Alkaline keratinase from Bacillus sp. DRS4 efficiently biodegrades chicken feathers to synthesize improved keratin/bacterial nanocellulose-based bioplastics.

Chicken feathers represent an abundant and sustainable resource that can be harnessed for multiple value-added products. Bioplastic reinforced with bacterial nanocellulose was synthesized using enzymatically digested chicken feathers. A highly efficient keratinolytic bacterium, identified as Bacillus sp. DRS4 through biochemical characterization and 16S rRNA gene sequence analysis, was isolated from deposit soils of Lake Chitu in Ethiopia. Bacillus sp. DRS4 was able to completely degrade chicken feathers within 48 h. Optimization of the physicochemical parameters increased the enzyme yield from Bacillus sp. DRS4 by 30%. The enzyme showed optimal keratinolytic activity at 37 °C and pH 11, hydrolyzing white chicken feathers in 72 h and providing hydrolysates with a total protein content of 251.145 mg/mL. Further, the mechanical and thermal properties of a bioplastic made from hydrolysates and reinforced with bacterial nanocellulose were assessed. The bioplastic exhibited a remarkable tensile strength of 5.769 MPa and reached a melting temperature of 127.5 °C, suggesting that bacterial nanocellulose acts as an effective stabilizer. Fourier Transform Infrared spectroscopy (FTIR) analysis revealed additional peaks in BNC-reinforced plastic films, indicating a binding interaction that enhanced the bioplastic properties. Overall, Bacillus sp. DRS4 is a potential strain for alkaline keratinase production and a promising candidate for upgrading chicken feathers into high-value-added products.

Copper nanoparticles embedded fungal chitosan as a rational and sustainable bionanozyme with robust laccase activity for catalytic oxidation of phenolic pollutants.

Despite their potential for oxidation of persistent environmental pollutants, the development of rational and sustainable laccase nanozymes with efficient catalytic performance remains a challenge. Herein, fungal-produced chitosan-copper (CsCu) is proposed as a rational and sustainable bionanozyme with intrinsic laccase activity. The CsCu nanozyme was prepared by in situ reduction of copper on chitosan extracted from Irpex sp. isolate AWK2 a native fungus, from traditional fermented foods, yielding a low molecular weight chitosan with a 70% degree of deacetylation. Characterizations of the nanozyme using SEM-EDX, XRD, and XPS confirmed the presence of a multi-oxidation state copper on the chitosan matrix which is consistent with the composition of natural laccase. The laccase memetic activity was investigated using 2,4-DP as a substrate which oxidized to form a reddish-pink color with 4-AP (λmax = 510 nm). The CsCu nanozyme showed 38% higher laccase activity than the pristine Cu NPs at pH 9, indicating enhanced activity in the presence of chitosan structure. Further, CsCu showed significant stability in harsh conditions and exhibited a lower Km (0.26 mM) which is competitive with that reported for natural laccase. Notably, the nanozyme converted 92% of different phenolic substrates in 5 h, signifying a robust performance for environmental remediation purposes.

Bacterial Nanocellulose/Copper as a Robust Laccase-Mimicking Bionanozyme for Catalytic Oxidation of Phenolic Pollutants.

Industrial effluents containing phenolic compounds are a major public health concern and thus require effective and robust remediation technologies. Although laccase-like nanozymes are generally recognized as being catalytically efficient in oxidizing phenols, their support materials often lack resilience in harsh environments. Herein, bacterial nanocellulose (BNC) was introduced as a sustainable, strong, biocompatible, and environmentally friendly biopolymer for the synthesis of a laccase-like nanozyme (BNC/Cu). A native bacterial strain that produces nanocellulose was isolated from black tea broth fermented for 1 month. The isolate that produced BNC was identified as Bacillus sp. strain T15, and it can metabolize hexoses, sucrose, and less expensive substrates, such as molasses. Further, BNC/Cu nanozyme was synthesized using the in situ reduction of copper on the BNC. Characterization of the nanozyme by scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed the presence of the copper nanoparticles dispersed in the layered sheets of BNC. The laccase-mimetic activity was assessed using the chromogenic redox reaction between 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP) with characteristic absorption at 510 nm. Remarkably, BNC/Cu has 50.69% higher catalytic activity than the pristine Cu NPs, indicating that BNC served as an effective biomatrix to disperse Cu NPs. Also, the bionanozyme showed the highest specificity toward 2,4-DP with a Km of 0.187 mM, which was lower than that of natural laccase. The bionanozyme retained catalytic activity across a wider temperature range with optimum activity at 85 °C, maintaining 38% laccase activity after 11 days and 46.77% activity after the fourth cycle. The BNC/Cu bionanozyme could efficiently oxidize more than 70% of 1,4-dichlorophenol and phenol in 5 h. Thereby, the BNC/Cu bionanozyme is described here as having an efficient ability to mimic laccase in the oxidation of phenolic compounds that are commonly released into the environment by industry.

Renal Angiomyolipoma Rupture Following COVID-19 Infection: A Case Report.

The novel Coronavirus (COVID-19) is one of the most recent Pandemics that invaded the earth and is still active. It caused and is still causing hundreds of thousands of patients high morbidity and mortality rates, with no definitive cure at this moment. COVID-19 has been proven to be associated with pathologic changes in coagulation, characterized by either thromboembolic or bleeding events. We describe this case of a 44-year-old male patient who walked into our emergency department with flank pain and was later discovered to have had renal angiomyolipoma (AML) rupture during his COVID-19 infection, ultimately requiring admission for hemorrhage control via interventional radiology (IR) drainage. Here, we discuss the role of front-line physicians and how they should keep a low threshold for the different presentations that could be associated with COVID-19 infection, such as what was found in this case.

Toxicity of Heavy Metals and Recent Advances in Their Removal: A Review.

Natural and anthropogenic sources of metals in the ecosystem are perpetually increasing; consequently, heavy metal (HM) accumulation has become a major environmental concern. Human exposure to HMs has increased dramatically due to the industrial activities of the 20th century. Mercury, arsenic lead, chrome, and cadmium have been the most prevalent HMs that have caused human toxicity. Poisonings can be acute or chronic following exposure via water, air, or food. The bioaccumulation of these HMs results in a variety of toxic effects on various tissues and organs. Comparing the mechanisms of action reveals that these metals induce toxicity via similar pathways, including the production of reactive oxygen species, the inactivation of enzymes, and oxidative stress. The conventional techniques employed for the elimination of HMs are deemed inadequate when the HM concentration is less than 100 mg/L. In addition, these methods exhibit certain limitations, including the production of secondary pollutants, a high demand for energy and chemicals, and reduced cost-effectiveness. As a result, the employment of microbial bioremediation for the purpose of HM detoxification has emerged as a viable solution, given that microorganisms, including fungi and bacteria, exhibit superior biosorption and bio-accumulation capabilities. This review deals with HM uptake and toxicity mechanisms associated with HMs, and will increase our knowledge on their toxic effects on the body organs, leading to better management of metal poisoning. This review aims to enhance comprehension and offer sources for the judicious selection of microbial remediation technology for the detoxification of HMs. Microbial-based solutions that are sustainable could potentially offer crucial and cost-effective methods for reducing the toxicity of HMs.

A sharp interface Lagrangian-Eulerian method for flexible-body fluid-structure interaction.

This paper introduces a sharp-interface approach to simulating fluid-structure interaction (FSI) involving flexible bodies described by general nonlinear material models and across a broad range of mass density ratios. This new flexible-body immersed Lagrangian-Eulerian (ILE) scheme extends our prior work on integrating partitioned and immersed approaches to rigid-body FSI. Our numerical approach incorporates the geometrical and domain solution flexibility of the immersed boundary (IB) method with an accuracy comparable to body-fitted approaches that sharply resolve flows and stresses up to the fluid-structure interface. Unlike many IB methods, our ILE formulation uses distinct momentum equations for the fluid and solid subregions with a Dirichlet-Neumann coupling strategy that connects fluid and solid subproblems through simple interface conditions. As in earlier work, we use approximate Lagrange multiplier forces to treat the kinematic interface conditions along the fluid-structure interface. This penalty approach simplifies the linear solvers needed by our formulation by introducing two representations of the fluid-structure interface, one that moves with the fluid and another that moves with the structure, that are connected by stiff springs. This approach also enables the use of multi-rate time stepping, which allows us to use different time step sizes for the fluid and structure subproblems. Our fluid solver relies on an immersed interface method (IIM) for discrete surfaces to impose stress jump conditions along complex interfaces while enabling the use of fast structured-grid solvers for the incompressible Navier-Stokes equations. The dynamics of the volumetric structural mesh are determined using a standard finite element approach to large-deformation nonlinear elasticity via a nearly incompressible solid mechanics formulation. This formulation also readily accommodates compressible structures with a constant total volume, and it can handle fully compressible solid structures for cases in which at least part of the solid boundary does not contact the incompressible fluid. Selected grid convergence studies demonstrate second-order convergence in volume conservation and in the pointwise discrepancies between corresponding positions of the two interface representations as well as between first and second-order convergence in the structural displacements. The time stepping scheme is also demonstrated to yield second-order convergence. To assess and validate the robustness and accuracy of the new algorithm, comparisons are made with computational and experimental FSI benchmarks. Test cases include both smooth and sharp geometries in various flow conditions. We also demonstrate the capabilities of this methodology by applying it to model the transport and capture of a geometrically realistic, deformable blood clot in an inferior vena cava filter.

Kerosene Biodegradation by Highly Efficient Indigenous Bacteria Isolated From Hydrocarbon-Contaminated Sites.

Kerosene is widely used in Ethiopia as a household fuel (for lighting and heating), as a solvent in paint and grease, and as a lubricant in glass cutting. It causes environmental pollution and escorts to loss of ecological functioning and health problems. Therefore, this research was designed to isolate, identify, and characterize indigenous kerosene-degrading bacteria that are effective in cleaning ecological units that have been contaminated by kerosene. Soil samples were collected from hydrocarbon-contaminated sites (flower farms, garages, and old-aged asphalt roads) and spread-plated on mineral salt medium (Bushnell Hass Mineral Salts Agar Medium: BHMS), which consists of kerosene as the only carbon source. Seven kerosene-degrading bacterial species were isolated, 2 from flower farms, 3 from garage areas, and 2 from asphalt areas. Three genera from hydrocarbon-contaminated sites were identified, including Pseudomonas, Bacillus, and Acinetobacter using biochemical characterization and the Biolog database. Growth studies in the presence of various concentrations of kerosene (1% and 3% v/v) showed that the bacterial isolates could metabolize kerosene as energy and biomass. Thereby, a gravimetric study was performed on bacterial strains that proliferated well on a BHMS medium with kerosene. Remarkably, bacterial isolates were able to degrade 5% kerosene from 57.2% to 91% in 15 days. Moreover, 2 of the most potent isolates, AUG2 and AUG1, resulted in 85% and 91% kerosene degradation, respectively, when allowed to grow on a medium containing kerosene. In addition, 16S rRNA gene analysis indicated that strain AAUG1 belonged to Bacillus tequilensis, whereas isolate AAUG showed the highest similarity to Bacillus subtilis. Therefore, these indigenous bacterial isolates have the potential to be applied for kerosene removal from hydrocarbon-contaminated sites and the development of remediation approaches.

Multi-faceted CRISPR-Cas9 strategy to reduce plant based food loss and waste for sustainable bio-economy - A review.

Currently, international development requires innovative solutions to address imminent challenges like climate change, unsustainable food system, food waste, energy crisis, and environmental degradation. All the same, addressing these concerns with conventional technologies is time-consuming, causes harmful environmental impacts, and is not cost-effective. Thus, biotechnological tools become imperative for enhancing food and energy resilience through eco-friendly bio-based products by valorisation of plant and food waste to meet the goals of circular bioeconomy in conjunction with Sustainable Developmental Goals (SDGs). Genome editing can be accomplished using a revolutionary DNA modification tool, CRISPR-Cas9, through its uncomplicated guided mechanism, with great efficiency in various organisms targeting different traits. This review's main objective is to examine how the CRISPR-Cas system, which has positive features, could improve the bioeconomy by reducing food loss and waste with all-inclusive food supply chain both at on-farm and off-farm level; utilising food loss and waste by genome edited microorganisms through food valorisation; efficient microbial conversion of low-cost substrates as biofuel; valorisation of agro-industrial wastes; mitigating greenhouse gas emissions through forestry plantation crops; and protecting the ecosystem and environment. Finally, the ethical implications and regulatory issues that are related to CRISPR-Cas edited products in the international markets have also been taken into consideration.

Nanocellulose/Fe3O4/Ag Nanozyme with Robust Peroxidase Activity for Enhanced Antibacterial and Wound Healing Applications.

Peroxidase memetic nanozymes with their free radical-mediated catalytic actions proved as efficacious antibacterial agents for combating bacterial resistance. Herein, nanocellulose (NC) extracted from Eragrostis teff straw was used to prepare NC/Fe3O4/Ag peroxidase nanozyme as an antibacterial and wound healing agent. Characterization of the nanozyme with XRD, FTIR, SEM-EDX, and XPS confirmed the presence of silver NPs and the magnetite phase of iron oxide dispersed on nanocellulose. The peroxidase activity of the prepared nanozyme was examined using TMB and H2O2 as substrates which turned blue in acidic pH (λmax = 652 nm). With a lower Km (0.387 mM), the nanozyme showed a comparable affinity for TMB with that reported for the HRP enzyme. Furthermore, the nanozyme remained efficient over a broader temperature range while maintaining 61.53% of its activity after the fourth cycle. In vitro, antibacterial tests against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacterial strains showed that NC/Fe3O4/Ag exhibits concentration-dependent and enhanced antibacterial effect for Escherichia coli compared to NC and NC-Fe3O4 and negative control. Furthermore, the wound-healing performance of the NC-Fe3O4-Ag nanozyme was investigated in vivo using an animal model (mice). The nanozyme showed 30% higher wound healing performance compared to the control base ointment and is comparable with the commercial nitrofurazone ointment. The results show the potential of the prepared nanozyme for wound-healing purposes.

Ultrastructural analysis of zinc oxide nanospheres enhances anti-tumor efficacy against Hepatoma.

Zinc oxide nanomaterial is a potential material in the field of cancer therapy. In this study, zinc oxide nanospheres (ZnO-NS) were synthesized by Sol-gel method using yeast extract as a non-toxic bio-template and investigated their physicochemical properties through various techniques such as FTIR, XR, DLS, and TEM. Furthermore, free zinc ions released from the zinc oxide nanosphere suspended medium were evaluated by using the ICP-AS technique. Therefore, the cytotoxicity of ZnO nanospheres and released Zn ions on both HuH7 and Vero cells was studied using the MTT assay. The data demonstrated that the effectiveness of ZnO nanospheres on HuH7 was better than free Zn ions. Similarly, ZnO-Ns were significantly more toxic to HuH7 cell lines than Vero cells in a concentration-dependent manner. The cell cycle of ZnO-Ns against Huh7 and Vero cell lines was arrested at G2/M. Also, the apoptosis assay using Annexin-V/PI showed that apoptosis of HuH7 and Vero cell lines by ZnO nanospheres was concentration and time-dependent. Caspase 3 assay results showed that the apoptosis mechanism may be intrinsic and extrinsic pathways. The mechanism of apoptosis was determined by applying the RT-PCR technique. The results revealed significantly up-regulated Bax, P53, and Cytochrome C, while the Bcl2 results displayed significant down-regulation and the western blot data confirmed the RT-PCR data. There is oxidative stress of the ZnO nanospheres and free Zn+2 ions. Results indicated that the ZnO nanospheres and free Zn+2 ions induced oxidative stress through increasing reactive oxygen species (ROS) and lipid peroxidation. The morphology of the HuH7 cell line after exposure to ZnO nanospheres at different time intervals revealed the presence of the chromatin condensation of the nuclear periphery fragmentation. Interestingly, the appearance of canonical ultrastructure features of apoptotic morphology of Huh7, Furthermore, many vacuoles existed in the cytoplasm, the majority of which were lipid droplets, which were like foamy cells. Also, there are vesicles intact with membranes that are recognized as swollen mitochondria.

Neutrophil-to-lymphocyte ratio as a predictor of clinical outcomes in critically ill COVID-19 patients: A retrospective observational study.

Background: Timely identification of patients at risk of worse clinical outcomes is vital in managing coronavirus disease 2019 (COVID-19). The neutrophil-to-lymphocyte ratio (NLR) calculated from complete blood count can predict the degree of systemic inflammation and guide therapy accordingly. Hence, we did a study to investigate the role of NLR value on intensive care unit (ICU) admission in predicting clinical outcomes of critically ill COVID-19 patients. Methods: We conducted a retrospective analysis of electronic health records of COVID-19 patients admitted to ICUs at Hazm Mebaireek General Hospital, Qatar, from March 7, 2020 to July 18, 2020. Patients with an NLR equal to or higher than the cut-off value derived from the receiver operating characteristic curve were compared to those with an NLR value below the cut-off. The primary outcome studied was all-cause ICU mortality. The secondary outcomes evaluated were the requirement of mechanical ventilation and ICU length of stay (LOS). Results: Five hundred and nineteen patients were admitted to ICUs with severe COVID-19 infection during the study period. Overall, ICU mortality in the study population was 14.6% (76/519). NLR on ICU admission of ≥6.55 was obtained using Youden's index to predict ICU mortality, with a sensitivity of 81% and specificity of 41%. Mortality was significantly higher in patients with age ≥60 years (p < 0.001), chronic kidney disease (p = 0.03), malignancy (p < 0.002), and NLR ≥ 6.55 (p < 0.003). There was also a significant association between the requirement of mechanical ventilation (34.7% vs. 51.8%, p < 0.001) and increased ICU LOS (8 vs. 10 days, p < 0.01) in patients with ICU admission NLR ≥ 6.55. Conclusion: Higher NLR values on ICU admission are associated with worse clinical outcomes in critically ill COVID-19 patients.

Assessment of COVID-19 Symptoms Distribution According to Tobacco Products Consumption and Khat Chewing: A Potential Antinociceptive Role of Nicotine Among COVID-19 Patients.

Purpose: To assess the distribution of COVID-19 symptoms according to the consumption of tobacco products and khat chewing among samples of Saudi Arabian individuals. Methods: This retrospective cohort study was conducted in the Jazan region of Saudi Arabia. Data was collected online via a self-administered questionnaire. The questionnaire measured demographic variables, COVID-19 symptoms and vaccination, comorbidities history, tobacco product consumption, and khat chewing. In addition, logistic regression was performed to assess the association between the clinical presentation of COVID-19 with tobacco product consumption and khat chewing. Results: A total of 1026 subjects were recruited. The mean age of the participants was 31 years, and more than half were male (53%). Among the reported tobacco product consumption, hookah smoking was more frequently reported as a currently consumed tobacco product (14.3%), followed by cigarette smoking (11.5%) and chewing tobacco (3.8%). Thirteen percent (134) were khat chewers at the time of recruitment. The odds of reporting five symptoms or more were higher among patients who have never been tobacco product consumers (OR: 1.6, 95% CI: 1.15-2.35) while accounting for khat chewing, age, vaccination status, and history of comorbidities. Nonetheless, the difference in symptom distribution with khat chewing status was not statistically significant. Conclusion: The findings of the current investigation suggest the presence of a potential impact of nicotine toxicity in masking pain among the subjects infected with COVID-19. Therefore, it is possible to hypothesize that, with the potential masking effect of nicotine, infected smokers may be less likely to suffer from the symptoms and seek official healthcare services, including diagnostic services.

Evaluation of anti-gastric ulcer activity of aqueous and 80% methanol leaf extracts of Urtica simensis in rats.

Background: Gastric ulcer is a major public health problem globally and associated with severe complications including hemorrhages, perforations, gastrointestinal obstruction, and malignancy. Urtica simensis is widely used for traditional management of gastric ulcer in different parts of Ethiopia. The present study was undertaken to evaluate the anti-gastric ulcer activity of aqueous and 80% methanol extracts of U.simensis in rats. Methods: The leaf extracts were prepared using decoction (aqueous) and maceration (80% methanol) techniques and in vivo anti-gastric ulcer effects of various doses of U. simensis extracts and the effect were determined using the pylorus ligation, indomethacin and ethanol induced gastric ulcer models. Results: In pylorus ligation induced gastric ulcer model, both aqueous and 80% methanol extracts at doses of 200 and 400 mg/kg were exhibited significant reduction in total acidity, volume of gastric secretion (p < 0.001) and substansial rise in pH (p˂0.05) of the gastric secretion. In indomethacin induced ulcer model, both aqueous and methanol extracts were exhibited dose dependent increment in gastric wall mucus compared to control (p < 0.001). In ethanol induced ulcer model, all doses of extract produced significant increment in gastric wall mucus from 46.66 ± 0.96 (AQ100) to 75.87 ± 1.52 (ME 400) µg alcian blue/g wet stomach. Five days pre-treatment with 200 mg/kg of both and aqueous and methanolic extracts exhibited significant (P < 0.001) ulcer inhibition in both indomethacin and ethanol-induced ulcer models. Conclusion: Both extracts of U.simensis exhibited a promising anti-gastric ulcer activity in all of the three models and this findings supports for traditional claimed use of the leaf of U. simensis.

Isolation and Characterization of Diesel-Degrading Bacteria from Hydrocarbon-Contaminated Sites, Flower Farms, and Soda Lakes.

Hydrocarbon-derived pollutants are becoming one of the most concerning ecological issues. Thus, there is a need to investigate and develop innovative, low-cost, eco-friendly, and fast techniques to reduce and/or eliminate pollutants using biological agents. The study was conducted to isolate, characterize, and identify potential diesel-degrading bacteria. Samples were collected from flower farms, lakeshores, old aged garages, asphalt, and bitumen soils and spread on selective medium (Bushnell Haas mineral salt agar) containing diesel as the growth substrate. The isolates were characterized based on their growth patterns using optical density measurement, biochemical tests, and gravimetric analysis and identified using the Biolog database and 16S rRNA gene sequencing techniques. Subsequently, six diesel degraders were identified and belong to Pseudomonas, Providencia, Roseomonas, Stenotrophomonas, Achromobacter, and Bacillus. Among these, based on gravimetric analysis, the three potent isolates AAUW23, AAUG11, and AAUG36 achieved 84%, 83.4%, and 83% diesel degradation efficiency, respectively, in 15 days. Consequently, the partial 16S rRNA gene sequences revealed that the two most potent bacterial strains (AAUW23 and AAUG11) were Pseudomonas aeruginosa, while AAUG36 was Bacillus subtilis. This study demonstrated that bacterial species isolated from hydrocarbon-contaminated and/or uncontaminated environments could be optimized to be used as potential bioremediation agents for diesel removal.

Response of hrpZPsph-transgenic N. benthamiana plants under cadmium stress.

The hrpZPsph gene from Pseudomonas syringae pv. phaseolicola, in its secretable form (SP/hrpZPsph), has previously proven capable of conferring resistance against rhizomania disease as well as abiotic stresses in Nicotiana benthamiana plants, while enhancing plant growth. This study aimed at investigating the response of SP/hrpZPsph-expressing plants under cadmium stress. Transgenic N. benthamiana lines, homozygous for the SP/hrpZPsph gene, and wild-type plants were exposed to Cd at different stress levels (0, 50, 100, 150 µΜ CdCl2). Plants' response to stress was assessed at germination and at the whole plant level on the basis of physiological and growth parameters, including seed germination percentage, shoot and root length, total chlorophyll content, fresh and dry root weight, as well as overall symptomatology, and Cd content in leaves and roots. At germination phase, significant differences were noted in germination rates and post-germination growth among stress levels, with Cd effects being in most cases analogous to the level applied but also among plant categories. Although seedling growth was adversely affected in all plant categories, especially at high stress level, lines #6 and #9 showed the lowest decrease in root and shoot length over control. The superiority of these lines was further manifested at the whole plant level by the absence of stress-attributed symptoms and the low or zero reduction in chlorophyll content. Interestingly, a differential tissue-specific Cd accumulation pattern was observed in wt- and hrpZPsph-plants, with the former showing an increased Cd content in leaves and the latter retaining Cd in the roots. These data are discussed in the context of possible mechanisms underlying the hrpZPsph-based Cd stress resistance.

Elevated Level of Imipenem-Resistant Gram-Negative Bacteria Isolated from Patients Attending Health Centers in North Gondar, Ethiopia.

BACKGROUND: The frequent identification of resistant bacteria in hospitals constantly presents antimicrobial therapy with a challenge. Imipenem, once considered an extremely powerful antibiotic against multidrug-resistant bacterial infections, is losing its effectiveness. Its use in empirical therapy with inadequate or nonexistent antimicrobial stewardship programs has further triggered bacterial resistance in low-income countries. Therefore, this study aimed at identifying imipenem-resistant Gram-negative bacteria from patients who were referred to health centers in North Gondar, Ethiopia. METHODS: A total of 153 sputum samples were used to isolate Gram-negative bacteria. The isolates, which were resistant to imipenem, were identified by standard biochemical tests and 16S rRNA sequencing. The Kirby-Bauer disk diffusion method was used to determine the sensitivity or resistance of the isolate to diverse antimicrobial agents. RESULTS: The study identified 79 imipenem-resistant bacterial isolates from eight genera with clinically relevant microorganisms, including Acinetobacter baumannii (20.77%), Klebsiella pneumoniae (19.48%), Pseudomonas aeruginosa (16.88%), and Serratia marcescens (14.28%). Overall, imipenem-resistant bacterial isolates were detected in 31 samples (20.26%). Additionally, a remarkably high level of resistance to most antibiotics was observed among isolates of Klebsiella pneumoniae and Acinetobacter baumannii. Gentamycin is the most active antibiotic against many of the isolates, while ß-lactams appear to be less effective. CONCLUSION: The study indicated that many Gram-negative bacteria were resistant to imipenem with parallel resistances to other antimicrobials. Hence, the prescription of imipenem within the region should be according to the antibiotic resistance profiles of the multi-drug resistant bacteria.

In Vivo Diuretic Activity of Hydromethanolic Extract and Solvent Fractions of the Root Bark of Clerodendrum myricoides Hochst. (Lamiaceae).

INTRODUCTION: Clerodendrum myricoides (Lamiaceae) has been traditionally used for the treatment of various ailments, including body swelling and urine retention. The present study aimed to evaluate the diuretic activity of a crude extract and solvent fractions of the root bark of C. myricoides. Methodology. The coarsely powdered root bark of C. myricoides was extracted by a cold maceration method using 80% methanol. A portion of the extract was fractionated based on the polarity index of solvents to obtain chloroform, ethyl acetate, and aqueous fractions. To investigate the diuretic activity of the plant, rats were divided into fifteen groups. The normal control groups received either water or 2% tween 80, the standard group received furosemide (10 mg/kg), and the test groups were administered the hydromethanolic extract and solvent fractions at the doses of 100, 200, and 400 mg/kg by the oral route. The urine volume, urine pH, urine, and serum electrolytes were determined and compared with the standard and normal control groups. RESULTS: The crude hydromethanolic extract, ethyl acetate, and chloroform fractions induced significant diuresis at a dose of 400 mg/kg (P < 0.001) compared to the aqueous fraction. The hydromethanolic extract at 200 mg/kg and 400 mg/kg also caused noticeable diuresis (P < 0.001) compared to the standard, furosemide. Rats treated with hydromethanolic extract, ethyl acetate, and chloroform fractions showed delayed onset and prolonged diuresis in a dose-dependent fashion compared to the aqueous fraction (P < 0.05). The hydromethanolic extract and solvent fractions produced the highest saliuretic and natriuretic index compared to the standard, furosemide. The crude hydromethanolic extract also failed to produce any sign of toxicity up to 2000 mg/kg. CONCLUSION: From this study, the hydromethanolic extract and ethyl acetate fraction of the root bark of C. myricoides produced a prominent diuretic effect in rats.

Glycopeptides as Potential Interventions for COVID-19.

Coronavirus disease 2019 (COVID-19), an infectious disease that primarily attacks the human pulmonary system, is caused by a viral strain called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The outbreak emerged from Wuhan, China, and later spread throughout the world. Until the first week of May 2020, over 3.7 million cases had been reported worldwide and more than 258,000 had died due to the disease. So far, off label use of various drugs has been tried in many clinical settings, however, at present, there is no vaccine or antiviral treatment for human and animal coronaviruses. Therefore, repurposing of the available drugs may be promising to control emerging infections of SARS-COV2; however, new interventions are likely to require months to years to develop. Glycopeptides, which are active against gram-positive bacteria, have demonstrated significant activity against viral infections including SARS-COV and MERS-COV and have a high resemblance of sequence homology with SARS-COV2. Recent in vitro studies have also shown promising activities of aglycon derivative of glycopeptides and teicoplanin against SARS-COV2. Hydrophobic aglycon derivatives and teicoplanin, with minimal toxicity to human cell lines, inhibit entry and replication of SARS-COV2. These drugs block proteolysis of polyprotein a/b with replicase and transcription domains. Teicoplanin use was associated with complete viral clearance in a cohort of patients with severe COVID-19 symptoms. This review attempts to describe the activity, elucidate the possible mechanisms and potential clinical applications of existing glycopeptides against corona viruses, specifically SARS-COV2.