Minimum Inhibitory Concentration Values Research Articles

Nanocellulose-alginate composite beads for improving Ciprofloxacin bioavailability

Nanocellulose is a potential material utilized in numerous biomedical applications. However, its hydrophilic characteristic and uncontrolled encapsulated drug release hinders nanocellulose uses in oral drug administration. Thus, this work developed novel nanocellulose/alginate composite (CNC/Alg) beads for oral delivery and bioavailability enhancement of a model drug, Ciprofloxacin (CIP). CNC was green synthesized employing electrolysis process from sugarcane bagasse. CNC/Alg beads were formulated by dropwise adding CNC-Alg mixture in CaCl2 solution at room temperature. CIP was incorporated into CNC/Alg beads by adsorption technique. X-ray diffractometry and Fourier-transform infrared spectra images showed that the beads were effectively produced with high crystallinity of 75.5 %, and the typical bond of cellulose and alginate. Within 4 h of adsorption, CIP loading efficiency reached 45.27 %, with 87.2 % molecules in the zwitterionic state. The adsorption followed Elovich and pseudo-second-order models, indicating a multi-mechanism including both physical and chemical adsorptions. Importantly, in gastrointestinal tract, the beads could protect CIP from acidic stomach environment while releasing it sustainably in simulated intestinal condition (75.05 %). The beads also showed strong antibacterial activity against both Gram(−) and Gram(+) bacteria, as evidenced by low IC50 and minimum inhibitory concentration values. Finally, CNC/Alg beads could improve CIP bioavailability for effective oral drug delivery route.

Resistance to Antifungals in Non-albicans Candida Species Isolates in the Southeast Region

Background: Antimicrobial resistance is a growing problem in Candida spp., leading to treatment challenges and increased morbidity and mortality. The World Health Organization (WHO) fungal priority pathogens list classifies C. glabrata, C. tropicalis, and C. parapsilosis as high priority and leading causes of candidemia with high fluconazole resistance. In the US, these organisms are the most frequently isolated non-albicans Candida species. In 2016, the Antibiotic Resistance Laboratory Network (ARLN) was created to monitor resistance threats, including in Candida spp. This study describes the proportion of resistance in C. glabrata, C. parapsilosis, and C. tropicalis isolates sent to the Southeast ARLN from 2017 to 2023. Methods: This study evaluated C. glabrata, C. parapsilosis, and C. tropicalis submitted to the Southeast ARLN from Alabama, Florida, Georgia, Louisiana, Mississippi, and Tennessee from February 2017- September 2023. Species identification was confirmed by Bruker Biotyper matrix assisted laser desorption-ionization time of flight (MALDI-TOF). Antifungal susceptibility testing (AFST) was performed using TREK frozen broth microdilution panels. Minimum inhibitory concentration values from the clinical instrument were used to determine susceptibility based on Clinical and Laboratory Standards Institute (CLSI) standard interpretations from the 2020 CLSI M60 guidelines. Data were extracted from the laboratory information management system. Analyses were conducted using SAS v9.4. Results: AFST testing was performed on 660 C. glabrata, 500 C. parapsilosis, and 233 C. tropicalis isolates from within the Southeast region. The predominant specimen sources by species were blood 25.30% C. glabrata; other/not specified 27.80% C. parapsilosis; and lower respiratory 36.91% C. tropicalis. Resistance to fluconazole is as follows: C. glabrata, 12.88%; C. parapsilosis, 3.41%; C. tropicalis, 36.64%. Resistance to voriconazole is as follows: C. parapsilosis, 1.00%; C. tropicalis 30.04%. Resistance to at least one echinocandin (Anidulafungin, Capsofungin, Micafungin) is as follows: C. glabrata, 1.67%; C. parapsilosis, 0.60%; C. tropicalis, 0.43%. Overall, there was a decreasing trend in resistance to fluconazole, and voriconazole in all three species between 2017 and 2023. Conclusions: Antifungal resistance in non-albicans Candida species represents an emerging public health threat, however, within the Southeast region, ARLN data has shown a decreasing trend of azole resistance. This may be due in part to changes in reporting requirements and submission criteria from within the region. Nevertheless, C. tropicalis showed high resistance to azoles within the Southeast region. These Candida species should be monitored to inform clinical decision making and identify resistance patterns in other US regions due to their increase in resistance worldwide.

Antibacterial Properties of Fucoidan from Thirteen Indian Brown Seaweeds against Various Pathogenic Bacteria

The present study aimed to evaluate the antibacterial properties of hot water extracted fucoidan from thirteen Indian brown seaweeds against various pathogenic bacteria. The agar-well diffusion method was used to assess the antibacterial test of different fucoidan. The results revealed that S. vulgare fucoidan had higher antibacterial activity against many pathogenic bacteria, while fucoidan from other brown seaweeds had the least or no antibacterial activity in comparison to S. vulgare fucoidan. Therefore, we evaluated the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and brine shrimp toxicity assay in S. vulgare fucoidan. The MIC and MBC values were found to be 1.25 mg/mL and 10 mg/mL in S. vulgare fucoidan against pathogenic bacteria. S. vulgare fucoidan were found to be nontoxic as no mortality (Artemia) was found at different fucoidan concentrations. In addition, characterizations such as ultraviolet-visible spectroscopy, fourier-transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy were studied in Sargassum vulgare fucoidan and revealed the properties of fucoidan. This study revealed that hot water extracted fucoidan may have other biological activities but not antibacterial action. Furthermore, studies may reveal the mode of action in fucoidan.

Total synthesis and antibacterial evaluation of nicrophorusamides A and B

This paper reports the total synthesis of antibacterial cyclic hexapeptides nicrophorusamides A (1) and B (2), isolated from the actinomycete strain UTG9 belonging to the genus Microbacterium. The synthesis involved solid-phase peptide elongation and solution-phase macrolactamization, followed by the removal of the protecting groups. Synthetic 1 and 2 demonstrated inhibitory effects on the growth of S. aureus, with minimum inhibitory concentration (MIC) values of 8 μg/mL and 16 μg/mL, respectively, determined using the broth microdilution method.

Synthesis and characterization of Azo-Azomethine derivatives bearing thiazole moiety: In vitro antimicrobial, in vitro and in vivo anti-inflammatory, and cytotoxicity assessment, accompanied by computational molecular docking, RDG, ELF, DFT, and MEP analysis

In this study, a novel series of Azo-azomethine derivatives incorporating thiazole moieties (5a-h) were synthesized and thoroughly characterized using NMR (1H and 13C), FT-IR spectroscopy, and ESI-MS methods. The synthesized compounds underwent screening for their antimicrobial, anti-inflammatory (both in vitro and in vivo), and cytotoxic activities. Notably, compound 5d exhibited significant activity against S. aureus and S. epidermidis, with minimum inhibitory concentration (MIC) values as low as 20 μg/L. Additionally, compound 5d demonstrated the most potent anti-inflammatory activity both in vitro (84.72%) and in vivo. Furthermore, molecular analyses including RDG, ELF, DFT, and MEP were conducted to investigate molecular interactions, electron distribution, electronic configuration, and electrostatic potential, thus facilitating a deeper understanding of the molecular characteristics and aiding in the refinement and design of these molecules. Moreover, the compounds' efficacy against bacterial proteins was assessed through molecular docking calculations. Utilizing the PASS and pkCSM platforms, an examination of the compounds' bioactivity regulation and physicochemical attributes was conducted, highlighting their potential as prospective novel active agents.

Synthesis of Silver Nanoparticles Using Azadirachta indica and Syzygium aromaticum Extract and Its Antibacterial Action Against Enterococcus faecalis: An In Vitro Study.

Introduction Nanotechnology is the study of manipulating matter at the atomic scale involving particles smaller than 100 nm. Silver nanoparticles (AgNPs) are gaining popularity across diverse sectors including medical, food, healthcare, consumer goods, and industrial fields due to their distinctive physical and chemical characteristics. The eco-friendly synthesis of AgNPs offers a straightforward, cost-effective, and environmentally benign method devoid of hazardous chemicals. Methodology Eighty milliliters (mL) of silver nitrate mixed with 20 mL of Azadirachta indica and Syzygium aromaticum plant extract underwent two days of magnetic stirring for AgNP synthesis. Characterization was done via ultraviolet-visible (UV-vis)-spectroscopy (300-700 nm), and antimicrobial properties, which were checked with Enterococcus faecalis, were assessed using the agar-well diffusion method. Results The change in color and peak observed in the UV-vis spectrum confirmed the successful synthesis of AgNPs. Both neem and clove extract-mediated synthesis of AgNPs exhibited antibacterial activity against E. faecalis. However, neem extract synthesized AgNPs displayed a larger inhibitory zone diameter and lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values compared to those synthesized using clove extract. Conclusion Incorporating neem and clove extracts in AgNP synthesis offers a practical, eco-friendly, and cost-efficient method with notable efficacy. These AgNPs exhibit antibacterial activity against E. faecalis, suggesting their viability as potent antibacterial agents for addressing oral pathogens. Their sustainable synthesis underscores a promising avenue for developing effective antimicrobial solutions in oral healthcare.

Phytochemical screening and antibacterial properties of Sungkai (Peronema canescens Jack.) leaf extract and fraction

Abstract Sungkai (Peronema canescens Jack.) is a natural ingredient used as a traditional treatment for diarrhea, fever, toothache, mouthwash, and antiseptics. The objective of the study was to assess the antibacterial properties of Sungkai leaf extracts and fractions against pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella thypimurium) and to identify chemical compounds with antibacterial properties. The investigation starts with extraction and then continues with liquid-liquid fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water as solvents. Extracts and various fractions of Sungkai leaf were analyzed using phytochemical screening. The antibacterial property assay used the microdilution and paper disc method. The active component of the extract or fraction was determined by Gas Chromatography-Mass Spectrometry (GC-MS). The phytochemical screening results indicated that the ethanol extract included flavonoids, alkaloids, and steroids. Both the n-hexane fraction and chloroform fraction consist of alkaloid and steroid compounds. The ethyl acetate fraction contains phenolic compounds, while the n-butanol and water fractions contain flavonoid compounds. The microdilution method revealed that the chloroform fraction had the highest performance, with a Minimum Inhibitory Concentration (MIC) value of 1000 µg/ml against Pseudomonas aeruginosa. However, the paper disc approach demonstrated that both the extract and the fraction did not produce an inhibitory zone against the four tested bacteria. The GC-MS analysis identified 17-Octadecynoic acid in the chloroform fraction as the most effective chemical compound against Pseudomonas aeruginosa. The chloroform fraction of Sungkai leaf contains active compounds that have the potential for antibacterial activity.

Anti-fouling poly(lactic)acid membrane incorporating titanium dioxide‐coated biochar composites for the separation of lipopeptides from Bacillus subtilis fermentation broth

This study focuses on developing anti-fouling membranes composed of poly(lactic)acid (PLA) incorporating titanium dioxide-coated biochar composites, aiming to separate the lipopeptide biosurfactants from clarified Bacillus subtilis fermentation broth efficiently. The surface area of the Ti-biochar composites, incorporated into the PLA membrane, was measured as 191.69 m2/g and the water contact angle of the optimal PLA/Ti-biochar membrane was determined to be 62.3°, indicating its hydrophilic nature. The PLA membrane's pure water flux, containing 1 wt % Ti-biochar was 174.61±0.5 L m–2h–1 with the water content of 86.73±0.8 %, and porosity of 44.72±0.3 %. Then, Bacillus subtilis lipopeptides were separated by the optimal PLA/Ti-biochar membrane, and their characteristics were compared to the crude sample. Additionally, the purified lipopeptides demonstrated enhanced antimicrobial properties, with a significantly lower minimum inhibitory concentration (MIC) of 1.7±0.52 µg/ml against Staphylococcus aureus and 1.5±0.24 µg/ml against Fusarium oxysporum, compared to the crude lipopeptides, which had MIC values of 5.5±0.26 µg/ml and 4.2 ±0.45 µg/ml, respectively. The purified lipopeptides were confirmed by high-performance liquid chromatography and mass spectrometry. These results underscore the antifouling characteristics of the fabricated PLA/Ti-biochar membrane, positioning it as a promising candidate for the separation of biological molecules.

Antibacterial potential of extracts and metabolites isolated from the endophytic fungus Chaetomium cochliodes against phytopathogenic bacteria

Summary Five fungal endophytes, Alternaria sp., Aspergillus sp., Chaetomium sp., Rhizopus sp. and Curvularia sp., were isolated from an Egyptian herbaceous plant, Tribulus terrestris, and tested for their antibacterial activity against three phytopathogenic bacteria (Pectobacterium carotovorum subsp. carotovorum, Ralstonia solanacearum, Pseudomonas syringae pv. syringae). Chaetomium sp. showed the highest antibacterial activity. This strain was identified morphologically and molecularly as Chaetomium cochliodes MS03 (MW898133) based on the ITS1-5.8S rRNA-ITS2 genomic region. Chaetomium cochliodes caused 15 and 8 mm inhibition zones of P. carotovorum subsp. carotovorum and R. solanacearum, respectively. Chaetomium cochliodes isolate was fermented and extracted with ethyl acetate. The crude extract of C. cochliodes showed strong antibacterial activity against P. carotovorum subsp. carotovorum (inhibition zone = 27 mm). Bioassay guided isolation of the crude extract using silica gel column chromatography was conducted to isolate bioactive secondary metabolites. Minimum inhibitory concentrations (MICs) were 500, 32 and 4 mg/L for C. cochliodes extract, fraction 14 and fraction 15, respectively, against P. carotovorum subsp. carotovorum. Bioactive fractions were analyzed by GC/MS. The bioactive pure compound was identified as 9,12-octadecadienoic acid (Z,Z) and the chemical structure was confirmed by H1 NMR and C13 NMR spectral analysis. The isolated compound showed a promising antibacterial activity against P. carotovorum subsp. carotovorum with MIC value of 32 mg/L.

Antifungal Properties of Dracaena cinnabari Resin Extracts Against Candida albicans

Background: Candida albicans is the most prevalent fungal pathogen in humans, capable of causing a range of clinical infections from mucocutaneous conditions like oral thrush to life-threatening systemic diseases. While Candida species are typically part of the normal oral flora in about 75% of the global population, the rising resistance to antifungal drugs has become a significant concern. This highlights the urgent need to explore alternative antimicrobial agents, including natural phytochemicals derived from plants, as potential substitutes for synthetic chemicals to address the growing issue of antifungal resistance. Methods: This study aimed to evaluate the antifungal properties of Dracaena cinnabari resin extracts (methanol and water) against Candida albicans. The antifungal activity was assessed using the direct contact agar diffusion test, while the minimal inhibitory concentration (MIC) of the extracts was determined through the broth dilution method. Results: The antifungal susceptibility tests demonstrated that C. albicans was susceptible to both methanol and water extracts of D. cinnabari resin, with zones of inhibition measuring 32.2 ± 0.8 mm and 29.0 ± 1.1 mm, respectively. The MIC values ranged between 2.50 and 5.00 mg/mL for both extracts. Conclusion: The antifungal effectiveness of D. cinnabari resin extracts was comparable to that of the miconazole control, showing significant potential as a natural treatment option against Candida albicans. These findings suggest that Dracaena cinnabari resin could play a valuable role in the treatment and management of candidiasis, particularly oral candidiasis.

Zn(II) and Cu(II) Coordination Enhances the Antimicrobial Activity of Piscidin 3, but Not That of Piscidins 1 and 2.

Piscidins, antimicrobial peptides isolated from fish, are potent against a variety of human pathogens; they show minimum inhibitory concentration values comparable to those of commercially used antimicrobials. Piscidins 1 and 2 are generally more effective than piscidin 3 when applied alone; the contrary is observed for their metal complexes: Zn(II) and Cu(II) coordination does not enhance the efficacy of piscidins 1 and 2, while a moderate enhancement is observed for piscidin 3. All three piscidins bind Cu(II) in a so-called albumin-like binding mode, while for Zn(II) complexes, two coordination modes are observed: piscidins 1 and 2 bind Zn(II) by imidazole nitrogens from His4, His11, and His17 side chains; piscidin 3 coordinates Zn(II) by His3, His4, and His11 imidazole nitrogens and additionally supports the interaction, formed by carbonyl oxygen from His4. Most likely, the high antimicrobial activity of piscidin complexes is due to neither the stability of their complexes nor the change in their secondary structure. Copper(II) complexes with piscidins 1 and 2 can form hydroxyl radicals, which could be responsible for the antimicrobial membrane damaging activity of these complexes. Clearly, a different mechanism (most likely an intercellular targeted one) is observed for piscidin 3 metal complexes; in most cases, the coordination of Cu(II) and Zn(II) enhances the antimicrobial potency of piscidin 3, showing that not only piscidin 3 alone but also its metal complexes have a different mode of action than piscidins 1 and 2.

Effectiveness of Citronella Extract (Cymbopogon nardus) Mouthwash From Microwave-Assisted Extraction Method Against Streptococcus mutans

Cymbopogon nardus, or citronella has a distinctive aroma is known as a source of essential oils. Extract of citronella can be use as mouthwash to reduce bad breath and protect teeth from bacteria that cause dental caries. C. nardus contains antibacterial compounds such as flavonoid, essential oils, polyphenols, and saponin which are also act as antioxidant compounds. This research was carried out to formulate mouthwash using citronella extract and determine the antibacterial activity of the citronella mouthwash against S. mutans bacteria using disc diffusion method. The microwave extraction method (MAE) was used to obtain extract using 70 % and 96 % ethanol as a solvents. The mouthwash were made in 3 formulas i.e. formula 1, formula 2, and formula 3 each contain 25 % w/v, 30 % w/v, and 35 % w/v) respectively. The quality of mouthwash includes organoleptic, pH, viscosity and hedonic was evaluated and antibacterial activity was determined by measuring the value of minimum inhibitory concentration (MIC) and diameter of inhibition zone. The MIC value of citronella extract was achieved at concentration 20 %. All mouthwash formula met the requirements for a good mouthwash. Formula 1 was the most preferred formula by the panelists based on the hedonic test. Formula 3 had the strongest antibacterial activity with diameter inhibitory of 17.6 ± 0.52 mm. It was concluded that citronella mothwash has the potential to be developed into an antibacterial mouthwash.

Chemical Profiling of Drimys granadensis (Winteraceae) Essential Oil, and Their Antimicrobial, Antioxidant, and Anticholinesterase Properties.

A complete and comprehensive chemical and biological study of Drimys granadensis, a native Ecuadorian aromatic plant, was conducted. By conventional steam distillation from dried leaves, a yellowish, translucent essential oil (EO) with a density of 0.95 and a refractive index of 1.5090 was obtained. The EO was analyzed by gas chromatography coupled to a mass spectrometer (GC/MS) and an FID detector (GC/FID), respectively. Enantiomeric distribution was also carried out by GC/MS using a chiral selective column (diethyl tert-butylsilyl-BETA-cyclodextrin). The microdilution broth method was employed to assess the antibacterial and antifungal activity of the EO against a panel of opportunistic microorganisms. Antioxidant capacity was measured using diphenyl picryl hydrazyl (DPPH) and azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Finally, the inhibitory potential of the EO against acetylcholinesterase was also valued. Sixty-four chemical compounds, constituting 93.27% of the total composition, were identified, with major components including γ-muurolene (10.63%), spathulenol (10.13%), sabinene (5.52%), and δ-cadinene (4.22%). The characteristic taxonomic marker of the Drimys genus, Drimenol, was detected at very low percentages (<2%). Two pairs of enantiomers ((1S,5R)-(+)-α-pinene/(1S,5S)-(-)-α-pinene; (1S,5R)-(+)-β-pinene/(1S,5S)-(-)-β-pinene) and one pure enantiomer (1R,4S)-(-)-camphene were identified. Regarding antimicrobial potency, the EO exhibited a significant moderate effect on Listeria monocytogenes with a minimal inhibitory concentration (MIC) value of 250 µg/mL, while with the remaining microorganisms, it exerted less potency, ranging from 500 to 2000 µg/mL. The EO displayed moderate effects against the ABTS radical with a half scavenging capacity of 210.48 µg/mL and no effect against the DPPH radical. The most notable effect was noticed for acetylcholinesterase, with a half inhibition concentration (IC50) of 63.88 ± 1.03 µg/mL. These antiradical and anticholinesterase effects hint at potential pharmacological applications in Alzheimer's disease treatment, although the presence of safrole, albeit in low content (ca. 2%), could limit this opportunity. Further in vivo studies are necessary to fully understand their potential applications.

Potensi Antimikroba dan Antioksidan Beberapa Ekstrak Daun Benalu (Scurrula ferruginea (Roxb. ex Jack) Danser dari Archidendron sp. terhadap Staphylococcus aureus, Escherichia coli, dan Candida albicans

Scurrula ferruginea (Roxb. ex Jack) Danser is known for its role as an antimicrobial and antioxidant agent due to its content of phenolic compounds, alkaloids, and terpenoids. S. ferruginea has been widely used in traditional medicine for skin infections, diarrhea, hypertension, and digestive tract diseases. This study aims to determine the antimicrobial and antioxidant potential of various treatments of S. ferruginea mistletoe extracts. The experimental method used in this research is the nested pattern experiment. The extract treatments applied include fresh extract, boiled dry extract, boiled fresh extract, brewed dry extract, and brewed fresh extract. Antimicrobial potential was assessed using disc diffusion and dilution methods. Antioxidant activity (IC50) was determined using the DPPH (1,1-Diphenyl-2-Picryl-Hydrazine) method, and Total Phenolic Content (TPC) was also determined. The results indicate that the highest antimicrobial activity against Escherichia coli and Staphylococcus aureus was found in the strong category of fresh extract treatment, whereas there was no significant effect on Candida albicans growth. The fresh extract treatment exhibited the highest antimicrobial activity with a total phenolic content of 20.77321 mgGAE/mL. The Minimum Inhibitory Concentration (MIC) values for the fresh extract against S. aureus and E. coli were 6.25%, and the Minimum Bactericidal Concentration (MBC) values were 12.5% against both bacteria. The antioxidant value of the fresh extract was 101.26 μg/mL, categorized as moderate. Based on the conducted research, it can be concluded that S. ferruginea leaf extract can inhibit the activities of S. aureus and E. coli, while showing no effect on Candida albicans growth.

In-vitro Antibacterial Activity of Crude Extracts of Annona senegalensis Against Selected Bacteria Associated with Urinary Tract Infections

The study assessed the antibacterial activity of aqueous, ethyl acetate and methanol extracts of leaves, bark, and roots of A. senegalensis against selected bacteria associated with urinary tract infections (UTIs). The extracts of A. senegalensis were obtained by soxhlet extraction method. Qualitative phytochemical screening of the extracts was carried out using standard procedures. The bacteria tested were Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from urine samples of UTI patients. Antimicrobial susceptibility testing was carried out using the agar well diffusion method, while minimum inhibitory concentration (MIC) was determined by broth dilution method using two-fold serial dilutions. The qualitative phytochemical analysis showed the presence of phenols, tannins, terpenoids, flavonoids, steroids, saponins, and cardiac glycosides. Zones of inhibition of extracts ranged between 16.33±0.58 – 24.67±0.58 mm (leaf extracts), 14.00±1.00 – 21.33 ±0.58 mm (bark extracts) and 14.67±0.58 – 21.00±1.00 mm (root extracts). The higest zone of inhibition (24.67±0.58 mm) observed was against Pseudomonas aeruginosa with aqueous leaf extract, while the least inhibition (14.00±1.00 mm) was with ethyl acetate bark extract, also against Pseudomonas aeruginosa. MIC values ranged from 25 – 100 mg/mL, while MBC values were from 50 – 200 mg/mL against the test isolates. A. senegalensis demonstrated great antibacterial potential, and can be recommended for the treatment of UTIs.

Evaluation of Phytochemical Constituents and Antimicrobial Activity of Calotropis procera Root Extract against some Pathogenic Microorganisms in Yola, Adamawa State, Nigeria

Study’s Novelty/Excerpt This study evaluates the antimicrobial potential of Calotropis procera root extracts, traditionally used in Nigerian medicine, by scientifically validating their therapeutic properties. The research identified various phytochemical constituents, including tannin, saponin, alkaloids, phenolics, flavonoids, and reducing sugars, with terpenoids uniquely present in the aqueous extract. The significant antimicrobial activity observed, particularly with the chloroform extract showing the largest inhibition zone against Staphylococcus aureus, underscores the potential of C. procera roots as a rich source of bioactive compounds for developing alternative treatments for infectious diseases. Full Abstract Calotropis procera has been traditionally used for medicinal purposes in Nigeria, with various parts of the plant utilized by traditional healers without scientific validation of their therapeutic properties. Therefore, this study sought to assess the phytochemical constituents and antimicrobial efficacy of root extracts from C. procera against pathogenic microorganisms. The extraction of C. procera roots was carried out using aqueous, chloroform, and n-hexane solvents, and the qualitative analysis of the phytochemical constituents was conducted following standard procedures. The antimicrobial activity of the extracts was evaluated against Staphylococcus aureus, Salmonella typhi, Klebsiella pneumoniae, Candida albicans, and Aspergillus flavus through the agar well diffusion method. Phytochemical screening identified the presence of tannin, saponin, alkaloids, phenolics, flavonoids, and reducing sugars in all extracts, with terpenoids exclusively found in the aqueous extract and cardiac glycosides absent in all extracts. The extracts demonstrated significant antimicrobial activity against all tested pathogens, with the chloroform extract exhibiting the largest inhibition zone (23.50±0.38 mm) against S. aureus, while the n-hexane extract displayed the smallest inhibition zone (6.38±0.52 mm) against A. flavus. Minimum inhibitory concentration (MIC) values were determined as 25 mg/ml for the chloroform extract against S. aureus and S. typhi, and 50 mg/ml for both aqueous and n-hexane extracts against K. pneumoniae and C. albicans. The minimum bactericidal concentration (MBC) was established at 100 mg/ml for S. aureus, S. typhi, and all extracts. The root extracts of C. procera exhibited promising antimicrobial effects against S. aureus and S. typhi, indicating its potential as a rich source of bioactive compounds and a viable alternative to antibiotics for treating infectious diseases.

Surface modification of polyacrylonitrile nanofiber membrane by Bimetallic organic frameworks for enhanced antibacterial properties

With the increasing environmental degradation, bacterial contamination is threatening human health. Thus, it is crucial to develop an efficient and safe antimicrobial strategy. In this work, the polyacrylonitrile (PAN) nanofiber membranes contained Co/Zn-metal organic framework (Co/Zn-MOF@PAN) were fabricated via electrospinning technique and surface modified method. The optimal preparation condition for nanofiber membranes were further regulated by adjusting 2-methylimidazole (2-MIM) concentration and secondary growth time. The antibacterial activity of Co/Zn-MOF@PAN against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were determined by turbidimetry and plate colony-counting methods. As the 2-MIM concentration and secondary growth time increased, the hydrophilicity and surface roughness of Co/Zn-MOF@PAN nanofiber membranes increased. In addition, when the 2-MIM concentration was 0.16 mol/L, the Co/Zn-MOF@PAN nanofiber membranes had an antibacterial rate of over 99% against E. coli and S. aureus., and the minimum inhibitory concentration (MIC) value of Co/Zn-MOF@PAN nanofiber membranes was 0.75 mg/mL. It could be indicated that Co/Zn-MOF@PAN nanofiber membranes exhibited an excellent antibacterial effect. The main antibacterial mechanism of nanofiber membranes was that ROS produced by MOFs could destroy the physiological activities of the bacteria lead to death. The Co/Zn-MOF@PAN nanofiber membranes will have a wide range of applications value in the fields of antibacterial packaging materials and sterilization of water resources.

Exploring treatment and antifungal resistance in an outbreak of tinea caused by Microsporum audouinii

AbstractBackgroundMicrosporum audouinii has resurged recently. Infections with the dermatophyte are difficult to treat, which raises the question if we treat M. audouinii infections with the most effective antifungal (AF) agent.ObjectivesThe aims of this study was to investigate an outbreak of tinea capitis (TC) in Denmark, address the challenges in outbreak management and to conduct two reviews regarding previous outbreaks and minimal inhibitory concentration (MIC).MethodsWe used Wood's light, culture, direct microscopy, and PCR for screening and antifungal susceptibility testing (AFST) for treatment optimization. We performed two reviews to explore M. audouinii outbreaks and MIC values using broth microdilution method.ResultsOf 73 screened individuals, 10 had confirmed M. audouinii infections. Clinical resistance to griseofulvin was observed in 4 (66%) cases. While previous outbreaks showed high griseofulvin efficacy, our study favoured terbinafine, fluconazole and itraconazole in our hard‐to‐treat cases. AFST guided the choice of AF. Through the literature search, we identified five M. audouinii outbreaks, where differences in management included the use of Wood's light and prophylactic topical AF therapy. Terbinafine MIC values from the literature ranged from 0.002 to 0.125 mg/L.ConclusionUse of Wood's light and preventive measurements were important for limiting infection. The literature lacked MIC data for griseofulvin against M. audouinii, but indicated sensitivity for terbinafine. The clinical efficacy for M. audouinii treatment was contradictory favouring both terbinafine and griseofulvin. AFST could have a key role in the treatment of difficult cases, but lack of standardisation of AFST and MIC breakpoints limits its usefulness.

Effect and mechanism of Qingre Huashi decoction on drug-resistant Helicobacter pylori.

Helicobacter pylori (HP), the most common pathogenic microorganism in the stomach, can induce inflammatory reactions in the gastric mucosa, causing chronic gastritis and even gastric cancer. HP infection affects over 4.4 billion people globally, with a worldwide infection rate of up to 50%. The multidrug resistance of HP poses a serious challenge to eradication. It has been de-monstrated that compared to bismuth quadruple therapy, Qingre Huashi decoction (QHD) combined with triple therapy exhibits comparable eradication rates but with a lower incidence of adverse reactions; in addition, QHD can directly inhibit and kill HP in vitro. To explore the effect and mechanism of QHD on clinically multidrug-resistant and strong biofilm-forming HP. In this study, 12 HP strains were isolated in vitro after biopsy during gastroscopy of HP-infected patients. In vitro, the minimum inhibitory concentration (MIC) values for clinical HP strains and biofilm quantification were determined through the E-test method and crystal violet staining, respectively. The most robust biofilm-forming strain of HP was selected, and QHD was evaluated for its inhibitory and bactericidal effects on the strain with strong biofilm formation. This assessment was performed using agar dilution, E-test, killing dynamics, and transmission electron microscopy (TEM). The study also explored the impact of QHD on antibiotic resistance in these HP strains with strong biofilm formation. Crystalline violet method, scanning electron microscopy, laser confocal scanning microscopy, and (p)ppGpp chromatographic identification were employed to evaluate the effect of QHD on biofilm in strong biofilm-forming HP strains. The effect of QHD on biofilm and efflux pump-related gene expression was evaluated by quantitative polymerase chain reaction. Non-targeted metabolomics with UHPLC-MS/MS was used to identify potential metabolic pathways and biomarkers which were different between the NC and QHD groups. HP could form biofilms of different degrees in vitro, and the intensity of formation was associated with the drug resistance of the strain. QHD had strong bacteriostatic and bactericidal effects on HP, with MICs of 32-64 mg/mL. QHD could inhibit the biofilm formation of the strong biofilm-forming HP strains, disrupt the biofilm structure, lower the accumulation of (p)ppGpp, decrease the expression of biofilm-related genes including LuxS, Spot, glup (HP1174), NapA, and CagE, and reduce the expression of efflux pump-related genes such as HP0605, HP0971, HP1327, and HP1489. Based on metabolomic analysis, QHD induced oxidative stress in HP, enhanced metabolism, and potentially inhibited relevant signaling pathways by upregulating adenosine monophosphate (AMP), thereby affecting HP growth, metabolism, and protein synthesis. QHD exerts bacteriostatic and bactericidal effects on HP, and reduces HP drug resistance by inhibiting HP biofilm formation, destroying its biofilm structure, inhibiting the expression of biofilm-related genes and efflux pump-related genes, enhancing HP metabolism, and activating AMP in HP.

Antibacterial Activity of Calcium Hydroxide and Zinc Oxide Combined with Several Solutions against Enterococcus faecalis Growth

Abstract Objective This study aims to compare the antimicrobial activity of calcium hydroxide (CaOH) and zinc oxide (ZnO) when incorporated with other solutions such as 2% chlorhexidine (CHX), 2.5% sodium hypochlorite (NaOCl), 1% povidone-iodine (PVP-I), and sterilized distilled water (ddH2O) against Enterococcus faecalis. Materials and Methods The materials were prepared by mixing CaOH and ZnO with other solutions (CHX, PVP-I, NaOCl, and ddH2O) separately. The antibacterial activity of CaOH and ZnO mixtures against E. faecalis was done by using disk diffusion assay (DDA). Twofold serial dilutions of the mixtures were used against E. faecalis to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Biofilm inhibition of E. faecalis had been measured by using crystal violet assay. Statistical Analysis The quantitative data of this study had been analyzed by using two-way analysis of variance with software SPSS version 27. The result is considered as significant if the value of analysis is p-value less than 0.05. Results From the DDA results, the lowest zone of inhibition toward E. faecalis was CaOH-PVP-I (6.00 ± 0.00 mm), while the highest zone of inhibition toward E. faecalis was CaOH-CHX (22.73 ± 0.02 mm). Besides that, ZnO-PVP-I showed the lowest zone of inhibition (16.50 ± 0.06 mm), while ZnO-CHX showed the highest zone of inhibition (18.30 ± 0.08 mm) against E. faecalis. The MIC and MBC values of CaOH-CHX and ZnO-CHX were 0.78 and 6.25 mg/mL, respectively. In biofilm assay, CaOH-CHX and ZnO-CHX were reduced biofilm formation of E. Faecalis. Conclusion Both CaOH-CHX and ZnO-CHX showed the highest antimicrobial activities toward E. faecalis. CaOH and ZnO alone showed no antimicrobial activities against E. faecalis.