Antibiotic Properties Research Articles

Design and evaluation of composite films for in situ synthesis and antibacterial activity of allicin vapour

Although allicin has potent antibiotic properties, its low stability, which is responsible for its persistent biological activity, has posed a significant challenge to its practical application in modern medicine. To harness the healing benefits of this phytochemical, known by humans for thousands of years, we propose a controlled in situ synthesis of allicin vapour near the site of infection. Considering the critical need for novel approaches to prevent pandemic scenarios caused by MDR bacteria, we suggest encapsulating and physically separating allicin precursors (substrate alliin and enzyme alliinase) in alginate-based films and spray-dried chitosan microparticles. The mechanical properties of the hydrogel films of various compositions were evaluated, as well as their ability to protect the encapsulated alliinase against thermal stress and control the overall rate of allicin release upon hydration. Furthermore, the non-contact antibacterial efficacy of free alliin/alliinase reaction mixture (aqueous solution) and three compartmentalised configurations, i.e. film-solution, film-particles, and double-film, were tested against selected bacterial strains, i.e. E. coli, S. epidermidis, and S. aureus. The results indicate that the formation of allicin vapour using the proposed compartmentalised systems addresses allicin’s stability issues and provides better control over the rate of allicin production. The observed antibacterial effect was comparable with directly formed allicin using higher initial amounts of both substances, which is given by diffusion limitations associated with encapsulation. These findings illustrate the potential of compartmentalised systems in developing nature-based wound dressings for infection prevention and promoting healing.

Study on the Distribution Characteristics and Risk Assessment of Antibiotics and Resistance Genes in Water Sources of Wuhan.

In contemporary society, the improper use of antibiotics leads to their persistent presence in the ecological environment. Due to the diverse physical and chemical properties of antibiotics, their spatial and temporal distribution in the environment varies. Moreover, antibiotics can stimulate the emergence of antibiotic resistance genes (ARGs), which complicates the monitoring and regulation of antibiotics and poses a significant threat to both aquatic and terrestrial environments. This study investigated the distribution of 15 antibiotics and 11 typical ARGs across four categories at 19 sites of drinking water sources in Wuhan, China. The findings revealed that the concentration of antibiotics during the dry season (nd~61,883 ng/L) was significantly higher compared to both the normal water season (nd~49,883 ng/L) and the wet season (nd~28,686 ng/L). Sulfamethoxazole (SMX), sulfamethoxazole (SMD), sulfadiazine (SD), and roxithromycin (RTM) were the predominant antibiotics in the target water environments. The study indicated that most of the antibiotics analyzed posed little to no risk to aquatic organisms. The primary ARGs detected in the surface water of the study area were sul1, qnrD, and tetO. Furthermore, some ARGs showed a negative correlation with their respective antibiotics. Additional research is necessary to evaluate the impact of these emerging pollutants (antibiotics and ARGs) on the safety of high-quality drinking water for residents in Wuhan City.

Subtask-Aware Representation Learning for Predicting Antibiotic Resistance Gene Properties via Gating-Controlled Mechanism.

The crisis of antibiotic resistance has become a significant global threat to human health. Understanding properties of antibiotic resistance genes (ARGs) is the first step to mitigate this issue. Although many methods have been proposed for predicting properties of ARGs, most of these methods focus only on predicting antibiotic classes, while ignoring other properties of ARGs, such as resistance mechanisms and transferability. However, acquiring all of these properties of ARGs can help researchers gain a more comprehensive understanding of the essence of antibiotic resistance, which will facilitate the development of antibiotics. In this paper, the task of predicting properties of ARGs is modeled as a multi-task learning problem, and an effective subtask-aware representation learning-based framework is proposed accordingly. More specifically, property-specific expert networks and shared expert networks are utilized respectively to learn subtask-specific features for each subtask and shared features among different subtasks. In addition, a gating-controlled mechanism is employed to dynamically allocate weights to subtask-specific semantics and shared semantics obtained respectively from property-specific expert networks and shared expert networks, thus adjusting distinctive contributions of subtask-specific features and shared features to achieve optimal performance for each subtask simultaneously. Extensive experiments are conducted on publicly available data, and experimental results demonstrate the effectiveness of the proposed framework on the task of ARGs properties prediction.

Effects of probiotics on productive performances and serum lipid profile of broiler as substitute of antibiotics.

The present research was accomplished to characterize probiotics from broiler gastrointestinal tract (GIT) by profiling biochemical, antimicrobial, and antibiotic sensitivity properties. Eventually, probiotic potentiality was evaluated as a substitute for antibiotic supplements in broiler focusing growth performance, carcass characteristics, and serum lipid profile. Probiotic bacteria were characterized based on morphological, physiological, and several biochemical tests. Antibacterial activity against a broad spectrum of antibiotics and bacterial pathogens was detected. An in vivo trial was conducted on 40-day-old Ross 308 broiler strains during 21 days in an in vivo trial. The chicks were divided into total of five groups, a control group and four experimental groups (Antibiotic1, Antibiotic2, Probiotic1, and Probiotic2) in a completely randomized design. Probiotic was supplemented in broiler feed (2× 109 CFU/g feed) or by direct oral gavage (1× 109 CFU/chick). The variables of production performance like body weight (BW), average daily gain (ADG), feed intake (FI), and feed conversion ratio (FCR), carcass characteristics and serum lipid profile were measured. 10 probiotic bacteria were presumptively identified as Lactobacillus sp. based on the morphological, physiological, and strong resistance properties in several biochemical tests. The mixture of Lactobacillus had favorable effects on productive performance of broilers regarding BW, ADG, and FCR (p < .05) compared with chickens that had no additive or had antibiotic during overall period of in vivo trial. Additionally, noteworthy efficacy on carcass characteristics and serum lipid profile were found (p < .05) in Lactobacillus mixture fed chicken groups of in vivo trial. Mixed Lactobacillus sp. can be considered as a potential additive for broiler diet attributable to noteworthy efficacy on growth performance, carcass characteristics, and serum lipid profile. Accordingly, the research highlights the need for suitable alteration of antibiotics through probiotic characterization and proper inclusion in broiler diet.

A New Nanoplatform Under NIR Released ROS Enhanced Photodynamic Therapy and Low Temperature Photothermal Therapy for Antibacterial and Wound Repair.

Skin injury, often caused by physical or medical mishaps, presents a significant challenge as wound healing is critical to restore skin integrity and tissue function. However, external factors such as infection and inflammation can hinder wound healing, highlighting the importance of developing biomaterials with antibiotic and wound healing properties to treat infections and inflammation. In this study, a novel photothermal nanomaterial (MMPI) was synthesized for infected wound healing by loading indocyanine green (ICG) on magnesium-incorporated mesoporous bioactive glass (Mg-MBG) and coating its surface with polydopamine (PDA). In this study, Mg-MBG and MMPI was synthesized via the sol-gel method and characterized it using various techniques such as scanning electron microscopy (SEM), the energy dispersive X-ray spectrometry (EDS) system and X-ray diffraction (XRD). The cytocompatibility of MMPI was evaluated by confocal laser scanning microscopy (CLSM), CCK8 assay, live/dead staining and F-actin staining of the cytoskeleton. The antibacterial efficiency was assessed using bacterial dead-acting staining, spread plate method (SPM) and TEM. The impact of MMPI on macrophage polarization was initially evaluated through flow cytometry, qPCR and ELISA. Additionally, an in vivo experiment was performed on a mouse model with skin excision infected. Histological analysis and RNA-seq analysis were utilized to analyze the in vivo wound healing and immunomodulation effect. Collectively, the new photothermal and photodynamic nanomaterial (MMPI) can achieve low-temperature antibacterial activity while accelerating wound healing, holds broad application prospects.

Uji Aktivitas Antibakteri Kombinasi Ekstrak Etanol 70% Daun Jarak Pagar (Jatropha curcas L.) dan Daun Belimbing Wuluh (Averrhoa bilimbi L.) terhadap Bakteri Staphylococcus epidermidis

Staphylococcus epidermidis is a gram-positive bacterium that can cause acne. It is part of the normal flora found on the skin and is non-pathogenic. Metabolite compounds such as tannins, saponins, triterpenoids, and flavonoids present in starfruit leaves and castor leaves have antibiotic properties. The aim of this study was to determine the effectiveness of the combination of starfruit leaf extract and castor leaf extract, and to identify the most effective concentration ratio of these extracts in inhibiting Staphylococcus epidermidis bacteria. The research method used was experimental, conducting in-vitro antibacterial activity tests against Staphylococcus epidermidis. The results of the antibacterial test using a combination of starfruit leaf extract and castor leaf extract showed that at the highest ratio of 1:3, it produced an average inhibition zone of 15.73 mm against Staphylococcus epidermidis bacteria. This result was higher compared to the positive control Clindamycin HCl.

Unveiling the adsorption mechanisms of macrolides by mesoporous carbons through molecular dynamics simulation and multilinear regression modelling

Mesoporous carbon materials (MCs) are known for their high specific surface area and porous structure, rendering them promising candidates for efficient antibiotic adsorption. However, the influence of antibiotic properties and the porous structure of MCs on adsorption remains unclear. This study investigated the adsorption behaviors of ten macrolides (MLs) onto four MCs with porous structures, aiming to understanding the key factors governing their adsorption. The results revealed that the adsorption rate constant (k2) and adsorption constant of Freundlich isotherm (KF) were influenced by the McGowan molar volume of MLs. Molecular dynamics simulations uncovered that a distance of approximately 4 Å between adsorbed MLs from the material surface, suggesting hydrophobic interactions play a crucial role. Moreover, ML diffusion was more favorable on the surface of 10 nm pore compared to 2 nm pores, highlighting the impact of pore size on diffusion. Additionally, the diffusion coefficient of MLs was mainly determined by logKow, emphasizing the significance of hydrophobic interactions in diffusion. Multilinear regression modelling further supports hydrophobic interactions as the main adsorption mechanism for MLs. Overall, this study provides valuable insights into the complex adsorption mechanisms of MLs on MCs, informing the development of more effective antibiotic removal strategies.

Is lecanoric acid a good antioxidant?

Lecanoric acid (LA), an abundant chemical found in lichens, has demonstrated a wide range of biological activities, including anti-cancer cytotoxic, antibiotic, antimycobacterial, antiviral, and anti-hepatocarcinoma properties. The antioxidant capacity of this molecule, while inferred from certain experimental findings, is doubtful based on structural characteristics and therefore remains to be established. DFT calculations are used in this work to conduct a comprehensive evaluation of the mechanism and kinetics governing the antiradical activity of LA in lipidic and aqueous solvent environments. Although the DPPH/ABTS+ assays revealed good antioxidant activity in vitro, the modeling yielded mixed results. The data suggests that LA is an efficient scavenger of the HO radical with rate constants of 2.01 × 1010 and 2.80 × 108 M−1 s−1 in polar and lipid media, respectively, by the FHT and RAF mechanisms. However, the data also suggests that LA exhibits only weak activity against the HOO radical in all physiological environments. This is consistent with structural features that predict low activity.

Characterization of a methyltransferase for iterative N-methylation at the leucinostatin termini in Purpureocillium lilacinum

N-methyltransferase (NMT)-catalyzed methylation at the termini of nonribosomal peptides (NRPs) has rarely been reported. Here, we discover a fungal NMT LcsG for the iterative terminal N-methylation of a family of NRPs, leucinostatins. Gene deletion results suggest that LcsG is essential for leucinostatins methylation. Results from in vitro assays and HRESI-MS-MS analysis reveal the methylation sites as NH2, NHCH3 and N(CH3)2 in the C-terminus of various leucinostatins. LcsG catalysis yields new lipopeptides, some of which demonstrate effective antibiotic properties against the human pathogen Cryptococcus neoformans and the plant pathogen Phytophthora infestans. Multiple sequence alignments and site-directed mutagenesis of LcsG indicate the presence of a highly conserved SAM-binding pocket, along with two possible active site residues (D368 and D395). Molecular dynamics simulations show that the targeted N can dock between these two residues. Thus, this study suggests a method for increasing the variety of natural bioactivity of NPRs and a possible catalytic mechanism underlying the N-methylation of NRPs.

Identification of Inhibitors for Flagellar Assembly Protein FliN of Uropathogenic Escherichia coli using Virtual Screening and Molecular Dynamics Simulation Study.

Escherichia coli (E. coli) is a gram-negative bacterial pathogen that poses a significant clinical and epidemiologic challenge. The selection pressure brought by the insufficient use of antibiotics has resulted in the emergence of multi-drug-resistant E. coli in the past ten years. Computational and bioinformatics methods for screening inhibitors have significantly contributed to discovering novel antibacterial agents. One possible target for novel anti-virulence drugs is motility. Motility inhibitors are generally effective at concentrations lower than those required for the antibacterial properties of traditional antibiotics, and they are likely to exert less selective pressure than current medicines. Motility may be essential for bacteria to survive, find nutrients, and escape unfavorable environments and biofilm formation. The FliN is a protein forming the bulk of the C ring of the flagella and is present in multiple copies (more than 100) in bacteria. Its absence in mammals makes it an attractive drug target for drug discovery. Two-thousand seven hundred seventy-eight natural compounds from the ZINC library were screened against FliN (PDB ID: 4YXB) using PyRx AutoDock Vina, and the top compounds were selected for secondary screening after sorting the results based on their binding energy. Based on interactional analysis, binding energy (- 7.78kcal/mol), and inhibition constant (1.98µM), ZINC000000619481 was the best inhibitor. This compound binds exactly as per the defined active site residues of the receptor protein. Also, molecular dynamics was performed. The eigenvalue of the selected complex was 1.241657e-05. There were no ADME properties outside of the specified range for the identified hit; it fitted exactly to the binding site of the FliN receptor well and was found to be stable in MD simulation studies. Further in vitro and in vivo studies are needed to confirm its anti-bacterial activity and use as a potential antimicrobial drug against urinary tract infections caused by E. coli.

EVALUATION OF CEPHALOSPORIN’S LIPOPHILIC PROPERTIES

As a part of the study, a comparative analysis of different generations three representative’s lipophilic properties of cephalosporin antibiotics, namely cefazolin, cefotaxime and cefepime, was carried out. Lipophilicity is a very important physicochemical property of medicinal substances, since it determines their ability to pass through protective barriers, distribute, accumulate in tissues and body fluids, be broken down and excreted, which, in turn, affects the manifestation of antibacterial activity and the cytotoxic effect of antibiotics. During the experiment, a series of drugs aqueous solutions were prepared, then the antibiotics were extracted with highly purified olive oil, after which the aqueous phase was taken and the osmolality value for it was determined. Based on the calibration dependences of the osmolality value on the concentration of the antibiotic in the aqueous phase after extraction, the logarithms of the distribution coefficients in the «oil/water» system were calculated, which is a numerical indicator of the lipophilicity of substances. Using the capabilities of the online platform «Molinspiration Cheminformatics Software», the theoretical values of the studied drugs distribution coefficients logarithms were also determined, and the theoretical values correlated with the experimental ones. Based on the data obtained, it was revealed that the studied antibiotics have low lipophilicity, which decreases in the order: cefotaxime &gt; cefazolin &gt; cefepime. The work also assessed the relationship between solution pH and lipophilic properties. Pearson's r-coefficients between pH and antibiotic concentrations in oil after extraction of cefotaxime and cefazolin show a weak inverse relationship between the studied parameters. For cefepime solutions, a similar linear correlation coefficient demonstrates a direct high relationship between the pH of the solution and the lipophilicity of the antibiotic. The results of the study can be taken into account during antibiotic therapy with appropriate cephalosporins, as well as when creating a new generation of antibiotics. For citation: Kataeva N.N., Naronova N.A., Golitsyna K.O., Belokonova N.A., Shulepova K.E. Evaluation of cephalosporin’s lipophilic properties. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 55-62. DOI: 10.6060/ivkkt.20246707.7018.

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.

Nanoformulations for lysozyme-based additives in animal feed: An alternative to fight antibiotic resistance spread

Abstract The problem of antibiotic resistance (AR) in pathogenic bacteria due to the massive use of antibiotics in animals is an underestimated issue. Finding alternatives to reduce or eliminate the appearance and spread of AR is a pressing issue for humanity. Enzymes with antibiotic properties may serve as antimicrobial agents, less prone to generating AR due to their proteic nature and mode of action. Lysozyme is a natural antimicrobial agent, amenable to replacing small-molecule antibiotics in animal farming (poultry and livestock) due to its similar effects on animal health and growth. Moreover, it is safe for human and animal consumption and environmentally friendly due to its biodegradability. The development and testing against pathogens of lysozyme-containing nanomaterials fabricated with biocompatible polymers, particularly polysaccharides is reviewed, focusing on their antimicrobial properties, often superior to lysozyme alone due to a synergistic effect of the nanoscaled materials.

Effect of a garlic drench on Galectin gene expression in ovine whole blood

Garlic, known for its immune-modulating and antibiotic properties, contains lectins that possess antimicrobial and immunomodulatory effects. Galectins (Gals), which bind β-galactosides, play a role in modulating immunity and pathological processes. It is hypothesized that garlic’s lectin components interfere with animal lectins. St. Croix sheep, known for their resistance to parasites and adaptability, are influenced by dietary supplements for innate immunity. This study evaluated the impact of garlic drench on Galectin gene expression in St. Croix sheep. Adult non-lactating ewes received either garlic juice concentrate or sterile distilled water for four weeks. Blood samples were collected, and plasma and whole blood cells were separated. Galectin secretion was assessed using a Sheep-specific ELISA, while Galectin gene transcription was analyzed through real-time PCR. Garlic administration upregulated LGALS-3 gene expression and significantly increased total plasma protein concentration. Garlic supplementation also affected Galectin secretion, with Gal-1, Gal-3, and Gal-9 showing differential effects.

Antibacterial Screening of Chromolaena odorata Root Extracts and in silico Physico-chemical Properties of their Bioactive Compounds

Bacterial infection constitutes global health challenges due to antimicrobial resistance prevalence, and the search for natural and potent antibacterial agents continues. This study aimed to evaluate the antibacterial activity Chromolaena odorata root aqueous and methanolic extracts, and to also predict in silico the physicochemical properties of their bioactive compounds. The plant roots were air-dried and ground into fine powder using mortar and pestle. The aqueous and methanolic extracts were prepared using the C. odorata root powder. The chemical composition of the two extracts was analyzed using gas chromatography-mass spectrometry (GC-MS) to identify their bioactive compounds. The physicochemical properties of the identified compounds were then predicted using the SwissADME server. Additionally, the antibacterial properties of the extracts were evaluated by testing their inhibitory effects on the growth of four bacterial species: Staphylococcus aureus, Escherichia coli, Klebsiella spp., and Salmonella spp. The aqueous and methanolic extracts of C. odorata roots showed 20 compounds having 10 peaks, and 19 compounds having 10 peaks respectively. This study's findings highlight two compounds from C. odorata roots with promising physicochemical properties, making them potential drug candidates: 1-dioxide-4-methyl-3-(4-methyl-1-piperzinyl) from the methanolic extract and 2,3-dihydroxylpropylelaidate from the aqueous extract. The methanolic extract demonstrated superior antibacterial activity against S. aureus, E. coli, and Salmonella spp., while the aqueous extract showed greater efficacy against Klebsiella spp. Although the targeted bacteria may develop resistance to these extracts, our results indicate that both extracts possess antibiotic properties, warranting further investigation.

Characterization of Uropathogenic Escherichia coli by Phylogenetic Grouping, Integron, and Antibiotic Resistance Properties

Characterization of Uropathogenic Escherichia coli by Phylogenetic Grouping, Integron, and Antibiotic Resistance Properties

Antibiotic-loaded cement in total joint arthroplasty: a comprehensive review.

This review evaluates the decision-making framework for using antibiotic-loaded cement (ALC) in the management of prosthetic joint infection (PJI). Drawing on available literature, we offer orthopaedic surgeons a guided discussion on several critical considerations. First, we explore the impact of antibiotic-loading on the mechanical properties of polymethylmethacrylate (PMMA) cement, assessing both strength and durability. We then explore the optimal antibiotic dosage to load into cement, aiming to achieve effective local concentrations for infection control without compromising mechanical stability. Furthermore, we explore how cement and antibiotic properties affect the overall antibiotic elution characteristics of ALC. Finally, we discuss risks of systemic toxicity, particularly acute kidney injury, when using ALC. The principal goal in this review is to provide a balanced approach based on best available evidence that optimises antibiotic elution from ALC whilst minimising potential harms associated with its use.

Новий метаболіт Myrothecium cinctum 910 трихотеценової природи та його біологічні властивості

Fungi of the Myrothecium genus are well-known producers of macrocyclic trichothecenes, characterized by the acute toxic effect on warm-blooded organisms and fungicidal action against a wide range of fungi. At the same time, as established by us earlier, M. cinctum (current name Striaticonidium cinctum) 910 shows a wide spectrum of antibacterial activity: along with antifungal activity against mycelial, yeast-like and phytopathogenic test-cultures it strongly inhibited the growth of gram-positive test-strains and to lesser extend – the growth of gram-negative and phytopathogenic bacteria. This strain also revealed significant phytotoxic potential suppressing the growth of green algae Chlorella strains. The aim of the work was to isolate, to purify and to obtain in crystalline form the biological active metabolites of M. cinctum 910 and to study their physicochemical characteristics and biological activity. Methods. To obtain biologically active metabolites in the purified crystalline form, the extraction followed by separation by column chromatography and recrystallization was used; physicochemical methods and microbiological tests were used for characterization of their properties. Results. Three substances which showed the wide spectrum of biological activity to indicator test-cultures were obtained in crystalline form: preparation МС910 with high antibiotic activity and preparations from fractions 8/2 and 9 with high antifungal and phytotoxic activities. Taking into account the data of spectroscopy in the UV-range of spectrum, of spectrums of antibiotic activity and of qualitative reaction with 4-(4-nitrobenzyl)pyridine, it can be concluded that active fractions 8/2 and 9 contain macrocyclic trichothecenes whereas the metabolite МС910 (which is proved by data of IR-spectroscopy) belongs to simple trichothecenes – substances like to macrocyclic trichothecenes but without macrocyclic fragment in their structure. Conclusions. Antibiotic properties of M. cinctum 910 are due to the complex of biological active metabolites with different biological and physicochemical properties. In view on the biological activity of MC910, it can be argued that it has atypical for trichothecenes, including macrocyclc trichothecenes, antibacterial properties as well as it is non-toxic and does not reveal dermatocidal activity in studied concentrations. Therefore, we assume that MC910 is new, not described earlier metabolite of trichothecene nature, which needs further studies. At the same time, active metabolites from fractions 8/2 and 9 are represented by macrocyclic trichothecenes, which is also indicated by the spectra of their biological activity.

Antibiotic potentiating effect of Bauhinia purpurea L. against multidrug resistant Staphylococcus aureus.

Bauhinia purpurea L. is a medium-sized tree from the family Fabaceae. The plant is traditionally used as medicine by different tribes in Sikkim. The present study aimed to evaluate the modulation in minimum inhibitory concentration (MIC) of the bark methanol extract of Bauhinia purpurea L. against the clinical isolates of multidrug resistant Staphylococcus aureus. The synergistic activity of the test plant extract with different classes of antibiotics was also evaluated. The methanol extract of Bauhinia purpurea exhibited modulation by a 16-fold reduction in the MIC of clindamycin against both resistant and susceptible isolates, followed by penicillin and gentamicin, whereas a maximum of only a 4-fold MIC reduction was observed with ciprofloxacin. The lowest minimum inhibitory concentration and minimum bactericidal concentration showed by the plant extract was 0.48 and 0.97 mg/mL, respectively. The methanol extract of Bauhinia purpurea exhibited synergistic activity with penicillin, gentamicin, ciprofloxacin, and clindamycin against most of the tested isolates of multidrug-resistant Staphylococcus aureus (MDR-SA). Gas chromatography-mass spectrometry analysis of Bauhinia purpurea L. bark methanol extract revealed 16 phytocompounds. The results provide an insight into the potential antibacterial property of the plant extract in terms of its antibiotic MIC modulation and synergistic properties with the selected antibiotics. This is the first report of the antibiotic potentiation property of Bauhinia purpurea L., collected from Sikkim, India.

Meta-analysis unravels the complex combined toxicity of microplastics and antibiotics in aquatic ecosystems

The aquatic ecosystem, a repository for various pollutants, has been identified as a crucial zone where microplastics (MPs) serve as vectors for antibiotics, facilitating their spread. Despite this, the influence of MPs on the toxicity of antibiotics remains a topic of debate. In this study, we conduct a global meta-analysis, examining 730 datasets from 29 laboratory studies. Our findings reveal that the impact of MPs on antibiotic toxicity is highly dependent on biological response pathways, microplastic concentration, antibiotic properties, and exposure time. We observed that MPs amplify the accumulation of antibiotics in aquatic organisms, significantly heightening their adverse effects on growth, development, and immune functions. Intriguingly, MPs appear to mitigate the reproductive toxicity caused by antibiotics. A notable inverse relationship was identified between antibiotic toxicity and microplastic concentration and exposure time. Furthermore, antibiotic concentration predominantly affects growth, development, and reproductive health, whereas exposure time is critical in determining antibiotic accumulation and immune-related toxicity. These insights underscore that microplastic co-exposure can modify the toxicological profile of antibiotics. The outcomes of this research enhance our comprehensive understanding of the intricate combined effects of MPs and antibiotics on aquatic life, emphasizing the necessity for informed scientific management of these emerging contaminants.