fishery of Kuwait was monitored daily from January 1989 to May 1990. Landings of pearl oysters in 1989 totaled 287 tons with a market value of U.S. $1.0 million. Commercial pearls (\u3e3 mm) were estimated to be present in one of every 4200 oysters. Most of the pearl oysters landed were new recruits with hinge lengths between 40-56 mm. There was a curvilinear relationship between total weight and size of oysters (length) and the sex ratio approached 1:1. Spawning occurs throughout the year, with a spat settlement peak in early fall. Over the size range examined there was no relationship between the size of oysters and the size of pearls and subsequent resource management strategies are discussed

Gamma-Ray Protection Properties of Bismuth-Silicate Glasses Against Some Diagnostic Nuclear Medicine Radioisotopes: A Comprehensive Study

This study aimed to perform an investigation for the potential implementation of bismuth silicate glasses as novel shield equipment instead of ordinary shields in nuclear medicine facilities. Accordingly, a group of Bi2O3 reinforced silicate glass system were investigated and compared with ordinary shields in terms of their gamma-ray attenuation properties in diagnostic nuclear medicine radioisotope energies emitted from99mTc,111 In,67Ga,123 I,131 I,81mKr,201Tl,133Xe. Mass attenuation coefficient (µm) results for glass samples were calculated comparatively with the XCOM program and MCNPX code. The gamma-ray attenuation parameters such as half value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Zeff ) were obtained in the diagnostic gamma ray energy range from 75 to 336 keV. To confirm the attenuation performance of superior sample, obtained results were extensively compared with ordinary shielding materials. According to the results obtained, BISI6 glass sample with the highest Bi2O3 additive has an excellent gamma-ray protection. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program

Clinical Pathway and Monthly Feedback Improve Adherence to Antibiotic Guideline Recommendations for Community-Acquired Pneumonia

Background: Compliance with community-acquired pneumonia (CAP) guidelines remains poor despite a substantial body of evidence indicating that guideline-concordant care improves patient outcomes. The aim of this study was to compare the relative effectiveness of a general educational and a targeted emergency department intervention on improving physicians’ concordance with CAP guidelines. Methods: Two distinct interventions were implemented over specific time periods. The first intervention was educational, focusing on the development of local CAP guidelines and their dissemination through hospital-wide educational programmes. The second intervention was a targeted one for the emergency department, where a clinical pathway for the initial management of CAP patients was introduced, followed by monthly feedback to the emergency department (ED) physicians about concordance rates with the guidelines. Data on the concordance rate to CAP guidelines was collected from a retrospective chart review. Results: A total of 398 eligible patient records were reviewed to measure concordance to CAP guidelines over the study period. Concordance rates during the baseline and educational intervention periods were similar (28.1% vs. 31.2%; p > 0.05). Significantly more patients were treated in accordance with the CAP guidelines after the ED focused intervention when compared to the baseline (61.5% vs. 28.1%; p < 0.05) or educational period (61.5% vs. 31.2%; p < 0.05). Conclusions: A targeted intervention with a CAP clinical pathway and monthly feedback was a successful strategy to increase adherence to empirical antibiotic recommendations in CAP guidelines

Therapeutic Potential of N-Acetylcysteine for Wound Healing, Acute Bronchiolitis, and Congenital Heart Defects

Wound healing is a composite and vital process in which devitalized tissue layers and cellular structures repair themselves. Bronchiolitis is generally prompted by respiratory syncytial virus or human metapneumovirus; this condition is an acute inflammatory injury of bronchioles. Heart problems that develop before birth are known as congenital heart defects (CHDs), and pregestational diabetes is considered a major predisposing factor of CHDs. N-Acetylcysteine (NAC) is a transformed kind of amino acid cysteine which restores the intracellular levels of the natural antioxidant glutathione when taken internally, thereby assisting the cells’ ability to diminish the damaging effects of reactive oxygen species (ROS)

Chemotherapeutic Agents: Taxol and Vincristine Isolated from Endophytic Fungi

Endophytic fungi are abundant and have been found asymptomatically in most plants species. Endophytic fungi are considered as hidden members of the microbial world and represent an under-utilized resource of natural bioactive compounds for agricultural, industrial and medicinal uses. As reported previously, several valuable natural products with anticancer, antimicrobial, and insecticidal properties have been successfully extracted from the endophytic fungi. Chemotherapy yields the first promise of destroying cancer cells that has distributed into the body. This is due to the fact that chemotherapeutic agents overlap with the process of dividing cancer cells, which in turn leads to establishing new cells. Vincristine (vinca alkaloids) and podophyllotoxin prohibit the microtubules polymerization at high drug concentrations whereas Taxol™ and Taxotere stimulate the microtubules polymerization and stabilize the microtubules as well at high concentrations. In This review, we critically attempt to summarize the mechanisms of the cancer chemotherapeutic drugs, namely, Taxol and Vincristine (vinca alkaloids) on the need for more the research in the field of cancer chemotherapy

Novel Compounds Targeting InhA for TB Therapy

Tuberculosis (TB) is described as lethal disease in the world. Resistant to TB drugs is the main reason to have unfavourable outcomes in the treatment of TB. Therefore, new agents to replace existing drugs are urgently needed. Previous reports suggested that InhA inhibitors, an enoyl-ACP-reductase, might provide auspicious candidates which can be developed into novel antitubercular agents. In this review, we explain the role of InhA in the resistance of isoniazid. Furthermore, five classes of InhA inhibitors, which display novel binding modes and deliver evidence of their prosperous target engagement, have been debated

Preliminary Phylogenetic Analysis of Thermophilic Bacteria Producing Protease isolated from Kuantan Malaysia

Thermophilic bacteria grow in relatively high temperature between 50 to 60°C. These organisms can produce specific enzymes that have been used in industrial and biotechnological applications. The basic method to derive a sequence for a uncultured bacteria is to use universal primers against the 16S rRNA gene region in a PCR step to increase the amount of DNA and then to sequence the amplicon. This study was carried out to screen the ability of thermophilic bacterial isolates for degrading protein by protease and to identify the most potent isolates using molecular techniques inferred by 16S rRNA gene. We are dependent on accurate sequences in databases, appropriate names associated with those sequences, and an accurate sequence for the isolate to be identified. Thirty seven bacterial isolates were cultured and characterized using nutrient casein plate method. Twenty out of thirty seven bacterial isolates have been recognized to be positive for casein test and selected for Gram staining method. Total DNA genomic were extracted by using I-genomic DNA Extraction Mini Kit, and polymerase chain reaction (PCR) operation assay was performed for appropriate target isolates. The phylogenetic analysis of these strains revealed that the genus of Bacillus is the most closely matched to the data from the GenBank. Bacillus subtilis, Bacillus sp, Bacillus amyloliquefaciens and Bacillus licheniformis were identified as species for the potential bacterial isolates. Two samples which are RSS6 and JF OUTER 2B have not been characterized through the phylogenetic tree. This might refer to either rare or new bacteria

Production of Xylanase Enzyme from AspergillusTerreus SUK-1

Xylanase productionfrom AspergillusterreusSUK-1 was carried out in submerged culture fermentation (SCF). The fermentation process was performed by using 0.30% ofxylan and 0.75% -cellulose as substrates of carbon source at 30°C, 150 rpm in the shaker for 7 days. Two processes, which were used for xylanaseproduction, were shake flask culture and fermenter. In the shake flask culture, the maximum xylanase activity was 52.18U/mL U/mL with xylan as a substrate, while 63.29U/mL was for a-cellulose as substrate; after 5 days. In 5 L fermenter with 3 L working volume, the xylanase activity reached the maximum value which was 78.65U/mLafter five days. Two conditions were studied to get the optimum conditions for xylanase activities which were pH and temperature by using xylan as substrate. The highest activity was at pH 6.5 and constant temperature 37°C. While the optimum temperature was 50°C with constant pH 5