Evaluation and comparison of the effects of biosynthesized selenium and silver nanoparticles using plant extracts with antifungal drugs on the growth of Aspergillus and Candida species

Characterizations of biogenic selenium nanoparticles and their anti-biofilm potential against Streptococcus mutans ATCC 25175

INTRODUCTION

S. mutans has been identified as the primary pathogenic bacterium in biofilm-mediated dental caries. The biogenic selenium nanoparticles (SeNPs) produced by L. plantarum KNF-5 were used in this study against S. mutans ATCC 25175.

OBJECTIVES

The aims of this study were: (1) the biosynthesis of SeNPs by L. plantarum KNF-5, (2) the characterization of SeNPs, (3) the investigation of the inhibitory effect of biogenic SeNPs against S. mutans ATCC 25175, and (4) the determination of the anti-biofilm potential of SeNPS against S. mutans ATCC 25175.

METHODOLOGY

3 mL of the culture was added to 100 mL of MRS medium and incubated. After 4 h, Na2SeO3 solution (concentration 100 μg/mL) was added and incubated at 37 °C for 36 h. The color of the culture solution changed from brownish-yellow to reddish, indicating the formation of SeNPs. The characterization of SeNPs was confirmed by UV-Vis spectrophotometry, FTIR, SEM-EDS and a particle size analyzer. The antibacterial activity was determined by the disk diffusion method, the MIC by the micro-double dilution method, and the biofilm inhibitory potential by the crystal violet method and the MTT assay. The effect of SeNPs on S. mutans ATCC 25175 was determined using SEM and CLSM spectrometry techniques. The sulfate-anthrone method was used to analyze the effect of SeNPs on insoluble extracellular polysaccharides. The expression of genes in S. mutans ATCC 25175 was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).

PREPARATION OF NANOPARTICLES

SeNPs produced by probiotic bacteria are considered a safe method. In this study, L. plantarum KNF-5 (probiotic strain) was used for the production of SeNPs.

RESULTS

The biogenic SeNPs were spherical and coated with proteins and polysaccharides and had a diameter of about 270 nm. The MIC of the SeNPs against S. mutans ATCC 25175 was 3.125 mg/mL. Biofilm growth was also significantly suppressed at this concentration. The expression of genes responsible for biofilm formation (GtfB, GtfC, BrpA and GbpB,) was reduced when S. mutans ATCC 25175 was treated with SeNPs.

CONCLUSION

It was concluded that the biogenic SeNPs produced by L. plantarum KNF-5 was highly effective to inhibit the growth of S. mutans ATCC 25175.

NOVELTY STATEMENT

The application of biogenic SeNPs, a natural anti-biofilm agent against S. mutans ATCC 25175. In the future, this study will provide a new option for the prevention and treatment of dental caries.

Antibacterial Potential of Biosynthesized Silver Nanoparticles Using Berberine Extract Against Multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa

The emergence of multidrug resistance in bacterial infections has limited the use of antibiotics. Helping the action of antibiotics is one of the needs of the day. Today, the biosynthesis of nanoparticles (NPs) is considered due to its safety and cost-effectiveness. In this study, we investigated the effect of biosynthesized silver nanoparticles (AgNPs) by Berberine plant extract against standard strains of multidrug-resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa. Utilized UV-Vis, FTIR, FESEM/EDX, XRD, DLS, and Zeta potential techniques to confirm the biosynthesis of NPs. Then, disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed using common classes of standard antibiotics and AgNPs on the mentioned bacteria. The synergistic action between AgNPs and antibiotics was evaluated by the checkerboard method. First, we obtained the confirmation results of the biosynthesis of AgNPs. According to the DDA test, both standard bacterial strains were sensitive to NPs and had an inhibition zone. Also, the MIC values showed that AgNPs inhibit the growth of bacteria at lower concentrations than antibiotics. On the other hand, the results obtained from checkerboard monitoring showed that AgNPs, in combination with conventional antibiotics, have a synergistic effect. The advantage of this study was comparing the antibacterial effect of AgNPs alone and mixed with antibiotics. The antibacterial sensitivity tests indicated that the desired bacterial strains could not grow even in low concentrations of AgNPs. This property can be applied in future programs to solve the drug resistance of microorganisms in bacterial diseases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01136-y.

Effect of lipopeptide extracted from Bacillus licheniformis on the expression of bap and luxI genes in multi-drug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa

Recently, opportunistic pathogens like Acinetobacter baumannii and Pseudomonas aeruginosa have caused concern due to their ability to cause antibiotic resistance in weakened immune systems. As a result, researchers are always seeking efficient antimicrobial agents to tackle this issue. The hypothesis of the recent study was that probiotic products derived from bacteria would be effective in reducing drug resistance in other bacteria. This research aimed to investigate the antimicrobial properties of probiotic products from various bacterial strains, including Lactobacillus rhamnosus, Pediococcus acidilactisi, Bacillus coagulans, Bacillus subtilis, and Bacillus licheniformis. These were tested against multi-drug-resistant (MDR) standard strains A. baumannii and P. aeruginosa. B. licheniformis was found to be the most effective probiotic strain, possessing the LanA and LanM lantibiotic genes. The lipopeptide nature of the probiotic product was confirmed through high-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FTIR) techniques. The anti-biofilm and antimicrobial properties of this probiotic were measured using an SEM electron microscope and minimum inhibitory concentration (MIC) test. Real-time PCR (qPCR) was used to compare the expression of bap and luxI genes, which are considered virulence factors of drug-resistant bacteria, before and after treatment with antimicrobial agents. The MIC results showed that the probiotic product prevented the growth of bacteria at lower concentrations compared to antibiotics. In addition, the ΔΔCqs indicated that gene expression was significantly down-regulated following treatment with the obtained probiotic product. It was found that B. licheniformis probiotic products could reduce drug resistance in other bacteria, making it a potential solution to antibiotic resistance.

A comprehensive review on potential applications of metallic nanoparticles as antifungal therapies to combat human fungal diseases

Human pathogenic fungi are responsible for causing a range of infection types including mucosal, skin, and invasive infections. Life-threatening and invasive fungal infections (FIs) are responsible for mortality and morbidity, especially for individuals with compromised immune function. The number of currently available therapeutic agents against invasive FIs is limited compared to that against bacterial infections. In addition, the increased mortality and morbidity caused by FIs are linked to the limited number of available antifungal agents, antifungal resistance, and the increased toxicity of these agents. Currently available antifungal agents have several drawbacks in efficiency, efficacy, toxicity, activity spectrum, and selectivity. It has already been demonstrated with numerous metallic nanoparticles (MNPs) that these nanoparticles can serve as an effective and alternative solution as fungicidal agents. MNPs have great potential owing to their intrinsic antifungal properties and potential to deliver antifungal drugs. For instance, gold nanoparticles (AuNPs) have the capacity to disturb mitochondrial calcium homeostasis induced AuNP-mediated cell death in Candida albicans. In addition, both copper nanoparticles and copper oxide nanoparticles exerted significant suppressive properties against pathogenic fungi. Silver nanoparticles showed strong antifungal properties against numerous pathogenic fungi, such as Stachybotrys chartarum, Mortierella alpina, Chaetomium globosum, A. fumigatus, Cladosporium cladosporioides, Penicillium brevicompactum, Trichophyton rubrum, C. tropicalis, and C. albicans. Iron oxide nanoparticles showed potent antifungal activities against A. niger and P. chrysogenum. It has also been reported that zinc oxide nanoparticles can significantly inhibit fungal growth. These NPs have already exerted potent antifungal properties against a number of pathogenic fungal species including Candida, Aspergillus, Fusarium, and many others. Several strategies are currently used for the research and development of antifungal NPs including chemical modification of NPs and combination with the available drugs. This review has comprehensively presented the current and innovative antifungal approach using MNPs. Moreover, different types of MNPs, their physicochemical characteristics, and production techniques have been summarized in this review.

Biogenic selenium nanoparticles with antifungal activity against the wood-rotting fungus Oligoporus pelliculosus

Selenium nanoparticles (SeNPs) have antimicrobial and antifungal activity. SeNPs using Se resistant bacteria is a low cost and eco-friendly technology. Fungal contamination of wood during drying is one of the main causes of economic losses in the wood industry. The bacterium Delftia sp. 5 resistance to Se and its ability to produce SeNPs able to inhibit the growth of the wood brown-rotting fungus Oligoporus pelliculosus was analyzed. The strain showed an optimal SeNPs production when selenite concentration was 160 mg L ^-1. The SeNPs were spherical with an average size 192.33 ± 8.6 nm and a zeta potential of -41.4 ± 1.3 nm. The SeNPs produced by Delftia sp. 5 (33.6 ± 0.1 mg L ^-1 Se) inhibited the growth of O. pelliculosus in agar plates and in Nothofagus pumilio (Lenga) wood samples. Delftia sp. 5 SeNPs could be used for embedding lenga wood prior to drying for preventing the growth of the deteriorating fungi O. pelliculosus.

Effect of biosynthesized selenium nanoparticles using Nepeta extract against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii

The problems of drug resistance in bacteria have become one of the daily challenges of the clinical treatment of patients, which inevitably forces us to use agents other than common antibiotics. Among these, we can take help from different properties and applications of nanoparticles (NPs). In this work, we evaluate the antibacterial activity of biosynthesized selenium nanoparticles (SeNPs) against standard strains of multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The production of biosynthesized SeNPs was proved by ultraviolet-visible, Fourier transform infrared, X-ray diffractometer, Field Emission Scanning Electron Microscopy, Dynamic light scattering, and Zeta potential methods. The cytotoxicity effect of SeNPs was investigated by MTT assay. Disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed on the mentioned bacteria using different classes of standard antibiotics and SeNPs separately. The impact of SeNPs combined with the desired antibiotics for better treatment of these infections was evaluated by checkerboard assay to determine the synergism effect. After the confirmation results based on the biosynthesis of SeNPs, both standard bacterial strains were susceptible to SeNPs and had a zone of inhibition using the DDA test. Also, the results of MICs showed that biosynthesized SeNPs in lower concentrations than antibiotics cause no growth of bacteria. On the other hand, according to the checkerboard assay, SeNPs had a synergistic effect with conventional antibiotics. The antibacterial sensitivity tests demonstrated the inhibition of bacterial growth in the presence of lower concentrations of SeNPs than common antibiotics. This property can be exerted in future applications to solve the drug resistance obstacle of microorganisms in bacterial diseases.

Monitoring the effects of fungi isolated from archival document on model albumen silver prints

Fungi are a common problem in the photographic collection, so the aim of this study focused on isolating and molecular identification of fungi from old albumen prints dating to an archive of Dr. Francis and belonging to the Al-Hagar Family and dating back to 1880-1890. The isolated fungi were identified according to their morphological traits and PCR sequencing. The ability of these isolates to cause deterioration was evaluated on model samples (2 × 2 cm) of albumen silver prints. The effect of these fungi on the morphology and structure of the tested samples were examined by SEM, ATR-FTIR, and chromatic alternations. Four fungal species Aspergillus sydowii, A. flavus, Talaromyces atroroseus, and Penicillium chrysogenum were identified. All isolates were able to grow on the surface of the model Albumen silver print and were capable of causing damage to the binder and able to extend their growth to the paper fibers. A. sydowii, A. flavus, and P. chrysogenum caused hydrolysis and oxidation to the albumen prints, while no significant chemical damage to the albumen was detected for the photographic sample infected with T. atroroseus. All the inoculated samples were significantly affected in terms of color change and the high-light areas have become darker. ATR-FTIR spectra showed the degradation of the protein content in Albumen silver prints inoculated with A. sydowii, A. flavus, and P. chrysogenum.

Green synthesis of selenium nanoparticles and evaluate their effect on the expression of ERG3, ERG11, and FKS1 antifungal resistance genes in Candida albicans and Candida glabrata

Drug resistance in Candida species has been considerably increased in the last decades. Given the opposition to antifungal agents, toxicity, and interactions of the antimicrobial drugs, identifying new antifungal agents seems essential. This study assessed the antifungal effects of nanoparticles (NPs) on the standard strains of Candida albicans and Candida glabrata and determined the expression genes, including ERG3, ERG11, and FKS1. Selenium nanoparticles (Se-NPs) were biosynthesized with a standard strain of C. albicans and approved by several methods including, UV-Vis spectrophotometer, XRD technique, FTIR analysis, FESEM microscopy, and EDX diagram. The antifungal susceptibility testing performed the minimum inhibitory concentrations (MICs) using the CLSI M27-A3 and M27-S4 broth microdilution method. The expression of the desired genes was examined by the real-time PCR assay between untreated and treated by antifungal drugs and Se-NPs. The MICs of itraconazole, amphotericin B, and anidulafungin against C. albicans and C. glabrata were 64, 16, and 4 µg/ml. In comparison, reduced the MIC values ​​for samples treated with Se-NPs to 1 and 0.5 µg/ml. The results obtained from real-time PCR and analysis of the ∆∆C_q values showed that the expression of ERG3, ERG11, and FKS1 genes was significantly down-regulated in Se-NPs concentrations (P<0.05). This study's evidence implies biosafety Se-NPs have favorable effects on the reducing expression of ERG3, ERG11, and FKS1 antifungal resistance genes in C. albicans and C. glabrata.

Interventional Effect of Nanosilver Paint on Fungal Load of Indoor Air in a Hospital Ward

Hospital ward environments contain various types of microorganisms, in which fungal agents are one of the main contaminants that may cause hospital-acquired infections. Regarding this, the aim of the present study was to evaluate the effect of nanosilver paint on reducing fungal contaminants of indoor air in an educational, research, and treatment center. Two rooms in the hematology ward were selected. One room was painted using usual paint (control room) and the other room was painted with paint containing nanosilver particles (experimental room). One hundred and twelve samples were collected using active (Anderson BioSampler) and passive (settle plate or open plate) air sampling techniques. The samples were incubated for 3–7 days at 35°C, and the positive fungal cultures were examined according to morphological and microscopic characteristics. Following active sampling, the mean and standard deviation of the number of colony-forming units (CFU/m³) of fungi colonies in the experimental and control rooms were 29.21 ± 17.99 and 22.50 ± 10.02 before intervention and 13.79 ± 6.20 and 31.07 ± 21.1 after intervention, respectively. Following passive sampling, the number of CFU/plate in the experimental and control rooms was 6 and 0 before and 1and 1 after intervention, respectively. The use of the nanosilver paint was effective in reducing air fungal contamination. Moreover, the active sampling method was more sensitive to measuring the concentration changes for fungal bioaerosols.