Human Pathogenic Microorganisms Research Articles

An In-vitro Antioxidant and Antimicrobial Activity of Vitis vinifera Leaf Extract

Background: Vitis vinifera (Flame red grape) is known for its hepatoprotective, nephroprotective and cardioprotective activity of ethanolic and aqueous extracts of aerial parts has been reported but, due to presence of polyphenols, glycosides, saponins and alkaloid, the antioxidant and antimicrobial activity yet not to evaluated on salad plant and bacteria, respectively. Aim: This research examined grape (V. vinifera flaming red) leaf ethanolic extract (EE) as a bioactive resource. Methods: Ethanolic extract test, primarily to calculate the overall phenolic content by using the Folin-Ciocalteu technique and gallic acid taking as a reference. Similarly, flavonoid content measured using quercetin as a calibration curve. Antioxidant properties was confirmed by getting positive responses from different methods (DPPH, H2O2, FRAP and Phospho-Molybdenum). Antimicrobial activity tested against gram-positive bacteria (Lactobacillus cereus and Staphylococcus aureus) and gramnegative bacteria (Escherichia coli and Staphylococcus enterica ser. Typhimurium) in a broth microdilution test. The ethanolic extract (EE) are rich in antioxidant-rich phenolic compounds show minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) for every given bacterium on beetroot and spinach leaves. Results: We investigate this extract’s total phenol, total flavonoid, and antioxidant and antibacterial properties. We also identify its main phenolic components, revealing its phytochemical diversity. We found that the EE had 39.29 gGAkg-1 dw of phenol and 96.05 gQE kg-1 dw of flavonoids. The EE scavenges DPPH, H2O2, FRAP, and PM radicals at 142, 168, 275, and 172 g TE kg-1, respectively. We reveal the complex character of this extract by revealing catechins, flavonoids, tannins, malic acid, enzymes, resveratrol, phenolic acids, flavonols, procyanidins, and anthocyanins. Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus are all inhibited by EE with a MIC range of 16 to 18 gL-1 (E. coli). The extract affects bacterial growth at different stages. The EE reduces spinach and beetroot leaf total bacterial load by 1.159 to 2.456 log drop when used as a sanitizer at 25 gL-1 (1.156–2.858 log reduction). Conclusion: This research work highlights grape leaf EE as a novel and appealing source of bioactive components with its strong antibacterial and antioxidant activities against common foodborne infectious agents. Our research reveals that leaf ethanolic extract could reduce human pathogenic microorganisms in fresh green vegetables, improving food safety.

An In-vitro Antioxidant and Antimicrobial Activity of Vitis vinifera Leaf Extract

Background: Vitis vinifera (Flame red grape) is known for its hepatoprotective, nephroprotective and cardioprotective activity of ethanolic and aqueous extracts of aerial parts has been reported but, due to presence of polyphenols, glycosides, saponins and alkaloid, the antioxidant and antimicrobial activity yet not to evaluated on salad plant and bacteria, respectively. Aim: This research examined grape (V. vinifera flaming red) leaf ethanolic extract (EE) as a bioactive resource. Methods: Ethanolic extract test, primarily to calculate the overall phenolic content by using the Folin-Ciocalteu technique and gallic acid taking as a reference. Similarly, flavonoid content measured using quercetin as a calibration curve. Antioxidant properties was confirmed by getting positive responses from different methods (DPPH, H2O2, FRAP and Phospho-Molybdenum). Antimicrobial activity tested against gram-positive bacteria (Lactobacillus cereus and Staphylococcus aureus) and gramnegative bacteria (Escherichia coli and Staphylococcus enterica ser. Typhimurium) in a broth microdilution test. The ethanolic extract (EE) are rich in antioxidant-rich phenolic compounds show minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) for every given bacterium on beetroot and spinach leaves. Results: We investigate this extract’s total phenol, total flavonoid, and antioxidant and antibacterial properties. We also identify its main phenolic components, revealing its phytochemical diversity. We found that the EE had 39.29 gGAkg-1 dw of phenol and 96.05 gQE kg-1 dw of flavonoids. The EE scavenges DPPH, H2O2, FRAP, and PM radicals at 142, 168, 275, and 172 g TE kg-1, respectively. We reveal the complex character of this extract by revealing catechins, flavonoids, tannins, malic acid, enzymes, resveratrol, phenolic acids, flavonols, procyanidins, and anthocyanins. Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus are all inhibited by EE with a MIC range of 16 to 18 gL-1 (E. coli). The extract affects bacterial growth at different stages. The EE reduces spinach and beetroot leaf total bacterial load by 1.159 to 2.456 log drop when used as a sanitizer at 25 gL-1 (1.156–2.858 log reduction). Conclusion: This research work highlights grape leaf EE as a novel and appealing source of bioactive components with its strong antibacterial and antioxidant activities against common foodborne infectious agents. Our research reveals that leaf ethanolic extract could reduce human pathogenic microorganisms in fresh green vegetables, improving food safety.

GC-MS based identification of anti-microbial bioactive compounds, isolated from Bacillus halotolerans of marine sediment

Marine environments are known for their complex habitats due to the spread of industrial pollutants, and microorganisms that endure adverse conditions are evolving as extremophiles. The present study is designed to explore the antimicrobial activity of microbes present in marine ecosystems that secrete bioactive compounds. The bacterial strains VT-2, VT-4, and VT-5 isolated from the marine sediment exerted an inhibitory effect against the human pathogenic microorganisms Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). Among the three strains, VT-5 exhibited efficient antibiotic potential. Based on biochemical characterisation, the VT-5 strain is gram-positive, rod-shaped, and demonstrates resilience to stress, salt, and drought. The 16 s r-RNA analysis confirmed Bacillus halotolerans, having a similarity of 99.75%. Bioactive compounds released by the VT-5 strain had efficient antibacterial activity, which was also observed in FESEM micrographs as deformation of cellular structure in pathogens. The chromatographic extraction of VT-5 was identified to have antibacterial bioactive compounds, and that was further determined by using FTIR and GC/MS. The peaks observed in the FTIR spectrum with different functional groups showed similarity to the structures of these isolated bioactive compounds. GC/MS analysis also revealed the presence of nine vital bioactive compounds, most of which have been reported to exhibit antimicrobial activity. Our study further strengthens that VT-5 (Bacillus halotolerans) is resistant to MDR (Pseudomonas aeruginosa) and MRSA (Staphylococcus aureus) pathogenic strains. Furthermore, this study explores marine-associated microbes as a promising avenue for new antimicrobial drugs, revealing possibilities for marine organism-derived compounds.

Inactivation efficacy of four commercial post-process treatments against Listeria monocytogenes and impact on the commercial quality of leafy greens

The problem of product contamination with human pathogenic microorganisms is still unsolved. Although prevention through the implementation of good agricultural practices and good manufacturing practices is the gold standard, product decontamination strategies can be used to complement preventive measures. Different bioprotective treatments have been suggested to reduce the risk of listeriosis in fresh produce, but more information is needed before industrial implementation. This study focused on the efficacy of four commercial treatments against Listeria monocytogenes growth and their effect on the organoleptic quality of baby spinach, cut romaine, cut iceberg, and shredded cabbage. The treatments included SafePro® (CHR Hansen, DK) and Holdbac® (DowDuPont, US), based on the use of lactic acid bacteria (LAB) cultures as well as two different bacteriophage solutions, ListShield (Intralytix, US) and PhageGuard Listex™ (PhageGuard, US). The selected treatments were tested under simulated commercial conditions. The application was performed after processing and before packaging using a fine mist spray. In all the trials, Listex™ showed the best results in reducing L. monocytogenes growth during shelf life in the four leafy greens chosen. Microbial reductions were close to 2 log units. L. monocytogenes reductions were observed 1 day after Listex™ application and the efficacy was maintained during storage (15 days at 7 °C). Organoleptic quality, including flavor, texture, browning/yellowing, decay, and visual appearance of the four leafy greens was not significantly affected by the application of Listex™ when compared to the untreated products. Post-process treatment with Listex™ based on bacteriophages effectively reduced L. monocytogenes and can be recommended as a control tool to reduce the risks for the presence of L. monocytogenes in leafy greens.

Synthesis of Silver Nanoparticles by Solanum trilobatum L. Aqueous Extract and Their Antibacterial Activity

ABSTRACT Solanum trilobatum L. (Solanaceae), commonly known as nightshade, has been traditionally used by various populations to treat a variety of ailments. Environment-friendly alternatives to chemical and physical procedures for the synthesis of nanomaterials have been proposed. In this research, the hot plate combustion method is used to synthesize nickel oxide nanoparticles (AgNPs) from silver nitrate and S. trilobatum leaf extract. According to X-ray diffraction (XRD) tests, the cubic phase was face-centered, had good crystallinity, and had average crystallite sizes. According to morphological studies, the surface has a cylindrical and rod-like morphology, and average particle size estimates from UV-visible spectroscopy (UV), Fourier transform infrared (FT-IR), concur well with XRD, and the bio-reduced silver nanoparticles were characterized. Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Pseudomonas aeruginosa, and the human pathogenic microorganisms were used to investigate the antibacterial efficacy (12.5, 25, 50 μg/mL) of these biologically created silver nanoparticles.

Colonization of Raphanus sativus by human pathogenic microorganisms.

Contamination of vegetables with human pathogenic microorganisms (HPMOs) is considered one of the most important problems in the food industry, as current nutritional guidelines include increased consumption of raw or minimally processed organic vegetables due to healthy lifestyle promotion. Vegetables are known to be potential vehicles for HPMOs and sources of disease outbreaks. In this study, we tested the susceptibility of radish (Raphanus sativus) to colonization by different HPMOs, including Escherichia coli PCM 2561, Salmonella enterica subsp. enterica PCM 2565, Listeria monocytogenes PCM 2191 and Bacillus cereus PCM 1948. We hypothesized that host plant roots containing bactericidal compounds are less prone to HPMO colonization than shoots and leaves. We also determined the effect of selected pathogens on radish growth to check host plant-microbe interactions. We found that one-week-old radish is susceptible to colonization by selected HPMOs, as the presence of the tested HPMOs was demonstrated in all organs of R. sativus. The differences were noticed 2 weeks after inoculation because B. cereus was most abundant in roots (log10 CFU - 2.54), S. enterica was observed exclusively in stems (log10 CFU - 3.15), and L. monocytogenes and E. coli were most abundant in leaves (log10 CFU - 4.80 and 3.23, respectively). The results suggest that E. coli and L. monocytogenes show a higher ability to colonize and move across the plant than B. cereus and S. enterica. Based on fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM) approach HPMOs were detected in extracellular matrix and in some individual cells of all analyzed organs. The presence of pathogens adversely affected the growth parameters of one-week-old R. sativus, especially leaf and stem fresh weight (decreased by 47-66 and 17-57%, respectively). In two-week-old plants, no reduction in plant biomass development was noted. This observation may result from plant adaptation to biotic stress caused by the presence of HPMOs, but confirmation of this assumption is needed. Among the investigated HPMOs, L. monocytogenes turned out to be the pathogen that most intensively colonized the aboveground part of R. sativus and at the same time negatively affected the largest number of radish growth parameters.

Fungal Endophytes - An Alternative Source of Bioactive Compounds from Plant Species for Prospective Applications – Review

Plant derived compounds have a strong antagonistic activity on pathogenic microorganisms using tremendous natural bioactive compounds accumulated in different parts of plants. Limonoids are important group of metabolically altered triterpene in Meliaceae. Out of 300 limonoids known today, Melia azedarach (melianone, meliarachin, meliacine), Melia dubia (nimbin, meliacarpin) and Azadirachta indica (azadirachtin, nimbolide) contributes about one-third of limonoids. Endophytic fungi are plant symbionts that act as an elicitor for the production of secondary metabolites which serves as an excellent source of drugs for various ailments. It has a great potential to synthesize several novel bioactive compounds which paved a way for commercial exploitation of secondary metabolites for pharmaceutical and agricultural sectors. Many dominant endophytic fungi isolated from these plants includes Colletotrichum sp, Trichoderma sp, Penicillium citrinum, Fusarium solani, Aspergillus sp, Nigrospora sp and Alternaria sp which acts on human pathogenic microorganisms such as Escherichia coli Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans common causative agents for Urinary Tract Infections (UTI) predominantly occurring in women. This review aims to delineate the overview on sources of limonoids present in the leaves and the endophytic fungi isolated from these leaves of Meliaceae. The isolated endophytic fungi from the leaves exhibited antagonistic activity on UTI causing pathogens which often leads to infertility among young women. Thus, the sources of limonoids and isolation of endophytic fungi can be enhanced by reinforcing the production of commercial bioactive secondary metabolites that can be substantially utilized by pharmaceutical and agricultural industries to safeguard human beings.

Cold plasma treatment for fungal keratitis

Aims/Purpose: Fungal keratitis is serious ocular infection caused by any of the fungi species. It is treated with antifungal medications, in worst scenario with cornea transplantation. The therapy is still challenging due to poor drug penetration into the cornea. Cold plasma, produced by ionization of argon gas, contains especially reactive species but also UV radiation which damage microorganisms. The aim of this study is to determine the effect of cold plasma on human corneal epithelial cells (HCE), corneal tissue and multiple pathogen microorganisms to assess the opportunity of cold plasma treatment for fungal keratitis.Methods: The effect of cold plasma on HCE was analysed by the light microscopy, Live/Dead assay, metabolic activity assay, and immunohistochemistry. Disinfecting potential was analysed by plating prevalent yeasts (Candida albicans, C. krusei, C. parapsilosis, C. glabrata) on agar plates and treated with cold plasma. Plasma treatment of infected human donor corneas with C. albicans was determined by measurement of O.D. of liquid culture.Results: The treatment of HCE by cold plasma led to the change of the morphology, significantly lower viability, metabolic activity and proliferation of the cells. Yeast strains were significantly eradicated completely after 5 min of cold plasma treatment (p ≤ 0.001). Cold plasma therapy of the infected human donor corneas showed the decrease of the infection in all tested time intervals with statistical significance (p ≤ 0.01, p < 0.05 and p ≤ 0.001 respectively for 1, 2 and 5 min treatment).Conclusions: Cold plasma treatment showed negative impact on the culture of HCE. The analysis of its effect on the whole corneal tissue is in progress. On the contrary, a significant reduction of CFU was observed in all examined Candida spp. and significant decrease of infection was determined in infected corneas. Therefore, the cold plasma technology showed a potential to be an effective treatment for fungal keratitis.

Evaluating biochemical and pharmacological properties of Curcuma longa L. grown organically in two locations of Odisha, India: In vitro study

Organic farmers use nitrogen-fixing cover crops, herbicides, and biological fertilizers derived chiefly from animal and plant wastes. Curcumin levels are higher in this turmeric variety than in other types with differing pharmacological effects. Growing concerns about the safety of chemical fertilizers have heightened the need to identify locally adapted microbial strains that can be employed as a growth-promoting inoculum. Although research on the microbial diversity of the soil in Kandhamal and Koraput, India, was published, there is still a lack of information about the microbial community of the turmeric that is indigenous to these regions. This research compares and contrasts organically grown turmeric's growth-promoting and antibacterial activities with normally developed turmeric. This is a preliminary study that focuses on the microbiota communities of the study region. In vitro results showed that these properties have been shown to positively affect the development and nutritional content of studied turmeric plants; hence, they are regarded as key plant growth promoters. Using conventional and organic soil, both Kandhamal and Koraput rhizome sample was planted. The aqueous and methanolic rhizome extracts from both soil conditions were extracted. The Agar well diffusion method examined the rhizome extract's antibacterial activity. Bacteria were isolated and characterized from the rhizosphere and conducted various biochemical experiments. When tested against nine human pathogenic microorganisms, rhizomes harvested with vermicompost showed significantly increased antibacterial activity. The rhizospheric bacteria isolated from the organic soil region also help promote plant growth and development and provide adequate nutrients for growth and development. In every single experiment, the organically produced rhizome yielded superior results. The present study concludes that organic turmeric showed better and more effective results in increasing nutrient content, antibacterial activity and yield. Potential field applications necessitate more study into these rhizobacteria's molecular and functional characterization. Future improvements to biocontrol methods may come from studies examining the viability of deploying integrative, long-term bio-formulations in the field. The present research can potentially be used to investigate antibiotic synthesis by microbial communities in turmeric soil.

Analysis of antiviral and antimicrobial activity of Opuntia Stricta (red prickly pear) extract treated cotton fabric by cationization technique for healthcare and hygiene textiles

The aim of this work is to produce an effective antiviral and antimicrobial cotton fabric with adequate wash fastness effects on the Opuntia Stricta (red prickly pear) extracted treated textile materials for healthcare and hygiene application. Since humans are more prone to bacterial and viral infections which are deadly and contagious, proper use of these fabrics will effectively reduce the spread of human pathogenic microorganisms. Cotton fabric is taken because it has a good absorbency, comfort and durability. Cotton fabric is subjected to cationization process using chitosan and sericin. The extract of plant Opuntia Stricta is obtained from its fruits by aqueous extraction technique. The Opuntia Stricta fruit are highly effective and possess various flavonoids that inhibit the growth and spread of human pathogenic microorganisms and the Opuntia Stricta extract were applied on to the cotton material using herbal dyeing technique. The effectiveness of the finished fabric were analyzed by AATCC method for qualitative evaluation of antimicrobial activity of the treated samples, its shows excellent zone of inhibition in both gram positive Staphylococcus aureus and gram negative bacteria Echerichia coli.

Relationship between the gut microbiome and endometriosis and its role in pathogenesis, diagnosis, and treatment: a systematic review.

Endometriosis is a chronic inflammatory disease affecting approximately 10% of women. It is defined as endometrial tissue outside of the uterus and produces a variety of symptoms including pelvic pain, dysmenorrhea, dyspareunia, and intermenstrual bleeding. Although several theories have been postulated regarding the pathogenesis of endometriosis, no theory has provided a complete explanation, therefore limiting our progress in diagnostic tools and management of endometriosis. Recently, much attention has been paid to the importance and role of the gut microbiome in endometriosis. As defined by Joshua Lederberg - microbiome is a set of the genome of microorganisms inhabiting a human body, including commensal, symbiotic and pathogenic microorganisms. The aim of this systematic review was to conduct a search in the Embase, Medline, and PubMed databases for literature from July 2013 to July 2023 regarding the relationship between the gut microbiome and endometriosis. 147 records were screened, of which 26 met the eligibility criteria, and 16 were included in this review. Our review concludes that patients with endometriosis show an altered gut microbiome, and that this has the potential to provide insight for pathogenesis, markers for diagnosis, as well as therapeutic options for treatment of endometriosis. Future research is necessary to confirm this and further investigate the relationship between the gut microbiome and endometriosis.

A Comprehensive Review for the Surveillance of Human Pathogenic Microorganisms in Shellfish.

Bivalve molluscan shellfish have been consumed for centuries. Being filter feeders, they may bioaccumulate some microorganisms present in coastal water, either naturally or through the discharge of human or animal sewage. Despite regulations set up to avoid microbiological contamination in shellfish, human outbreaks still occur. After providing an overview showing their implication in disease, this review aims to highlight the diversity of the bacteria or enteric viruses detected in shellfish species, including emerging pathogens. After a critical discussion of the available methods and their limitations, we address the interest of technological developments using genomics to anticipate the emergence of pathogens. In the coming years, further research needs to be performed and methods need to be developed in order to design the future of surveillance and to help risk assessment studies, with the ultimate objective of protecting consumers and enhancing the microbial safety of bivalve molluscan shellfish as a healthy food.

Chitosan-coated ZnO nanocomposites of Lantana camara and Rhamnus triquetra for effective antimicrobial activity

The sustainability agenda has been greatly influenced by numerous studies, particularly in the field of green revolution involving plants. The innovative aspects of green synthesis have opened up new avenues of research in the scientific community. In this study, we conducted a systematic investigation into the plant-based synthesis of zinc oxide nanoparticles coated with chitosan polymer, using the leaf extracts of Lantana camara and Rhamnus triquetra. To verify the nano-scale size, structural, and morphological characteristics, the synthesized zinc oxide nanoparticles were subjected to various characterization techniques such as UV–Vis spectroscopy, SEM, FTIR, XRD, and Zeta Potential. The XRD results confirmed the crystalline structure of ZnO NPs in the hexagonal wurtzite phase. The magnitude of zeta potential supported the stability of the nano compounds. The FESEM analysis revealed that all the nanocomposites exhibited uniform, dense, and agglomerated particle arrangements with diameters ranging from 22.93 nm to 32.58 nm. FTIR spectroscopy identified the presence of various functional groups. The antibacterial activities were assessed against human pathogenic bacteria, Staphylococcus aureus, and Escherichia coli. The nanocomposites (sample 2) displayed the highest antibacterial zone against Staphylococcus aureus (22.66 mm), while the highest antibacterial zone of inhibition was observed for (sample 4) against E. coli (20.66 mm). In addition, the anticandidal activities were analyzed against the human pathogenic microorganism Candida albicans, and the maximum activity was shown for sample 3 (23.33 mm). Sample 2 also exhibited the greatest growth inhibition against the plant pathogenic fungus Rosellinia necatrix with (33.33%). Our research demonstrates the potential of Lantana camara and Rhamnus triquetra as green sources for the environmentally friendly production of ZnO NPs, which possess strong antibacterial properties against harmful microbes. This study emphasizes the significance of exploring green synthesis techniques for environmentally friendly nanotechnology practices.

Pharmacognostical and Phytochemical Analysis of Curcuma longa Leaves Extract with its Antimicrobial Activity

Aims: The purpose is to study Pharmacognostical characteristics, Physicochemical evaluation, Phytochemical study and Antimicrobial assay of Curcuma longa leaves extract. Methods and Material: Different qualitative tests were performed to confirmed the presence of phytochemical compounds under consideration followed by quantitative analysis using sophisticated techniques such as spectrophotometric, Thin layer chromatography (TLC) and column chromatography. Results: In pharmacognostic study the moisture content of Curcuma longa leaves is 1.75%, water and alcohol soluble extractive value is 19.25 and 12.6 % respectively, total ash obtain is 3.35%. Acid insoluble and water-soluble ash value is 1 and 1.2% respectively. phytochemical analysis of Curcuma longa was carried out by using various solvent (methanol, acetone and aqueous) extract crude sample for presence of secondary metabolites. The qualitative phytochemical analysis showed the presence of cumarin, fatty acids, terpenoids, tannin, phenolic compounds, flavonoids, reducing sugar and glycosides in respective solvent extract. The quantitative estimation of total phenolic content of Curcuma longa leaf extract for methanol, acetone and aqueous are (1.52,1.22 and 0.46). and for the flavonoid content of Curcuma longa leaf extract for methanol, acetone and aqueous are (1.46,1.34 and 0.78). the antimicrobial activity of Curcuma longa leaves extract against human pathogenic microorganisms (E. coli and B. thurengenesis). And one species of fungus (A. niger) by paper diffusion assay method performed on nutrient agar and Potato dextrose agar respectively. In antimicrobial analysis methanol and acetone extract was effective against E. coli and B. thurengenesis. The inhibitory zone was found to be ranging from 8mm to 20mm in diameter. Conclusions: This study may be useful a source of information concerned to various field such as pharmacology, ethnology, phytochemistry and industrial microbiology for future aspect. KEYWORDS: Quercetin, Curcuma longa leaves extract, Thin layer chromatography, Column chromatography, Spectrophotometry, antimicrobial assay, Phytochemical screening, Pharmacognostic study

Antimicrobial Activity the Essential Oil from Croton pluriglandulosus Carn. Leaves against Microorganisms of Clinical Interest.

Multiresistant pathogens pose a serious threat to human health. The genus Candida is one class of human pathogenic yeasts responsible for infections affecting healthy and immunocompromised patients. In this context, plant essential oils emerged as a future natural alternative to control the diseases caused by these pathogens. Based on that, the present study aimed to evaluate the antimicrobial potential of essential oil from C. pluriglandulosus and understand the mechanism of action. Here, it highlighted antimicrobial activity and the mechanisms of action of the essential oil extracted from C. pluriglandulosus Carn.-Torres & Riina (CpEO) leaves on human pathogenic microorganisms in planktonic and biofilm lifestyles. In addition, for the first time, the oil composition was revealed by GC-MS analysis and the toxicity to human red blood cells (HRBC). Twenty-six chemical compounds were identified in CpEO, elemicin, bicyclogermacrene, caryophyllene, brevifolin, and 2,4,6-trimethoxy-styrene. Through hemolytic assay, it was shown that CpEO has no toxicity to human RBCs. At the concentration of 50 μg mL-1, CpEO did not show great antibacterial potential. However, promising data were found for C. krusei and C. parapsilosis inhibiting by 89.3% and 80.7% of planktonic cell growth and 83.5% and 77.9% the biofilm formation, respectively. Furthermore, the mechanisms of action CpEO were elucidated by fluorescence. Scanning electron microscopy revealed damage to the cell membrane and pore formation, ROS overproduction, and induction of apoptosis in candida cells. Our results reinforce the potential of CpEO as an effective alternative molecule of pharmaceutical interest.

Synthesis, antimicrobial activity, molecular docking and pharmacophore analysis of new propionyl mannopyranosides

Carbohydrates are considered as biomolecules playing numerous biological roles and can act as receptors part for several microbial pathogens as well as a barrier to microbial infection. Here we synthesize five novel methyl α-D-mannopyranoside (1) analogues following regioselective acylation, where, methyl 6-O-propionyl-α-D-mannopyranoside was converted into 2,3,4-tri-O-propionyl analogues with excellent percentage of yields. Structural configurations of the synthesized methyl α-D-mannopyranoside analogues were confirmed by spectroscopic, physicochemical, and elemental study. Prediction of activity spectra for substances (PASS) and in vitro antimicrobial experiment of the methyl α-D-mannopyranoside analogues against seven human and plant pathogenic microorganisms transpired solid antibacterial and antifungal activities are studied. Most of the compounds exhibited salient antibacterial potentiality with minimum inhibitory concentration (MIC) values ranging from 0.25 µg/mL to 2.00 µg/mL and minimum bactericidal concentration (MBC) values ranging from 8.00 µg/mL to 16.00 µg/mL. The above observations were rationalized by molecular docking against Escherichia coli and Bacillus cereus (4V7S and 1KZN), Aspergillus flavus (6K3H) and Aspergillus niger (3K4Q) specific targets to search the binding affinities and different interactions of methyl α-D-mannopyranoside analogues. Compounds 3 and 6 were discovered to be the most promising for binding with the target due to their high affinity energy and the stability of the docked complexes were confirmed by molecular dynamics. Combination of in silico ADMET prediction and drug-likeness had shown assuring results for compounds 3 and 6 due to their improved kinetic parameters in terms of biological activity. Overall, the findings are encouraging for the development of novel drugs for the treatment of human and plant pathogens.

Chemical Characterization and Evaluation of Antimicrobial Properties of the Wild Medicinal Mushroom Ganoderma lucidum Growing in Northern Moroccan Forests.

Ganoderma lucidum is an extensively famous medicinal mushroom distributed worldwide. Despite being widely grown in Moroccan forests, there are no studies on its nutritional, nutraceutical and pharmaceutical values. Herein, the objective of this study was to investigate the chemical characterization and antimicrobial properties of G. lucidum methanolic extract. Total phenolic, flavonoid, tannin, ascorbic acid and carotenoid contents were determined by spectrophotometry. The results revealed that the most prevalent bioactive compounds were phenolics and flavonoids, with total values of 154.60 mg GAE/g of dry methanolic extract (dme) and 60.55 mg CE/mg of dme, respectively. A GC-MS analysis identified 80 biologically active molecules, which were mainly divided into the following major groups: sugars (49.49%), organic acids (8.89%), fatty acids (7.75%), amino acids (7.44%), steroids (7.32%), polyphenols (5.92%), and others (13.16%). Additionally, 22 individual phenolic compounds were identified and quantified using HPLC-MS, with emphasis on kaempferol (1714 µg/g of dry weight (dw)), apigenin (1955 µg/g dw) and quercetin (947.2 µg/g dw). The methanolic extract of G. lucidum indicated strong antioxidant capacity by means of the following: DPPH radical-scavenging activity (53.7 µg/mL), β-carotene/linoleate assay (43.75 µg/mL), and reducing power assay (76.62 µg/mL). Furthermore, the extract exhibited potent antimicrobial properties against seven human pathogenic microorganisms, including two bacteria and five fungal strains, at concentrations ranging from 1 to 16 mg/mL. The most sensitive pathogen was Epidermophyton floccosum (MIC = MFC = 1 mg/mL), while Aspergillus fumigatus was the most resistant one (MIC = 16 mg/mL and MFC ≥ 16 mg/mL). Overall, our findings demonstrated valuable nutritional and bioactive compound attributes, and potent antioxidant and antimicrobial properties, of G. lucidum growing in Moroccan forests. Moreover, these findings suggest that the Moroccan mushroom can be extremely useful for the food and medicinal industries to positively affect socioeconomic status.

Human Pathogens in Primary Production Systems

Human pathogenic micro-organisms can contaminate plants [...].

Antimicrobial activity of Dibenzalacetone (C17H14O)

Dibenzalacetone was synthesized via the base catalysed condensation reaction between acetone and benzaldehyde. This study was done to evaluate the antimicrobial activity of the synthesized compound dibenzalacetone (C17H14O) against four human pathogenic microorganisms: Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginiosa and the fungus Candida albicans. The highest area of zone of inhibition of 68.23 mm2 was induced against Candida albicans and the lowest AZOI of 37.55 mm2 was induced against E.coli. Staphylococcus aureus was totally resistant to the drug, in that zero zone of inhibition was induced against dibenzalacetone. The order of antimicrobial potency followed the sequence: Candida albicans > Klebsiella pneumoniae > Pseudomonas aeruginosa > Staphylococcus aureus. However, its antimicrobial potency was lowered than that of standard synthetic drug, Ampicillin and Ketoconazole.

Human pathogens in ticks removed from humans in Hebei, China

Ticks are the hosts or vectors of many human pathogens, including viruses, bacteria and protozoa, and can transmit these causative agents to humans when feeding on human bodies. In this study, 26 ticks removed from humans in Hebei, China were tested for the presence of human-pathogenic microorganisms by Polymerase Chain Reaction (PCR) or Reversed Transcript PCR (RT-PCR). As a result, 11 ticks tested positive for at least one human pathogen. Specifically, four validated human pathogens, including Rickettsia raoultii, Candidatus Rickettsia tarasevichiae, Babesia venatorum, and Borrelia garinii, as well as Anaplasma ovis with zoonotic potential, were identified in Ixodes persulcatus, Dermacentor silvarum and Haemaphysalis concinna. Importantly, this is the first report of Anaplasma and Babesia species pathogenic to humans in Hebei province. Moreover, the co-infections, including double infection and quadruple infection were observed. In addition, Candidatus R. principis with unknown pathogenicity was identified in one tick, which may be the same species as Candidatus R. hongyuanensis based on the nucleotide identity and phylogenetic analysis. Concluding, four validated tick-borne pathogens and one with zoonotic potential were identified in ticks parasitizing humans, suggesting the potential high public health risk in the local human population.