Evaluation Of Antibacterial Activity Research Articles

Evaluation of Microbiological quality and antibacterial activity of Cannabis artisanal oil used in Brazil

The medicinal use of Cannabis sativa has been highlighted as an alternative in the treatment of neurological diseases, due to the cannabidiol (CBD), with anticonvulsant properties. This study evaluated the microbiological quality and antibacterial activity of Cannabis extracts used by patients with refractory epilepsy in order to bring more safety in their use and prescription. Around of 70 samples of Cannabis extracts were evaluated, 10 of them used for antibacterial activity tests. Microbiological quality was measured by observing the growth of bacteria, after the inoculation of the Cannabis extract into BHI Agar, BEM Agar, MacConkey Agar and Mueller-Hinton Agar culture media. For antimicrobial activity, a modified Kirby-Bauer method was performed with 11 bacterial isolates considered potentially pathogenic. Of the analyzed samples, 70 showed no bacterial contamination during its preparation, distribution and storage process, making them safe from a microbiological perspective for human consumption. Regarding antimicrobial activity, the 10 samples tested showed no inhibitory activity against the listed bacteria. The product may not interfere with the microbiota of users being treated, as some of the isolates are part of the human microbiota. Analysis of the microbiological quality and antibacterial activity of cannabis used in patients with severe neurological disorder is of fundamental importance to ensure better safety in its use. Therefore, all Cannabis extracts tested are free of microbial contamination that may compromise product quality, and none of the extracts used in this study inhibited the in vitro growth of the tested bacteria.

Evaluation of antibacterial activities of hemolymph and methanol extracts from black soldier fly (Hermetia illucens)

Abstract Black soldier fly (BSF) has been recently recognized as a promising source of antibacterial substances such as antimicrobial peptides (AMPs) and medium-chain fatty acids (MCFAs). This study aimed to isolate and identify the antibacterial activities of hemolymph and methanol extracts from BSF. The BSF larvae hemolymph increased the growth of bacteria which is likely due to its nutritional effects. However, the bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella typhimurium, and Escherichia coli) treated with the hemolymph from bacteria inoculated BSF larvae showed slower growth when compared with the bacteria treated with the unchallenged hemolymph, and such a difference was dramatically eliminated by proteinase K and proteins/peptides between 3-10 kDa were the most active substances that affected the growth of bacteria. However, the antibacterial activity of BSF hemolymph was not strong enough to develop a visible inhibition zone in the Zone of Inhibition test against any of the four bacteria strains above. Methanol extracts from III instar BSF larvae, V instar BSF larvae, and BSF prepupae showed strong antibacterial activities in the Zone of Inhibition test against the four bacteria strains, and it is resistant to proteinase K treatment. The antibacterial activity and the percentage of fatty acids in the methanol extracts increased with age. Heating at 130 °C for 60 min significantly improved the antibacterial ability of methanol extracts against Staphylococcus aureus without changing its fatty acid profile. In conclusion, bacteria-inoculated BSF larvae develop AMPs in hemolymph which exhibit weak antibacterial activities. The methanol extracts of BSF can be produced in large quantities using larvae and have strong antibacterial activity which is attributed to lauric acid and some unknown compounds.

Total Synthesis of Dragmacidins G and H.

The total synthesis of dragmacidins G and H was achieved for the first time by employing nucleophilic aromatic substitution and site-selective cross-coupling reactions using appropriately functionalized pyrazines as substrates. The evaluation of antibacterial activities of dragmacidin G, dragmacidin H, and synthetic analogues against Staphylococcus aureus and the efflux pump-deficient Salmonella Typhimurium revealed that the presence of a Br group on the indole ring adjacent to the sulfide unit was important for increasing antibacterial activities.

Eco-friendly chitosan polymer synthesis using Rhizopus arrhizus RL strain and evaluation of antibacterial activity

Eco-friendly chitosan polymer synthesis using Rhizopus arrhizus RL strain and evaluation of antibacterial activity

Evaluation of antibacterial, antifungal and antibiofilm activities of A. baumannii-derived tannase and gallic acid against uropathogenic microorganisms

One of the most prevalent infectious diseases and a key driver of antibiotic prescriptions in pediatrics is urinary tract infection (UTI). Due to the emergence of more resistant uropathogenic bacterial and fungal strains, current treatments are no longer effective, necessitating the urgent development of novel antibacterial and antifungal drugs. In this study, the antifungal, antibacterial, and anti-biofilm capabilities of compounds, such as tannase (TN) and gallic acid (GA), which were produced from a novel natural source, Acinetobacter baumannii (AB11) bacteria, were assessed for the inactivation of uropathogenic microorganisms (UMs). Ammonium sulphate precipitation, ion exchange, high-performance liquid chromatography, and gel filtration were used to purify TN and GA that were isolated from A. baumannii. A 43.08 % pure TN with 1221.2 U/mg specific activity and 10.51 mg/mL GA was obtained. The antibacterial, antifungal and anti-biofilm activities of TN and GA were evaluated against UMs and compared to those of commercially available antibiotics including sulfamethoxazole (SXT), levofloxacin (LEV), ciprofloxacin (CIP), amikacin (Ak), and nitrofurantoin (F). The results showed that TN and GA were superior to commercial antibiotics in their ability to inactivate UMs and considerably reduced biofilms formation. Additionally, the GA emerges as the top substitute for currently available medications, demonstrating superior antibacterial and antibiofilm properties against all UMs evaluated in this study. The results of this investigation showed that A. baumannii-derived TN and GA could be utilized as an alternative medication to treat UTIs.

Boron nitride nanoparticles: Preparation, characterization, stability and evaluation of antibacterial activities

Boron nitride nanoparticles: Preparation, characterization, stability and evaluation of antibacterial activities

Preparation, Characterization of Two Modified Irradiated Pulp Capping Materials and Evaluation of Anti-Bacterial Activity and Compressive Strength

Preparation, Characterization of Two Modified Irradiated Pulp Capping Materials and Evaluation of Anti-Bacterial Activity and Compressive Strength

Evaluation of antioxidant and antibacterial activities of silver nanoparticles derived from Limonia acidissima L. fruit extract

In the rapidly expanding field of nanoscience and research, AgNPs and their diverse by-products have been acknowledged as having a green approach. Fruit extract of Limonia acidissima L. is capable of bio-reducing AgNO3 and stabilizing AgNPs. AgNPs distinctive absorption peak at 417 nm at pH 8 was visible on the UV-Vis spectrophotometer. The fruit extract contained bioactive chemicals, which may be the cause of the AgNPs bio-capping and stabilizing properties, according to Fourier transform infrared (FT-IR) spectroscopy. Using an X-ray diffractometer (XRD) examination, the AgNPs solid crystalline nature and size of 29.05 nm were investigated. Lastly, AFM and HR-TEM studies verified the AgNPs surface morphology, particularly their size and form. The DPPH assay method was used to measure the AgNPs capacity for radical scavenging. As compared to normal ascorbic acid and fruit extract (control), the AgNPs produced from the fruit extract demonstrated good antioxidant effectiveness. To evaluate the antibacterial activity of the AgNPs sample, it was additionally evaluated against E. coli, S. typhi, V. cholera, and S. aureus. With the greatest zone of inhibition and thus the strongest antibacterial activity, S. aureus (12.03 ± 0.043 mm) was the organism that displayed it. On the other hand, the least active strain was V. cholera (9.09 ± 0.013 mm). The data indicates that bio-fabricated silver nanoparticles (AgNPs) exhibited dose-dependent inhibitory efficacy together with a notable zone of inhibition. Additionally, S. aureus was shown to be more effective than V. cholera. Future health and pharmaceutical fields may benefit from the biocompatible method of separating AgNPs from L. acidissima fruit extract.

Biochemical Evaluation of Potential Antibacterial Activities of (2,6-Diethylphenyl)-5-Oxopyrrolidine Derivatives via In-Silico Study

Biochemical Evaluation of Potential Antibacterial Activities of (2,6-Diethylphenyl)-5-Oxopyrrolidine Derivatives via In-Silico Study

Evaluation of time-dependent ion-release and antibacterial activity of three adhesive resin cements

Aim This in-vitro study aimed to evaluate time-dependent ion-release and antibacterial activity of three self-adhesive resin cements. Materials and methods Sixty cement discs of the three tested self-adhesive resin cements were fabricated according to the manufacturer’s instructions in a plastic transparent mold, their dimensions were 6 mm in diameter and 2 mm in height. They were divided into three main experimental groups according to the self-adhesive resin cement type: group A (Thera-Cem), group B (G-Cem), and group C (RelyX Unicem 2) (20 each). Then, each main group was further subdivided into subgroup 1 (n = 10) for antibacterial assessment against Streptococcus mutans and subgroup 2 (n = 10) for ion-release assessment of fluoride and calcium. Direct contact test was used to monitor the bacterial outgrowth. Fluoride and calcium ions release were measured by ion chromatography and atomic absorption spectrometer respectively. All results were analyzed by one-way analysis of variance then multiple comparison Tukey’s test. Results All the evaluated cements exhibited antibacterial effects against S. mutans; fluoride and calcium were released by all the three cements in varying concentrations after aging. Conclusion Based on the results of this in-vitro study and within its limitations, it can be concluded that self-adhesive resin cements seem to provide promising antibacterial and remineralizing effects as being bioactive materials.

Synthesis, spectral study and evaluation of antibacterial activity of some novel 4-(6-methoxynaphthalen-2-yl)-6-(substituted aryl)pyrimidine-2(1H)-thiones

Abstract The objective of this study was to synthesize some novel substituted 4-(2-methoxynaphthalen-6-yl) pyrimidine- 2(1H)-thione compounds using sodium hydroxide catalyzed three component condensation and cyclization reaction of substituted 6-methoxy-2-acetonapthone, various substituted benzaldehydes and thiourea. These thione derivatives were characterized by their analytical, physical, and spectroscopic data. In addition, the in vitro antibacterial activities of these pyrimidine derivatives were evaluated using Bauer-Kirby disc diffusion method.

Design, synthesis and antibacterial activity evaluation of ebselen derivatives in NDM-1 producing bacteria.

New Delhi-β-lactamase-1 (NDM-1) is a type of metal-β-lactamase. NDM-1-expressing bacteria can spread rapidly across the globe via plasmid transfer, which greatly undermines the clinical efficacy of the carbapenem. Research on NDM-1 inhibitors has attracted extensive attention. However, there are currently no clinically available NDM-1 inhibitors. Our research group has reported that 1,2-benzisoselenazol-3(2H)-one derivatives as covalent NDM-1 inhibitors can restore the efficacy of meropenem (Mem) against NDM-1 producing strains. In this study, 22 compounds were designed and synthesized, which restored the Mem susceptibility of NDM-1-expressing Escherichia coli. and its minimum inhibitory concentration (MIC) was reduced by 2-16 times. Representative compound A4 showed significant synergistic antibacterial activity against NDM-1-producing carbapenem-resistant Enterobacteriaceae (CRE) isolates. The in vitro NDM-1 enzyme inhibitory activity test showed that the IC50 was 1.26 ± 0.37 μM, which had low cytotoxicity. When combined with meropenem, it showed good combined antibacterial activity. Electrospray ionization mass spectrometry (ESI-MS) analysis demonstrates that compound A4 covalently binds to NDM-1 enzyme. In summary, compound A4 is a potent NDM-1 covalent inhibitor and provides a potential lead compound for drug development in resistant bacteria.

Pharmaceutical Analysis and Evaluation of In-vitro Antibacterial Activity of Gomutra Ghana: A Concentrated and Solidified Form of Cow’s Urine

Introduction: Cow’s urine has been described as a highly effective animal-derived substance. Its therapeutic and pharmacological actions make it effective in the treatment of a variety of disorders. One of its notable properties is its antibacterial action, where the drug’s ability to target and inhibit the growth of bacteria. However, due to the pungent odour and taste of cow’s urine, it is difficult to consume in its natural form. Additionally, the collection of fresh cow’s urine can be challenging, especially in urban areas where access to cows may be limited. So, it is important to modify it into a dosage form, like Gomutra Ghana, which improves palatability and shelf life. Aim: To study the pharmaceutical development, quality control assessment, and in-vitro antibacterial activity evaluation of Gomutra Ghana. Materials and Methods: The pharmaceutical and analytical studies were carried out in Mahatma Gandhi Ayurved College Hospital and Research Centre and Dattatraya Ayurved Pharmacy, Salod (H), Wardha, Maharashtra, India. The in-vitro (antibacterial) study was carried out in JNMC, Sawangi (M), Wardha, Maharashtra, India, from April 2022 to August 2023. The in-vitro antibacterial study of cow’s urine and Gomutra Ghana was performed on five bacterial strains. Fresh cow’s urine was collected from a goshala (cowshed), and Gomutra Ghana was prepared in three batches by boiling the cow’s urine to a thicker consistency, then sun-drying it, followed by drying in an electric dryer. The final product was stored in a clean, sealed glass jars. Analytical parameters like pH, loss on drying at 105ºC, total ash, water-soluble ash, acid-insoluble ash, water-soluble extractives, alcohol-soluble extractives, and microbial contamination were studied. The in-vitro antibacterial activity was evaluated using the agar disc diffusion method at concentrations of 5 μL, 10 μL, and 15 μL, with results compared to those of a broad-spectrum and commonly used antibiotic, ciprofloxacin (5 μg). Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 27.0, employing Analysis of Variance (ANOVA) to compare three groups (Ciprofloxacin, cow’s urine, and Gomutra Ghana) at all three concentrations. A significance level was set with a p-value of <0.05 for the antibacterial study. Results: High-Performance Thin-Layer Chromatography (HPTLC) showed a peak from cow’s urine and Gomutra Ghana, with maximum heights of 500.1 and 450.4, which were nearly the same, so they may contain similar constituents. An extra peak was observed in Gomutra Ghana, suggesting the presence of additional compounds formed during its preparation. Gomutra Ghana extract showed the highest zone of inhibition against Escherichia coli. Conclusion: Gomutra Ghana showed antibacterial properties, which warrant further exploration in humans for safety and efficacy in humans.

Antimicrobial Activity of Hydrophilic Sealants incorporated with Green Synthesized Silver nanoparticles-An invitro Study

Background: Dental caries formation is highly prevented by applying pit and fissure sealant but was associated with microleakage and secondary caries formation. Aim and Objectives: To synthesize novel pit and fissure sealant with green synthesized silver nanoparticles and evaluation of antibacterial activity against Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans. Materials and Methods: Green synthesis of silver nanoparticles was done using beetroot, characterized using FTIR (Fourier transform infrared), EDAX (Energy Dispersive X-ray Analysis), and Scanned Electron Microscope Analysis. A novel pit and fissure sealant was made by incorporating synthesized Ag nanoparticles and hydrophilic nature from Ultra seal XT Hydro. Using amoxicillin as a control, an agar well diffusion method was used to conduct an antimicrobial test for a new sealant against Staphylococcus aureus, Streptococcus mutants, Enterococcus faecalis, and Candida albicans in Muller Hinton Agar for each organism. Result: Zone of inhibition was measured, showing statistically significant antimicrobial activity against Streptococcus mutans with the ZOI value at concentration of Ag nanoparticles in sealant material. Conclusion: Novel Hydrophilic pit and fissure sealant with Ag nanoparticles are potentially antibacterial against the cariogenic microorganism. Thus, it can be utilized for the better efficiency of topical pit and fissure sealant preventive therapy.

The preparation, characterization, and antibacterial activity evaluation of nanoliposomes incorporated with terebinth extract

Nanoliposomes are drug release systems that increase bioavailability and are used for encapsulation of therapeutic active ingredients. Terebinth, which is a medicinal plant that grows in many parts of Türkiye, has antibacterial, antioxidant, and anti-inflammatory activity. The antibacterial activity of nanoliposomes incorporated with ethanol extract of terebinth leaves (TLE) was investigated to determine the effects of formulation. The nanoliposome formulation was prepared in two steps which were high pressure and high intensity homogenization techniques. Characterization parameters (zeta potential, particle size and distribution, polydispersity index, and encapsulation efficiency) were determined. After third cycle of microfluidization, the zeta potential charge of nanoliposome dispersion was measured -66.6 mV and 91.13 nm in size. The PDI was 0.231. Also, the nanoliposome encapsulation efficiency was calculated as 91.90%. The TLE was encapsulated with nanoliposomes and their antibacterial activity was examined by disk diffusion and minimum inhibition concentration tests against Escherichia coli ATTC 25922 and Staphylococcus aureus ATTC 25923. Nanoliposome encapsulated TLE (NLTLE) has antibacterial activity against S. aureus ATTC 25923. While NLTLE has less active substance, it displays the same antibacterial activity as TLE.

Evaluation of secondary metabolites and antibacterial effect of Boerhavia diffusa roots with chromatographic studies

India has a vast diversity of medicinal herbs. Around 3,000 years ago, these herbs were acknowledged and used as medicinal plants helpful for treating people. New scientific research has established that some plants and herbs have presence of many active compounds and possess specific pharmacological properties.Boerhavia diffusa is one of the renowned medicinal plants used to treat large number of human ailments as mentioned in Ayurveda. The plant in whole or its peculiar parts (aerial parts and roots) have a numerous medicinal properties. It shows antibacterial, hepato-protective, antistress and also in treatment of stress, abdominal pain, inflammation and jaundice. Various phytochemical, Pharmacological, experimental and clinical investigations were done on Boerhavia diffusa by many scientists to clearly understand the ancient ayurvedic usage of punarnava. The evaluation of secondary metabolites and antibacterial activities of punarnava root extract were investigated on pathogens using the well diffusion method. HPTLC analysis of Boerhavia diffusa extracts were also carried out in different solvent.

Evaluation of Anti-bacterial Activity Induced by Penicillium mallochii in the Hemolymph of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Anti-microbial peptides (AMPs) exhibit anti-bacterial, anti-fungal and anti-parasite activity and are essential effectors for the immune response of insects. Insect hemolymph contains AMPs, which are one of the sources of antibiotics effective on drug-resistant microorganisms. This study was conducted to induce antimicrobial activity in hemolymph by topical application of different doses of Penicillium mallochii conidia and its metabolite to Ephestia kuehniella larvae. Tetracycline antibiotic disks (TE-10 µg, Sigma), Sulfametaxozole trimethoprim (SXT-25 µg, Sigma), PBS, sterile water, and non-induced hemolymphs of larvae were used as control groups. In total hemolymph induced with metabolite extract, 24-h application was determined to be more effective on test bacteria than 48-h application. The largest zone diameter was observed against Escherichia coli (20mm) in hemolymph collected 24 h after metabolite application. Antimicrobial activity was highly increased (24h and 48h) when larvae were induced with P. mallochii conidial suspension. The largest zone diameter was observed against Proteus vulgaris and Klebsiella pneumonia (20 and 24 mm) in hemolymph collected 24 h after conidial suspension application. When larvae were induced with fungus metabolite and conidia, the zone of inhibition was 1.5-2.5-fold larger than that of the control hemolymph, indicating a higher antimicrobial activity after application. In general, this study provides a novel contribution to the knowledge regarding enhancement of antimicrobial activity in response to fungal infections in larvae.

Evaluation of cytotoxicity and antibacterial activity of different pulp capping liners

This study compares the cytotoxicity and antibacterial activity of five pulp capping liners. This in vitro study was conducted on Fuji II LC glass ionomer, Dycal, Calcimol LC, TheraCal LC, and ACTIVA BioACTIVE. For cytotoxicity, the (MTT) methyl thiazolyl tetrazolium assay was performed on 3 samples from each group of human dental pulp cells (HDPSCs) after 24 h of incubation. The direct contact test (DCT) for antibacterial activity, 6 samples (3 for each material, and 3 for negative control), from each liner were made to evaluate Streptococcus mutans (S. mutans), Lactobacillus casei (L. casei), and Lactobacillus acidophilus (L. acidophilus). Data were analyzed by one-way ANOVA and Tukey’s post-hoc test (alpha = 0.05). Data analysis showed that the cytotoxicity of the materials was significantly different (p < 0.001). Fuji II LC and ACTIVA BioACTIVE showed strong cytotoxicity, TheraCal LC moderate cytotoxicity, and Dycal and Calcimol LC slight cytotoxicity. The analysis also revealed a significant difference among the materials regarding antibacterial activity (p < 0.001). Tukey’s test showed that the mean percentage of reduction in colony count was significant for all liners compared with the positive control (p < 0.001). The mean percentage of reduction in colony count for Dycal was significantly greater than that of Fuji II LC (p = 0.014), Calcimol LC (p = 0.003), and TheraCal LC (p = 0.001). ACTIVA BioACTIVE did not significantly differ from the other materials as regards antibacterial activity. Dycal showed significantly higher antibacterial activity than the other materials.

UPLC–QTOF-MS/MS analysis of saponin-enriched fractions from Calliandra umbellifera Benth and evaluation of antibacterial activity against multidrug-resistant bacteria

The genus Calliandra, rich in diterpenes, flavonoids, tannins and saponins, has several species with medicinal use. The species Calliandra umbellifera has abundant saponins in its composition, it is a glycoside that acts in defense against insects and pathogens. Due to these properties, saponins have been described to have antibacterial, antifungal, antiparasitic, anti-inflammatory and antiviral activity. Thus, the present work aimed to isolate the saponin-rich fraction of the Calliandra umbellifera species (FRSCu) and to evaluate the antibacterial activity against standard and multidrug-resistant bacterial species. The fraction was obtained from the preparation of the ethanolic extract of the species, being characterized by chromatography, using the method ultra-efficient liquid chromatography coupled to quadrupole/time of flight system (UPLC–QTOF-MS/MS). Minimum inhibitory concentration (MIC) assays were performed to verify the inhibition of bacterial growth for standard and multiresistant strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, as well as the evaluation of the activity when combined with the antibiotics: gentamicin, norfloxacin and ampicillin. The chemical analysis of FRSCu allowed the identification of the presence of phenolic compounds, flavonoids, condensed tannins and saponins. The intrinsic antibacterial activity of FRSCu did not show relevant results against the bacteria used. However, it showed promising results when combined with antibiotics, enhancing the effect of gentamicin against two gram-negative strains E. coli and P. aeruginosa and also when combined with norfloxacin against P. aeruginosa. Thus, this work presents an innovative and biotechnological potential that can contribute to future pharmaceutical formulations and knowledge about the C. umbellifera species.

Identification of isothiazolones analogues as potent bactericidal agents against antibiotic resistant CRE and MRSA strains

Carbapenem-resistant Enterobacterales (CRE) has emerged as a worldwide spread nosocomial superbug exhibiting antimicrobial resistance (AMR) to all current antibiotics, leaving limited options for treating its infection. To discovery novel antibiotics against CRE, we designed and synthesized a series of 14 isothiazol-3(2H)-one analogues subjected to antibacterial activity evaluation against Escherichia coli (E. coli) BL21 (NDM-1) and clinical strain E. coli HN88 for investigating their structure–activity relationships (SAR). The results suggested that 5-chloroisothiazolone core with an N-(4-chlorophenyl) substitution 5a was the most potent antibacterial activity against the E. coli BL21 (NDM-1) with MIC value of less than 0.032 μg/mL, which was at least 8000-fold higher than the positive control Meropenem (MRM). It also displayed 2048-fold potent than the positive control MRM against E. coli HN88. Additionally, SAR analysis supported the conclusion that compounds with a chloro-group substituted on the 5-position of the heterocyclic ring was much more potent than other positions. The board spectrum analysis suggested that compound 5a showed a promising antimicrobial activity on MRSA and CRE pathogens. Meanwhile, cytotoxicity study of compound 5a suggested that it had a therapeutic index value of 875, suggesting future therapeutic potential. In vivo efficacy study declared that compound 5a could also protect the BALB/c mice against American type culture collection (ATCC) 43,300. Further screening of our compounds against a collection of CRE strains isolated from patients indicated that compound 5 g displayed much stronger antibacterial activity compared with MRM. In conclusion, our studies indicated that isothiazolones analogues could be potent bactericidal agents against CRE and MRSA pathogens.