Lowest Minimum Inhibitory Concentration Value Research Articles

Minimal Inhibitory Concentration of Clofazimine Among Clinical Isolates of Nontuberculous Mycobacteria and Its Impact on Treatment Outcome

Clofazimine has been regarded as a promising agent for the treatment of nontuberculous mycobacteria pulmonary disease (NTM-PD). However, its overall effectiveness invitro and in the clinic remains unknown. What is the minimal inhibitory concentration (MIC) of clofazimine in clinical isolates and the association between MICs and treatment outcome? MICs for clofazimine were measured in clinical isolates from NTM-PD patients who participated in a prospective study at Seoul National University Hospital. The MIC was determined by using the broth microdilution concentration method. Correlation between MIC and conversion to negative of sputum culture with clofazimine was determined. Of a total 189 isolates, 133 strains were Mycobacterium avium complex (MAC) and 40 strains were M abscessus. Although the clofazimine MICs for MAC ranged from 0.031mg/L to 8mg/L, the values obtained for M abscessus ranged from 0.031mg/L to 16mg/L. Of 20 patients who were treated with a regimen including clofazimine, eight achieved negative conversion of sputum culture. All patients with isolates exhibiting clofazimine MIC values≤ 0.25mg/L achieved culture conversion. The likelihood of culture conversion in patients with MIC value≤ 0.25mg/L was much higher than that of patients with MIC value > 0.5mg/L (OR, 39.3; P= .021). The MICs of clofazimine varied widely in clinical isolates from patients with NTM-PD. Negative conversion of sputum culture with clofazimine use was associated with a lower MIC value. Clofazimine use could be considered in patients with NTM-PD when the MIC value is≤ 0.25mg/L. ClinicalTrials.gov; No.: NCT01616745; URL: www.clinicaltrials.gov.

Antimicrobial Activity of Selected Red and White Wines against Escherichia coli: In Vitro Inhibition Using Fish as Food Matrix.

Five different wines (standard Graševina, macerated Graševina with and without sulfur, rosé, and standard Plavac Mali), all typical Croatian wines, were tested to determine the antimicrobial activity against two Escherichia coli bacterial strains (ATCC® 25922 and ATCC® 8739) in vitro and using sea bass (Dicentrarchus labrax) fillets as food matrix. The chemical composition of wines (pH, acidity, alcohol, total phenolics, anthocyanins, tannins, and sulfur content) and antimicrobial activity (minimal inhibitory concentration (MIC), agar-well diffusion method) were determined. The total phenolic content of the wines ranged from 305–3210 mg gallic acid equivalents per liter (GAE/L), and did not correlate to antimicrobial activity. The two wines with the lowest phenolic content (standard Graševina and rosé) had the lowest MIC values (122 and 429 mg GAE/L). A specific relation between the winemaking process and a particular MIC value was not established. There was also no relation found between the pH value, ethanol content, sulfur, or phenolics in regards to the antimicrobial effect. In fish fillets marinated in wine + water mixture (v/v = 1:1) and inoculated with 7 log colony forming units (CFU)/25 g the growth of bacteria was reduced after three days of storage at 4 °C. Subsequent storage resulted in the growth of bacteria in all samples, with the lowest growth of E. coli ATCC® 25922 in macerated Graševina and E. coli ATCC® 8739 in standard Graševina. All wines showed the capacity to reduce the number and growth of heavily infected sea bass filets, but correlation with specific wine constituents was not found. Taking into account the numerous reactive mechanisms between food and wine, all in vitro studies in controlled laboratory conditions should be further verified in the relevant environment, and additional research is needed to clarify the role of individual wine components in the mechanism of antimicrobial activity.

Antibacterial Activity Evaluation of Psidium guajava L. (Myrtaceae) Crude Extracts Against Selected Bacterial Pathogens

Methanol, ethanol, acetone, ethyl acetate and hot water extracts of different parts (leaves, seeds, fruits and twigs fractions) of Psidium guajava L. were investigated for their antibacterial activities against 8 bacterial isolates. Inhibitory effects of P. guajava L. extracts have been screened by disc- diffusion method (Zone of inhibition, ZI), activity index (AI) and minimum inhibitory concentration (MIC) determination. Ciprofloxacin antibiotic was used as standard for P. guajava L. antimicrobial activity comparison. From the ZI, AI and MIC values, methanolic and hot water extracts of twigs < 1cm diameter were the most potent against all tested micro-organisms by showing the highest ZI and AI value and the lowest MIC values. Whereas, no inhibitory activity was recorded for both seeds and fruits extracts using all tested solvents. These observations make this plant a potential source that can be used in management of bacterial infections. Moreover, methanolic and hot water extracts of twigs < 1cm required further in depth study.
 
 

Comparison of In Vitro Antibacterial Activity of Epaltes divaricata and Vetiveria zizanioides against Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital- and community-acquired infections worldwide. Therefore, this study was conducted to explore the antibacterial activity of the two medicinal plants Epaltes divaricata and Vetiveria zizanioides against strains of MRSA which were isolated from patients with skin and soft tissue infections. Hexane, ethanol, and water extracts of E. divaricata (whole plant) and V. zizanioides (roots) were prepared. Clinical isolates of MRSA strains (n = 20) were used for the study. Bacterial susceptibility was tested using a disc diffusion assay. Minimum inhibitory concentration (MIC) was determined by a broth microdilution method. Vancomycin was used as the positive control. Hexane, ethanol, and water extracts of E. divaricata showed inhibitory zones against MRSA. Except for water extract, both hexane and ethanol extracts of V. zizanioides showed inhibitory zones. MIC ranges of hexane, ethanol, and water extracts in E. divaricata were 0.012–0.32 mg/mL, 0.019–2.4 mg/mL, and 0.019–0.48 mg/mL, respectively. Respective MIC ranges of hexane and ethanol extracts of V. zizanioides were 0.003–0.032 mg/mL and 0.019–2.4 mg/mL. The hexane extract of V. zizanioides inhibited 55% of the selected MRSA strains at a relatively low MIC value of 0.012 mg/mL. The hexane extract of both plants demonstrated inhibition of 75% of MRSA strains at a MIC value of 0.064 mg/mL. Ethanol extract of V. zizanioides and E. divaricata, respectively, inhibited 70% and 45% of MRSA strains at the MIC of 0.096 mg/mL, whereas water extract of E. divaricata inhibited 80% of MRSA strains at the same MIC. Both E. divaricata and V. zizanioides were equally effective against MRSA at a MIC of 0.064 mg/mL. But V. zizanioides was more effective since the hexane extract inhibited more than 50% of MRSA strains at significantly a lower MIC value of 0.012 mg/mL. Fractionation, purification, and identification of active compounds will warrant further evaluation of the therapeutic potential of both plant extracts.

Using minimum inhibitory concentration values of common topical antibiotics to investigate emerging antibiotic resistance: A retrospective study of 134 dogs and 20 horses with ulcerative keratitis.

To identify the minimum inhibitory concentration (MIC) distribution for commonly used topical antibiotics from isolates of dogs and horses with ulcerative bacterial keratitis, and to investigate changes in MIC values over time and following treatment with topical fluoroquinolones. One hundred thirty-four client-owned dogs and 20 client-owned horses with bacterial ulcerative keratitis. Minimum inhibitory concentration values for 14 topical antibiotics were reported for canine and equine cases of bacterial ulcerative keratitis between 2013 and 2018. Changes in MIC values over time and after treatment with topical fluoroquinolones were reported. The three most common bacterial genera isolated were Staphylococcus, Streptococcus, and Pseudomonas. Together, these represented 79.4% of canine cases and 77.4% of equine cases. Overall, isolates from horses tended to have lower MIC values, as did Pseudomonas isolates from both dogs and horses, compared to other bacterial genera, especially Staphylococcus spp. The MIC values of erythromycin and trimethoprim sulfa for Staphylococcus spp., and the MIC value of moxifloxacin for Pseudomonas significantly increased over time. Previous topical fluoroquinolone use was associated with a significant increase in the MIC value of ofloxacin in canine and equine Staphylococcus isolates and current topical fluoroquinolone use was associated with significant increases in the MIC values of ciprofloxacin, moxifloxacin, and ofloxacin in canine Staphylococcus isolates. Patients previously or currently treated with topical fluoroquinolones, particularly in Staphylococcus infections, may require alternative antibiotics or additional antibiotic classes other than fluoroquinolones. Bacterial culture with MIC susceptibility testing should be highly recommended when a Staphylococcal infection is suspected.

Epidemiological Pattern of Malassezia, its Phenotypic Identification and Antifungal Susceptibility Profile to Azoles by Broth Microdilution Method

AbstractBackground:Malassezia though known for its cutaneous infections can potentially cause invasion. The skin infections caused by Malassezia have poor patient compliance due to its chronicity and recurrent nature of the disease. There is also a lack of standardised antifungal susceptibility profile for Malassezia due to its complex growth requirement. Objective: This study was performed to understand the epidemiological pattern of disease and to study the antifungal susceptibility testing (AFST) profile so as to choose the appropriate drug/drugs to treat the infections caused by Malassezia. Materials and Methods: Samples were collected and processed, species were identified by conventional method and AFST was done by broth microdilution method. Results: The epidemiological pattern showed adolescent females commonly affected in torso. The most common lesion was pityriasis versicolor. The systemic antifungal of choice was itraconazole with the lowest minimum inhibitory concentration (MIC) of 0.125–1 μg/ml. The best topical drug with the lowest MIC value was clotrimazole 0.03–0.5 μg/ml. Conclusion: AFST is important as it will help the dermatologist to choose the appropriate antifungal agents for the patient and thereby reduce the chronicity of the disease with good patient compliance

Acacia senegal Extract Rejuvenates the Activity of Phenicols on Selected Enterobacteriaceae Multi Drug Resistant Strains.

This study reported the phytochemical composition of two hydroethanolic extracts of Acacia senegal and Acacia seyal trees from Burkina Faso and their activities, alone or in combination with selected antibiotics, against multidrug resistant bacteria. High performance thin layer chromatography (HPTLC) method was used for phytochemical screening. Total phenolic and total flavonoid ant tannins in leaves extracts contents were assessed by spectrophotometric method. The minimal inhibitory concentrations (MICs) of plant extracts and antibiotics were determined using the microdilution method and p-iodonitrotetrazolium chloride. Combinations of extracts and antibiotics were studied using checkerboard assays. Screening revealed the presence of phenolic compounds, flavonoids, and tannins in the hydroethanolic extract (HE) of the leaves. The HE of A. seyal showed the highest total phenolic (571.30 ± 6.97 mg GAE/g), total flavonoids (140.41 ± 4.01 mg RTE/g), and tannins (24.72 ± 0.14%, condensed; 35.77 ± 0.19%, hydrolysable tannins). However, the HE of A. senegal showed the lowest total phenolic (69.84 ± 3.54 mg GAE/g), total flavonoids (27.32 ± 0.57 mg RTE/g), and tannins (14.60 ± 0.01%, condensed; 3.09 ± 0.02%, hydrolysable). The MICs for HE and antibiotics were in the range of 2–512 and 0.008–1024 mg/L, respectively. All tested HE presented an MIC greater than 512 mg/L except HE of A. senegal. The lowest MIC value (128 mg/L) was obtained with HE of A. senegal against Klebsiella aerogenes EA298 and Escherichia coli AG100A. Interesting restoring effects on chloramphenicol and florphenicol activity were detected with alcoholic extracts of A. senegal against resistant E. coli and K. aerogenes strains that overproduce AcrAB or FloR pumps. The adjuvant effect of HE of A. senegal suggests that the crude extract of leaves could be a potential source of molecules for improving the susceptibility of bacteria to phenicols antibiotics.

A novel copper-based 3D porous nanocomposite for electrochemical detection and inactivation of pathogenic bacteria

An economical and reliable theranostic unit is essential for the detection and treatment of bacterial infections. MRSA is one of the most prevalent superbugs in the world at present, hence requires urgent attention. Here, we present a novel copper-based 3-D porous nanocomposite modified with vancomycin (Van) for simultaneous detection and treatment of methicillin-resistant S. aureus (MRSA). The composite contains copper/copper oxide nanoparticles which are reduced by the hydroxyl groups of β-cyclodextrin (β-CD). On addition of graphene oxide (GO), it achieves a porous structure due to π-π stacking and formation of hydrogen bonds between β-cyclodextrin (β-CD) and reduced graphene oxide sheets. Conjugation of Van to the composite provides highly specific binding towards gram-positive bacteria. Differential pulse voltammetry (DPV) was used to carry out the electrochemical detection of MRSA and achieved a very low limit of detection (LOD) 5 CFU mL−1 along with a minimum inhibitory concentration (MIC) value of 1.93 μg mL−1. The low LOD and MIC values are due to the good electrochemical response of the composite and the synergetic antibacterial effect of vancomycin and copper/copper oxide nanoparticles, respectively. The current work provides a more effective and economic unit as electrode modifier simultaneous detection and powder for the elimination of pathogenic bacteria.

The Sensitivity Modifying Activity of Nerolidol and α-Bisabolol Against Trichophyton spp.

Trichophyton spp. is one of the main causative agents of dermatophytosis such as tinea ungium and tinea pedis. Resistance to antifungal drugs is a significant clinical problem in dermatophytosis. The main molecular mechanism of antifungal resistance to conventional therapy in dermatophytes is the expression of efflux pumps. Efforts aimed at improving the efficacy of current antifungals such as griseofulvin are relevant. Given this, sesquiterpenes such as α-bisabolol and nerolidol found in essential oils represent promissing alternatives. Griseofulvin sensitivity modulation activity in T. rubrum, T. interdigitale H6, and T. interdigitale Δmdr2 (mutant strain of T. interdigitale) promoted by α-bisabolol and nerolidol were investigated. The minimum inhibitory concentration (MIC) of the test drugs were determined by microdilution. Subsequently, the effect of the drugs tested on plasma membrane functionality (K+ release) was analyzed. The MIC of griseofulvin was determined at sub-inhibitory sesquiterpene concentrations (modulation assay). An association study was performed with griseofulvin and sesquiterpenes (checkerboard). α-bisabolol was more potent than nerolidol; presenting lower MIC values. All of the fungi were sensitive to griseofulvin, starting at 8 µg/mL. With the exception of griseofulvin, all of the test drugs increased K+ release (p < 0.05). Nerolidol modulated the sensitivity of all strains to griseofulvin; α-bisabolol sensitivity modulation was limited to T. interdigitale H6 and T. interdigitale Δmdr2. In association with griseofulvin: nerolidol and α-bisabolol respectively presented synergism and additivity. Finally, the results of our study suggest using α-bisabolol and nerolidol compounds as potential antifungal agents and griseofulvin sensitivity modulators for Trichophyton spp.

Investigation of Copaifera genus as a new source of antimycobaterial agents.

Aim:This paper reports on the antimycobacterial activity of the oleoresins and extracts obtained from Copaifera spp.Materials & methods:The minimum inhibitory concentration (MIC) and fractional inhibitory concentration index techniques helped to evaluate the effect of these oleoresins and extracts against six strains of mycobacteria that cause tuberculosis.Results & conclusion:Among the assayed oleoresins and plant extracts, the Copaifera langsdorffii, Copaifera duckei, Copaifera reticulata and Copaifera trapezifolia oleoresins provided the lowest MIC values against some of the tested strains. The combination of Copaifera spp. samples with isoniazid did not evidence any synergistic action. Some Copaifera spp. oleoresins may represent a future source for the discovery of new antimycobacterial drugs due to their low MIC values.

Comparison of Biochemical, Antimicrobial and Cytotoxic Activities of Different Propolis Samples from Malatya and Bilecik

Propolis is a resinous natural mixtures collected and produced by honey bees. It is rich in essential oils and phenolic components so it has high levels of antioxidant, antimicrobial, anti-inflammatory and anti-tumoral activity. In this study the biochemical activity of propolis extracts were determined. The antimicrobial activity and cytotoxic activity of the extracts of the nine different propolis samples were invastigated. Their antimicrobial activities were tested by microdillution metod and define as minimum inhibitory concentration (MIC). Chemical composition of extracts was determined by using GC-MS equipment. Total phenolic content and antioxidant activity of the extracts was measured. Antimicrobial and cytotoxic activity of the extracts was carried out as well. All of the extracts showed antimicrobial activity on bacteria and yeasts used. Extracts had generally lower MIC values on yeasts. Therefore, yeasts were detected as more susceptible against the propolis extracts than the bacteria. Cytotoxic activity of extract were determined aganist A549 and Beas2B cell lines and IC50 values were calculated. Ma-Arapgir had the highest cytotoxic activity on A549 and Beas2B. They were determined as 6.72 and 26.44 mg/mL, respectively. It could be concluded that propolis extracts have antimicrobial and cytotoxic activity thus, propolis could be used in the treatment of cancer.

Investigation of the In Vitro Effectiveness of Aztreonam/Avibactam, Colistin/Apramycin, and Meropenem/Apramycin Combinations Against Carbapenemase-Producing, Extensively Drug-Resistant Klebsiella pneumoniae Strains.

This study aimed at investigating the in vitro effectiveness of aztreonam/avibactam, colistin/avibactam, colistin/apramycin, and meropenem/apramycin combinations against carbapenemase-producing, extensively drug-resistant (XDR) Klebsiella pneumoniae strains. This study evaluated 38 carbapenem-resistant, carbapenemase-producing, and XDR K. pneumoniae strains. The checkerboard method was used to examine the efficacy of aztreonam/avibactam, and meropenem/apramycin combinations in all strains and the colistin/apramycin combination in colistin-resistant strains (n = 26). It was found that when used alone, aztreonam and avibactam had high minimum inhibitory concentration values in all strains and that all strains were resistant to aztreonam. Nevertheless, the aztreonam/avibactam combination was found to have a synergistic effect against all strains. Apramycin alone was effective against 30 K. pneumoniae strains (79%); however, 8 strains (21%) were found to be resistant. In the synergy testing of 26 colistin-resistant strains with the checkerboard method, the colistin/apramycin combination was found to have a synergistic effect against 4 strains (15.3%), an antagonistic effect against 8 strains (30.7%), and an additive effect against 14 strains (54%). By comparison, the meropenem/apramycin combination had a synergistic effect against 20 strains (52%) and an additive effect against 12 strains (31%). The aztreonam/avibactam combination showed a high in vitro synergistic effect on carbapenemase-producing and XDR K. pneumoniae strains, such as Metallo-β-lactamase, and provided good prospects for the successful treatment. The meropenem/apramycin combination was also highly synergistic. The synergistic effects were low for the colistin/apramycin combination that was tested on colistin-resistant strains. However, it is promising that apramycin has low minimal inhibitory concentration values.

Improvement of the pharmacokinetic/pharmacodynamic relationship in the treatment of invasive aspergillosis with voriconazole. Reduced drug toxicity through novel rapid release formulations

Voriconazole (VCZ) is currently the first-line treatment for invasive aspergillosis, although the doses are limited by its poor solubility and high hepatic toxicity. The aim of this study was to develop a solid self-dispersing micellar system of VCZ to improve the pharmacokinetic/pharmacodynamic (PK/PD) relationship and reduce hepatotoxicity. In this work, solid micellar systems of VCZ are formulated with different polysorbate 80 ratios using mannitol as a hydrophilic carrier. The novel micellar systems were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and dissolution studies. Self-dispersing micellar systems reduced VCZ crystallinity, leading to an improvement in its dissolution rate. The in vitro susceptibility test also revealed that the most common microorganisms in invasive aspergillosis exhibited low minimum inhibitory concentration (MIC) values for micellar systems. Pharmacokinetic studies indicated an improvement in bioavailability for MS-1:3:0.05, and changes in its biodistribution to different organs. MS-1:3:0.05 showed an increased concentration in lungs and a significant decrease in VCZ accumulated in the liver.

Assessment of Antimicrobial Susceptibility of Virulent Strains of Rhodococcus equi Isolated From Foals and Soil of Horse Breeding Farms With and Without Endemic Infections

Rhodococcus equi is an opportunistic, intracellular saprophyte that causes severe pyogranulomatous pneumonia in foals. The bacterium displays in vitro susceptibility to many antibiotics. The highest efficacy against R. equi in vitro and in vivo is achieved by using a combination of rifampicin and macrolide antibiotics. Recent years have seen an upward trend in the minimum inhibitory concentration (MIC) of rifampicin and erythromycin, suggesting increasing resistance of R. equi to these antibiotics. The aim of the study was to determine the antimicrobial activity of 24 selected antibiotics against R. equi strains isolated from dead foals and from the environment of horse breeding farms with and without endemic R. equi infections. Minimum inhibitory concentration gradient strips were used to determine the lowest concentration of the antibiotic that inhibited the growth of R. equi. Based on normal MIC distribution, an epidemiologic cutoff values (ECOFF) were assessed for particular antibiotics and R. equi strains. The results were compared with ECOFFs for S. aureus, according to the European Committee on Antimicrobial Susceptibility Testing data. The data indicate that the lowest MIC values were obtained for clarithromycin, rifampicin, imipenem, and vancomycin. The majority of R. equi strains can be classified as wild type in relation to the majority of antibiotics. A small percentage of strains presented non-WT (NWT) with the exception of SXT, for which 35% of strains were classified as NWT. The lack of interpretative criteria for R. equi creates a real problem in the assessment of antibiotic sensitivity both for clinical and scientific purposes.

Phytogreen synthesis of multifunctional nano selenium with antibacterial and antioxidant implications

The exploitation of plant extracts for the synthesis of nano selenium having antibacterial and antioxidant activities is an exciting approach to counteract the prevalence of infections caused by antibiotic-resistant bacteria, which holds relevance for medical and food industries. In the present work, a green and facile method for the preparation of nano selenium (nSe) using the fruit extract of Indian gooseberry (Phyllanthus Emblica) has been reported. The optical and structural properties of the as-synthesized nSe were studied through various characterization techniques. Eventually, the antioxidant potential of nSe was investigated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl free radical scavenging assays. Parallely, the antibacterial activity of nSe against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was evaluated. The antioxidant assays indicated that even low dosage of nSe showed excellent activity with EC50 values of 0.21 μg ml−1 and 3.34 μg ml−1, respectively. Moreover, nSe exhibited significant inhibition in bacterial growth at low minimum inhibitory concentration (MIC) values against Escherichia coli (16 μg ml−1), Staphylococcus aureus (32 μg ml−1) and Pseudomonas aeruginosa (48 μg ml−1) compared to MIC values for standard drug ampicillin. Importantly, nSe did not induce any cytotoxic effects on normal human keratinocytes (HaCaT) at the tested concentrations; representing their biocompatible nature. The data obtained demonstrated the versatility of phytogreen nSe as a potent antioxidant and antibacterial agent to effectively prevent as well as treat multidrug-resistant bacterial infections.

A Survey of Antifungal Activity of Selected South African Plant Species Used for the Treatment of Skin Infections

Dermatophytosis is a fungal infection of the skin caused by a group of pathogenic fungi known as dermatophytes. Therefore, we investigated those medicinal plants that were being used by local people and traditional healers to treat skin infections in the Mopani District, Limpopo Province. A survey was conducted through the use of a semistructured program to gather information on the common names, plant parts used, methods of preparation, and administration of the medicine. Findings of the survey revealed that over 30 plant species were used for the treatment of skin infections in the area. The most common local mode of medicinal preparation to treat skin was decoction (37%), followed by paste (21%), infusion (19%), poultice (9%), smoke (7%), maceration (5%), and steam (2%). Of the species, only 12 ( Ficus sur L., Peltophorum africanum Sond., Vangueria infausta Burch. subsp. infausta, Diospyros mespilliformis Hochst. ex. A. DC., Ziziphus mucronata Willd. subsp. mucronata, Euclea divinorum Hiern, Ximenia caffra Sond., Dombeya rotundifolia Hochst., Ficus sycomorus L., Sideroxylon inerme L. subsp inerme, Parinari curattellifolia Planch. ex Benth., and Maytenus undata (Thunb.) Blakelock) were selected based on literature and ethnobotanical information. We further investigated the antifungal activity of acetone and aqueous extracts of the above mentioned selected plant species using serial dilution assay against Trichophyton rubrum, Microsporum canis, and Candida albicans. All plant extracts were active against the tested microorganisms with minimum inhibitory concentration (MIC) values ranging between 0.02 mg/mL and 1.25 mg/mL. In the bioautography assay, more active compounds were visible in acetone and water extracts of E. divinorum. No active compounds were observed in some plant extracts with excellent antifungal activity, as shown in the microdilution assay. Findings, in general, suggest that the identified plant species, especially those with extracts showing relatively low MIC values, are playing a big role in treating skin infections in Mopani District.

Thalictrum foliolosum DC: An unexplored medicinal herb from north western Himalayas with potential against fungal pathogens and scavenger of reactive oxygen species

The aim of the present study was to evaluate the antifungal, antioxidant activity and quantification of berberine in different solvent extracts of leaves of Thalictrum foliolosum DC. Cold maceration method was employed for the preparation of extracts using solvents of different polarities (petroleum ether, chloroform, and methanol). Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, and antifungal activity of T. foliolosum extracts were investigated using various in vitro assays. A high-performance thin-layer chromatography (HPTLC) method was used for the quantification of berberine. In silico studies confirmed the results of in vitro assays and showed that berberine showed a good binding affinity with cytochrome P450 14 alpha-sterol demethylase (CYP51) (antifungal receptor protein) and human peroxiredoxin 5 (antioxidant receptor). TPC and TFC were highest in methanolic extract. HPTLC quantification of berberine showed a higher amount of berberine in chloroform extract followed by methanol extract). Chloroform extract showed the highest antifungal activity as indicated by a diameter of zone of inhibition and lower minimum inhibitory concentration (MIC) value against fungal strains [Candida albicans (ATCC90028), C. albicans (MTCC277) and Saccharomyces cerevisiae (H1068)]. Among three extracts, maximum antioxidant activity was shown by chloroform extract as evident from the lowest half-maximal inhibitory concentration (IC50) value with DPPH and FRAP assay. Molecular docking study also showed that berberine interacts strongly with cytochrome P450 14 alpha-sterol demethylase (CYP51) and human peroxiredoxin 5 proteins. Thus, T. foliolosum leaves can be exploited as an alternative source of berberine, with potent antioxidant and antifungal activity.

Synthesis and Characterization of New Fluoro/Trifluoromethyl-Substituted Acylthiourea Derivatives with Promising Activity against Planktonic and Biofilm-Embedded Microbial Cells

The aim of this study was preparation of new derivatives based on 2-((4-chlorophenoxy)methyl)-N-(arylcarbamothioyl)benzamide structure; the new compounds were characterized by IR, NMR (1H, 13C) spectroscopy, and elemental analysis. The obtained compounds were evaluated for their in vitro antimicrobial activity against planktonic and biofilm-embedded microbial cells (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans), by qualitative and quantitative assays. Some of the compounds revealed promising antibacterial and antifungal activities, with low minimum inhibitory concentration values between 0.15 and 2.5 mg/mL and minimal biofilm eradication concentrations of 0.019–2.5 mg/mL. To investigate the potential target of their antibacterial activity, in silico drug-likeness and molecular docking screenings on Staphylococcus aureus DNA gyrase were performed. The compound with the best antibacterial activity (1g) was docked into topoisomerase II DNA gyrase enzymes (PDB ID: 2XCS) and showed valuable interactions with the target protein along with good docking scores, suggesting that it can act by the inhibition of DNA replication. The tested compounds exhibited only a poor antioxidant activity, as revealed by the in vitro assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.

Luliconazole, a highly effective imidazole, against Fusarium species complexes.

Luliconazole is a new antifungal that was primarily used for the treatment of dermatophytosis. However, some studies have shown that it has excellent efficacy against Aspergillus and Candida species in vitro. The present study aimed to evaluate of luliconazole activity against some Fusarium species complex isolates. In this study, 47 isolates of Fusarium were tested against several antifungals including luliconazole. All species were identified using morphology features, and PCR sequencing and antifungal susceptibility were performed according to CLSIM38 A3 guideline. Our results revealed that luliconazole has a very low minimum inhibitory concentration value (0.0078-1µg/ml) in comparison with other tested antifungals. Amphotericin B had a poor effect with a high MIC90 (64µg/ml), followed by terbinafine (32µg/ml), posaconazole (16µg/ml), caspofungin (16µg/ml), voriconazole (4µg/ml), and itraconazole (4µg/ml). Overall, our findings indicated that luliconazole has great activity against environmental and clinical Fusarium species complexes in comparison to tested antifungals.

Highlighting of the antialgal activity of organic extracts of Moroccan macrophytes: potential use in cyanobacteria blooms control.

Many studies have demonstrated the effectiveness of algicidal compounds produced by macrophytes against microalgae. The aim of this study was to assess the algicidal activity of seven Moroccan macrophyte ethyl acetate extracts (MEA) to control harmful algal blooms (HABs). The response and sensitivity of prokaryotic toxic cyanobacteria (Microcystis aeruginosa) and eukaryotic microalgae (Chlorella sp.) were highlighted. The algicidal effect of MEA extracts against the two microalgae was assessed using both the paper disc diffusion and microdilution methods. This last was used in order to evaluate the minimum inhibitory concentrations (MIC) and minimum algicidal concentrations (MAC). Results showed that the growth of both microalgae was significantly inhibited by all MEA extracts. Myriophyllum spicatum organic extract shows the highest growth inhibition activity against M. aeruginosa (35.33 ± 1.53) and Chlorella sp. (30.33 ± 1.15mm). This stronger inhibitory activity was confirmed by the low MIC (6.25, 12.5mg/L) and MAC (6.25, 12.5mg/L) values. Furthermore, results showed different sensitivity between the prokaryotic and eukaryotic microalgae into MEA extracts. Based on the MIC and MAC values, we can distinguish two groups of plants. The first one, including M. spicatum, Ranunculus aquatilis, and Enteromorpha sp., can be considered as a preferable anti-prokaryotic group with a stronger inhibitory activity on M. aeruginosa growth. The second group, constituted by Potamogeton natans, Nasturtium officinale, Elodea sp., and Ceratophyllum sp., has a preferable and stronger inhibitory effect against eukaryotic algae (Chlorella sp.). Overall the results reveal the potential algicidal activity of macrophytes and suggested that MEA extracts could play an important role in biocontrol of HABs.