Mean Zone Of Inhibition Research Articles

Exploring the photosensitizing potential of Nanoliposome Loaded Improved Toluidine Blue O (NLITBO) Against Streptococcus mutans: An in-vitro feasibility study.

Streptococcus mutans is a major contributor to dental caries due to its ability to produce acid and survive in biofilms. Microbial resistance towards common antimicrobial agents like chlorhexidine and triclosan has shifted the research towards antimicrobial Photodynamic therapy (PDT). In this context, Toluidine Blue O (TBO) is being explored for its photosensitizing properties against Streptococcus mutans. There is a huge variation in the effective concentration of TBO among the current studies owing to the differences in source of and delivery system TBO as well as the time, power and energy densities of light. The primary objectives of this study are to encapsulate improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO), characterize it, and evaluate its antibacterial photosensitizing potential against Streptococcus mutans suspensions in vitro. ITBO was synthesised as per Indian patent (number -543908). NLITBO was prepared using the thin-film hydration method. Dynamic light scattering experiment determined the vesicle size, polydispersity index (PDI), and zeta potential. Surface features were characterized by Scanning and Transmission Electron microscopy. ITBO release from NLITBO was assessed using the extrapolation method. The antibacterial activity of the NLITBO was determined by evaluating the zone of inhibition (ZOI) in the Streptococcus mutans culture and comparing with 2% chlorhexidine gluconate. The minimum inhibitory concentration (MIC) of NLITBO as a photosensitizer with red light (wavelength 650nm, power density 0.1 W/cm2, energy density 9-9.1 J/ cm2, 90seconds time) was evaluated against Streptococcus mutans cells by colorimetric method in 96 well plate. Percentage drug loading, loading efficiency, yield percentage, vesicle size, PDI, Zeta potential of NLTBO was reported as 9.3±0.4%, 84.4±7.6%, 73.5%, 123.52 nm, 0.57, -39.54mV respectively. Clusters of uni-lamellar nanovesicles with smooth non-perforated surfaces were observed in SEM and TEM. The size of the vesicle was within 100 nm. At 24 hours, a cumulative 79.81% of ITBO was released from NLITBO. Mean ZOI and MIC of NLITBO (1 μg /ml) were found to be 0.7±0.2 mm, 0.6μg/ml respectively. We have synthesized and encapsulated improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO) and thoroughly characterized the formulation. The antibacterial efficacy of NLITBO without light was demonstrated by ZOI which is similar to 2% chlorhexidine gluconate. MIC of NLITBO as a photosensitiser along with the optimal light parameter was also proposed in this study. These findings suggested that NLITBO could serve as an effective alternative to conventional antibacterial treatments in managing Streptococcus mutans rich biofilms. It can have potential pharmaceutical application in oral health care.

Evaluation of antimicrobial activity of plant extracts and column fractions of hexane extract against Mycobacterium kansaii

The aim of this study is to assess the antibacterial efficacy of aerial parts of the Ageratum conyzoides plant extracts and column fractions against Mycobacterium kansaii. The antimicrobial experiments were performed using five doses (0.1 µg/ml, 1 µg/ml, 10 µg/ml, 100 µg/ml, 1000 µg/ml) of plant extracts and column fractions. The results showed notable inhibitory effects on Mycobacterium kansaii. The results indicated that the extract of A. conyzoides exhibited action against all the tested bacterial isolates, with the level of activity varying depending on the concentration. The hexane extract exhibited antibacterial activity, with mean zones of inhibition measuring 97.88±9.46 and 27.1±3.33, while the ethanol extract showed a mean zone of inhibition of 100.6±3.42 and 36.77±1.74 against M.kansaii, respectively. Nevertheless, the hexane extract's three column fractions exhibited average inhibition zones of 98.60±1.0 and 23.11±4.35, 90.02±10.22 and 21.94±6.77, 99.32±3.04 and 17.23±5.26 for the third, fourth, and fifth (last sample) respectively. The findings of this study provide evidence for the conventional utilization of the Ageratum plant and emphasize the necessity for further comprehensive research to explore potential alternatives to current antibacterial medications.

Antibacterial, phytochemical and GC-MS analyses of argel (Solanum argel) leaves.

Finding novel, efficient antimicrobial drugs is crucial in this age of pressing global health challenges. The medicinal qualities of the leaves of the argel plant (Solanum argel, or S. argel) have been recognized in traditional medicine for quite some time. The medicinal potential of these leaves may be due to the presence of bioactive substances such as alkaloids, flavonoids, and phenolic acids. S. argel leaf antibacterial, phytochemical, and gas chromatography-mass spectrometry (GC-MS) characteristics are the focus of this investigation. To conduct the study, bioactive compounds would be extracted from the leaves and tested against a panel of bacterial pathogens. Then, the compounds would be identified using GC-MS analysis. Mean inhibition zones of 15.30±1.0 mm, 14.67±0.42 mm, 15.0±0.01 mm, and 15.56±0.22 mm for the bacteria E. coli, Staph. aureus, and Sal. typhimurium, respectively, were seen in the antibacterial results at a concentration of 3 µg/disc. Secondary metabolites such as alkaloids, flavonoids, phenolic substances, and tannins were identified using phytochemical investigation. Antimicrobial, antioxidant, and anti-inflammatory are just a few of the many bioactivities associated with these phytochemicals. Argel plant leaves contain bioactive chemicals that show they could be a source of new pharmaceuticals. Argel leaves were analyzed using GC-MS and 37 different chemicals were found. The most abundant compounds were 4H-Pyran-4-one and 2,3-dihydro-3.5-hydroxy, followed by 3-Pentanol, 2,2,4,4-tetramethyl, and 2,2-Dimethyl-3-[3-methyl-5-(phenylthio)-, with areas of 11.80%, 10.6%, and 9.47%, respectively. The analysis was performed within a time range of 5.070 to 34.464 minutes. According to the research, Argel leaf has powerful antioxidant and antibacterial capabilities, making it an excellent substance for medical and food preservation applications.

Synergistic invitro antimicrobial activity of polyherbal combination of Morinda lucida fruit and Pterocarpus santalinoides seed against multi-drug resistant clinical bacterial isolates

Background: Synergistic drug combination has been shown to be a way of bypassing drug resistance and reducing the amounts of antimicrobials consumed. As infections caused by multi-drug resistant organisms (MDROs) continue to pose global threat, it is important to search for new antimicrobial combinations of plant origin that are safe and readily available. The objective of this study is to evaluate the synergistic antimicrobial activity of extracts of Morinda lucida fruit and Pterocarpus santalinoides seed against multi-drug resistant (MDR) bacterial isolates Methodology: Morinda lucida and P. santalinoides fruits were plucked and washed clean, and the fruits of P. santalinoides were deseeded to remove the seeds. They were cut into smaller pieces and dried under shade before being milled into smooth powder and extracted with methanol. The clinical bacterial isolates used were MDR Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The phytochemical constituents of the extracts were determined using the standard method. The invitro antimicrobial assay of the extracts was done at a concentration of 50 to 400 mg/ml using the agar well diffusion technique. The minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) of each extract were determined using the Checker-board micro-titration method, and the FIC result obtained for each isolate was used to calculate the fractional inhibitory concentration index (FICI) of the combined extracts. The time kill assay was performed to confirm the synergistic and bactericidal activities from the MIC values obtained. Results: The phytochemical analysis revealed that the extracts of both herbal plants contained alkaloids, phenol, tannin, saponin, glycosides, and terpenoids. The antimicrobial assay results showed that the polyherbal combination of the extracts was active against all the MDR bacterial isolates tested with varying zones of inhibition. The mean inhibition zone diameters of individual M. lucida and P. santalinoides ranged from 18.0±0.9mm to 26.0±1.4mm and 17.0±0.1mm to 24.0±0.2mm respectively, while the MIC ranged from 6.25mg/ml to 12.5mg/ml for M. lucida and 12.5 mg/ml for P. santalinoides. The mean inhibition zone diameter of the polyherbal combination of the two plant extracts ranged from 25.00±00mm to 34.0±0.4mm, which compared favorably with that of levofloxacin control (28.0±0.0mm to 32.00±0.0mm), while their MIC ranged from 0.39mg/ml to 1.56mg/ml. The FIC of M. lucida extract ranged from 0.06mg/ml to 0.25mg/ml while that of P. santalinoides ranged from 0.03mg/ml to 0.13mg/ml. The FICI of combined extracts ranged from 0.09mg/ml to 0.38 mg/ml for all the MDR isolates, which is less than 0.5mg/ml, indicating synergism against all the isolates. The time of kill assay confirmed the synergistic and bactericidal activities with a 3log10 CFU/ml decrease in the number of viable cells within 6 hours of incubation.Conclusion: Our findings showed synergistic antibacterial actions of extracts of M. lucida fruit and P. santalinoides seed against MDR clinical bacterial isolates, comparable to levofloxacin. Combination of these herbal plants may serve as alternative sources of antimicrobial agents for the treatment of infections caused by MDR bacterial pathogens.

Development of synergistic antifungal in situ gel of miconazole nitrate loaded microemulsion as a novel approach to treat vaginal candidiasis

Limited solubility is the main cause of the low local availability of anti-candidiasis drug, miconazole nitrate (MN). The study’s objective was to develop and characterize microemulsion (ME) based temperature-triggered in situ gel of MN for intravaginal administration to enhance local availability and antifungal activity. The solubility of MN was initially studied in different oils, surfactants, and co-surfactants. Then, pseudo-ternary phase diagrams were constructed to select the best ratio of various components. The ME formulations were characterized by thermodynamic study, droplet size, polydispersity index (PDI), viscosity, and in-vitro antifungal mean inhibition zone (MIZ). Selected MEs were incorporated into different in situ gel bases using a combination of two thermosensitive polymers (poloxamer (PLX) 407 and 188), with 0.6% of hydroxypropyl methylcellulose (HPMC K4M) and gellan gum (GG) as mucoadhesive polymer. ME-based gels (MG) were investigated for gelation temperature, gelation time, viscosity, spreadability, mucoadhesive strength, in vitro release profile, and MIZ test. Furthermore, the optimum MG was assessed for in vivo animal irritation test and FESEM investigation. Tea tree oil, lavender oil, tween 80, and propylene glycol (PG) were chosen for ME preparation for the optimal formulation; formulation ME7 and ME10 were chosen. After incorporation of the selected formulation into a mixture of P407 and P188 (18:2% w/w) with 0.6% mucoadhesive polymer, the resultant MG formulation (MG1) revealed optimum gelation temperature (33 ± 0.01℃) and appropriate viscosity with enhanced sustained release (98%) and retention through sheep vaginal mucosa, MG1 exhibited a better MIZ compared to the 2% MN gel formulation and the marketed MN product, and no rabbit vagina irritation. In conclusion, the miconazole nitrate-loaded MG-based formula sustained the duration of action and better antifungal activity than the marketed miconazole nitrate formulation.

Antibacterial Potentials and Phytochemical Screening of Eucalyptus globulus Leaves Extract against Selected Isolates

In recent decades, medicinal plants have been of great interest as they have been the sources of natural products. As a result, there is a need to analyse the phytochemical and antibacterial properties of Eucalyptus globulus against Escherichia coli, Bacillus cereus, Staphylococcus aureus and Pseudomonas aeruginosa. This study was carried out to determine the percentage yield, phytochemical properties, antibacterial activity, minimum inhibitory and minimum bactericidal concentration (MIC/MBC) of the crude extracts using the reflux extraction, qualitative phytochemical, agar well diffusion and broth dilution method respectively; while aqueous, normal hexane and ethyl acetate were used as extraction solvents. Aqueous extract has the highest yield of 16.08%, ethyl acetate extract (8.76%) while n-hexane extract had 3.84%. Phytochemicals such as tannins, alkaloids, and phenols were present in all three solvent extracts; while terpenoids, glycosides and steroids were absent. Saponins and flavonoids were present in water extract, flavonoids were present only in the ethyl acetate extract. The most active with mean inhibition zone (MIZ) diameter of 13.33±0.58mm and 10.33±0.58mm against Bacillus cereus and Staphylococcus aureus respectively at 50mg/mL while the lowest activity of MIZ diameter of 8.00±2.00mm was obtained with same extract and concentration against Escherichia coli. N-hexane and ethyl acetate extracts show no activity against the test organisms. The lowest MIC of 15.6mg/mL and MBC of 31.3mg/mL were obtained against Escherichia coli. Based on these results, it can be concluded that Eucalyptus globulus leaf extracts possess antibacterial activity against some of the test organisms and can be considered for drug development.

Testing the Inhibitory Activity of Bajakah Tampala (Spatholobus littoralis Hassk) Wood Extract from South Kalimantan on the Growth of Pseudomonas aeruginosa Bacteria

Background: Dental root canal treatment aims to eliminate microorganisms that cause infection in the tooth root canal, one of which is Pseudomonas aeruginosa bacteria. Disinfection of dental root canals with 0.5% - 5.25% NaOCl irrigation solution is still constrained so it is necessary to look for alternatives. The bajakah tampala plant (Spatholubus littoralis Hassk) is known to contain antibacterial compounds, namely flavonoids, saponins, tannins, and polyphenols. Objective: To evaluate the inhibitory activity of bajakah tampala wood extract (Spatholobus littoralis Hassk) from South Kalimantan against the growth of Pseudomonas aeruginosa bacteria. Method: Post test-only with control group design. The test groups were 100%, 75%, 50% bajakah tampala wood extract solution and positive control 2.5% NaOCL solution. Extraction using maceration method. Bacterial growth inhibition was tested by well diffusion method. Inhibition zone was measured using a caliper. Results: The growth inhibition from the largest to the smallest was shown by 75%, 100% and 50% bajakah wood extracts with mean inhibition zone diameters of 5.05 mm, 3.84 mm and 2.02 mm respectively, meanwhile the positive control was 16.14 mm. One Way Anova test showed significant difference in inhibition (p<0.05) in all groups. Post hoc test showed no significant difference in the inhibition of 75% bajakah tampala wood extract with 100% extract. The inhibition of 100% and 75% extracts was significantly greater than 50% extract. The inhibition of NaOCL 2.5% was significantly greater than all groups of test extracts. Conclusion: Bajakah tampala wood extract has inhibitory activity against the growth of Pseudomonas aeruginosa bacteria.

Antimicrobial Properties of Newer Calcium Silicate-Based Pulp-Capping Agents Against Enterococcus Faecalis and Streptococcus Mutans: An In-Vitro Evaluation.

This study aimed to evaluate the antibacterial activity of calcium silicate-based pulp-capping agents against Enterococcus faecalis and Streptococcus mutans using an agar diffusion test. The agar diffusion method was used to evaluate the antibacterial properties of pulp-capping agents. The materials used included Bio-C® Temp (Angelus, Brazil), Dia-Root™ Bio mineral trioxide aggregate (MTA) (Diadent Europe B.V., Almere, Netherlands), Biodentine™ (Septodont, Saint-Maur-des-Fossés, France), and TheraCal LC (Bisco Inc., Schaumburg, IL). Eighteen petri dishes, nine for S. mutans and nine for E. faecalis, were divided into four parts each (one for each agent), for a total sample size of 72. The bacterial suspensions were transferred to the petri dishes using a sterile swab. Four wells with a diameter of 4 mm were then punched in each petri dish. The wells were filled with the pulp-capping agents, which had been mixed according to the manufacturer's instructions, and the petri dishes were incubated. The zone of inhibition was measured at 24 and 48 hours to assess the pulp-capping agents' antimicrobial efficacy against E. faecalis and S. mutans. The readings were tabulated and subjected to statistical analysis. At 24 hours, the highest zone of inhibition was found in the Biodentine™ group (15.83 ± 0.79 mm), followed by Dia-Root™ Bio MTA (14.5 ± 0.88 mm), TheraCal LC® (12.56 ± 0.53 mm), and the shortest in the Bio-C Temp (9.61 ± 0.70 mm) against S. mutans. Analysis of variance (ANOVA) test showed a high statistical significance. After 48 hours, there was no statistically significant difference in the mean zone of inhibition. At 24 hours, the highest zone of inhibition was found in the Biodentine™ group (20.56 ± 0.73 mm), followed by Dia-Root™ Bio MTA (20.06 ± 1.33 mm), TheraCal LC® (18.22 ± 0.97 mm), and the shortest in the Bio-C Temp (14.11 ± 0.78 mm) against E. faecalis. The ANOVA test indicated no statistically significant difference between the Biodentine™ and the Dia-Root™ Bio MTA groups. After 48 hours, there was no statistically significant difference in the mean zone of inhibition. Biodentine™ has higher antibacterial efficacy against S. mutans, while Biodentine™ and Dia-Root™ Bio MTA have comparably high antibacterial activity against S. mutans and E. faecalis at 24 and 48 hours.

Optimizing Dermal Delivery of Linezolid for Treating Skin and Soft Tissue Infections: NLC-Based Gel Formulation Using Taguchi Design

Background: Uncomplicated skin and soft tissue infections account for approximately 200 million visits to ambulatory care settings annually. Linezolid (LNZ) is an oxazolidinone that has proven its effectiveness in combating skin and soft tissue infections caused by gram-positive pathogens. LNZ is administered via oral suspension, tablets, or an intravenous route in most in-stances. However, its extended therapy leads to undesirable side effects like diarrhoea, thrombo-cytopenia, myelosuppression, lactic acidosis, etc. and even life-threatening complications. The dermal administration of LNZ offers an alternative route, ensuring localized and sustained release at the site of infection. This approach may reduce systemic exposure and allow for lower doses compared to oral ingestion, which can decrease the risk of adverse effects. Objective: This research aimed to develop a nanostructured lipid carrier (NLC)-based gel for de-livering LNZ via the dermal route to treat uncomplicated skin and soft tissue infections. Methods: NLC were developed by high-shear homogenisation and sonication method using glyc-eryl trimyristate as a solid lipid and neem oil as a liquid lipid. The Taguchi design was employed to optimize NLCs using surfactant concentration (mg), drug-to-lipid ratio, and sonication time (sec) as independent variables. Their effect on particle size, zeta potential, and entrapment effi-ciency was studied. The optimized nanocarriers were developed into a gel product and evaluated for drug release, permeation, and antibacterial activity. Results: The optimised process parameters to attain outcomes were 2% surfactant, 1:1 drug-to-lipid ratio and 300 seconds of sonication. The resulting NLC had an average size of 191.2 ± 2.76 nm, a zeta potential of -30.7 ± 4.50 mV, and 84.89 ± 2.76% drug entrapment. NLC-based gel dis-played anomalous transport with a 90.16 % drug release. The gel showed a strong antibacterial effect against Staphylococcus aureus with a 7.57 ± 0.12 cm mean zone of inhibition. Ex-vivo skin permeation studies revealed 24.19 ± 0.19 % drug permeation and 64.46 ± 0.58% cutaneous depo-sition. NLC-based gel demonstrated a significant decrease in colony-forming units in infected an-imal models. Conclusion: The ex-vivo investigations demonstrated the presence of LNZ at the infection site, enhancing therapeutic effectiveness. In vitro and in-vivo findings illustrated the substantial anti-bacterial efficacy of LNZ NLC-based gel. The adoption of NLC-based gel exhibits promising po-tential as a carrier for dermal delivery of LNZ.

Copper and nickel complexes based on 4-((4-nitrophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol; synthesis, characterization, X-ray studies, DFT calculations, molecular docking and antimicrobial activity

Two new copper(II) and nickel(II) complexes were prepared using 4-((4-nitrophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol (ndtp) and well-characterized spectroscopically and thermally and via X-ray studies. X-ray studies confirmed the formation of two octahedral complexes, containing two ndtp and two coordinated DMF molecules. The two complexes were evaluated in vitro against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus. [Ni(ndtp)2(DMF)2] showed an enhanced antibacterial activity against the different bacterial strains compared to the free ligand and that of the [Cu(ndtp)2(DMF)2]. The mean inhibition zones exhibited by [Ni(ndtp)2(DMF)2] were 14.7±0.6, 14.0±1.0, and 16.3±0.6 mm against Escherichia coli, Staphylococcus aureus and Bacillus cereus, respectively. Molecular docking studies of the two complexes were performed with DNA gyrase of Escherichia coli (PDB ID: 6F86) to evaluate the potential antibacterial activities, and it was proved that the complexes were efficient for the receptor.

Cladophora spp. Extracts Show Remarkable Antibacterial Potential Against Pseudomonas aeruginosa

Background: Bacterial resistance, influenced by genetic processes and adaptive strategies, necessitates the discovery of novel antibacterial agents, especially from natural sources. Specific Background: Pseudomonas aeruginosa, a notorious pathogen in urinary tract infections (UTIs), demonstrates considerable resistance to conventional therapies, necessitating alternative therapeutic approaches. Knowledge Gap: Research indicates that while natural sources like Cladophora spp. offer antibacterial agents, their effectiveness in combating P. aeruginosa resistant strains remains underexplored. Aims: This study aims to evaluate the antibacterial potential of Cladophora spp. algae extracts against Pseudomonas aeruginosa isolated from UTIs, utilizing solvent extraction, MIC determination, disc diffusion assays, and GC-MS analysis to identify bioactive compounds. Results: All extracts, including those prepared with water, ethanol, and hexane, demonstrated inhibitory effects on P. aeruginosa. The hexane extract exhibited the most significant activity, with a mean zone of inhibition of 13.0 ± 0.7 mm at a concentration of 50%. GC-MS analysis identified several bioactive compounds potentially responsible for these effects. Novelty: This study is among the first to investigate Cladophora spp. as a source of antibacterial agents specifically targeting P. aeruginosa, providing new insights into the potential of algae-based therapeutics. Implications: Cladophora spp. holds promise as a source of novel antibacterial compounds, with potential for multidrug-resistant infections treatments. Further research is needed for clinical application. Highlights: Hexane Extract: Most effective against Pseudomonas aeruginosa. Novel Source: Cladophora spp. shows potential as antibacterial agent. GC-MS Findings: Identified key bioactive compounds. Keywords: Cladophora spp., Pseudomonas aeruginosa, antibacterial agents, natural extracts, GC-MS analysis

Comparative Evaluation of Antifungal Efficacy of 3% Sodium Hypochlorite, 2% Chlorhexidine Gluconate, Ozonated Water, Alum Water, and Normal Saline Solutions against Endodontopathogenic Microorganism, Candida Albicans: A Microbiological In Vitro Study.

To compare and evaluate the antifungal efficacy of 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gluconate, 4 mg/mL ozonated water, and 2M alum water against Candida albicans (C. albicans). A total of 35 patients were selected from those attending the outpatient department of Pedodontics and Preventive Dentistry at Santosh Dental College and Hospitals, Ghaziabad. Their salivary samples were taken and cultured on a Sabouraud's dextrose agar (SDA) plate. The antifungal efficacy of 3% NaOCl, 2% CHX gluconate, 4 mg/mL concentration of ozonated water, and 2M alum water was assessed against clinical strains of C. albicans with the help of agar well diffusion method. The microbial isolates were inoculated into 10 mL of sterile peptone water and incubated at 37°C for 8 hours. The cultures were swabbed on the surface of sterile Mueller-Hinton agar plates using a sterile cotton swab. Five wells of 6 mm diameter were punched in each Petri dish. Around 100 µL of each test solution was poured into the designated wells. Further, the plates were incubated in an upright position at 37°C for 24 hours. The antifungal activity of the test solutions was determined by measuring the diameter of the inhibition zone in mm produced against the Candida isolates, and means were calculated. It was observed that all test solutions used in this study were inhibitory against C. albicans but with a variation in the size of inhibitory zones. According to the means of the diameter of inhibitory zones for all test solutions, the 3% NaOCl represented the statistically significant largest average zones of inhibition against C. albicans, followed by 2% CHX when compared with the other two test solutions alum water and ozonated water. Ozonated water produced the smallest mean inhibitory zone. Sharma A, Naorem N, Srivastava B, et al. Comparative Evaluation of Antifungal Efficacy of 3% Sodium Hypochlorite, 2% Chlorhexidine Gluconate, Ozonated Water, Alum Water, and Normal Saline Solutions against Endodontopathogenic Microorganism, Candida Albicans: A Microbiological In Vitro Study. Int J Clin Pediatr Dent 2024;17(S-1):S17-S24.

Anticandidal activity of a wild Bacillus subtilis NAM against clinical isolates of pathogenic Candida albicans

BackgroundResistance to antifungal medications poses a significant obstacle in combating fungal infections. The development of novel therapeutics for Candida albicans is necessary due to the increasing resistance of candidiasis to the existing medications. The utilization of biological control is seen as a more advantageous and less hazardous strategy therefore the objective of this study is to identify the antifungal properties of Bacillus subtilis against pathogenic C. albicans.ResultsWe conducted a study to evaluate the antifungal properties of three bacterial isolates against the human pathogen Candida albicans. One of the bacterial isolates exhibited a potent antifungal activity against this fungal pathogen. This bacterium was identified as Bacillus subtilis based on the 16Sr RNA gene sequence. It exhibited inhibitory efficacy ranging from 33.5 to 44.4% against 15 Candida isolates. The optimal incubation duration for achieving the maximum antifungal activity was determined to be 48 h, resulting in a mean inhibition zone diameter of 29 ± 0.39 mm. The Potato Dextrose agar (PDA) medium was the best medium for the most effective antifungal activity. Incubation temperature of 25oC and medium pH value of 8.0 were the most favorable conditions for maximum antagonistic activity that resulted fungal growth inhibition of 40 ± 0.16 and 36 ± 0.94 mm respectively. Furthermore, the addition of 10.5 mg/ml of bacterial filtrate to C. albicans colonies resulted in 86.51%. decrease in the number of germinated cells. The fungal cell ultrastructural responses due to exposure to B. subtilis filtrate after 48 h were investigated using transmission electron microscopy (TEM). It revealed primary a drastic abnormality that lead to cellular disintegration including folding and lysis of the cell wall, total collapse of the yeast cells, and malformed germ tube following the exposure to the filtrate. However, the control culture treatment had a characteristic morphology of the normal fungal cells featuring a consistently dense central region, a well-organized nucleus, and a cytoplasm containing several components of the endomembrane system. The cells were surrounded by a uniform and intact cell wall.ConclusionThe current study demonstrates a notable antifungal properties of B. subtilis against C. albicans as a result of production of bioactive components of the bacterial exudate. This finding could be a promising natural antifungal agent that could be utilized to combat C. albicans.

Analysis of gauze pad made from coconut tree fiber infused with guava derived phenolic compounds

Abstract Gauze pad wound dressing plays a crucial role in protecting the wound and preventing it from factors that can prolong the healing process. However, due to the porous nature of gauze pads, it cannot completely block microbes from getting into the wound. This study analyzes coconut tree fiber as a gauze pad infused with guava derived phenolic compounds, known for its antimicrobial and antioxidant properties. The research assesses the extract’s effectiveness, focusing on phenolic compounds, antioxidant properties, and antimicrobial effects. By employing the disk diffusion method against Staphylococcus aureus, the study reveals that both 50% and 30% extracts exhibit inhibitory activity, with mean zones of inhibition at 8.5 mm and 8.33 mm, respectively, showing the antimicrobial property for both 50% and 30% extracts. The samples also demonstrated notable DPPH radical scavenging capacities for concentrations ranging from 0.006 to 1.27 (%w/v) for the 50% extract sample and from 0.006 to 1.25 for the 30% extract sample, ranging from 1.98% to 68.5% and 7.94% to 69.5%, respectively, indicating antioxidant property for both samples. The researchers have determined that there is no significant difference (p-value = 0.9187, α = 0.05) between the scavenging activity of both 50% and 30% extract. Furthermore, a minimal disparity in total phenolics was observed, with the former containing 1.25 and the latter 1.24 weight percent gallic acid. To determine if there is any negative skin reaction, a patch test was conducted in collaboration with a dermatologist using Stanford Health Care Medicine Standard. The test revealed no adverse skin reactions after three days of no removal usage of the coconut tree fiber gauze pad infused with phenolic compounds, as compared to a commercially available gauze pad. This study underscores the promise of guava extract and its antibacterial properties, particularly against skin pathogens, and its safe application when integrated with coconut fiber. This combination holds potential as a natural antimicrobial agent with diverse applications.

In vitro antibacterial activity of Bersama abyssinica Fresen crude extract against representative Gram-positive and Gram-negative bacterial isolates.

Bersama abyssinica Fresen is a plant that is used in folk medicine for the treatment of mastitis and other infectious diseases. The antibacterial activity of methanol crude extract of plant was evaluated against three common bacterial pathogens, including Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli and Pseudomonas aeruginosa). The antibacterial activities and minimum inhibitory concentration of B. abyssinica crude extracts were evaluated using agar-well diffusion and broth dilution methods according to the National Committee for Clinical Laboratory Standards (NCCLS). A significant difference in the antibacterial activity of crude extracts was observed among different levels of concentration against tested isolates. A higher mean inhibition zone diameter was recorded in E. coli (29.2 ± 1.5mm), followed by S. aureus (27.8 ± 1.1mm) and P. aeruginosa (18.0 ± 0.7mm) at a concentration of 100mg/mL. The antibacterial activity of crude plant extract at 100mg/mL was comparable with that of a standard antibiotic (27.6 ± 2.6) against S. aureus and E. coli isolates. The findings indicated that bacterial growth inhibition increased as the concentration of the crude extracts increased. E. coli and S. aureus isolates showed significantly higher susceptibilities to crude extracts than P. aeruginosa at all concentrations. The minimum inhibitory concentrations of extracts against S. aureus, E. coli and P. aeruginosa isolates were 0.78mg/mL, 1.56mg/mL and 1.56mg/mL, respectively. All tested pathogenic bacterial species were susceptible to plant leaf extract and broad-spectrum activity against Gram-positive and Gram-negative bacteria. The study recommends further fractionation of the B. abyssinica plant that contributes to its antibacterial activity and understands the mode of action of this plant against bacteria and other microbes.

Callistemon citrinus: A plant‐mediated synthesis of sustainable Rhodium nanoparticles and their antimicrobial activity

AbstractThis work investigates the potential of using Callistemon citrinu flower extract, commonly known as bottlebrush, in the environmentally friendly synthesis of Rhodium nanoparticles (Rh NPs). Callistemon citrinu flower extract contains a high concentration of flavonoids and other phytochemicals. Hence, the extract was used to provide the essential components for an environmentally, sustainable synthesis method of Rh NPs. Different characterization analyses were used to evaluate the different properties of the synthesized particles. UV spectroscopy analysis demonstrated a continuous UV absorption spectrum attributed to the formation of Rh NPs. The XRD data and SAED analysis showed an amorphous nature of the synthesized Rh NPs. The HRTEM imaging provided morphological information about the Rh NPs tested sample, where the efficiency of Callistemon citrinu flower extract as a capping agent was reported. Furthermore, Raman spectra displayed the characteristic vibrational bands of the synthesized Rh NPs. The antimicrobial activity of the synthesized samples was tested against several dental pathogens, that play a role in dental caries, Staphylococcus aureus (SA), Bacillus subtilis (BS), Candida albicans (CA), Escherichia coli (Eco), and Staphylococcus epidermidis (S. Epi). In comparison with the control, Chlorhexidine (CHX), Rh NPs showed a greater impact on C. albicans (20 ≤ Zone of inhibition (ZOI) (mm) ≤ 26). The statistical analysis demonstrated that Rh NPs had a greater mean ZOI than the Callistemon citrinu flower extract. These results reveal the considerable potential and biological capacity Rh NPs have as an antifungal agent for dental applications.

Antibacterial activities of honey bee against gram-positive bacteria isolated from urine

The medicinal benefits of honey have long been recorded in ancient days as a solution for various ailments and infections. This study x-rayed the effects of honey on common gram-positive bacteria isolated from urine. The study evaluated the in vitro susceptibility of two gram positive bacteria strains, isolated from urine of students of Nnamdi Azikiwe University, Awka Anambra state, Nigeria. The end point was achieved via macroscopic, microscopic methods and biochemical examinations which includes: gram staining, urease, catalase, coagulase testing to a hsoney sample. The evaluation of the antibacterial activity was ascertained by the agar diffusion well method. The results obtained in this study proved that the honey sample exhibited potent antibacterial activity against the tested strains, the zone of inhibition was at a mean value of 20.5 mm and 29.5 mm respectively at 100% concentration of honey. Staphylococcus epidermidis was found to be less susceptible than Enterococcus faecalis with a mean inhibition zones being 29.5 mm. This contribution has provided a broad overview of the antibacterial activity of honey and shown that honey bee has great potential for therapeutic use as an alternative therapy for infections caused by the isolates.

Antimicrobial Potency of the Biosynthesized Silver Nanoparticles (AgNPs) on Methicillin-Resistant Staphylococcus aureus (MRSA) Using Bridelia ferruginea Benth Plant Extract

Background:: Antibiotic resistance among pathogens has grown to be a major concern for the health of people around the world. One of the main subgroups of troublesome multidrugresistant bacteria that has recently undergone rapid evolution is Methicillin-resistant Staphylococcus aureus (MRSA). Methods:: In this study, silver nanoparticles were synthesized using an aqueous extract of Bridelia feeruginea leaves. The methicillin-resistant S. aureus was used to test the antibacterial properties of the produced Bridelia ferruginea-derived silver nanoparticles. These nanoparticles were characterized using XRD, UV-vis spectroscopy, FTIR, and SEM. Results:: The antibacterial activity of the silver nanoparticles was improved at doses of 50, 100, and 150 ug/ml, with mean zones of inhibition (ZOI) of 13.0, 16.4, and 17.4 mm (SD1). When combined with erythromycin medicines, silver nanoparticles showed significant antibacterial efficiency compared to when used alone. The ZOI was 23 mm at 150 ug/mL, compared to 21 mm at 50 and 100 ug/mL. At P=0.06, the outcomes were statistically significant. Conclusion:: This established that the antibacterial impact of combining antibiotics with AgNPs is enhanced. The current work showed that biosynthesized B. ferruginea silver nanoparticles (BFAgNPs) were effective in vitro.

Antibacterial Efficacy of Eucalyptus Essential Oil against Respiratory Infection Pathogens and Characterization of its Bioactive Compounds

Antibacterial activity of eucalyptus essential oils (EEO) against some respiratory pathogens and its mechanism of action were studied. Clinical pathogens used in the study were Enterobacter cloacae, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa. Disk diffusion, macro and microbroth dilution methods were respectively used to assess antibacterial assay, minimum inhibitory concentration (MIC) and growth inhibition assay using standard antibiotics as references. Gas chromatography Mass spectrometry was used to characterize the bioactive compounds present in EEO. Scanning electron microscopy was used to determine the mode of action of EEO on test pathogens. A total of 12 compounds were found to have bioactive functions with p-Cymene having 34.07%, gamma-Terpinene (7.01%), Cyclohexasiloxane (5.30%), 2-Aminobenzoic acid (4.59%). The EEO exerts varying antibacterial effects on susceptible organisms. At 100 mg/ml concentration the EEO antibacterial activities were observed on E. cloacae with 23.0 mm mean zone of inhibition, K. pneumoniae (22.7 mm) and S. aureus (16.0 mm) while no activity was recorded on P. aeruginosa. The MIC and MBC of the EEO on susceptible organisms were E. cloacae (6.25mg/ml, 12.5mg/ml); S. aureus (25mg/ml. 50mg/ml) respectively, while both MIC and MBC of EEO on K. pneumoniae was 50mg/ml. Scanning electron microscopy displayed noticeable damages of cell morphology and ultrastructure on two most susceptible pathogens (E. cloacae and K. pneumoniae), thus increase cell permeability and subsequent cell death. This study showed EEO is a potent antibacterials against some respiratory pathogens and can be further explored in treating respiratory and other infections caused by these pathogens. The positive effect of eucalyptus essential oil on the selected respiratory infection pathogens could make it an important part of drug (ointment formation) for the treatment of such infections. Keywords Essential Oils, Bioactive Compounds, Respiratory Pathogens, Susceptibility, GCMS

Invitro antibacterial activity of bark, leaf and root extracts of combretum molle plant against streptococcus equi isolated from clinical cases of strangles in donkeys and horses

BackgroundEffective therapy for many infections is becoming difficult due to the evolutionary development of drug resistance, and hence, the development of alternative treatment options mainly from herbs is crucial. The objective of this study was to investigate the antibacterial effects of ethanol extracts of stem bark, leaves and roots of Combretum molle against Streptococcus equi isolated from clinical cases of strangles using in vitro tests.MethodsPlant extraction was performed using a maceration technique with 80% ethanol. The mean zone of inhibition was determined using the agar well diffusion method. Six serial dilutions with different concentrations (10%, 5%, 2.5%, 1.25%, 0.625% and 0.3125%) of each plant extract were prepared using dimethyl sulfoxide (DMSO). A modified agar microdilution method was used to determine the minimum inhibitory concentration (MICs) of the extracts.ResultsThe results revealed that all plant extracts showed significant antibacterial activity. The root extract showed the best antibacterial effect compared to the others at all concentrations, with MZI values of 27.5, 23.225, 20.5, 17.9, 15.65 and 12.25 for the respective concentrations mentioned above and an MIC of 250 µg/ml. It was followed by the stem bark extract, which had MZI values of 24.67, 22.35, 18.225, 16.175, 11.125 and 8.2 millimeters and an MIC of 375 µg/ml. The leaf extract also had significant activity, with MZI values of 20.175, 18.25, 15.7, 13.125, 9.4 and 6.75 in millimeters and an MIC of 500 µg/ml. There was a direct relationship between the concentrations of the plant extracts and the level of inhibition.ConclusionThe test plant extracts were compared with the conventional antibiotic penicillin G, and the results indicated that the parts of the test plant have significant antibacterial activity, which may support traditional claims and could be candidates for alternative drug discoveries.