Human Pathogenic Strains Research Articles

Analysis of Antimicrobial potential of Marine red algae; Centroceras clavulatum (C. agardh) Montagne against selected strains of human pathogens

Finding novel antimicrobial components has achieved a global research focus as the contaminating and pathogenic microbes develop resistance against standard drugs. Current study encompasses Agar well diffusion mediated Antimicrobial (Antibacterial and Antifungal) analysis using methanol extract of marine red algae Centroceras clavulatum (C. agardh) Montagne collected from coasts of Kannur District, Kerala. Tests have performed against 5 pathogenic bacteria such as Bacillus aeruginosa, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae and 5 strains of pathogenic fungi such as Candida albicans, Candida auris, Candida pelliculosa, Candida parapsilosis, and Candida tropicalis using various concentrations of sample. When compared to the colony inhibition by standard (Chloramphenicol and Fluconazole) (10µl), 25 µl concentration of sample has effectively inhibited most of the tested strains. The study suggests Centroceras clavulatum (C.Agardh) Montagne as potential seaweed to be used for isolating various antimicrobial components.

Anti-Coccal Activity and Composition of the Essential Oils and Methanolic Extracts Obtained from Brewing Quality Humulus lupulus L. Hop Pellets.

This study examined the chemical composition and anti-coccal properties of essential oils and methanolic extracts of six different Humulus lupulus L. varieties from Poland: Iunga, Marynka, Sybilla, Magnum, Tradition and Chinook. The activity of an α-acid-enriched fraction of methanolic extracts was also studied. The chemical composition of essential oils and extracts was determined by gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) techniques. The compounds characteristic to H. lupulus extracts include xanthohumol, α-acids, β-acids, and prenylated flavonoids. Essential oil compositions showed a high prevalence of monoterpene hydrocarbon, myrcene and sesquiterpene hydrocarbons, α-humulene and β-caryophyllene. The antimicrobial activity was investigated against eight human cocci pathogenic strains: Staphylococcus aureus MRSA (ATCC 43300), S. aureus MRSA (29213), S. aureus MSSA (ATCC 29213), S. epidermidis (ATCC 12228), Enterococcus faecalis (ATCC 29212), E. faecalis VRE (ATCC 51299), E. faecium (ATCC 19434) and Micrococcus luteus (ATCC 10240). The lowest minimum inhibitory concentrations (MIC) were obtained for extracts and essential oils from Iunga hop samples. Extracts were significantly more active than essential oils. The most susceptible strain to both essential oils and extracts was M. luteus, whilst the least susceptible was E. faecium. The antimicrobial activity correlated with a high concentration of xanthohumol of active extracts rather than with the content of α-acids. Xanthohumol showed considerable activity against MRSA with an MIC value of 3.9 µg/mL. The activity of the α-acid-enriched fraction was mediocre compared to the results of all extracts.

Xanthone synthetic derivatives with high anticandidal activity and positive mycostatic selectivity index values

With the current massive increases in drug-resistant microbial infection as well as the significant role of fungal infections in the death toll of COVID-19, discovering new antifungals is extremely important. Natural and synthetic xanthones are promising derivatives, although only few reports have demonstrated their antifungal mechanism of action in detail. Newly synthetized by us xanthone derivative 44 exhibited strong antifungal activity against reference and fluconazole resistant C. albicans strains. Our results indicate that the most active compounds 42 and 44 are not substrates for fungal ABC transporters (Cdr1p and Cdr2p) and Mdr1p, the main representative of the major facilitator superfamily efflux pumps, membrane proteins that are responsible for the development of resistance. Moreover, fungicidal mode of action reduces the probability of persistent or recurrent infections and resistance development. In this light, the demonstrated killing activity of the examined derivatives is their undoubted advantage. Novel synthesized compounds exhibited moderate cytotoxicity against human cell lines, although the selectivity index value for human pathogenic strains remained favourable. Our results also indicate that novel synthetized compounds 42 and 44 with antifungal activity target yeast topoisomerase II activity. In summary, further validation of xanthones applicability as antifungals is highly valuable.

Deposition of Daldinia starbaeckii (ELF) functionalized silver nanoparticles on urinary catheter tube using chitosan polymer to prevent microbial biofilms formation during UTI infection.

Catheter-associated urinary tract infections (CAUTI) are the most common healthcare problem in hospitals. In this study, we isolated the Daldinia starbaeckii (An endolichenic fungus from Roccella montagnie) and its biomass extract were used to simultaneously synthesize and deposit DSFAgNPs on the inner and outer surfaces of the catheter tube using chitosan biopolymer via In-situ deposition method. Perfectly designed D. starbaeckii extract functionalized DSFAgNPs were characterized by UV spectroscopy, FTIR, SEM, EDS, TEM, and XRD. The microbial efficacy of DSFAgNPs & DSFAgNPs coated catheter (CTH3) was evaluated against eight human pathogenic gram (+ / -) ive strains and Candida albicans. Results indicated DSFAgNPs showed significant biological activity against both gram (+ / -) ive bacteria with an average MIC90 of 4µl/ml. The most promising activity was observed against Helicobacter pylori. When bacteria strains allow to grow with CTH3 we reported significant reduction in colony formation unit (CFU/ml) in broth culture assay with an average 70% inhibition. Further, antibiofilm activity of CTH3 against P. aeruginosa showed strong inhibition of biofilm formation (85%). The study explored an alternate approach for significantly prevent CAUTI among hospital patients. We isolated an endolichenic fungus from lichen Roccella montagnei. The molecular characterization of fungus identified as Daldinia starbaeckii (DSF). The DSF was cultured and its fungal biomass exudes were used to simultaneously construct DSF-AgNPs and its deposition on the catheter surface using biopolymer chitosan via In-situ deposition method. Further, antimicrobial and antibiofilm efficacy of DSF-AgNPs was checked against urinary catheter contaminating and human pathogenic bacterial strains. Based on our research, we determined that DSF-AgNPs coating on a urinary catheter through this method is a cost-effective, eco-friendly approach to prevent catheter contamination.

Bioinformatics characterization of BcsA-like orphan proteins suggest they form a novel family of pseudomonad cyclic-β-glucan synthases.

Bacteria produce a variety of polysaccharides with functional roles in cell surface coating, surface and host interactions, and biofilms. We have identified an 'Orphan' bacterial cellulose synthase catalytic subunit (BcsA)-like protein found in four model pseudomonads, P. aeruginosa PA01, P. fluorescens SBW25, P. putida KT2440 and P. syringae pv. tomato DC3000. Pairwise alignments indicated that the Orphan and BcsA proteins shared less than 41% sequence identity suggesting they may not have the same structural folds or function. We identified 112 Orphans among soil and plant-associated pseudomonads as well as in phytopathogenic and human opportunistic pathogenic strains. The wide distribution of these highly conserved proteins suggest they form a novel family of synthases producing a different polysaccharide. In silico analysis, including sequence comparisons, secondary structure and topology predictions, and protein structural modelling, revealed a two-domain transmembrane ovoid-like structure for the Orphan protein with a periplasmic glycosyl hydrolase family GH17 domain linked via a transmembrane region to a cytoplasmic glycosyltransferase family GT2 domain. We suggest the GT2 domain synthesises β-(1,3)-glucan that is transferred to the GH17 domain where it is cleaved and cyclised to produce cyclic-β-(1,3)-glucan (CβG). Our structural models are consistent with enzymatic characterisation and recent molecular simulations of the PaPA01 and PpKT2440 GH17 domains. It also provides a functional explanation linking PaPAK and PaPA14 Orphan (also known as NdvB) transposon mutants with CβG production and biofilm-associated antibiotic resistance. Importantly, cyclic glucans are also involved in osmoregulation, plant infection and induced systemic suppression, and our findings suggest this novel family of CβG synthases may provide similar range of adaptive responses for pseudomonads.

Physicochemical and Anti-fungal Studies of the Pharmaceutical Co-crystal/Salt of Fluconazole.

Crystal engineering is one green alternative to organic synthesis that can be used to manipulate molecular behavior promptly and economically. We report the preparation and characterization of the pharmaceutical organic salt (FLC-C) of fluconazole (FLC) and organosulfonate (NDSA-2H), based on the sulfonate-pyridinium supramolecular synthon. Structural studies validate the crystallization of the two-component stoichiometric crystal with two molecules of water in the triclinic P1̅ space group. The anticipated proton transfer between the crystal forms leads to ionic interactions, augmenting the organic salt's thermal stability. Hirshfeld studies of FLC-C help to understand the role and significance of different types of intermolecular interactions responsible for crystal packing. The structural and theoretical studies indicate the absence of π-π interactions in FLC-C, which account for the incipience of solid-state emission in the product. The solubility studies establish augmented aqueous solubility of FLC-C over pristine FLC at physiological pH values of 2 and 7. Interestingly, in in vitro studies, FLC-C appears to serve as a potential alternative to FLC, displaying a wide spectrum of antifungal activity. FLC-C is active against several human pathogenic yeast strains, including the leading and emerging Candida strains (Candida albicans and Candida auris, respectively), at comparable and/or lower drug concentrations without showing any enhanced host cell toxicity. Interestingly, the pharmaceutical co-crystal also displays fluorescence properties inside the Candida cells.

Antibacterial Activity and in Silico Investigation of 2-[(3-Substitutedphenyl) Azomethine] Phenol as anti-SARS-CoV-2 Mpro and anti-Plasmodium falciparum Agents

Imine derivatives are widely used in medicine for the treatment of several diseases causing human infections; we examined Schiff’s bases derivatives: 2-[(3-methylphenyl) azomethine] phenol (L1), 2-[(3-chlorophenyl) azomethine] phenol (L2) and 2-[(3-nitrophenyl) azomethine] phenol (L3) against three human pathogenic bacterial strains according to the disk diffusion test. In addition, to revealing the importances of the in silico study of these derivatives, in particular the molecular docking which is based on the protein structures: the main protease 3CL of SARS-CoV-2 and the aminopeptidase of the M1 family. Also, a molecular dynamics simulation was performed to examine the structural stability of the best docked conformation. The evaluation of the global reactivity parameters of the molecular system of Schiff base derivatives was applied by the DFT method with the hybrid functional (B3LYP)/6-31G (d) basis set. The results of the antibacterial activity showed a strong activity in the presence of the L3 ligand against Escherichia coli (ATCC 25922) with a diameter inhibition zone equal to 11 ± 0.61 mm. Molecular docking shows that the L3 ligand formed with protein targets more stable complexes by predicting interesting interactions: hydrogen, hydrophobic and electrostatic bonds with the residues of these targets 3CLpro and PfA-M1. Further, molecular dynamics simulations confirm a strong energy contribution with these interactions. Therefore, suggesting that our ligands could contribute to the development of anti-coronavirus-2 and anti-malarial drug properties.

Nanobubbles: a promising efficient tool for therapeutic delivery of antibacterial agents for the Staphylococcus aureus infections.

The current research is focused to address the implementation of nanobubbles technology to antibacterial agents against Staphylococcus aureus infections. Nanobubbles technology is a novel, latest research employed in many medical fields including drug discovery. In this present work, supramolecular nanoliquid formulation of potential antiseptic agent chloroxylenol-based Dettol and its enhanced antibacterial activity, biocompatibility assessment was studied. Nanobubble technology was adopted to prepare nanoformulation (NB-D) using a household hand mixer under thermostatically controlled conditions. A high-stability nanoformulation with high potential antibacterial activity against human pathogenic strains of Pseudomonas aeruginosa and Staphylococcus aureus was produced by the nanobubbles created in the antiseptic solution. The overall vitality of both strains was significantly reduced in all dose tests on NB-D treatment as a result of the antibacterial activity as assessed by the well-diffusion assay, turbidometric microdilution assay, biofilm inhibition assay, and total count reduction assay. Biocompatibility of the NB-D formulation was studied by the determination of cytotoxicity against HaCaT-human keratinocytes and hemocytes. NB-D treatment did not induce any notable cytotoxic effect on HaCaT cells by showing none of the changes in cell morphology and architecture. No toxic effect on the hematocytes was observed in NB-D treatment. The enhanced antibacterial activity and best biocompatibility of NB-D result shows that the nanobubble technology could be used as an effective strategy for the formulation of antiseptics or disinfectants against high health risk infectious organisms. The novelty of the work is the formation of supramolecular nanoformulation on antiseptic agent which promised the results enhanced than the raw antiseptic agent.

Ribosomal DNA Sequence-Based Taxonomy and Antimicrobial Activity of Prorocentrum spp. (Dinophyceae) from Mauritius Coastal Waters, South-West Indian Ocean

Microalgae are unicellular organisms and commonly present in the euphotic zone of marine ecosystems. From the western coast of Mauritius, three strains of Prorocentrum species were isolated from macrophytes and cultured under standard laboratory conditions. Morphologies were examined by light, fluorescence, and scanning electron microscopy, and phylogenetic analyses were based on partial large subunit LSU rDNA (D1-D2) and ITS1-5.8S-ITS2 (ITS) regions. Three Prorocentrum species, including the P. fukuyoi complex, P. rhathymum, and P. lima complex, were identified. The antimicrobial activities were assayed against potential human pathogenic bacterial strains. The highest zone of inhibition was recorded for intracellular and extracellular protein extracts of Prorocentrum rhathymum against Vibrio parahaemolyticus. The polysaccharide extracts of the Prorocentrum fukuyoi complex had a higher zone of inhibition (24 ± 0.4 mm) against MRSA at a minimum concentration of 0.625 μg/mL. The extracts from the three Prorocentrum species had different levels of activity against the pathogens used, and this can be of scientific interest in the search for antibiotics from natural marine sources.

Anti-diabetic potential of water-soluble polysaccharide from okra pods mucilage diabetes

Plant derived mucilage, due its role in promoting human health, has been extensively used as active constituent for the preparation of different pharmaceuticals, functional and nutraceutical products. Mucilage mainly consists of complex carbohydrates with extremely branched structure. Abelmoschus esculentus L. (Moench), belongs to family Malvaceae, is an annual herb commonly known as okra. The purpose of this study was the identification of bioactive polysaccharides present in the mucilage of okra pods and evaluation of their biological activities. Mucilage was extracted by soaking okra pods in water. The dried mucilage was fractionated in 75% ethanol, which resulted in soluble and insoluble fractions. Each fraction was screened which confirmed the presence of galacturonic acid, saturated and unsaturated polysaccharides. Crude, soluble and insoluble fractions were processed for investigating their biological activities. The results indicated that insoluble fraction was able to inhibit the growth of five human pathogenic bacterial strains i.e. Staphylococcus aureus (1.9 mm ± 0.27mm), Escherichia coli (2.8mm ± 0.44mm) and Shigella (2.9mm ± 0.85mm). However, no significant inhibition was observed against Klebsiella pneumonia and Salmonella typhi. Antioxidant capacity was determined through DPPH assay where the soluble fraction showed IC50 value 785.5 μg/mL while the insoluble fraction showed IC50 value 987.21 μg/mL.

Synthesis of Rumex hastatus-based silver nanoparticles induced the inhibition of human pathogenic bacterial strains

The development of antibiotic resistance in pathogenic bacterial strains has drawn attention to the quest for new natural antibacterial drugs. Therefore, in the present study, extracts of Rumex hastatus leaves were obtained in methanol and water, and R. hastatus-based silver nanoparticles (AgNPs) were synthesized. Structural and functional properties of synthesized silver nanoparticles were determined by UV–vis spectroscopy, XRD, FTIR and SEM. The synthesized AgNPs and crude extracts were tested to check their antibacterial potential against human pathogenic bacterial strains of Staphylococcus aureus, Staphylococcus haemoliticus, Bacillus cereus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa in well diffusion and broth dilution methods. The present investigation has revealed for the first time that the broth dilution method was found more reproducible than that of the well diffusion method even at lower concentrations of AgNPs and crude extracts. UV– Vis spectroscopic analysis of AgNPs revealed a peak at 367 nm. XRD pattern showed a face-centered cubical to the spherical structure of AgNP crystals. FTIR analysis revealed that flavonoids and terpenoids are responsible for the reduction of AgNO3 to Ag+. SEM analysis determined the spherical structure and 51 nm average diameter of nanoparticles. The antibacterial activity of R. hastatus-based (AgNPs) was found to be significantly higher than aqueous plant extract and silver nitrate alone. Bacterial growth was inhibited by R. hastatus-based AgNPs in a dose-dependent manner. To our knowledge, silver nanoparticles (AgNPs) of R. hastatus were synthesized and characterized for the first time in this study and, based on the findings of current research work R. hastatus extract-based silver nanoparticles are suggested to be used as an antibacterial drug instead of synthetic drugs for the treatment of various human diseases/infections caused by the tested bacterial strains.

Distribution of Candida infections in patients and evaluation of the synergic interactions of some drugs against emerging fluconazole- and caspofungin-resistant C. auris

Pathogenic multidrug-resistantCandidaspecies are considered some of the most important health risks. This work aimed to evaluate and monitor the prevalence of the human pathogenic Candida strains isolated from patients in King Fahd Medical City (KFMD), Riyadh, Saudi Arabia, and to evaluate the synergy of some antimicrobial agents against Candida species’ resistance to antifungal drugs. The retrospective analysis, identification using biochemical tests, minimal inhibitory concentrations using E-tests, determination of the fraction inhibitory concentration index value for synergic testing, and simulation of 100 experiments using Monte Carlo simulation methods were performed according to standard protocols. The findings showed that all age groups of males and females can be infected by Candida species; furthermore, human pathogenic Candida species can be isolated from several clinical samples and different human body sites. The minimal inhibitory concentration results showed that many multidrug-resistant Candida strains, such as C. albicans, emerged in 2020 compared to 2018. Candida albicans remains the most important pathogen among all Candia species, found in 51.7 % and 42.4 % of the isolates in 2018 and 2020, respectively. In 2018, many isolates of C albicans showed resistance to itraconazole, fluconazole, anidulafungin, amphotericin B, ketoconazole, voriconazole, caspofungin, and flucytosine. In 2018, all C. auris isolates (N = 94) were resistant to fluconazole, and more than 85 % (N = 76) of C. albicans isolates were resistant to itraconazole, while only 5.9 % (N = 2) were resistant in 2018. The study concluded that the resistance to antifungal drugs among pathogenic yeasts is increasing and constantly changing and that surveillance of these pathogens must continue. Also, the synergy between drugs remains an appropriate option for confronting this risk, especially between natural extracts and drugs. Despite the lack of evidence for any antifungal and antibacterial drug's ability to synergistically suppress the fluconazole- and caspofungin-resistant C. auris strains diagnosed in this study, the surveillance and synergic tactics continue to be viable options for dealing with these human pathogenic yeasts.

Crop protection practices and risks associated with human fungal infectious diseases: a One Health perspective

We review interactions between crop protection practices (developed to control plant pathogens and invertebrate pests) and human fungal infectious diseases. Unlike viral, bacterial and parasitic infections, fungal infections in humans are usually only superficial in healthy individuals, but can become invasive and pose serious risks to immunosuppressed individuals. Although their global impact is less than that of other infectious diseases, human fungal infections still pose serious public health issues. For instance, the use of synthetic agricultural fungicides, particularly the azole class, under conventional intensive, or efficiency improvement-based crop protection practices, is at risk as far as antimicrobial resistance is concerned, due to cases of cross-resistance to clinical azoles used to treat pulmonary aspergillosis, candidiasis and cryptococcocis. In this respect, the One Health approach, originally designed for other types of human pathogens, looks relevant for human pathogenic fungi. Additionally, some entomopathogenic fungi used as biocontrol products against crop pests in a substitution-based approach, may be potentially pathogenic to humans. Very few examples of redesign-based practices (i.e. Agroecological Crop Protection) emerged from our analysis on human fungal diseases. However, discontinuing agricultural azole fungicides (as practiced on organic farms, and which may to some extent be related to the redesign strategy) appears to be the best way to reduce selection pressure and hence the level of azole-resistant human pathogenic fungal strains in the environment.

Antibacterial and Antifungal Activities of Leaf Extract of Morinda elliptica

This work was designed to evaluate the antimicrobial potential of Morinda elliptica by determining the zone of growth inhibition of the leaf extract against selected bacterial and fungal strains. Antifungal and antibacterial properties of the extract at different concentrations (25, 50, 100, 250 and 500 μg/ml) were investigated after successive maceration in four solvents in order of increasing polarity [hexane (180 g), dichloromethane (342 g), ethyl acetate (471 g), and methanol (384)]. The agar disc diffusion method was used against selected human bacteria Escherichia coli, Salmonella typhii, Staphylococcus aureus, and the antifungal activity of the extract against Aspergillus brasiliences and A. flavus. Zones of growth inhibition of the extract were then compared with the standard antibiotic chloramphenicol (500 μg/ml) for the antibacterial activity, and against nystatin (500 μg/ml) for antifungal activity. The result of the study showed a remarkable bactericidal activity of the plant extract against the test organisms E. coli (14.667 + 0.577) and S. typhii (13.667 + 0.577) with a weak activity against the growth of S. aureus as compared to standard (21.667 + 0.577) at 500 μg/ml. The result of the antifungal activity showed considerable activity of the plant extract against the growth of A. brasiliences (11 + 0.1000) and weak activity against the growth A. flavus at 500 μg/ml. The findings of the study indicated that the leaf extract of M. elliptica is a reservoir of bioactive compounds. The compounds can be useful in the development of new pharmaceutical products that can be effective against human pathogenic strains E. coli and S. typhii. This could serve as a lead for understanding a novel mechanism of action in future research activities.

Probing of an Appreciable Antimicrobial Compound Producing Lactobacillus Strain from Milk Products of Thanjavur Region, Tamil Nadu and its Enhanced Production

ABSTRACT: Lactobacillus is a heterogeneous class of lactic acid strains that synthesize bioactive compounds which contribute many health benefits to our mankind. Focusing this view, different Lactobacillus strains were collected from dairy products and were screened for their bioactive efficiencies against an infant diarrheal bacterial pathogen. 11 morphologically unique Lactobacillus strains were procured from curd, yoghurt and buttermilk purchased from the Thanjavur region, Tamil Nadu, India. While screening on a microtiter plate-based test, YMP3 revealed the best antimicrobial activity against a human pathogenic Vibrio cholerae with 67.8±2.1% inhibition. Further, the most appreciable strain was molecularly identified as Lactobacillus apis YMP3 based on 16S rRNA sequencing methodology. Based on the growth kinetics profile, this strain showed maximum production of antimicrobial compound between 72 to 108hrs of incubation. Furthermore, this strain evidenced the cultural conditions of pH 6.5 and 35°C temperature for the appreciable production of the antimicrobial compound. Based on these overall observations, the research stood as the promising baseline data for the enhanced antimicrobial investigation of this probiotic L. apis YMP3 against many human pathogenic strains and its possibilities for drug development.

Bioactive Compounds from Endophytic Bacteria Bacillus subtilis Strain EP1 with Their Antibacterial Activities.

Endophytic bacteria boost host plant defense and growth by producing vital compounds. In the current study, a bacterial strain was isolated from the Boswellia sacra plant and identified as Bacillus subtilis strain EP1 (accession number: MT256301) through 16S RNA gene sequencing. From the identified bacteria, four compounds-1 (4-(4-cinnamoyloxy)phenyl)butanoic acid), 2 (cyclo-(L-Pro-D-Tyr)), 3 (cyclo-(L-Val-L-Phe)), and 4 (cyclo-(L-Pro-L-Val))-were isolated and characterized by 1D and 2D NMR and mass spectroscopy. Moreover, antibacterial activity and beta-lactam-producing gene inhibition (δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine synthetase (ACVS) and aminoadipate aminotransferase (AADAT)) assays were performed. Significant antibacterial activity was observed against the human pathogenic bacterial strains (E. coli) by compound 4 with a 13 ± 0.7 mm zone of inhibition (ZOI), followed by compound 1 having an 11 ± 0.7 mm ZOI. In contrast, the least antibacterial activity among the tested samples was offered by compound 2 with a 10 ± 0.9 mm ZOI compared to the standard (26 ± 1.2 mm). Similarly, the molecular analysis of beta-lactam inhibition determined that compounds 3 and 4 inhibited the two genes (2- to 4-fold) in the beta-lactam biosynthesis (ACVS and AADAT) pathway. From these results, it can be concluded that future research on these compounds could lead to the inhibition of antibiotic-resistant pathogenic bacterial strains.

First report on isolation of Mucor bainieri from honeybees, Apis mellifera: Characterization and biological activities

Fungi are potential biocontrol agents and rich sources of secondary metabolites with demonstrated biological activities. This study aimed to isolate and identify fungi from surface-sterilized honeybees (Apis mellifera), as well as to evaluate their biological activities. One fungal isolate was obtained and identified morphologically and genetically as Mucor bainieri MK-Bee-2. Gas chromatography-mass spectroscopy (GC–MS) analysis of fungus crude extract, showed the existence of six major metabolites representing 92.48% of the total peak area. The crude extract of Mucor bainieri MK-Bee-2 was tested for antimicrobial, antioxidant, and antitumor activities. It demonstrated wide antimicrobial activities against human pathogenic Gram-positive and Gram-negative bacterial strains, as well as Candida albicans, with MIC values ranged from 62.5 to 250 µg/ml. The results revealed that the extract exhibited considerable antioxidant activities indicated by strong inhibition of both DPPH and ABTS free radicals. Additionally, the extract exhibited greater potential anticancer activity against both adenocarcinomic human non-small cell lung cancer cells (A549) [IC50 = 6.45 μg/ml], and immortal cell line hepatoma G2 (HepG2) human liver cancer cells [IC50 = 27.48 μg/ml] and higher selectivity in cancer cells than normal cell lines. Furthermore, the extract showed less cytotoxic activity against normal cells with higher IC50 values of 106.99 and 132.57 μg/ml against human lung fibroblast Wistar-38 (Wi-38) and oral epithelial cells (OEC), respectively. Taken together, the Mucor bainieri MK-Bee-2 extract comprises bioactive compounds as promising potential therapeutic candidates for the treatment of lung cancer. Strikingly, the extract sensitizes the lung cancer cells A549 to the ionizing radiation through the pro-apoptotic pathway as indicated by the annexin V flow cytometry analysis which showed that the extract induced the apoptosis of lung cancer cells.

Magnetic chitosan nanoparticles loaded with Amphotericin B: Synthesis, properties and potentiation of antifungal activity against common human pathogenic fungal strains

Amphotericin B has long been regarded as the gold standard for treating invasive fungal infections despite its toxic potential. The main objective of this research was to develop a novel IONPs@CS-AmB formulation in a cost-effective manner in order to enhance AmB delivery performance, with lowering the drug's dose and adverse effects. The chitosan-coated iron oxide nanoparticles (IONPs@CS) were synthesized afterward, AmB-loaded IONPs@CS (IONPs@CS-AmB) prepared and characterized by AFM, FT-IR, SEM, EDX, and XRD. Biological activity of the synthesized NPs determined and the cytotoxicity of IONPs@CS-AmB evaluated using the MTT and in vitro hemolysis tests. The IONPs@CS-AmB was synthesized using the coprecipitation method with core-shell structure in size range of 27.70 to ∼70 nm. The FT-IR, XRD and EDX pattern confirmed the successful synthesis of IONPs @CS-AmB. The IONPs@CS-AmB exhibited significant antifungal activity and inhibited the metabolic activity of Candida albicans biofilms. The hemolysis and MTT assays showed that IONPs@CS-AmB is biocompatible with high cell viability when compared to plain AmB and fungizone. The IONPs@CS-AmB is more effective, less toxic and may be a suitable alternative to conventional drug delivery. IONPs@CS-AmB may be a viable candidate for use as a microbial-resistant coating on the surfaces of biomedical devices.

Binary Synergistic Combinations of Lavender and Fennel Essential Oils with Amoxicillin.

Microbial resistance is an important problem in modern healthcare systems. In addition to drug resistance, the side effects of current antibiotic applications are also known issues. In this present study, binary combinations of amoxicillin with European Pharmacopoeia quality lavender (Lavandula angustifolia) and fennel (Foeniculum vulgare) essential oils were evaluated against human pathogenic microbial strains. The checkerboard method was used to quantify the efficacy of the essential oils in combination with amoxicillin. As an initial result, remarkable in vitro antimicrobial activity was observed at relatively low amoxicillin concentrations using different oil combinations against Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579, Escherichia coli NRRL B-3008, Salmonella typhi (clinical isolate), respectively. Fractional inhibitory concentrations were calculated and interpreted in terms of addition, synergy, antagonism, or indifferent. A synergistic interaction with the combination F. vulgare essential oil and amoxicillin (fractional inhibitory concentration index = 8.05 × 10-4) was observed against the pathogens E. faecalis and Escherichia coli. Both essential oils together and in combination with amoxicillin showed a synergistic effect with possible future applications.

Biological Synthesis of Silver Nanoparticles by Amaryllis vittata (L.) Herit: From Antimicrobial to Biomedical Applications.

The current study sought to synthesize silver nanoparticles (AgNPs) from Amaryllis vittata (L.) leaf and bulb extracts in order to determine their biological significance and use the toxic plants for human health benefits. The formation of silver nanoparticles was detected by a change in color from whitish to brown for bulb-AgNPs and from light green to dark brown for leaf-AgNPs. For the optimization of silver nanoparticles, various experimental physicochemical parameters such as pH, temperature, and salt were determined. UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-ray dispersion spectroscopy, scanning electron microscopy, and energy dispersion spectroscopy analysis were used to characterize nanoparticles. Despite the fact that flavonoids in plant extracts were implicated in the reduction and capping procedure, the prepared nanoparticles demonstrated maximum absorbency between 400 and 500 nm. SEM analysis confirmed the preparation of monodispersed spherical crystalline particles with fcc structure. The bioinspired nanoparticles were found to show effective insecticidal activity against Tribolium castaneum and phytotoxic activity against Lemna aequincotialis. In comparison to plant extracts alone, the tested fabricated nanoparticles showed significant potential to scavenge free radicals and relieve pain. Antibacterial testing against human pathogenic strains, i.e., Escherichia coli and Pseudomonas aureginosa, and antifungal testing against Aspergillus niger revealed the significant potential for microbe resistance using AgNPs. As a result of the findings, the tested silver nanoparticles demonstrated promising potential for developing new and effective pharmacological and agricultural medications. Furthermore, the effects of biogenic AgNPs on an in vitro culture of Solanum tuberosum L. plants were investigated, and the findings indicated that bulb-AgNPs and leaf-AgNPs produced biomass and induced antioxidants via their active constituents. As a result, bulb-AgNPs and leaf-AgNPs may be recommended for use in Solanum tuberosum L. tissue culture for biomass fabrication and metabolic induction.