Assessment of antimicrobial activity and GC-MS using culture filtrate of local marine Bacillus strains.

Secondary metabolites produced by Bacillus species from marine sources encompass a variety of compounds such as lipopeptides, isocoumarins, polyketides, macrolactones, polypeptides and fatty acids. These bioactive substances exhibit various biological activities, including antibiotic, antifungal, antiviral, and antitumor properties. This study aimed to isolate and identify a particular species of Bacillus from marine water and organisms that can produce bioactive secondary metabolites. Among the 73 Bacillus isolates collected, only 5 exhibited antagonistic activity against various viral and bacterial pathogens. The active isolates were subjected to 16S rRNA sequencing to determine their taxonomical affiliation. Among them, Bacillus tequilensis CCASU-2024-66 strain no. 42, with the accession number ON 054302 in GenBank, exhibited the highest inhibitory potential. It displayed an inhibition zone of 21 mm against Bacillus cereus while showing a minimum zone of inhibition of 9 mm against Escherichia coli and gave different inhibition against pathogenic fungi, the highest inhibition zone 15 mm against Candida albicans but the lowest inhibition zone 10 mm was against Botrytis cinerea, Fusarium oxysporum. Furthermore, it demonstrated the highest percentage of virucidal effect against the Newcastle virus and influenza virus, with rates of 98.6% and 98.1%, respectively. Furthermore, GC-MS analysis was employed to examine the bioactive substance components, specifically focusing on volatile and polysaccharide compounds. Based on these results, Bacillus tequilensis strain 42 may have the potential to be employed as an antiviral agent in poultry cultures to combat Newcastle and influenza, two extremely destructive viruses, thus reducing economic losses in the poultry production sector. Bacteria can be harnessed for the purpose of preserving food and controlling pathogenic fungi in both human and plant environments. Molecular docking for the three highly active derivatives 2,3-Butanediol, 2TMS, D-Xylopyranose, 4TMS, and Glucofuranoside, methyl 2,3,5,6-tetrakis-O-(trimethylsilyl) was carried out against the active sites of Bacillus cereus, Listeria monocytogenes, Candida albicans, Newcastle virus and influenza virus. The data obtained from molecular docking is highly correlated with that obtained from biology. Moreover, these highly active compounds exhibited excellent proposed ADMET profile.

Assessment of Anti-Inflammatory and Antimicrobial Potential of Ethanolic Extract of Woodfordia fruticosa Flowers: GC-MS Analysis.

Currently, the potential utilization of natural plant-derived extracts for medicinal and therapeutic purposes has increased remarkably. The current study, therefore, aimed to assess the antimicrobial and anti-inflammatory activity of modified solvent evaporation-assisted ethanolic extract of Woodfordia fruticosa flowers. For viable use of the extract, qualitative analysis of phytochemicals and their identification was carried out by gas chromatography-mass spectroscopy. Analysis revealed that phenolic (65.62 ± 0.05 mg/g), flavonoid (62.82 ± 0.07 mg/g), and ascorbic acid (52.46 ± 0.1 mg/g) components were present in high amounts, while ß-carotene (62.92 ± 0.02 µg/mg) and lycopene (60.42 ± 0.8 µg/mg) were present in lower amounts. The antimicrobial proficiency of modified solvent-assisted extract was evaluated against four pathogenic bacterial and one fungal strain, namely Staphylococcusaureus (MTCC 3160), Klebsiellapneumoniae (MTCC 3384), Pseudomonasaeruginosa (MTCC 2295), and Salmonellatyphimurium (MTCC 1254), and Candidaalbicans (MTCC 183), respectively. The zone of inhibition was comparable to antibiotics streptomycin and amphotericin were used as a positive control for pathogenic bacterial and fungal strains. The extract showed significantly higher (p < 0.05) anti-inflammatory activity during the albumin denaturation assay (43.56-86.59%) and HRBC membrane stabilization assay (43.62-87.69%). The extract showed significantly (p < 0.05) higher DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay and the obtained results are comparable with BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene) with percentage inhibitions of 82.46%, 83.34%, and 84.23%, respectively. Therefore, the obtained results concluded that ethanolic extract of Woodfordia fruticosa flowers could be utilized as a magnificent source of phenols used for the manufacturing of value-added food products.

Comprehensive assessment of machine learning-based methods for predicting antimicrobial peptides.

Antimicrobial peptides (AMPs) are a unique and diverse group of molecules that play a crucial role in a myriad of biological processes and cellular functions. AMP-related studies have become increasingly popular in recent years due to antimicrobial resistance, which is becoming an emerging global concern. Systematic experimental identification of AMPs faces many difficulties due to the limitations of current methods. Given its significance, more than 30 computational methods have been developed for accurate prediction of AMPs. These approaches show high diversity in their data set size, data quality, core algorithms, feature extraction, feature selection techniques and evaluation strategies. Here, we provide a comprehensive survey on a variety of current approaches for AMP identification and point at the differences between these methods. In addition, we evaluate the predictive performance of the surveyed tools based on an independent test data set containing 1536 AMPs and 1536 non-AMPs. Furthermore, we construct six validation data sets based on six different common AMP databases and compare different computational methods based on these data sets. The results indicate that amPEPpy achieves the best predictive performance and outperforms the other compared methods. As the predictive performances are affected by the different data sets used by different methods, we additionally perform the 5-fold cross-validation test to benchmark different traditional machine learning methods on the same data set. These cross-validation results indicate that random forest, support vector machine and eXtreme Gradient Boosting achieve comparatively better performances than other machine learning methods and are often the algorithms of choice of multiple AMP prediction tools.

Assessment of chemically characterized Salvia sclarea L. essential oil and its combination with linalyl acetate as novel plant based antifungal, antiaflatoxigenic and antioxidant agent against herbal drugs contamination and probable mode of action.

The present investigation reports antifungal and antiaflatoxigenic efficacy of Salvia sclarea essential oil (SSEO) and its combination with Linalyl acetate (LA) (1:1) against herbal drug deteriorating molds and aflatoxin B1 contamination. GC-MS analysis of SSEO showed Linalyl Acetate (LA) (61.33%) and Linalool (LL) (17.59%) as major components. The SSEO and LA combination displayed better antifungal and antiaflatoxigenic activity as compared to SSEO and LA used individually. SSEO and LA combination was effective in reduction of ergosterol and enhanced leakage of vital ions and UV-absorbing materials in a dose dependent manner. The combination caused significant reduction in cellular methylglyoxal content, an aflatoxin inducer suggesting its future application for development of aflatoxin resistant herbal drug varieties through green transgenics. The combination also showed pronounced antioxidant activity as compared to SSEO and LA used separately. Interestingly, the combination showed significant in situ protection of Picrorhiza kurroa rhizomes against mould infestation.

Shortened derivatives from native antimicrobial peptide LyeTx I: In vitro and in vivo biological activity assessment.

In the continuing search for novel antibiotics, antimicrobial peptides are promising molecules, due to different mechanisms of action compared to classic antibiotics and to their selectivity for interaction with microorganism cells rather than with mammalian cells. Previously, our research group has isolated the antimicrobial peptide LyeTx I from the venom of the spider Lycosa erythrognatha. Here, we proposed to synthesize three novel shortened derivatives from LyeTx I (LyeTx I mn; LyeTx I mnΔK; LyeTx I mnΔKAc) and to evaluate their toxicity and biological activity as potential antimicrobial agents. Peptides were synthetized by Fmoc strategy and circular dichroism analysis was performed, showing that the three novel shortened derivatives may present membranolytic activity, like the original LyeTx I, once they folded as an alpha helix in 2.2.2-trifluorethanol and sodium dodecyl sulfate. In vitro assays revealed that the shortened derivative LyeTx I mnΔK presents the best score between antimicrobial (↓ MIC) and hemolytic (↑ EC50) activities among the synthetized shortened derivatives, and LUHMES cell-based NeuriTox test showed that it is less neurotoxic than the original LyeTx I (EC50 [LyeTx I mnΔK] ⋙ EC50 [LyeTx I]). In vivo data, obtained in a mouse model of septic arthritis induced by Staphylococcus aureus, showed that LyeTx I mnΔK is able to reduce infection, as demonstrated by bacterial recovery assay (∼10-fold reduction) and scintigraphic imaging (less technetium-99m labeled-Ceftizoxime uptake by infectious site). Infection reduction led to inflammatory process and pain decreases, as shown by immune cells recruitment reduction and threshold nociception increment, when compared to positive control group. Therefore, among the three shortened peptide derivatives, LyeTx I mnΔK is the best candidate as antimicrobial agent, due to its smaller amino acid sequence and toxicity, and its greater biological activity.

Comparative Assessment of Antifungal and Antibacterial Activities of Crude Extracts of the King Tuber Culinary-Medicinal Mushroom, Pleurotus tuber-regium (Agaricomycetes) from Cameroon.

Antifungal and antibacterial activities of crude extracts of carpophore compared with those of sclerotium of Pleurotus tuber-regium were investigated on 11 species of bacterial and 3 fungal human pathogens. The minimal inhibitory concentration (MIC) of carpophore extract was recorded to be 12.5 mg/mL on Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Escherichia cloacae, Proteus mirabilis, P. vulgaris, Klebsiella oxytoca, and K. aerogenes and 6.25 mg/mL on Staphylococcus aureus, Escherichia coli, and Mycobacterium smegmatis as well as on all three species of fungal pathogens including Candida albicans, Aspergillus fumigatus, and A. ochraceus. In comparison, the MIC of sclerotium was recorded to be 12.5 mg/mL on Bacillus subtilis and Klebsiella aerogenes; 6.25 mg/mL on Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Enterobacter cloacae, E. coli, Mycobacterium smegmatis, Proteus mirabilis, P. vulgaris, and Klebsiella oxytoca; and 3.13 mg/mL on the three fungal pathogens. Based on the abovementioned figures, it appears that strains of pathogenic fungi tested are much more sensitive to crude extracts than the abovementioned bacteria. In fact, antimicrobial activities of crude extracts of P. tuber-regium, no matter whether it is that of the carpophore or its sclerotium, are in general stronger on human pathogenic fungi than bacteria. These figures also demonstrate that crude extracts of sclerotium show a higher antimicrobial activity than that of carpophore. Carpophores and sclerotia of P. tuber-regium could therefore constitute a source of new molecules potentially more efficient than synthetic products against some human pathogenic fungi and bacteria.

Green Synthesis of Encapsulated Copper Nanoparticles Using a Hydroalcoholic Extract of Moringa oleifera Leaves and Assessment of Their Antioxidant and Antimicrobial Activities.

: The synthesis of metal nanoparticles using plant extracts is a very promising method in green synthesis. The medicinal value of Moringa oleifera leaves and the antimicrobial activity of metallic copper were combined in the present study to synthesize copper nanoparticles having a desirable added-value inorganic material. The use of a hydroalcoholic extract of M. oleifera leaves for the green synthesis of copper nanoparticles is an attractive method as it leads to the production of harmless chemicals and reduces waste. The total phenolic content in the M. oleifera leaves extract was 23.0 ± 0.3 mg gallic acid equivalent/g of dried M. oleifera leaves powder. The M. oleifera leaves extract was treated with a copper sulphate solution. A color change from brown to black indicates the formation of copper nanoparticles. Characterization of the synthesized copper nanoparticles was performed using ultraviolet-visible light (UV-Vis) spectrophotometry, Fourier-transform infrared (FTIR) spectrometry, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The synthesized copper nanoparticles have an amorphous nature and particle size of 35.8-49.2 nm. We demonstrate that the M. oleifera leaves extract and the synthesized copper nanoparticles display considerable antioxidant activity. Moreover, the M. oleifera leaves extract and the synthesized copper nanoparticles exert considerable anti-bacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (MIC values for the extract: 500, 250, 250, and 250 µg/mL; MIC values for the copper nanoparticles: 500, 500, 500, and 250 µg/mL, respectively). Similarly, the M. oleifera leaves extract and the synthesized copper nanoparticles exert relatively stronger anti-fungal activity against Aspergillus niger, Aspergillus flavus, Candida albicans, and Candida glabrata (MIC values for the extract: 62.5, 62.5, 125, and 250 µg/mL; MIC values for the copper nanoparticles: 125, 125, 62.5, and 31.2 µg/mL, respectively). Our study reveals that the green synthesis of copper nanoparticles using a hydroalcoholic extract of M. oleifera leaves was successful. In addition, the synthesized copper nanoparticles can be potentially employed in the treatment of various microbial infections due to their reported antioxidant, anti-bacterial, and anti-fungal activities.

Biogenic synthesis and characterization of silver nanoparticles using aqueous leaf extract of Scoparia dulcis L. and assessment of their antimicrobial property.

Naturally occurring phytochemicals serve as an excellent substitute in synthesizing nanomaterials. A process for the synthesis of silver nanoparticles (AgNPs) from the aqueous leaf extract of naturally occurring Scoparia dulcis is described here. The extracellular formation of AgNPs occurred within few minutes upon incubation of S. dulcis aqueous leaf extract (0.1 mL) (100% extract) with silver nitrate (2 mM AgNO3) at 90 °C for 30 min, is first of its kind work. The appearance of bright yellow color with λmax 420 nm confirm the formation of AgNPs. Zeta potential and X-ray diffraction (XRD) studies reveal stable AgNPs (-22.7 mV) and characteristic spectra for silver. Fourier transform infrared (FTIR) spectroscopy indicate the involvement of carboxyl, amine and hydroxyl groups in the synthetic process. Transmission electron microscopy (TEM) show the spherical nature of AgNPs measuring 3-18 nm in size. Additional characterization using Dynamic light scattering (DLS) revealed the average particle size distribution of AgNPs as around 8.2 nm. Further antimicrobial testing through agar disc diffusion plate method indicated that silver nanoparticles are potentially active against pathogenic bacteria such as Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus aureus and are only optimally active against fungi such as Aspergillus niger and Candida albicans and measurement of minimal inhibition concentration by standard microdilution method. In conclusion, the study suggests that successful synthesis of green nanoparticles (AgNPs) using aqueous S. dulcis leaf extract is simple, rapid, environmentally benign and economical. Moreover, these synthesized silver nanoparticles showed antimicrobial activity.

Risk assessment of the antifungal and insecticidal peptide Jaburetox and its parental protein the Jack bean (Canavalia ensiformis) urease.

Jaburetox (JBTX) is an insecticidal and antifungal peptide derived from jack bean (Canavalia ensiformis) urease that has been considered a candidate for developing genetically modified crops. This study aimed to perform the risk assessment of the peptide JBTX following the general recommendations of the two-tiered, weight-of-evidence approach proposed by International Life Sciences Institute. The urease of C. ensiformis (JBU) and its isoform JBURE IIb (the JBTX parental protein) were assessed. The history of safe use revealed no hazard reports for the studied proteins. The available information shows that JBTX possesses selective activity against insects and fungi. JBTX and JBU primary amino acids sequences showed no relevant similarity to toxic, antinutritional or allergenic proteins. Additionally, JBTX and JBU were susceptible to in vitro digestibility, and JBU was also susceptible to heat treatment. The results did not identify potential risks of adverse effects and reactions associated to JBTX. However, further allergen (e.g. serum IgE binding test) and toxicity (e.g. rodent toxicity tests) experimentation can be done to gather additional safety information on JBTX, and to meet regulatory inquiries for commercial approval of transgenic cultivars expressing this peptide.

Assessment of biological activities of chitosan Schiff base tagged with medicinal plants.

A chitosan Schiff base with an aromatic aldehyde was synthesized and characterized by FTIR and NMR spectroscopies. Furthermore, the degree of substitution was calculated based on the ratios of the area of the proton of the imine (Aimine ) and the area of the peak of the proton of the pyranose ring (AH-2 ). The antimicrobial activities were determined against bacterial and fungal strains, as well as multiple drug-resistant (MDR) bacteria. The chitosan Schiff base was also tagged with medicinal plants, for example, Curcuma longa, Peganum harmala, Lepidium sativam, and cruciferous vegetables, and the biological activities determined against pathogenic bacterial and fungal strains. The chitosan Schiff base showed maximum zone of inhibition of 22 mm against Staphylococcus aureus with a minimum zone of inhibition of 15 mm against Bacillus cereus. The chitosan Schiff base was fused with C longa, isothiocyanates and a combined mixture of P harmala and L sativam that has shown activities against Escherichia coli with a zone of inhibition of 28, 24, and 30 mm, respectively. The Schiff base of chitosan fused with medicinal plants also showed significant inhibitory activities against MDR bacteria.

Phytochemical screening and bioactivity assessment of leaves and fruits extract of Carica papaya.

The consumption of fruits and vegetables has increased in recent years due to their health benefits as fruits and vegetables contain secondary metabolites, those has been reported to possess different pharmacological effects against many human ailments. In the current study antioxidants, antimicrobial and cytotoxic effects of leaves and fruit extracts of Carica papaya were evaluated. The antioxidant activities of plant extracts were carried out by using 2,2 -diphenyl-1- picrylhydrazyl. (DPPH), H2O2, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and reducing power assays and were compared with standards compounds (Ascorbic acid and Rutin). Antibacterial and antifungal activities of leaves and fruit extracts were assessed against four bacterial and fungal strains and also their minimum inhibitory concentration (MIC) values were calculated. Whereas for evaluation of cytotoxicity of plant extracts, brine shrimps cytotoxic assay was performed. Plant extracts were finally analyzed for phytochemicals by using UV/Visible spectrophotometer and High performance liquid chromatography (HPLC). Results indicates that plants extracts contained important compounds (phenols, flavonoids and other secondary metabolites) those have higher antioxidants and antimicrobial as well as lower proportion of MIC values. Whereas cytotoxic index of plant extracts were minor that specifies its appropriateness to use as a pharmaceutical materials probably be essential for drugs preparation. It is expected that such drugs could be lesser toxic and have lower cost as compared to drugs already available in market.

In vitro assessment of antibacterial, antifungal, enzyme inhibition and hemolytic activities of various fractions of Rhynchosia pseudo-cajan.

The aims of the present investigation were to assess the antibacterial, antifungal, enzyme inhibition and hemolytic activities of various fractions of Rhynchosia pseudo-cajan Cambess. The methanolic extract of the plant was dissolved in the water (distilled) and then partitioned with the n-hexane, chloroform, EtOAc and n-BuOH sequentially. Antibacterial activity was checked against Escherichia coli, Pasturella multocida, Bacillus subtilis and Staphylococcus aureus by the disc diffusion method using streptomycin sulphate, a standard antibiotic, as positive control. Chloroform and ethyl acetate soluble fractions showed good activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus. These fractions also showed good MIC values. The n-butanol soluble and remaining aqueous fraction also showed good activity against some strains. Antifungal activity was studied against four fungi i.e. Aspergillus niger, Aspergillus flavus, Ganoderma lucidum and Alternaria alternata by the disc diffusion method using fluconazole, a standard antifungal drug, as positive control. Chloroform, n-butanol and ethyl acetate soluble fraction showed good activity only against G. lucidum. Enzyme inhibition studies were done against four enzymes i.e. α-glucosidase, butyrylcholinesterase, acetyl cholinesterase and lipoxygenase. Aqueous fraction possessed very good activity against α-glucosidase, even greater than acarbose, a reference standard drug. Its IC50 value was found as 29.81±0.12 µg/ml as compared to acarbose having IC50 38.62±0.04 µg/ml. Chlroform and ethyl acetate soluble fractions also showed good activity against α-glucosidase. Ethyl acetate soluble and remaining aqueous fractions showed good activity against lipoxygenase. All the studied fractions showed very less toxicity i.e. <2.5%.

The novel economical synthesis and antimicrobial activity of a trithiocarbonate derivative.

The compound diethyl 2,2'-(thiocarbonyl-bis(sulfanediyl))-diacetate 4 belongs to the trithiocarbonate class containing a trithiocarbonate function group flanked by ethyl acetate. In this procedure, a novel economic synthesis route to obtain compound 4 is described. This compound proved to possess broad-spectrum antimicrobial activity both in vitro and in vivo, and could be used as a lead compound. It is worth mentioning that this compound has been patented [No. US 9,988,348 B1; date of patent: June 5, 2018].

Scalable and cost-effective tosylation-mediated synthesis of antifungal and fungal diagnostic 6″-Modified amphiphilic kanamycins.

Amphiphilic kanamycins bearing hydrophobic modifications at the 6″ position have attracted interest due to remarkable antibacterial-to-antifungal switches in bioactivity. In this report, we investigate a hurdle that hinders practical applications of these amphiphilic kanamycins: a cost-effective synthesis that allows the incorporation of various connecting functionalities to which the hydrophobic moieties are connected to the kanamycin core. A cost-effective tosylation enables various modifications at the 6″ position, which is scalable to a 90-g scale. The connecting functionalities, such as amine and thiol, were not the dominant factor for biological activity. Instead, the linear chain length played the decisive role. Amphiphilic kanamycin attached with tetradecyl (C14) or hexadecyl (C16) showed strong antifungal and modest antibacterial activities than with shorter chains (C6-C10). However, increases in chain length were closely correlated with an increase in HeLa cell toxicity. Thus, a compromise between the antimicrobial activities and cytotoxicities, for optimal efficacy of amphiphilic kanamycins may contain chain lengths between C8 and C12. Finally, the described synthetic protocol also allows the preparation of a fluorescent amphiphilic kanamycin selective toward fungi.

Time to clinical response in sepsis associated with an algorithm for blood-culture pathogen identification using matrix-assisted laser desorption ionization time-of-flight mass spectroscopy.

PURPOSE: Antimicrobial stewardship programs (ASPs) can be aided by using rapid diagnostics (RDT). However, there are limited data evaluating the impact of ASPs and RDT on sepsis outcomes in the setting of the new Sepsis-3 guidelines. This study evaluates the impact of a low-resource method for ASPs with RDT on sepsis outcomes. METHODS: This was a prospective, quasi-experimental study with a retrospective double pretest. Patients ≥ 18 years old with sepsis and concurrent bacteremia or fungemia were included; patients who were pregnant, had polymicrobial septicemia or who were transferred from an outside hospital were excluded. In the first pretest (O1), polymerase chain reaction was used to identify Staphylococcal species from positive blood cultures, and traditional laboratory techniques were used to identify other species. Matrix-assisted laser desorption ionization time-of-flight mass spectroscopy and FilmArray were implemented in the second pretest (O2), and twice daily blood culture review was implemented in the posttest (O3). RESULTS: A total of 394 patients (157 in O1, 176 in O2, 61 in O3) were enrolled. Clinical response was 73.2%, 83.5%, and 88.5% in O1, O2, and O3, respectively, p = 0.013. By Cox regression, the O3 was associated with improved time to clinical response (hazard ratio, 1.388; 95% confidence interval, 1.004-1.919) as compared with O1. Mortality, hospital length of stay, and intensive care unit length of stay were unchanged between groups. CONCLUSION: Twice-daily blood culture review may be useful for implementing rapid diagnostics within low-resource ASPs. Further research is needed to identify the optimal method of blood culture follow-up within low-resource settings.

Is the Effect Assessment Approach for Fungicides as Laid Down in the European Food Safety Authority Aquatic Guidance Document Sufficiently Protective for Freshwater Ecosystems?

In Europe, the European Food Safety Authority aquatic guidance document describes the procedures for the derivation of regulatory acceptable concentrations (RACs) for pesticides in edge-of-field surface waters on the basis of tier-1 (standard test species), tier-2 (geometric mean and species sensitivity distributions [SSDs]), and tier-3 (model ecosystem studies) approaches. In the present study, the protectiveness of such a tiered approach was evaluated for fungicides. Acute and chronic RACs for tier-1 and tier-2B (SSDs) were calculated using toxicity data for standard and additional test species, respectively. Tier-3 RACs based on ecological thresholds (not considering recovery) could be derived for 18 fungicides. We show that tier-1 RACs, in the majority of cases, are more conservative than RACs calculated based on model ecosystem experiments. However, acute tier-2B RACs do not show a sufficient protection level compared with tier-3 RACs from cosm studies that tested a repeated pulsed exposure regime or when relatively persistent compounds were tested. Chronic tier-2B RACs showed a sufficient protection level, although they could only be evaluated for 6 compounds. Finally, we evaluated the suitability of the calculated RACs for 8 compounds with toxicity data for fungi. The comparison shows that the current RACs for individual fungicides, with a few exceptions (e.g., tebuconazole), show a sufficient protection level for structural and functional fungal endpoints. However, more data are needed to extend this comparison to other fungicides with different modes of action. Environ Toxicol Chem 2019;38:2279-2293. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Antifungal, antibacterial, antibiofilm and colorimetric sensing of toxic metals activities of eco friendly, economical synthesized Ag/AgCl nanoparticles using Malva Sylvestris leaf extracts.

Silver nanoparticles, one of the most popular nanomaterials, are used extensively in medicine and industries. The present study biosynthesized spherical Ag/AgCl nanoparticles with a size range of 10-50 nm in less than 5 min. The synthesis was performed in a single step, in a low-cost and eco-friendly manner, from the aqueous extract of Malva Sylvestris leaves. The aqueous extract had a large number of phenolic compounds and carbohydrates as reducing and capping agents. The nanoparticles also showed significant antibacterial and anti-biofilm activities against some multi drug resistant bacteria. They additionally showed antifungal activities on several Candida species. The highest concentration of Ag/AgCl-NPs (62.5 µg/ml) was required in order to inhibit P. aeruginosa B 52, C. glabrata and C. parapsilosis growth. The lowest concentration of Ag/AgCl-NPs (7.8125 µg/ml) inhibited the growth of C. orthopsilosis, P. aeruginosa ATCC 27853 and B. subtilis ATCC 6633. A total of 125 µg/ml of Ag/AgCl-NPs was used to prevent P. aeruginosa B 52 biofilm growth. The concentration of 62.5 µg/ml Ag/AgCl-NPs also eradicated both P. aeruginosa 48 and P. aeruginosa B 52 biofilms. The results showed that Hg2+ and Pb2+ contaminants in water could be colorimetrically detected by these nanoparticles.

Determination of azole fungal residues in soils and detection of Aspergillus fumigatus-resistant strains in market gardens of Eastern France.

Medical azole antifungals are major compounds used to prevent and to treat invasive aspergillosis (IA). Azole fungicides, called DMI (14-alpha demethylase inhibitors), are also widely used for crop protection and have been reported to be linked to azole-resistant A. fumigatus (aR-Af) development in the environment. The aim of this study was to determine whether or not market gardens that spray DMIs in Eastern France are also affected by the presence of aR-Af. Forty aR-Afs were detected in soils in only two of the four market gardens using DMIs, with 23% (7/30) and 10% (3/30) of soils containing aR-Af. A total of 87.5% of these isolates had the TR34/L98H mutation and 22.5% the TR46/Y121F/T289A mutation on the cyp51A gene. Analyses of residual azole concentrations in soils showed the presence of difenoconazole for up to 2 years after spraying, but only in soils of market gardens where aR-Af was detected. It is very important to identify professional activities that could lead to aR-Af development and to develop preventive measures for at-risk patients living near professional activities using DMIs. We have to better understand why, in some cases, the use of DMI is not linked to aR-Af. Measures should be taken to avoid the use of DMI conferring cross-resistance to preserve the efficiency of human therapeutics.

Interaction between Different Pharmaceutical Excipients in Liquid Dosage Forms-Assessment of Cytotoxicity and Antimicrobial Activity.

Nowadays, the safety of parabens as pharmaceutical preservatives is debated. Recent studies investigated their interference with the oestrogen receptors, nevertheless their carcinogenic activity was also proved. That was the reason why the re-evaluation of the biocompatibility and antimicrobial activity of parabens is required using modern investigation methods. We aimed to test the cytotoxic, antifungal and antibacterial effect of parabens on Caco-2 cells, C. albicans, C. parapsilosis, C. glabrata, E. coli, P. aeruginosa and S. aureus. Two complex systems (glycerol-Polysorbate 20; ethanol-Capryol PGMC™) were formulated to study-with the MTT-assay and microdilution method, respectively-how other excipients may modify the biocompatibility and antimicrobial effect of parabens. In the case of cytotoxicity, the toxicity of these two systems was highly influenced by co-solvents and surfactants. The fungi and bacteria had significantly different resistance in the formulations and in some cases the excipients could highly modify the effectiveness of parabens both in an agonistic and in a counteractive way. These results indicate that with appropriate selection, non-preservative excipients can contribute to the antimicrobial safety of the products, thus they may decrease the required preservative concentration.

Assessment of toxicity and differential antimicrobial activity of methanol extract of rhizome of Simaba ferruginea A. St.-Hil. and its isolate canthin-6-one.

ETHNOPHARMACOLOGICAL RELEVANCE: Simaba ferruginea A. St.-Hil., Simaroubaceae, popularly known as "calunga" is a typical subtropical shrub used in Central Brazil mainly for infection, anti-inflammatory, analgesic and gastric duodenal-ulcers. It presents in its composition the alkaloid canthin-6-one, an alkaloid indole ß-carboxylic. AIM: This study aims to investigate the toxicity, antimicrobial activities of methanol extract of Simaba ferruginea (MESf) and canthin-6-one by using different experimental models. METHODS: The present study evaluated the phytochemical analysis by high performance liquid chromatography (HPLC), toxicological potential of MESf and canthin-6-one, using the cytotoxicity, genotoxicity assays with CHO-K1 cells and in vivo acute test in mice. Antimicrobial activity was evaluated by the broth microdilution assays, while the antimicrobial mechanism of action was also assessed using different in vitro bacterial and fungal models. RESULTS: The HPLC analysis of MESf revealed the presence of canthin-6-one, kaempferol and morin. Differential in vitro toxicities were observed between MESf and canthin-6-one. In the cytotoxicity assay, MESf presented toxicity against CHO-K1, while canthin-6-one did not. In the case of in vitro genotoxicity, both showed to be potentially genotoxic. In the in vivo toxicity study, both MESf (up to 1000 mg/kg) and cantin-6-one (up to 100 mg/kg) caused no toxicologically relevant alterations and are thus considered not to be toxic. MESf was shown to be relatively safe with NOAEL (100 mg/kg) when administrate in mice. Both MESf and canthin-6-one also showed differential antimicrobial activities. On one hand, MESf demonstrated good spectrum of antibacterial action against Staphylococcus aureus (MIC 12.5 µg/mL) and Escherichia coli (MIC 25 µg/mL) and moderate activity against Enterococcus faecalis and Shigella flexneri (MIC 200 µg/mL) but no antifungal effect. On the hand, canthin-6-one showed no antibacterial activity, except against Staphylococcus aureus (100 µg/mL), but potent in vitro fungicidal activity against clinically important Aspergillus niger and Candida species at MFC intervals ranging from 3.12 to 25 µg/mL. Both MESf and canthin-6-one were bacteriostatic in action. MESf antimicrobial mechanism of actions are associated with changes in the permeability of bacterial membranes, evidenced by the increased entry of hydrophobic antibiotic in Shigella flexneri, intense K+ efflux (Shigella flexneri, Staphylococcus aureus) and nucleotides leakage (Staphylococcus aureus). In the antifungal mode of action, canthin-6-one inhibited Saccharomyces cerevisiae growth and including alteration in the cell membrane of Neurospora crassa. CONCLUSION: The results of this work demonstrated the differential antimicrobial activities of MESf and its alkaloid isolate, canthin-6-one with antibacterial and antifungal activities, respectively. The present study support the popular use of Simaba ferruginea in combatting afflictions related to bacterial infections, and demonstrate that canthin-6-one as a promising antifungal agent. Both MESf and canthin-6-one are considered non-toxic based on the in vitro toxicological study.