Minimum Inhibitory Concentration Values Research Articles

Efficacy of Zoliflodacin, a Spiropyrimidinetrione Antibiotic, Against Gram-Negative Pathogens.

Zoliflodacin is a spiropyrimidinetrione antibiotic that acts by binding to the GyrB part of the DNA gyrase enzyme in bacteria. Its effectiveness for the treatment of Neisseria gonorrhoeae infections has been investigated extensively. Since antibiotic resistance has been reached an alarming rate worldwide, researches on new antimicrobials are considered a priority, especially in the treatment of multidrug-resistant Gram-negative bacteria, such as Klebsiella pneumonia. The aim of this study is to test and compare the effectiveness of zoliflodacin with some traditional antibiotics which are frequently preferred in the treatment of Gram-negative pathogens, primarily K. pneumonia. Additionally, its ability to prevent biofilm formation has also been determined. The minimum inhibitory concentration (MIC) values of zoliflodacin along with levofloxacin, meropenem, gentamicin, ampicillin/sulbactam and ceftazidime/avibactam were evaluated by broth microdilution method against 15 Gram-negative clinical isolates and three standard strains. Also, the synergism potential of zoliflodacin with other antibiotics was evaluated by the checkerboard method against standard strains of K. pneumonia, Pseudomonas aeruginosa, and Acinetobacter baumannii. In addition, the inhibitory effects of zoliflodacin on biofilm formation of standard strains were determined. Zoliflodacin MICs were found to be in the range of 2-64µg/mL, and its combination with meropenem and ampicillin/sulbactam was found to be synergistic, especially against A. baumannii. Zoliflodacin significantly inhibited A. baumannii biofilm at sub-MIC values. These results indicated that zoliflodacin can be considered as an alternative against infections of Gram-negative pathogens, alone or in combination.

Fighting Emerging Caspofungin-Resistant Candida Species: Mitigating Fks1-Mediated Resistance and Enhancing Caspofungin Efficacy by Chitosan.

Invasive candidiasis poses a worldwide threat because of the rising prevalence of antifungal resistance, resulting in higher rates of morbidity and mortality. Additionally, Candida species, which are opportunistic infections, have significant medical and economic consequences for immunocompromised individuals. This study explores the antifungal potential of chitosan to mitigate caspofungin resistance in caspofungin-resistant Candida albicans, C. krusei, and C. tropicalis isolates originating from human and animal sources using agar well diffusion, broth microdilution tests, and transmission electron microscope (TEM) analysis of treated Candida cells. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was performed to assess the expression of SAGA complex genes (GCN5 and ADA2) and the caspofungin resistance gene (FKS) in Candida species isolates after chitosan treatment. The highest resistance rate was observed to ketoconazole (80%) followed by clotrimazole (62.7%), fluconazole (60%), terbinafine (58%), itraconazole (57%), miconazole (54.2%), amphotericin B (51.4%), voriconazole (34.28%), and caspofungin (25.7%). Nine unique FKS mutations were detected, including S645P (n = 3 isolates), S645F, L644F, S645Y, L688M, E663G, and F641S (one isolate in each). The caspofungin minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values before chitosan treatment ranged from 2 to 8 µg/mL and 4 to 16 µg/mL, respectively. However, the MIC and MFC values were decreased after chitosan treatment (0.0625-1 µg/mL) and (0.125-2 µg/mL), respectively. Caspofungin MIC was significantly decreased (p = 0.0007) threefold following chitosan treatment compared with the MIC values before treatment. TEM analysis revealed that 0.5% chitosan disrupted the integrity of the cell surface, causing irregular morphologies and obvious aberrant changes in cell wall thickness in caspofungin-resistant and sensitive Candida isolates. The cell wall thickness of untreated isolates was 0.145 μm in caspofungin-resistant isolate and 0.125 μm in sensitive isolate, while it was significantly lower in chitosan-treated isolates, ranging from 0.05 to 0.08 μm when compared with the cell wall thickness of sensitive isolate (0.03 to 0.06 μm). Moreover, RT-qPCR demonstrated a significant (p < 0.05) decrease in the expression levels of histone acetyltransferase genes (GCN5 and ADA2) and FKS gene of caspofungin-resistant Candida species isolates treated with 0.5% chitosan when compared with before treatment (fold change values ranged from 0.001 to 0.0473 for GCN5, 1.028 to 4.856 for ADA2, and 2.713 to 12.38 for FKS gene). A comparison of the expression levels of cell wall-related genes (ADA2 and GCN5) between caspofungin-resistant and -sensitive isolates demonstrated a significant decrease following chitosan treatment (p < 0.001). The antifungal potential of chitosan enhances the efficacy of caspofungin against various caspofungin-resistant Candida species isolates and prevents the development of further antifungal resistance. The results of this study contribute to the progress in repurposing caspofungin and inform a development strategy to enhance its efficacy, appropriate antifungal activity against Candida species, and mitigate resistance. Consequently, chitosan could be used in combination with caspofungin for the treatment of candidiasis.

Synergistic and potential antifungal properties of tailored, one pot multicomponent monoterpenes co-delivered with fluconazole encapsulated nanostructure lipid carrier

Frequent and variant infections are caused by the virtue of opportunistic fungi pathogens. Candidiasis, aspergillosis, and mucormycosis are pathogenic microorganisms that give rise to vast fungal diseases that alternate between moderate to fatal in severity. The use of fluconazole as an antifungal drug was limited due to the acquired resistance in some types of Candida and other fungal species. This study aims to consolidate fluconazole’s biological effectiveness against several pathogenic fungi. Six active monoterpenes (MTs) of carvacrol, linalool, geraniol, α-terpinene, citronellal, and nerolidol were selected and encapsulated in nanostructure lipid carrier (NLC) with (NLC-Flu-MTs) and/without (NLC-MTs) fluconazole in one nanoformulation to determine if they will act synergistically or not? The synthesized nanoformulation NLC-Flu-MTs and NLC-MTs exhibited very good particle size of 144.5 nm and 138.6 nm for size and zeta potential values of (− 23.5 mV) and (− 20.3 mV), respectively. Transmission electron microscope investigation confirmed that the synthesized NLCs have regular and spherical shape. The abundance and concentration of the six released monoterpenes were determined, as a novel approach, using GC–MS with very good results and validity. In-vitro antifungal screening was done before and after nano co-delivery against seven pathogenic, and aggressive fungi of Candida tropicalis, Candida krusei, Candida glabrata, Geotrichum Candidum, Candidaalbicans, Aspergillus Niger, and mucor circinelloides. Inhibition Zone diameter (IZD) and the minimum inhibitory concentration (MIC) were measured. Nanoformulations NLC-Flu-MTs and NLC-MTs manifested potential and unique biological susceptibility against all the tested microorganisms with reduced (MIC) values, especially against Candida Tropicalis (MIC = 0.97 µg/ml) which represents 16-fold of the value shown by NLC-MTs (MIC = 15.6 µg/ml) and 64-fold of fluconazole free before nanoformulation (MIC = 62.5 µg/ml). The efficiency of nanomaterials, particularly NLC-Flu-MTs, has become evident in the diminishing value of MIC which affirmed the synergism between fluconazole and the other six monoterpenes.

Salicylaldehyde salicyloyl hydrazone and its copper(II) complex: synthesis, characterization, DFT, optical band gap, antibacterial activity, and molecular docking analysis

A complex of Cu(II) with a bidentate Schiff base, salicylaldehyde salicyloyl hydrazone (SSH), was synthesized by refluxing copper(II) chloride with this ligand. The formation of the complex, the nature of bonding, and the geometry of the complex were established via physicochemical and spectroscopic techniques. The composition of the complex was found to be a 1:2 metal-ligand ratio as Cu(SSH)2. Electronic absorption spectral studies revealed that the copper adopts a distorted tetrahedral geometry upon complexation with SSH. The optical band energy for the complex was determined from absorption spectroscopy. The obtained band gap of 2.66 eV characterizes the complex as a semiconductor. The most stable conformations of the Schiff base (SSH) and Cu(SSH)2 complex have been computed, shedding light on their structural and electronic properties, and highlighting their potential reactivity and stability. The ligand exhibits a higher reactivity towards electrophiles, while the complex displays a greater affinity for nucleophiles. The in vitro antibacterial analysis with agar cup well method and in silico molecular docking analysis indicate that both the ligand and its complex with copper have potency to inhibit bacterial infections. Based on their growth inhibition, minimum inhibitory concentration (MIC) values, and robust interaction with studied proteins of the pathogens, these compounds hold a prospective avenue for the advancement of antibiotics.

QUANTITATIVE ANALYSIS OF CHITOSAN CONCENTRATION-DEPENDENT MODULATION OF PHYTOPATHOGENIC FUNGAL GROWTH

The study investigated the impact of varying concentrations of chitosan on fungal growth, measured by mycelial diameter, in a solid medium containing 2% malt extract agar (MEA). Concentrations of chitosan (0.05%, 0.10%, 0.15%, and 0.25%) were compared against a control group. The results demonstrated a notable decrease in fungal growth as chitosan concentration increased, indicating a linear relationship between fungal growth and chitosan concentration. The fungal mycelium covered the chitosan-amended medium within 7 days at lower (0.05%), while a prolonged duration (18-22 days) was required for growth at medium (0.10 and 0.15%) and higher concentrations (0.15 and 0.25%), compared to the control. Minimum inhibitory concentration (MIC) values for chitosan were determined at 0.25% for A. alternata, A. flavus, and S. rolfsii, while concentration &gt; 0.25% was required to achieve complete inhibition in the growth of M. phaseolina. Principal component analysis (PCA) was conducted to elucidate fungal growth inhibition at different chitosan concentrations signifying fungal sensitivity to chitosan concentrations. A. alternata exhibited a more sensitivity, followed by S. rolfsii and A. flavus, to chitosan concentrations. The findings of this study will contribute valuable insights into the potential utility of chitosan nanoparticles as an antimycotic agent against these pathogenic fungi

Antioxidant and antimicrobial activity of extracts from selected Mediterranean agro-food by-products, their mutual interaction and interaction with phenolic compounds

The by-products of Mediterranean agriculture that remain after the production of fruit wines, juices and extracts represent a large source of raw materials rich in phenolic compounds. As a contribution to the current state of knowledge, this study investigated the biological activity and phenolic composition of extracts obtained from blackberry, chokeberry and juniper by-products, as well as the interactions of the extracts in mixtures. The total phenolic content of the samples ranged from 44.42 to 250.28 mg gallic acid equivalents (GAE)/g dry extract, with the extracts from blackberry leaves and juniper needles being the highest. The highest concentration of phenolics detected by high performance liquid chromatography (HPLC) was also found in blackberry leaves (41.30 mg/g dry extract), with rutin dominating. The antioxidant activity of the samples, as measured by ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ranged from 3.4 to 26.8 mM Trolox equivalents (TE), 15.8–58.4 mM TE and 80.1%–91.8%, respectively. Among the extract mixtures, the highest synergistic interaction was observed between blackberry leaves and juniper by-products extracts at 1:2 and 2:1 ratios. The antimicrobial activity of the extracts was tested against Gram-positive and Gram-negative foodborne pathogens and spoilage bacteria, with the lowest minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values against Staphylococcus aureus, Listeria innocua, Bacillus cereus, Campylobacter jejuni, Pseudomonas spp. and Shewanella spp. On the other hand, the antimicrobial activity of blackberry leaf extract in combination with selected phenolic compounds (vanillic acid, catechin, rutin and apigenin) showed no synergy against the tested microorganisms. Overall, the results suggest that the tested by-products extracts could be utilized for the production of natural antioxidants and antimicrobials for further use in the food industry.

Drug to genome to drug: a computational large-scale chemogenomics screening for novel drug candidates against sporotrichosis.

Sporotrichosis is recognized as the predominant subcutaneous mycosis in South America, attributed to pathogenic species within the Sporothrix genus. Notably, in Brazil, Sporothrix brasiliensis emerges as the principal species, exhibiting significant sapronotic, zoonotic and enzootic epidemic potential. Consequently, the discovery of novel therapeutic agents for the treatment of sporotrichosis is imperative. The present study is dedicated to the repositioning of pharmaceuticals for sporotrichosis therapy. To achieve this goal, we designed a pipeline with the following steps: (a) compilation and preparation of Sporothrix genome data; (b) identification of orthologous proteins among the species; (c) identification of homologous proteins in publicly available drug-target databases; (d) selection of Sporothrix essential targets using validated genes from Saccharomyces cerevisiae; (e) molecular modeling studies; and (f) experimental validation of selected candidates. Based on this approach, we were able to prioritize eight drugs for in vitro experimental validation. Among the evaluated compounds, everolimus and bifonazole demonstrated minimum inhibitory concentration (MIC) values of 0.5µg/mL and 4.0µg/mL, respectively. Subsequently, molecular docking studies suggest that bifonazole and everolimus may target specific proteins within S. brasiliensis- namely, sterol 14-α-demethylase and serine/threonine-protein kinase TOR, respectively. These findings shed light on the potential binding affinities and binding modes of bifonazole and everolimus with their probable targets, providing a preliminary understanding of the antifungal mechanism of action of these compounds. In conclusion, our research advances the understanding of the therapeutic potential of bifonazole and everolimus, supporting their further investigation as antifungal agents for sporotrichosis in prospective hit-to-lead and preclinical investigations.

Bio-Activity of Crude Alcoholic Extracts of Buffel Grass in different Solvents against some Pathogenic Microbes

Background: Natural products have long been the focus of researchers aiming to improve human health, develop medicines with minimal adverse effects, and extend human lifespans. These products, derived from plants, animals, marine life, and microorganisms, contain secondary metabolites known as phytochemicals, which exhibit various biological activities. The current investigation aimed to assess the phytochemical properties and antimicrobial potential of Cenchrus ciliaris Linn. (CAZRI-358) against significant human pathogenic bacteria and fungi. Objective: The objective of this study was to conduct a phytochemical analysis and evaluate the inhibitory potential of crude alcoholic extracts of Cenchrus ciliaris Linn. against six important human pathogenic bacteria and three fungal strains. Methods: The plant material of Cenchrus ciliaris was shade-dried, crushed into powder, and successively extracted with methanol (CCWPM), hexane (CCWPH), and chloroform (CCWPC) using Soxhlet extraction. The antimicrobial activity of the extracts was assessed using both disc diffusion and serial dilution methods. The minimum inhibitory concentration (MIC) and zone of inhibition (IZ) were calculated. The bacterial strains tested included Shigella sonnei, Pseudomonas aeruginosa, Escherichia coli (Gram-negative), Staphylococcus aureus, Streptococcus pyogenes, and Bacillus subtilis (Gram-positive). The fungal strains tested included Microsporum canis, Aspergillus clavatus, and Candida albicans. Standard drugs imipenem (for bacteria) and miconazole (for fungi) were used as positive controls. Results: The highest yield was found in the methanolic extract (41.25 mg/g). Methanolic extracts showed maximum antibacterial activity with MIC values of 90.98 ± 0.05 µg/mL and IZ of 39 mm against Escherichia coli, 92.11 ± 0.06 µg/mL and IZ of 39 mm against Pseudomonas aeruginosa, and 95.33 ± 0.06 µg/mL and IZ of 39 mm against Streptococcus pyogenes. The methanolic extract also exhibited significant antifungal activity with an MIC of 91.97 ± 0.03 µg/mL and IZ of 40 mm against Microsporum canis. Other extracts demonstrated notable but lesser antimicrobial activities. Conclusion: Cenchrus ciliaris Linn. contains vital bioactive components with significant antimicrobial properties, particularly in methanolic extracts. These findings suggest its potential in developing treatments for infections, chronic diseases, and conditions like Benign Prostatic Hyperplasia (BPH). Further research is needed to isolate specific bioactive compounds and understand their mechanisms of action.

Green Synthesis of Silver Nanoparticles Using Plant Extract Blends and Its Impact on Antibacterial and Biological Activity

There is a strong interest in using green resources for synthesizing nanoparticles (NPs) of industrial and biomedical utility in a way to maintain desired material properties throughout use while not inducing any harmful effects. The use of various plant extracts as reducing, capping, or stabilizing agents is widely attempted in green nanotechnology. However, very little has been explored about incorporating plant extract blends into green NP synthesis routes. Here, we used the combination of tea and olive leaf extracts for the synthesis of silver NPs and evaluated the advantages it provided over both chemical and single-plant-mediated synthesis routes. Four different reducing agents (tannic acid, black tea leaves extract, olive leaves extract and their blend) were used to synthesize silver NPs (Ag NP) from silver nitrate (AgNO[Formula: see text]. The synthesized Ag NP was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), and ultraviolet-visible (US-Vis) spectroscopy. The antimicrobial properties of Ag NP were assessed against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus) using the colony-forming unit (CFU) assay and the minimum inhibitory concentration (MIC) assay. The cytotoxic potential of Ag NP on human colorectal adenocarcinoma (Caco-2) cells was assessed by the WST-1 assay. Results showed that Ag NP synthesized using plant extract mixtures had a primary particle size of 40[Formula: see text]nm and were very effective antibacterial agents, with the MIC values ranging from [Formula: see text]g/mL to 10[Formula: see text][Formula: see text]g/mL. While the particle size obtained in chemical synthesis was slightly lower, the resultant Ag NP did not serve as an effective antibacterial agents at low doses. Further understanding of how best to integrate extracts of different plants into green NP synthesis routes will enable wider and safer biomedical applications.

Synthesis of N-isonicotinic sulfonate chitosan and its antibiofilm activity against E. coli and S.aureus

N-(sodium 2-hydroxypropylsulfonate) chitosan (HSCS), N-sulfonate chitosan (SCS) and N-isonicotinic sulfonate chitosan (ISCS) were prepared. The structures of the prepared chitosan derivatives were characterized by nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–vis) spectroscopy and elemental analysis (EA). Antibacterial and antibiofilm activities of these chitosan derivatives were evaluated in vitro. The minimum inhibitory concentration (MIC) of HSCS and SCS against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were 0.625 mg/mL and 0.156 mg/mL, respectively. ISCS exhibited MIC values of 0.313 mg/mL and 0.078 mg/mL against E. coli and S. aureus, respectively. ISCS demonstrated superior antibacterial and antibiofilm properties compared to SCS and HSCS. These findings suggest that the incorporation of a pyridine structure into sulfonate chitosan enhances its antibacterial and antibiofilm activities, and the prepared ISCS has a promising application prospect for controlling the reproduction of microorganisms in the field of food packaging.

Induced production of defensive secondary metabolites from Aspergillus fumigatiaffinis by co-culture with Aspergillus alabamensis

Seven previously undescribed compounds, including four diketomorpholine alkaloids (1‒4), one indole diketopiperazine alkaloid (9), one chromone (10), and one benzoic acid derivative (13), and nine known compounds (5–8, 11, 12, and 14–16) were isolated from two different fungal sources. Nine of these metabolites (1–9) were obtained from a seagrass-derived Aspergillus alabamensis SYSU-6778, while the others were obtained from a mixed culture of A. alabamensis SYSU-6778 and a co-isolated fungus A. fumigatiaffinis SYSU-6786. The chemical structures of the compounds were deduced via spectroscopic techniques (including HRESIMS, 1D and 2D NMR), chemical reactions, and ECD calculations. It is worth noting that compound 10 was identified as a defensive secondary metabolite of strain SYSU-6786, produced through the induction of compound 8 under co-culture conditions. Compounds 3 and 4 possessed a naturally rare isotryptophan core. Moreover, compounds 1 and 2 exhibited potent inhibitory activities against fish pathogenic bacterium Edwardsiella ictalurid, with minimum inhibitory concentration values of 10.0 μg/mL for both compounds.

Comparative Antibacterial Effectiveness of Orange Peel Extracts from Five Varieties Against Strain of Multi Drug Resistance Escherichia coli

The purpose of this study was to investigate the antibacterial activity of orange peel extracts from five different orange varieties in North Sumatera against resistant Escherichia coli bacteria and compare it to the effectiveness of vancomycin and erythromycin. To assess antibacterial activity, orange peel extracts were prepared from five different orange varieties, namely Citrus aurantifolia, Citrus microcarpa Bunge, Citrus limon L., Citrus sinensis L., and Citrus hystrix. Antibacterial activities were evaluated using the microdilution method to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The best antibacterial activity was determined using the smallest MIC and MBC values. The research found that all five orange peel extracts exhibited significant antibacterial activity compared to the standard antibiotics vancomycin and erythromycin. The most potent inhibitory effect was observed with the Citrus hystrix peel extract, with the lowest MIC and MBC (125 and 250 µg/mL), followed by Citrus aurantifolia (250 and 500 µg/mL), and Citrus sinensis L. (500 and 500 µg/mL). The results showed significant antibacterial activity of orange peel extracts from five different orange varieties in North Sumatera against resistant Escherichia coli bacteria. Keywords: Antibiotic resistance, citrus peel extracts, Escherichia coli, MIC, MBC.

Antibacterial Effect of Spanish Honeys of Different Botanical Origins against Staphylococcus epidermidis.

Honey is traditionally used for its medicinal properties attributed to its antibacterial and antioxidant effects. It is considered a natural alternative to conventional antibiotics. This effect has been attributed to their physico-chemical properties, as various chemical parameters can synergistically influence this effect. The aim of this study is to assess Spanish honeys of diverse botanical origins for their antibacterial efficacy against Staphylococcus epidermidis, correlating their physico-chemical attributes, (poly)phenol content, and antioxidant activity. The methods included colour determination via two methodologies, acidity, pH, moisture content, and sugar concentration. (Poly)phenol content was quantified using the Folin-Ciocalteau method, while antioxidant activity was evaluated via the FRAP method. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against S. epidermidis were investigated with different concentrations of honeys. The results revealed a direct relationship between honey darkness, (poly)phenol concentration, antioxidant activity, and antibacterial efficacy. Darker honeys exhibited higher (poly)phenol levels, greater antioxidant activity, and consequently, lower MIC and MBC values, showing enhanced antibacterial properties. These findings underscore the potential of honey as a therapeutic agent against S. epidermidis, particularly in wound healing applications to avoid infection. Further research into honey's multifaceted properties is warranted to unveil novel therapeutic avenues in healthcare.

Earthworm Infusion as an Antimicrobial Against Bacteria Causing Diarrhea

Diarrhea is the second most common disease worldwide after Acute Respiratory Infection (ARI). One of the causes of diarrhea is the gastrointestinal infection caused by disease bacteria (microbe) such as Salmonella sp., Escherichia coli, Shigella sp., and Vibrio cholerae. The earthworm species Lubricus sp can be used as an alternative medication believed to be able to cure digestive diseases such as typhus, dysentery, and other indigestion like gastritis. This research is laboratory experimental research. The antibacterial activity is measured by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values of earthworm infusion (Lumbricus rubellus) using the tube dilution test. The bacteria used in this research are Escherichia coli, Shigella dysentriae, and Vibrio cholerae, isolated from the feces of diarrhea patients. This research aims to examine the earthworm infusion antibacterial (Lumbricus rubellus) activity to several bacteria that commonly cause diarrhea. The research results show that the average MIC value of earthworm infusion (Lumbricus rubellus) against Escherichia coli is &gt;50%, Shigella dysentriae 0,098%, and Vibrio cholerae &gt;50%. The average MBC value of earthworm infusion against Shigella dysentriae is 50%. .

Antifungal Activity, Mode of Action, and Cytotoxicity of 4-Chlorobenzyl p-Coumarate: A Promising New Molecule.

Fungal infections represent a serious health problem worldwide. The study evaluated the antifungal activity of 4-chlorobenzyl p-coumarate, an unprecedented semi-synthetic molecule. Docking molecular and assay experiments were conducted to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC), mode of action, effect on growth, fungal death kinetics, drug association, effects on biofilm, micromorphology, and against human keratinocytes. The investigation included 16 strains of Candida spp, including C. albicans, C. krusei, C. glabrata, C. tropicalis, C. dubliniensis, C. lusitaniae, C. utilis, C. rugosa, C. guilhermondi, and C. parapsilosis. Docking analysis predicted affinity between the molecule and all tested targets. MIC and MFC values ranged from 3.9 μg/mL (13.54 μM) to 62.5 μg/mL (217.01 μM), indicating a probable effect on the plasma membrane. The molecule inhibited growth from the first hour of testing. Association with nystatin proved to be indifferent. All concentrations of the molecule reduced fungal biofilm. The compound altered fungal micromorphology. The tested compound exhibited an IC50 of 7.90±0.40 μg/mL (27.45±1.42 μM) for keratinocytes. 4-chlorobenzyl p-coumarate showed strong fungicidal effects, likely through its action on the plasma membrane and alteration of fungal micromorphology, and mildly cytotoxic to human keratinocytes.

SYNERGISTIC EFFECT OF HERBAL TEA SAMPLES WITH CIPROFLOXACIN AGAINST MRSA AND THEIR ANTIOXIDANT ACTIVITIES

OBJECTIVE: Sambucus nigra L. (elderberry), Salvia sclarea L. (clary sage), Rosmarinus officinalis L. (rosemary), and Coriandrum sativum L. (coriander) are all consumed as flavoring agents for food and are well-known in traditional medicine for the treating various diseases worldwide. These herbs are also commonly used for microbial infections, especially to relieve cough, fever, and cold symptoms. This study aims to screen and compare the content of total phenols and antioxidant activity potential of three different extracts from each commercial sample of S. nigra, S. sclarea, R. officinalis and C. sativum from Türkiye. We also investigated the (Minimum Inhibitory Concentration (MIC) values against Staphylococcus aureus ATCC 29213 (methicillin-susceptible, MSSA) and Staphylococcus aureus ATCC 43300 (methicillin-resistant, MRSA) and the synergistic activity with an antibiotic, ciprofloxacin, by checkerboard assay. MATERIAL AND METHODS: The fruits of S. nigra and C. sativum, the aerial parts of S. sclarea, and the leaves of R. officinalis were purchased from a trading company that marketed them as herbal tea in Türkiye. This study investigated the total phenolic content and antioxidant potential of extracts from commercial samples. We also determined the synergistic effect of herbal tea samples with ciprofloxacin against methicillin-resistant Staphylococcus aureus (MRSA). RESULTS: R. officinalis (rosemary) and Salvia sclarea (clary sage) extracts showed high phenolic content and antioxidant activity, whereas it was determined that C.sativum (coriander) and S. nigra (elderberry) extracts exhibited lower antioxidant activity and low phenolic compounds. Moreover, ciprofloxacin in combination with the ethanolic extract of S. sclarea showed additive antibacterial activity against S. aureus ATCC 43300. CONCLUSIONS: We conclude that herbal tea prepared from commercial R. officinalis (rosemary) and S.sclarea (clary sage) samples can support the antioxidant activity with high phenolic content and that ciprofloxacin combined with the ethanolic extract of clary sage showed additive antibacterial activity against methicillin-resistant S. aureus ATCC 43300. Further studies are needed to understand the mechanism of additive action in detail.

Comparison of available methods to evaluate cefiderocol susceptibility in Acinetobacter spp

Recently, considerable uncertainty has arisen concerning the appropriate susceptibility testing for cefiderocol in gram-negative bacilli, particularly in the context of its application to Acinetobacter spp. The optimal method for assessing the susceptibility levels of Acinetobacter spp. to cefiderocol remains a subject of debate due to substantial disparities observed in the values obtained through various testing procedures. This study employed four minimum inhibitory concentration (MIC) methodologies and the disk diffusion to assess the susceptibility of twenty-seven carbapenem resistant (CR)-Acinetobacter strains to cefiderocol. The results from our study reveal significant variations in the minimum inhibitory concentration (MIC) values obtained with the different methods and in the level of agreement in interpretation categories between the different MIC methods and the disk diffusion test. Among the MIC methods, there was relatively more consistency in reporting the interpretation categories. For European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, the categorical agreement (CA) for MIC methods ranged between 66.7 and 81.5%. On the other hand, the essential agreement (EA) values were as low as 18.5–29.6%. The CA between MIC methods and disk diffusion was 81.5%. These results emphasize the need for a reliable, accurate, and clinically validated methodology to effectively assess the susceptibility of Acinetobacter spp. to cefiderocol. The wide variability observed in our study highlights the importance of standardizing the susceptibility testing process for cefiderocol to ensure consistent and reliable results for clinical decision-making.

Pioneering Topical Ointment Intervention for Unprecedented Antimicrobial and Diabetic Wound Management with Phenylpropanoids and Nano-Silver.

Addressing the intertwined challenges of antimicrobial resistance and impaired wound healing in diabetic patients, an oil/water emulsion-based nano-ointment integrating phenylpropanoids-Eugenol and Cinnamaldehyde-with positively-charged silver nanoparticles was synthesized. The process began with the synthesis and characterization of nano-silver, aimed at ensuring the effectiveness and safety of the nanoparticles in biological applications. Subsequent experiments determined the minimum inhibitory concentration (MIC) against pathogens such as Streptococcus aureus, Pseudomonas aeruginosa and Candida albicans. These MIC values of all three active leads guided the strategic formulation of an ointment base, which effectively integrated the bioactive components. Evaluations of this nano-ointment revealed enhanced antimicrobial activity against both clinical and reference bacterial strains and it maintained stability after freeze-thaw cycles. Furthermore, the ointment demonstrated superior in-vitro diabetic wound healing capabilities and significantly promoted angiogenesis, as shown by enhanced blood vessel formation in the Chorioallantoic Membrane assay. These findings underscore the formulation's therapeutic potential, marking a significant advance in the use of nanotechnology for topical wound care.

Pfaffia paniculata Extract, a Potential Antimicrobial Agent against Candida spp., Pseudomonas aeruginosa, and Streptococcus mutans Biofilms.

The World Health Organization (WHO) has prioritized developing new drugs against specific bacteria and fungi, such as Enterobacteriaceae and Candida spp. While Pfaffia paniculata is commonly called the "cure-everything", its scientifically proven benefits are limited to anti-inflammatory and antioxidant actions. Therefore, this study aims to determine the spectrum of antimicrobial activity of Pfaffia paniculata and assess its cytotoxicity. Thus, broth microdilution test was conducted according to the CLSI M7-A9 and M27-A3 reference methods. After screening, microbial species with minimum inhibitory concentration (MIC) values were selected for biofilm tests. These tests evaluated biomass using the crystal violet (CV) test, metabolic activity using the MTT assay, and structural analysis via Scanning Electron Microscopy (SEM). Cytotoxicity was evaluated in human gingival fibroblasts (FMM-1). There were reductions of 29.4 and 42.7% in CV and MTT assays for Candida spp. biofilm. S. mutans and P. aeruginosa biofilms showed a decrease of 15.7 and 28.6%, respectively. Cell viability tests indicated 55.1, 56.9, and 65.5% of viability after contact with 1.93, 0.96, and 0.48 mg/mL of the extract, respectively. The P. paniculata extract showed antimicrobial action, displayed MIC values, and antibiofilm action on P. aeruginosa, S. mutans, and C. albicans. The cytotoxicity on the FMM-1 cell line was dose-dependent. Therefore, P. paniculata extract holds significant potential for developing new drugs.

Marcytoglobosins A and B, Cytochalasans From a Marine Sponge Associated Chaetomium globosum 162105 Fungus.

Two new cytochalasans, marcytoglobosins A (1) and B (2) were isolated from the marine sponge associated fungus Chaetomium globosum 162105, along with six known compounds (3-8). The complete structures of two new compounds were determined based on 1D/2D NMR and HR-MS spectroscopic analyses coupled with ECD calculations. All eight isolates were evaluated for their antibacterial activity. Among them, compounds 3-8 displayed antibacterial effects against Staphylococcus epidermidis, Bacillus thuringiensis, Pseudomonas syringae pv. Actinidiae, Vibrio alginolyticus, and Edwardsiella piscicida with minimum inhibitory concentration (MIC) values ranging from 10 to 25 μg/mL.