54 research outputs found
Molecular Identification of Bacteria Isolated from Marketed <i>Sparus aurata</i> and <i>Penaeus indicus</i> Sea Products: Antibiotic Resistance Profiling and Evaluation of Biofilm Formation
No full textBackground: Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms. Methods: Bacteria isolated from Sparus aurata and Penaeus indicus collected from a local market in Hail region (Saudi Arabia) were isolated on selective and chromogenic media and identified by using 16S RNA sequencing technique. The exoenzyme production and the antibiotic susceptibility patterns of all identified bacteria were also tested. All identified bacteria were tested for their ability to form biofilm by using both qualitative and quantitative assays. Results: Using 16S RNA sequencing method, eight genera were identified dominated by Vibrio (42.85%), Aeromonas (23.80%), and Photobacterium (9.52%). The dominant species were V. natrigens (23.8%) and A. veronii (23.80%). All the identified strains were able to produce several exoenzymes (amylases, gelatinase, haemolysins, lecithinase, DNase, lipase, and caseinase). All tested bacteria were multidrug-resistant with a high value of the multiple antibiotic index (MARI). The antibiotic resistance index (ARI) was about 0.542 for Vibrio spp. and 0.553 for Aeromonas spp. On Congo red agar, six morphotypes were obtained, and 33.33% were slime-positive bacteria. Almost all tested microorganisms were able to form a biofilm on glass tube. Using the crystal violet technique, the tested bacteria were able to form a biofilm on glass, plastic, and polystyrene abiotic surfaces with different magnitude. Conclusions: Our findings suggest that marketed S. aurata and P. indicus harbor various bacteria with human interest that are able to produce several related-virulence factors
Effect of Adiantum philippense Extract on Biofilm Formation, Adhesion With Its Antibacterial Activities Against Foodborne Pathogens, and Characterization of Bioactive Metabolites: An in vitro-in silico Approach
No full textAdiantum philippense (A. philippense), an ethnomedicinally important fern, has become an interesting herb in the search for novel bioactive metabolites, which can also be used as therapeutic agents. Primarily, in this study, A. philippense crude extract was screened for its phytochemical constituents, antagonistic potential, and effect on bacterial adhesion and biofilm formation against common food pathogens. Phytochemical profiling of A. philippense was carried out by using High Resolution- Liquid Chromatography and Mass Spectroscopy (HR-LCMS) followed by antibacterial
activity via agar cup/well diffusion, broth microdilution susceptibility methods, and growth curve analysis. Antibiofilm potency and efficacy were assessed on the development, formation, and texture of biofilms through light microscopy, fluorescent microscopy, scanning electron microscopy, and the assessment of exopolysaccharide production. Correspondingly, a checkerboard test was performed to evaluate the combinatorial effect of A. philippense and chloramphenicol. Lastly, molecular docking studies of identified phytochemicals with adhesin proteins of tested food pathogens,
which helps the bacteria in surface attachment and leads to biofilm formation, were assessed. A. philippense crude extract was found to be active against all tested food pathogens, displaying the rapid time-dependent kinetics of bacterial killing. A. philippense crude extract also impedes the biofilm matrix by reducing the total content of exopolysaccharide, and, likewise, the microscopic images revealed a great extent of disruption in the architecture of biofilms. A synergy was observed between A. philippense crude extract and chloramphenicol for E. coli, S. aureus, and P. aeruginosa, whereas an additive effect was observed for S. flexneri. Various bioactive phytochemicals were categorized from A. philippense crude extract using HR-LCMS. The molecular docking of these identified phytochemicals was interrelated with the active site residues of adhesin proteins, IcsA, Sortase A, OprD, EspA, and FimH from S. flexneri, S. aureus, P. aeruginosa, and E. coli, respectively. Thus, our findings represent the bioactivity and potency of A. philippense crude extract against food pathogens not only in their planktonic forms but also against/in biofilms for the
first time. We have also correlated these findings with the possible mechanism of biofilm inhibition via targeting adhesin proteins, which could be explored further to design new bioactive compounds against biofilm producing foodborne bacterial pathogens
Chromobacterium violaceum and Pseudomonas aeruginosa PAO1: Models for Evaluating Anti-Quorum Sensing Activity of Melaleuca alternifolia Essential Oil and Its Main Component Terpinen-4-ol
No full textCeylan, Ozgur/0000-0002-1865-1093; De Feo, Vincenzo/0000-0002-1070-3207; Snoussi, Mejdi/0000-0002-2309-2601; Alreshidi, Mousa/0000-0002-3763-9698; DE MARTINO, LAURA/0000-0002-9948-0862WOS: 000451201400267PubMed ID: 30336602The problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 mu g/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO revealed anti-QS and anti-biofilm activities at very low concentrations, but it could be further investigated for new molecules useful for the treatment of MRSA infections.University of SalernoThe study was supported by The University of Salerno
HR-LCMS-Based Metabolite Profiling, Antioxidant, and Anticancer Properties of Teucrium polium L. Methanolic Extract: Computational and In Vitro Study
No full textIn this study, we investigate the phytochemical profile, anticancer, and antioxidant
activities of Teucrium polium methanolic extract using both in vitro and in silico approaches. The
results showed the identification of 29 phytochemical compounds belonging to 13 classes of
compounds and 20 tripeptides using High Resolution-Liquid Chromatography Mass Spectrometry
(HR-LCMS). 13R-hydroxy-9E,11Z octadecadienoic acid, dihydrosamidin, valtratum, and
cepharantine were the main compounds identified. The tested extract showed promising
antioxidant activities (ABTS-IC50 = 0.042 mg/mL; 1,1-diphenyl-2-picrylhydrazyl (DPPH)-IC50 = 0.087
mg/mL, β-carotene-IC50 = 0.101 mg/mL and FRAP-IC50 = 0.292 mg/mL). Using both malignant
Walker 256/B and MatLyLu cell lines, T. polium methanolic extract showed a dose/time-dependent
antitumor activity. The molecular docking approach revealed that most of the identified molecules
were specifically binding with human peroxiredoxin 5, human androgen, and human progesterone
receptors with high binding affinity scores. The obtained results confirmed that T. polium is a rich
source of bioactive molecules with antioxidant and antitumor potential
Allium subhirsutum L. as a Potential Source of Antioxidant and Anticancer Bioactive Molecules: HR-LCMS Phytochemical Profiling, In Vitro and In Vivo Pharmacological Study
No full textThis study investigated Allium subhirsutum L. (AS) anticancer and antioxidant eects
and inhibition of tumor angiogenesis in a murine model of skeletal metastases due to inoculation
of Walker 256/B cells. Phytochemical composition of AS extract (ASE) was studied by High
Resolution-Liquid Chromatography Mass Spectroscopy (HR-LCMS). Total phenolic and flavonoid
contents (TPC and TFC) were determined. In vitro, the antioxidant properties were evaluated by
reducing power and antiradical activity against DPPH. Cancer cells’ proliferation, apoptosis, metastatic
development and angiogenesis were evaluated usingWalker 256/B and MatLyLu cells. The p-coumaric
acid was the major phenolic acid (1700 g/g extract). ASE showed high levels of TPC and TFC and
proved potent antioxidant eects. ASE inhibited Walker 256/B and MatLyLu cells’ proliferation
(Half-maximal inhibitory concentration: IC50 ' 150 g/mL) and induced apoptosis. In silico and
in vivo assays confirmed these findings. ASE eectively acts as a chemo-preventive compound, induces apoptosis and attenuates angiogenesis and osteolytic metastases due to Walker 256/B
malignant cells
Pulicaria incisa (Lam.) DC. as a Potential Source of Antioxidant, Antibacterial, and Anti-Enzymatic Bioactive Molecules: Phytochemical Constituents, In Vitro and In Silico Pharmacological Analysis
No full textPlants with medicinal benefits are a crucial source of compounds for developing drugs. This study was designed to determine the chemical composition, antibacterial, antibiofilm, antioxidant, and anti-enzymatic activities of Pulicaria incisa (Lam.) DC. We also reported the molecular interaction between identified molecules and several receptors associated with antimicrobial and antibiofilm activities. A total of seventeen and thirteen compounds were identified in aqueous and methanolic extracts of P. incisa, respectively. The methanolic extract yielded a higher total content of polyphenols and flavonoids of about 84.80 +/- 2.8 mg GAE/g and 28.30 +/- 1.2 mg QE/g, respectively. Significant antibacterial activity was recorded for both extracts, with minimum inhibitory concentration (MIC) values ranging from 30 to 36 mu g/mL, and the result was comparable to the reference antibiotic control. Antibiofilm assays revealed that both extracts were able to reduce the attachment of bacterial cells to 96-well plates, but the highest antibiofilm activity was recorded against Staphylococcus aureus. The methanolic extract also showed anti-enzymatic potency and high antioxidant activity, as demonstrated by all assays used, including DPPH, FRAP, and ABTS. These results were further validated by in silico approaches, particularly the molecular interaction of the identified compounds with the targeted receptors. These findings present P. incisa as a significant source of antibacterial, antibiofilm, antioxidant, and anti-enzymatic molecules
Chromobacterium violaceum and pseudomonas aeruginosa pao1: Models for evaluating anti-quorum sensing activity of melaleuca alternifolia essential oil and its main component terpinen-4-ol
No full textThe problem of antibiotic resistance among pathogens encourages searching for novel active molecules. The aim of the research was to assay the anti-quorum sensing (anti-QS) and antibiofilm potential of Melaleuca alternifolia essential oil and its main constituent, terpinen-4-ol, to prevent the infections due to methicillin-resistant Staphylococcus aureus strains as an alternate to antibiotics. The tea tree oil (TTO) was evaluated for its potential in inhibiting QS-dependent phenomena such as violacein production in Chromobacterium violaceum, swarming motility of Pseudomonas aeruginosa PAO1, and biofilm formation in MRSA strains on glass. The results showed that terpinen-4-ol was able to inhibit MRSA strain biofilm formation on the glass strips by 73.70%. TTO inhibited the violacein production at a mean inhibitory concentration (MIC) value of 0.048 mg/mL by 69.3%. At 100 μg/mL TTO and terpinen-4-ol exhibited inhibition in swarming motility of PAO1 by 33.33% and 25%, respectively. TTO revealed anti-QS and anti-biofilm activities at very low concentrations, but it could be further investigated for new molecules useful for the treatment of MRSA infections
Comparative Computational Analysis of Dirithromycin and Azithromycin in Search for a Potent Drug against COVID-19 caused by SARS-CoV-2: Evidence from molecular docking and dynamic simulation
No full textDue to the emergency and uncontrolled situation caused by the COVID-19 pandemic that arising in the entire world, it is necessary to choose available drugs that can inhibit or prevent the disease. Therefore, the repurposing of the commercial antibiotic, dirithromycin has been screened for the first time against fifteen receptors and compared to the azithromycin using a molecular docking approach to identify possible SARS-CoV-2 inhibitors. Our docking results showed that dirithromycin fit significantly in the Furin catalytic pocket having the lowest binding score (-9.9 Kcal/mol) with respect to azithromycin (-9.4 Kcal/mol) and can interact and block both Asp154 and Ser368 residues by Van der Walls interaction as well as bound to His194 and Ser368 residues via hydrogen bonds. Good results were also obtained with the Tmprss-2 receptor. A Molecular Dynamic simulation was assessed to confirm this interaction. Additionally, detailed receptor-ligand interactions with SARS-CoV-2 and pro-inflammatory mediators were investigated suggesting more target information with interesting results. The findings of this study are very efficient and provide a basis for the development of dirithromycin for clinical trial applications to be efficient in treating SARS-CoV-2 infections
Metabolic Profiles of Clinical Strain of Staphylococcus aureus to Subtle Changes in the Environmental Parameters at Different Phases of Growth
No full textStaphylococcus aureusis an important pathogen that can lead to high number of infections worldwide.
The present study was aimed to investigate cytoplasmic metabolites of S. aureus at mid-exponential
and stationary phases following growth in a combination of conditions including variations in pH and
temperature. The result of metabolic analysis demonstrated that most of the metabolites measured at
stationary phase under optimal conditions were significantly altered in comparison to equivalent cells
harvested at mid- exponential phase. The major alteration was mainly observed in nitrogenous bases
and organic acids, which were relatively decreased in cells grown to stationary phase, while mannitol,
galactonic acid and adenosine were relatively increased in the cultures harvested at stationary phase.
At both phases, the metabolic profiles were substantially different between cultures grown under
ideal control conditions compared with those grown under more acidic and alkali conditions with
lower temperature of 35°C. The analyses of cells harvested from control and treatment samples at
mid-exponential phase showed that nitrogenous bases including uracil and adenine were significantly
decrease in treatment groups compared with reference controls. However, these metabolites were
relatively increased in the treatment cells grown to stationary phase. It was evident that variants in
environmental parameters led to differential profiles of cytoplasmic metabolites during adaptation
processes to applied conditions. These results provided robust evidence supporting the hypothesis
that specific alterations in cytoplasmic metabolites were essential for S. aureus to adapt and hence
survive under changes in the environmental parameters
Chemical and biological evaluation of essential oils from cardamom species
No full textTo highlight the importance of the spices in the Mediterranean diet, the aim of the paper was to study the essential oil compositions and to clarify the potential differences in the biological activities of the three cardamom species. In the study, we compared the phytochemical profiles and biological activities of essential oils from Elettaria cardamomum, Aframomum corrorima and Amomum subulatum. The oils were analyzed using the GC and GC/MS techniques and were mainly constituted of the oxygenated monoterpenes which represents 71.4%, 63.0%, and 51.0% of all compounds detected in E. cardamomum, A. corrorima and A. subulatum essential oils, respectively, 1,8-cineole was the main common compound between the tree tested volatile oil. The essential oils showed significant antimicrobial activity against Gram-positive and Gram-negative microorganisms tested especially the fungal strains. The Ethiopian cardamom was the most active essential oil with fungal growth inhibition zone ranging from 12.67 to 34.33 mm, MICs values ranging from 0.048 to 0.19 mg/mL, and MBCs values from 0.19 to 1.75 mg/mL. The three tested essential oils and their main component (1,8-cineole) significantly increased the production of elastase and protease production, and motility in P. aeruginosa PAO1 in a dose dependent manner. In fact, at 10 mg/mL concentration, the three essential oils showed more than 50% of inhibition of elastolytic and proteolytic activities in P. aeruginosa PAO1. The same oils inhibited also the violacein production in C. violaceum strain. It was also noticed that at high concentrations, the A. corrorima essential oil significantly inhibited the germination of radish. A thorough knowledge of the biological and safety profiles of essential oils can produce applications of economic importance
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