Agar Disc Diffusion Research Articles

Biological Activity of Essential Oil from Two Aromatic Species on the in vitro Control of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc.

Objective: Essential oils (EO) from aromatic and medicinal plants (AMP) are considered a viable alternative for controlling phytopathogenic fungi of agronomic importance. This study evaluated the antifungal activity of thyme (Thymus vulgaris L.) and rue (Ruta graveolens L.) essential oils against Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Design/Methodology/Approach: The antifungal activity was assessed using the agar disk diffusion method, with concentrations ranging from 10% to 100% of each EO. The phytochemical composition was analyzed using GC-MS. Morphological observations were conducted with a scanning electron microscope (SEM). Results: Significant antifungal activity was observed at concentrations of 50-100% of thyme EO. Rue EO exhibited a fungistatic effect for up to six days. Phytochemical analysis identified carvacrol (35.95%) and p-cymene (41.18%) as the major components in thyme EO, and 2-nonanone (24.24%) and 2-undecanone (68.69%) in rue EO. Findings/conclusions: The evaluated EOs significantly impacted fungal morphology at 60% concentration. The strong antifungal activity of thyme EO against C. gloeosporioides suggests its potential as an eco-friendly control alternative.

Exploring newly isolated thermotolerant, halotolerant and antimicrobial resistant Bacillus subtilis ProNTL1 from tannery waste and its alkaline protease production.

A hydrolytic enzyme called protease from microbial sources has expansive applications in leather as well as tannery industries and thus leaves no choice but to discover a potential candidate for efficient yield of protease with eccentric characteristics. In the current study, using skim milk agar medium, three bacterial strains (Pro SS14, Pro NTL1, Pro SM) were identified for protease production out of thirty tannery waste samples. The bacterial isolates were identified through morphological, biochemical and molecular basis and the highest protease producer (134U/mL) having the paramount protein content (8.75%) with the greatest biomass (absorbance 1.7 at 600nm) was further bioinformatically identified as Bacillus subtilis Pro NTL1. Moreover, the cultural conditions-pH, temperature, incubation period and salinity were tested to get the optimized condition for the three isolates where Bacillus subtilis Pro NTL1 gave best growth at pH 9 demonstrating alkaline protease producing capability, at 45°C for 72h proving its thermotolerance characteristics and at 3% NaCl concentration declaring its halotolerance property. Furthermore, following Kirby-Bauer agar disc diffusion technique, the antimicrobialsusceptibility pattern was investigated showing Bacillus subtilis Pro NTL1 was resistant to ampicillin, penicillin, sulfafurazole and sensitive to amoxicillin, gentamycin, cefotaxime, kanamycin, imipenem, tetracycline. Additionally, Bacillus subtilis Pro NTL1 showed antagonistic activity against three pathogens named Bacillus cereus, Bacillus megaterium and Escherichia coli. Thus, these findings suggest that Bacillus subtilis Pro NTL1 is a newly isolated strain with unique features which might help to contribute in several biotechnological purposes with significant industrial benefits.

Antimicrobial effects of eugenol-based micro- vs. nano-emulsions: Evaluation of shelf-life enhancement in Sikhye

This study investigated the antibacterial properties of micro-emulsions (MEs) and nano-emulsions (NEs) containing eugenol and rice bran oil to enhance the shelf life of Sikhye, a traditional Korean rice beverage. The emulsions were evaluated using the agar disk diffusion method and minimum inhibitory concentration (MIC) tests against Escherichia coli, Bacillus cereus, and Staphylococcus aureus. The results demonstrated that MEs exhibited larger inhibition zones and lower MIC values than NEs, indicating superior antibacterial activity. The application of these emulsions in Sikhye revealed that a higher eugenol content and larger droplet size effectively inhibited bacterial growth. The study also found that, while rice bran oil contributed to physical stability, it did not enhance the antimicrobial effect and, in some cases, promoted bacterial growth. Overall, these findings suggest that eugenol-rich MEs could serve as effective natural preservatives, improving the safety and shelf life of Sikhye and potentially other food products.

Synthesis and application of WO3/PVA nano composite for antibacterial and thermal insulation

Abstract Insulation of glass material is very important for sustainable environment in this real world without compromising its primary function. The aim of this research is to provide robust solution by synthesis the Nano Tungsten trioxide particles via the chemical precipitation method. Developed WO3 NPs Characterized by using x-ray diffraction for; crystal structure, compound composition, and average crystalline size. Scanning Electron Microscopy (SEM) employed to analyze the shape and dimensions of the WO3 NPs. Explored the potential thermal insulation and antibacterial attributes by coating 1%, 3%, 5% and 7% concentration of synthesized WO3 NPs in polyvinyl alcohol onto a sodium silicate glass substrate (4 × 4 inches; 2 mm thickness) by using 50 μm doctor blade. WO3/PVA solution showed the antibacterial properties measure by agar disc diffusion method on gram positive and negative bacterial culture S. coli and E. bacterial culture and the obtained results after incubation were showing very minor zone of incubation as compare to previous studies. Thermal insulation of coated glass samples were increased with % of WO3 NPs concentration in PVA and validate by significant coefficient of determination (R2 = 0.985).

Unveiling the chemical composition, antioxidant and antibacterial properties, and mechanistic insights of Convolvulus arvensis extract through molecular docking simulations

The use of herbal extracts has gained significant importance in modern health practices, making it essential to explore their properties and applications in detail. This study investigates the effect of ultrasound on the extraction yield of Convolvulus arvensis leaves, with a focus on its chemical composition, antioxidant properties, cytotoxicity, antimicrobial activities, and mechanism of action. Antimicrobial activity was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), well diffusion agar, and disk diffusion agar assays. The antioxidant properties were assessed through ferric reducing antioxidant power (FRAP) and DPPH free radical scavenging assays. High Performance Liquid Chromatography (HPLC) and Fourier transform infrared (FTIR) spectroscopy were utilized to identify the chemical composition and functional groups present in the extract. The findings revealed that ultrasound-assisted extraction exhibited significantly higher extraction efficiency (p < 0.05). The extract displayed significant antimicrobial activity against Listeria innocua, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The total phenolic and total flavonoid contents of the extract were measured at 328.85 ± 0.046 (mg GAE/100 g) and 226.23 ± 0.043 (mg QE/100 g), respectively. Moreover, the extract demonstrated notable radical scavenging activity against DPPH, with a value of 37.40 ± 0.111 (g/100 g). The FRAP assay revealed that the antioxidant activity of C. arvensis extract was quantified at 23.796 ± 0.045 μmol Fe²⁺. The highest amount of phenolic and alkaloid compounds in the extract was related to β-Phellandrene (341.52 µg/mL) and Swainsonine (360.24 µg/mL), respectively. Furthermore, the in vitro cytotoxic activity of the extract was evaluated against the Caco-2 cell line, with the IC50 value determined to be 26.55 mg/mL. The results of the docking study demonstrated that Ferulic acid displayed a significant binding energy of −6.2 kcal/mol, suggesting a robust interaction with the target enzyme and the potential to act as a modulator of glutathione peroxidases. The findings of the present study revealed that the alcoholic extract of C. arvensis possesses proper antioxidant and antimicrobial activities. Therefore, it has been used as a food preservative. However, further medical and clinical researches are required before any application in human health.

Synthesis, Antimicrobial and Antioxidant Activity with in silico ADMET Prediction, Molecular Docking and Dynamics Studies of Carbazole Ring Containing Thiazole Schiff Bases

AbstractTwelve thiazole hybrids (2 a–2 l) were synthesized in this study incorporating with Schiff base and carbazole scaffolds and characterized by spectral analyses. Antimicrobial activity and antioxidant potency were investigated by agar disc diffusion method and DPPH free radical scavenging assays where trimethyldihydrothiazole 2 c had revealed its higher efficacy in both biological studies. It had displayed IC50 of 25.55±0.40 μg/mL which is higher than the standard ascorbic acid (IC50=41.31±1.83 μg/mL) as well as dihydrothiazoylchromenone 2 e showed promising antioxidant activity with IC50 value of 40.82±0.54. The compound 2 c satisfied all the ADME properties and toxicological parameters with maximum drug score value (0.39) among all derivatives. Molecular docking was undertaken for higher bioactive compounds where 2 c revealed its wide range of interactions with different amino acid residues which was also endorsed with the output of molecular dynamics simulation.

Sodium Alginate Microneedles Loaded with Vancomycin for Skin Infections

Background: Skin and soft tissue infections (SSTIs) present significant treatment challenges. These infections often require systemic antibiotics such as vancomycin, which poses a risk for increased bacterial resistance. Topical treatments are hindered by the barrier function of the skin, and microneedles (MNs) offer a promising solution, increasing patient compliance and negating the need for traditional needles. Methods: This study focused on the use of sodium alginate MNs for vancomycin delivery directly to the site of infection via a cost-effective micromolding technique. Dissolving polymeric MNs made of sodium alginate and loaded with vancomycin were fabricated and evaluated in terms of their physical properties, delivery ability, and antimicrobial activity. Results: The MNs achieved a 378 μm depth of insertion into ex vivo skin and a 5.0 ± 0 mm zone of inhibition in agar disc diffusion assays. Furthermore, in ex vivo Franz cell experiments, the MNs delivered 34.46 ± 11.31 μg of vancomycin with around 35% efficiency, with 9.88 ± 0.57 μg deposited in the skin after 24 h. Conclusions: These findings suggest that sodium alginate MNs are a viable platform for antimicrobial agent delivery in SSTIs. Future in vivo studies are essential to confirm the safety and effectiveness of this innovative method for clinical use.

Comprehensive analysis of antioxidant and antibacterial activities of water and methanol extracts of Hibiscus flower

This study provides a comprehensive investigation into the antioxidant and antibacterial properties of Hibiscus flower extracts, highlighting their potential for future applications in functional foods. The research addressed key challenges by employing a multi-faceted approach, including four distinct methods for evaluating antioxidant potential: DPPH and FRAP assays, reducing power, and chelating ability of Fe ions. Total phenolic content was quantified using the Folin–Ciocalteu method, while tannins and flavonoids were assessed via vanillin–HCl and aluminum chloride assays. Additional analyses included spectrophotometric measurement of total flavonols and anthocyanins. Antibacterial activity was determined using a modified agar disk diffusion method, with results indicating significant inhibition of Salmonella typhimurium and Staphylococcus aureus by both aqueous and methanolic extracts. Colorimetric analysis revealed a reduction in chroma and hue angles, while FTIR spectroscopy identified key functional groups, such as suberin, lipids, and polysaccharides. Notably, the antioxidant efficacy varied depending on the solvent used, with aqueous extracts showing higher total phenolic content (4325.12 mg GAE/100 g) compared to methanolic extracts (3487.05 mg GAE/100 g). The study concludes that Hibiscus flower extracts, rich in antioxidants like tannins and anthocyanins, possess significant potential for use as natural preservatives and colorants in food products, supporting their role in developing novel functional foods.

Increased incidence of methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis in the skin and nasal carriage among healthcare workers and inanimate hospital surfaces after the COVID-19 pandemic.

Healthcare workers in hospitals are exposed to infectious diseases that occur in the hospital making them a source of infection for the patients. It is interfaced as cross-contamination agents for MRSA and MR-CoNS, and preventive measures need to be adapted accordingly. The study aimed to assess Methicillin-Resistant Staphylococcus (MRS) on the skin and nasal cavities of healthcare workers (HCWs) and identifying isolates to the species level. Swab samples were cultured on mannitol salt agar (MSA) to obtain MRS and determine their ability to produce coagulase. Their susceptibility to antibiotics were determined by agar screening and disk diffusion methods and further identification was done at the species level. The highest percentage of methicillin resistant coagulase positive Staphylococci (MRCoPS) was reported among skins of male HCWs, (71.4%) were identified as MRSA. The highest levels of methicillin resistant coagulase negative Staphylococci (MRCoNS) were mainly detected in both nasal cavities, (75%) were identified as MRSE. MRSA was reported from doctors (p-value 0.033), whereas the highest incidence of MRSE was obtained from the nurses (p-value 0.048). This study highlighted that incidence of MRSA was mainly detected in doctors and MRCoNS in both nasal cavities. The highest percentage of MRCoNS was recovered from the patients' room followed by the reception table. Moreover, vancomycin is suggested to be highly effective in managing and controlling S. aureus, MRSA- and MRSE related infections.

Ten-year comparison of the efficiency of legal regulations of foodborne pathogens in broilers in Türkiye

Broiler meats are the primary source of foodborne pathogens, such as Campylobacter jejuni and Salmonella spp., and E. coli O157. The illegal use of antibiotics for preventive purposes or the habit of using broad-spectrum antibiotics in farms causes antibiotic resistance in these pathogens. This study compared C. jejuni, Salmonella spp. and E. coli O157 and their antibiotic resistance patterns in broiler meats in 2011-2012 and 2021-2022. The research we conducted in 2011-2012 to observe the effectiveness of the legal regulations enacted in Türkiye in 2014 and 2018 for controlling pathogens and monitoring the use of antibiotics was also repeated with a similar sample set in 2021-2022. The results showed the prevalence of C. jejuni, Salmonella spp., and E. coli O157 in 2011-2012 and 2021-2022 with 68.0%, 30.4%, 0.8% and 10.08%, 7.77%, 0.21%, respectively. The antimicrobial susceptibility tests against gentamicin, streptomycin, erythromycin, ciprofloxacin, enrofloxacin, tetracycline and oxytetracycline were performed by agar disk diffusion method. According to results in 2011-2012, all C. jejuni and Salmonella spp. were resistant to at least one tested antibiotic, with 31.57% Salmonella spp. and 16.47% C. jejuni being multidrug-resistant. In addition, one of the E. coli O157 strains was resistant to one antibiotic, and the other was resistant to two antibiotics. In 2021-2022, 81.3% C. jejuni, 46% Salmonella spp., and only one E. coli O157 were resistant to at least one tested antibiotic. Isolated strains of 8.33% C. jejuni and 21.62% Salmonella spp. were multidrug-resistant. In the past, antibiotics were used for preventative purposes, as indicated by the survey results. Today, it is evident that these rates have decreased to low levels as a result of legal regulations and monitoring.

Anti-Bacterial Action of Silver Nanoparticles Against MDR Bacteria Isolated from Hospital

Hospital-associated infections (HAIs) are considered to be a major source of infections in patients, especially in patients with permanently impaired immunity. There is alarming increase of multi drug resistant (MDR) bacteria and Antibacterial medication resistance has been deemed a serious hazard to public health by the World Health Organisation (WHO). The study aimed to isolate and identify main bacteria caused nosocomial infection, and trying to treatments by using nanoparticles. By measuring the antibacterial activity of the synthesised AgNPs using the agar disc diffusion technique, AgNPs demonstrated antibacterial properties against the Pseudomonas aeruginosa and Staphylococcus aureus MDR.

Escherichia coli Occurrence and Antimicrobial Resistance in a Swine Slaughtering Process.

The swine production chain can be a reservoir of antimicrobial-resistant Escherichia coli, which transfers resistance genes to other bacteria, serving as an important biomarker in the One Health approach. This study aimed to identify the frequency and antimicrobial resistance profile of E. coli in the swine production chain, assess the presence of extended-spectrum beta-lactamases (ESBL), and compare resistance profiles across different sample types. A total of 622 samples of swine carcasses from various points of the slaughter process (n = 400), swine feces (n = 100), commercial cuts (n = 45), environment (n = 67), and feces from employees (n = 10) of a pig slaughterhouse certified by the Federal Inspection Service, located in São Paulo state, Brazil, were collected. A total of 1260 E. coli isolates were obtained from the samples, with 73.6% of the samples testing positive. The agar disk diffusion test was performed with 10 different classes of antimicrobials. To confirm the production of ESBLs, the isolates were submitted to a double-disk synergism test using cefotaxime, ceftazidime, and amoxicillin with clavulanic acid. Of the total isolates, 80.71% were multidrug resistant. All ESBL-producing isolates were multidrug resistant and resistant to amoxicillin, tetracycline, and chloramphenicol. Isolates from human feces samples had less chance of being multidrug resistant than samples from other sources. The diversity of resistance profiles was verified in the samples, not clustering according to the sources, except for human feces isolates that clustered, evidencing lower antimicrobial resistance variability of these samples. Antimicrobial resistance is significantly present in the pork production chain, necessitating a comprehensive multidisciplinary approach to effectively mitigate risks within the One Health framework.

A comprehensive review on in-vitro methods for anti- microbial activity

Microbes, also referred to as microscopic creatures because of their minuscule size and invisibility to human sight, are single-celled microorganisms. The first microorganism was discovered between 1665 and 1683 by Robert Hooke and Antoni van Leuwenhoek. There are two categories of techniques for examining microbial activity. methods used in vitro and in vivo. Experiments and tests carried out in a laboratory setting, typically without the presence of a living organism, are referred to as in vitro methods. By creating microbial cultures, cell lines, cell cultures, etc., we may do in vitro experiments. Scientists can study biological processes, assess the effects of medications, and understand systems without having to deal with the complexities of a whole organism by employing in vitro techniques. Growing cells outside of the body in a controlled setting for a range of studies is known as cell culture. Tissues are grown and kept in a lab setting for tissue culture. It is essential to research creating anti-infection therapies. To evaluate a substance's antibacterial activity, in vitro methods such as the brothdilution method and discdiffusion method are commonly used. There are different methods available for the testing of antimicrobial activity and the methods are the agar disk diffusion method, Agar well diffusion method, cross streak method, Bioautography, dilution method, Time kill test, ATP bioluminescence etc. Techniques for determining novel antimicrobial agents and testing for antibiotic susceptibility have been employed. Compared to in-vivo procedures, in vitro methods are less costly. To guarantee an accurate experimental approach, these techniques may be the answer.

Comparison of the antibacterial activity of six medicinal plants, sodium hypochlorite, and chlorhexidine against enterococcus faecalis (In vitro study)

Enterococcus faecalis is a gram-positive, facultative anaerobic bacterium recognized for its resistance to various antimicrobial agents. This organism is associated with the failure of endodontic treatments, even when potent antimicrobial irrigants are employed. Numerous medicinal plants have demonstrated antimicrobial properties that could be potentially effective against this bacterium.To evaluate the antibacterial properties of six medicinal plants in comparison to sodium hypochlorite and chlorhexidine against E. faecalis.Antibacterial susceptibility tests against E. faecalis (ATCC 29212) were performed for 200 mg/ml ethanolic extracts of Acacia Senegal, Capparis decidua, Capparis micracantha, Acacia nilotica/ Adansonia, Dobera glabra, and Moringa oleifera by Agar Disc Diffusion method. Chlorhexidine 0.2% and Sodium hypochlorite 1% were used as positive controls, and ethanol 20% as a negative control. The diameters of the inhibition zones were measured. Acacia nilotica/adansonii leaves showed the largest inhibition zone diameter against E. faecalis. It displayed a significantly greater inhibitory effect against E. faecalis than Acacia Senegal (p-value =0.005), Capparis decidua (p-value =0.02), Capparis micracantha branches (p-value =0.000), Dobera glabra leaves (p-value =0.008), and Moringa olifera leaves (p-value =0.000).Acacia nilotica leaves displayed a similar inhibition zone diameter against E. faecalis as chlorhexidine gluconate 0.2%, but it showed no statistical significance. Acacia nilotica leaves (L) and pods (P), as well as Dobera glabra branches (B), displayed a larger inhibition zone diameter against E. faecalis than Sodium hypochlorite 1%, but with no statistical significance. The leaves of Acacia nilotica exhibit the most potent antibacterial properties against E. faecalis when compared to other plants parts. They outperform the antibacterial effectiveness of 1% sodium hypochlorite and demonstrate a similar antibacterial impact to that of 0.2% chlorhexidine. Therefore, Acacia nilotica leaves could serve as an ideal irrigant potentially substituting the chemical options.

In vitro antioxidant and antibacterial activities of Ajuga integrifolia leaf extracts obtained with different solvents

BackgroundMany diseases are increasingly recognized as public health concerns worldwide because of the increasing incidence of multidrug-resistant bacteria. Recently, interest in the use of indigenous medicinal plants to treat infectious illnesses has increased, highlighting the need to find new bioactive phytochemicals. Ajuga integrifolia is a plant commonly utilized in traditional drugs to treat a wide range of diseases, although its effectiveness has not been scientifically validated. The present study aimed to evaluate the total phenolic and flavonoid contents and assess the biological activities of A. integrifolia leaf extracts produced via different solvent systems.MethodsSoxhlet extraction was employed to obtain crude extracts from different solvents (methanol, ethanol and water). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing power assays were used to measure the antioxidant activity, and the antibacterial activity of the extract was evaluated on the basis of its minimum inhibitory concentration (MIC) against two gram-negative bacteria (Escherichia coli (ATCC-25922) and Pseudomonas aeruginosa (ATCC-43495)) and two gram-positive bacteria (Staphylococcus aureus (ATCC-25923) and Streptococcus pyogenes (ATCC-19615)) via the agar disk-diffusion technique.ResultsA significant amount of total phenolic content (TPC) and flavonoid content (TFC) were present in all the extracts. The extracts presented powerful antioxidant activity in all the assays. The disc diffusion and MIC results revealed the ability of the methanol and ethanol extracts of A. integrifolia leaves to inhibit S. aureus growth at a concentration of 3.125 mg/mL. However, the water extracts were ineffective against E. coli and P. aeruginosa.ConclusionsThese findings indicate that A. integrifolia leaf extracts have reasonable biological activities. These findings underscore the importance of A. integrifolia leaves as a source of health benefits.

Extraction, Characterization, and Encapsulation of Cinnamon Hydrosol Obtained via Microwave-Assisted Hydrodistillation: Analysis of Antioxidant and Antimicrobial Activities

Microwave-assisted hydrodistillation (MAHD) method was employed to extract cinnamon oil and hydrosol (a byproduct). The total polyphenol content (TPC) of the cinnamon hydrosol (CH) was determined using the Folin-Ciocalteu method, and its antioxidant power was assessed through the DPPH radical reduction method. Gas chromatography was utilized to quantify the main bioactive compound (cinnamaldehyde). The disc agar diffusion method was applied to evaluate the inhibition of pathogenic microorganisms. To protect the bioactive compound, an encapsulation method involving cross-linking with calcium alginate was utilized. The capsules were examined using environmental scanning electron microscopy (ESEM). The TPC content was found to be 15.63 ± 0.21 mg gallic acid/g dry matter, and the DPPH radical inhibition rate was 84.26 ± 1.35%. CH exhibited a significant inhibitory effect against Escherichia coli, and a moderate inhibition effect against Shigella flexneri, Salmonella spp., Salmonella typhimurium, and Escherichia coli EPEC. Finally, successful encapsulation of CH was achieved using sodium alginate, resulting in bead sizes ranging between 1.75 and 2.75 mm.

Chemical composition and antimicrobial investigation of the essential oil isolated from Montanoa bipinnatifida (Kunth) K. Koch leaves

Montanoa bipinnatifida is a perennial shrub belonging to family Asteraceae and geographically distributed in Mexico, Central America and Northern South America. This study aimed to investigate the chemical composition of the essential oil isolated from M. bipinnatifida leaves through GC-MS analysis accompanied by in-depth investigation of antimicrobial properties against wide arrays of microbial strains via agar diffusion method and disk diffusion method. The GC-MS analysis of the tested oil revealed presence of sixteen components (∼99.99%), predominated by germacrene D (37.22%), β-caryophyllene (30.73%), α-pinene (4.56%) and β-germacrene (4.48%). The undiluted oil exhibits varying levels of activity against different microbes. The leaf oil showed a significant inhibition against Proteus mirabilis, Staphylococcus aureus, Bacillus subtilis (both vegetative and spores), Mycobacterium phlei, and Candida albicans. However, its activity against Sarcina lutea, Escherichia coli, Klebsiella pneumoniae appears to be less pronounced. Thus, the leaf oil of M. bipinnatifida demonstrates broadspectrum antimicrobial activity and is recommended in the pharmaceutical industry to overcome the current problem related to the microbial resistance to antibiotics. Further experimental studies are warranted to investigate the underlying mechanism of action and the responsible individual components.

Active packaging coating based on Lepidium sativum seed mucilage and propolis extract: Preparation, characterization, application and modeling the preservation of buffalo meat.

Buffalo meat is naturally perishable, making it susceptible to spoilage due to its high moisture content and vulnerability to microbial contamination. Edible coatings have attracted attention as a packaging method that can prolong the shelf life of meat. The study aimed to examine the impact of a combination of Lepidium sativum mucilage (LS) coating and propolis extract (PE) on prolonging the shelf life of buffalo meat. The chemical characteristics (chemical compounds, total phenol content (TPC), total flavonoid content (TFC), antioxidant activity, and cytotoxicity) and antimicrobial activity of the PE (disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration) were investigated. The effect of the PE on the cell wall of pathogenic bacteria was examined using a scanning electron microscope. Biological properties of LS (TPC, TFC, antioxidant activity and antimicrobial effect (pour plate method)) was investigated. Different concentrations of PE (0, 0.5, 1.5, and 2.5%) were added to the coating mixture containing LS, and their effects on extending the shelf life of buffalo meat samples stored at 4°C for 9 days were assessed. The PE included gallic acid, benzoic acid, syringic acid, 4-3 dimethoxy cinnamic acid, p-coumaric acid, myricetin, caffeic acid, luteolin, chlorogenic acid, and apigenin. The PE was determined to have a TPC of 36.67 ± 0.57 mg GAE/g and a TFC of 48.02 ± 0.65 mg QE/g. The extract's radical scavenging activity ranged from 0 to 76.22% for DPPH radicals and from 0 to 50.31% for ABTS radicals. The viability of C115 HeLa cell was observed to be 94.14 μg/mL. The PE and LS, exhibited strong antimicrobial properties against pathogenic bacteria. The LS was determined to have a TPC of 15.23 ± 0.43 mg GAE/g and a TFC of 11.51± 0.61 mg QE/g. The LS was determined to have a DPPH of 429.65 ± 1.28 μg/mL and a ABTS of 403.59 ± 1.46 μg/mL. The microbiological analysis revealed that the LS+2.5%PE treatment was the most effective in inhibiting the growth of total viable count (6.23 vs. 8.00 log CFU/g), psychrotrophic bacteria count (3.71 vs. 4.73 log CFU/g), coliforms count (2.78 vs. 3.70 log CFU/g), and fungi count (2.39 vs. 3.93 log CFU/g) compared to the control sample. The addition of PE to the edible coating also demonstrated a concentration-dependent effect on preserving the moisture, pH, color, and hardness of the buffalo meat. Sensory evaluation results suggested that incorporating PE into the edible coating extended the shelf life of buffalo meat by three days. In the second stage of this paper, this investigation employed two distinct forecasting methodologies: the Radial Basis Function (RBF) and the Support Vector Machine (SVM), to predict a range of quality indicators for coated meat products. Upon comparison, the RBF model exhibited a higher level of accuracy, showcasing its exceptional capacity to closely match the experimental outcomes. Therefore, this type of food coating, renowned for its strong antimicrobial properties, has the potential to effectively package and preserve perishable and delicate food items, such as meat.

Evaluating the Antibacterial and Anti‐Biofilm Properties of Chitosan Nanoemulsion Containing Euphorbia hebecarpa Plant Extract Against Escherichia coli and Staphylococcus aureus

ABSTRACTThe use of nanoparticles as drug‐carrying systems in medicine has received much attention, and on the other hand, the use of plants with medicinal properties has advantages over synthetic drugs. This study aims to improve the antibacterial and anti‐biofilm properties of Euphorbia hebecarpa plant extract using chitosan nanoparticles. Extraction were performed using the modified maceration and methanol solvent. The agar disc diffusion method was carried out to investigate the antimicrobial effects and MIC at an optical density (OD) of 630 nm. The anti‐biofilm agent's influence was measured at OD 570 nm, and the metabolic activity of bacteria in the damaged biofilm was determined using triphenyl tetrazolium chloride (TTC) staining. The nanoparticles were obtained by following the ionic gelation method and its characteristics were evaluated. Chitosan nanoparticles loaded with plant extract were found to be spherical shape with hydrodynamic diameter of 142 nm, a polydispersity index (PDI) of 0.184, a zeta potential of +28.6 mV. It was determined that the loading capacity (% LC) and encapsulation efficiency (% EE) percentages were 33% and 40%, respectively. The diameter of the inhibition zone in the agar disc diffusion test for both bacteria using nanoparticles loaded with the extract increased compared with control groups. Also, at a concentration of 4 mg/mL of loaded nanoparticles, 49.33% of Escherichia coli biofilm and 62.7% of Staphylococcus aureus biofilm were destroyed. The data obtained from the tests performed in this study show that the use of Euphorbia plant extract in the form of chitosan nanoparticles can have more antimicrobial and anti‐biofilm effects.

Phytochemical Characterization and Synergistic Antibacterial Effects of Colebrookea Oppositifolia Essential Oil as Adjuvants to Modern Antibiotics in Combating Drug Resistance.

The global threat of multi-drug-resistant bacteria has severely limited the options available for effective antibiotics. This study focuses on the antimicrobial activity and phytochemical characterization of C. oppositifolia extracts, aiming to identify novel plant-based therapeutic agents. C. oppositifolia specimens-leaves and inflorescence. Specimens were cleaned, sterilized, dried, and ground into a fine powder. Extracts were obtained using methanol and petroleum ether via a Soxhlet apparatus, followed by fractionation with chloroform, n-butanol, and ethyl acetate. Volatile oil was extracted through hydro distillation using a Clevenger apparatus. Phytochemical analysis was conducted to identify bioactive compounds. Biophysical techniques, including UV-visible spectrophotometry, TLC, HPLC, GC-MS, FTIR, and NMR, were employed for characterization. Antimicrobial activity was tested against S. aureus ATCC25922 and E. coli ATCC25922 using agar well and disc diffusion methods, and synergistic effects were assessed with erythromycin and amoxicillin. Methanol extract exhibited bacteriostatic activity with inhibition zones of 13.0 ± 0.2 mm for both S. aureus and E. coli. Petroleum ether, chloroform, n-butanol, and ethyl acetate fractions showed varying inhibition zones. Erythromycin demonstrated bactericidal activity, which was enhanced synergistically when combined with methanol extract and volatile oil, increasing inhibition zones against S. aureus. Phytochemical analysis identified phenols, flavonoids, tannins, coumarins, alkaloids, terpenoids, saponins, and glycosides. FTIR analysis revealed functional groups such as amines, aldehydes, nitriles, alkenes, and sulfones. GC-MS identified 24 compounds, with α-pinene, caryophyllene, and carene as major components. NMR spectra indicated no complex formation between oils and antibiotics, suggesting the compounds act as synergists. The C. oppositifolia extracts possess significant antimicrobial activity and synergistic potential, particularly against S. aureus. The presence of various bioactive compounds suggests a promising role in developing new plant-based therapeutics.