The rapid evolution and spread of multidrug resistance among bacterial pathogens has significantly outpaced the development of new antibiotics, underscoring the urgent need for alternative therapies. Antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy have emerged as promising treatments. Antimicrobial photodynamic therapy relies on the interaction between light and a photosensitizer to produce reactive oxygen species, which are highly cytotoxic to microorganisms, leading to their destruction without fostering resistance. Antimicrobial sonodynamic therapy, a novel variation, substitutes ultrasound for light to activate the sonosensitizers, expanding the therapeutic reach. To increase the efficiency of antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy, the combination of these two methods, known as antimicrobial photo-sonodynamic therapy, is currently being explored and considered a promising approach. Recent advances, particularly in the application of nanomaterials, have further enhanced the efficacy of these therapies. Nanosensitizers, due to their improved reactive oxygen species generation and targeted delivery, offer significant advantages in overcoming the limitations of conventional sensitizers. These breakthroughs provide new avenues for treating bacterial infections, especially multidrug-resistant strains and biofilm-associated infections. Continued research, including comprehensive clinical studies, is crucial to optimizing nanomaterial-based antimicrobial photo-sonodynamic therapy for clinical use, ensuring their effectiveness in real-world applications.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Bacteria drug effects MeSH
- Bacterial Infections * drug therapy microbiology therapy MeSH
- Biofilms drug effects MeSH
- Photochemotherapy * methods MeSH
- Photosensitizing Agents * pharmacology MeSH
- Humans MeSH
- Nanoparticles chemistry MeSH
- Nanostructures chemistry MeSH
- Reactive Oxygen Species metabolism MeSH
- Ultrasonic Therapy MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Among carotenoids, ꞵ-carotene has the highest biological activity and is found as an all-trans isomer in many biological systems. Blakeslea trispora is a microorganism that is of interest to industries for the commercial production of ꞵ-carotene. This study investigated the effect of different bacteria on carotenogenesis in B. trispora. The B. trispora bisexual mold was cultured in a production medium, and different bacterial cells were added to it after 24 h. Then, the culture conditions and the culture medium were optimized in the presence of the selected bacteria using the experimental design. The percentage of carotenoids obtained from the mixed culture was determined using high-performance liquid chromatography (HPLC). Results showed that Kocuria rhizophila had the greatest effect on increasing the production of carotenoids in B. trispora. The highest content of carotenoids obtained during optimization was 770 ± 7.5 mg/L, a 6.8-fold increase compared to the control. HPLC analysis of carotenoids indicated the presence of two main peaks, ꞵ-carotene and γ-carotene, in which the primary carotenoid was ꞵ-carotene followed by γ-carotene with a lower content. Therefore, due to the importance of ꞵ-carotene in industry, the use of biostimulants is one of the appropriate strategies to increase the production of this pigment in industry.
Oral microorganisms are closely related to oral health, the occurrence of some oral diseases is associated with changes in the oral microbiota, and many studies have demonstrated that traditional smoking can affect the oral microbial community. However, due to the short time since the emergence of e-cigarettes, fewer studies are comparing oral microorganisms for users of e-cigarettes versus cigarettes. We collected saliva from 40 non-smokers (NS), 46 traditional cigarette smokers (TS), and 27 e-cigarette consumers (EC), aged between 18 and 35 years. We performed 16S rRNA gene sequencing on the saliva samples collected to study the effects of e-cigarettes versus traditional cigarettes on the oral microbiome. The results showed that compared with the NS group, the alpha diversity of oral flora in saliva was altered in the TS group, with no significant change in the e-cigarette group. Compared with the NS and EC groups, the relative abundance of Actinomyces and Prevotella was increased in the TS group. However, compared with the NS and TS groups, the relative abundance of Veillonella was increased, and the relative abundance of Porphyromonas and Peptostreptococcus was decreased in the EC group. These results showed that both e-cigarettes and traditional cigarettes could alter the structure and composition of oral microbiota. The use of traditional cigarettes promotes the growth of some anaerobic bacteria, which may contribute to dental decay and bad breath over time. E-cigarettes have a different effect on the structure and composition of the oral microbial community compared to conventional cigarettes. In order to better understand the effects of e-cigarettes and traditional cigarettes on users' mouths, future studies will investigate the relationship between diseases such as dental caries and periodontitis and changes in oral microbial species levels.
- MeSH
- Bacteria * classification isolation & purification genetics MeSH
- Adult MeSH
- Smokers * MeSH
- Humans MeSH
- Microbiota * MeSH
- Adolescent MeSH
- Young Adult MeSH
- Pilot Projects MeSH
- RNA, Ribosomal, 16S * genetics MeSH
- Saliva * microbiology MeSH
- Electronic Nicotine Delivery Systems MeSH
- Tobacco Products adverse effects MeSH
- Mouth * microbiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
The gut microbiota has recently come to the forefront of scientific interest, particularly due to its broad spectrum of action not only on tissues that it comes into direct contact with, but also - through a variety of agents - on distant tissues and organs. There are a number of previously described mechanisms through which gut-colonizing microorganisms can affect the host's immune or endocrine systems as well as the central nervous system and behaviour of the host. A number of research teams are studying the microbiome in relation to neurological diseases, investigating the possible effect of specific microorganisms and microbial metabolites on the development and progression of these diseases. This publication deals with those diseases that have been most widely studied and described in this context.
- MeSH
- Alzheimer Disease diagnosis etiology MeSH
- Humans MeSH
- Brain-Gut Axis * physiology genetics MeSH
- Parkinsonian Disorders diagnosis etiology MeSH
- Autism Spectrum Disorder diagnosis etiology genetics MeSH
- Multiple Sclerosis diagnosis etiology MeSH
- Gastrointestinal Microbiome * genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
BACKGROUND AND OBJECTIVE: Microbial selenium (Se) supplementation is an essential area of biotechnological research due to differences in the bioavailability and toxicity of different forms of selenium. To date, research has focused mainly on the use of selenized yeast. However, in recent years, scientific interest has also increased in other microorganisms, such as lactic acid bacteria (LAB), which have several unique properties that can affect the quality and bioavailability of selenium. LAB, unlike yeast, can also act as probiotics, which may bring additional health benefits related to improving the intestinal microbiota and supporting the health of the gastrointestinal tract. METHODS: This study investigates the in vitro bioaccessibility and bioavailability of Se from two lactic acid bacterial strains, Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922 A. We evaluated Se accumulation, speciation, and stability during simulated gastrointestinal digestion and Se permeation through a Caco-2 cell monolayer model. RESULTS: Both strains accumulated Se, metabolizing it predominantly into selenium nanoparticles (SeNPs, 64-77 % of total Se), with only a minor fraction (<5 % of total Se) of organic Se species. Experiments revealed that while organic Se species had high bioavailability (up to 90 %), their bioaccessibility during digestion was very low (<0.1 % of total Se). In contrast, SeNPs showed high bioaccessibility (∼90 %) and moderate transport efficiency through the intestinal model (16-19 % after 4 hours). CONCLUSION: These results highlight the potential of SeNPs produced by lactic acid bacteria as a bioaccessible form of Se for dietary supplementation. Further research is required to explore the behavior of SeNPs within the human body to fully understand how they can be used safely and effectively in nutrition or other applications.
- MeSH
- Biological Availability * MeSH
- Models, Biological MeSH
- Caco-2 Cells MeSH
- Intestinal Barrier Function MeSH
- Lactobacillales metabolism MeSH
- Humans MeSH
- Permeability MeSH
- Selenium * metabolism MeSH
- Streptococcus thermophilus metabolism MeSH
- Digestion MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Diseases caused by staphylococci and streptococci are a serious burden on livestock production, causing significant losses. In addition, the associated antibiotic resistance of these pathogens often makes treatment impossible or prolonged. Cannabis sativa L. contains many compounds with antibacterial properties and shows great potential as a natural antimicrobial agent for agricultural use against both of these bacterial species. The aim of this study was to compare the in vitro antibacterial activity of ethanol extracts from five cultivars of hemp, namely, Bialobrzeskie, Felina 32, Futura 75, mixed and Santhica 27, against Staphylococcus aureus, Streptococcus agalactiae and Streptococcus dysgalactiae. All five cultivars exhibited a certain degree of inhibitory effect against all the pathogens tested with minimum inhibitory concentrations (MICs) ranging from 128 to 2048 μg/mL. The extract from the Santhica 27 cultivar was the most effective antibacterial agent with the lowest MIC value of 128 μg/mL against Str. agalactiae and two clinical isolates of S. aureus, followed by Bialobrzeskie and mixed cultivars with the same growth-inhibitory potential against Str. agalactiae. The extracts from the Felina 32 and Futura 75 cultivars presented only weak activity with MIC values ranging from 256 to 2048 μg/mL. The extract from the Santhica 27 cultivar appears to be a promising product for future use in the treatment of staphylococcal and streptococcal infections in livestock.
- Publication type
- Journal Article MeSH
Quorum sensing, a bacterial cell-to-cell communication mechanism, plays a key role in bacterial virulence and biofilm formation. Targeting quorum-sensing pathways represents a promising strategy for the development of novel antibacterial agents. This study evaluated the anti-quorum-sensing activities of 18 natural compounds, including cannabinoids, arylbenzofurans, flavonoids, caffeine, and chlorogenic acid, using the luminescent biosensor strain Vibrio harveyi MM30. V. harveyi MM30, a mutant strain deficient in the production of autoinducer-2 (AI-2) but responsive to exogenous AI-2, was used to assess the activity of test compounds on the AI-2 receptor pathway. Test compounds were incubated in AI-2-containing media, and luminescence was measured to evaluate quorum-sensing inhibition. Comparisons were made in the absence of AI-2 to determine AI-2-independent inhibitory activity. The most active compounds were further tested on methicillin-resistant Staphylococcus aureus (MRSA 7112) to determine their effects on AI-2 production in spent media. Among the tested compounds, the non-prenylated arylbenzofuran moracin M and the prenylated arylbenzofuran moracin C exhibited significant quorum-sensing inhibitory activity in the AI-2-mediated pathway. None of the test compounds significantly inhibited quorum sensing in the absence of AI-2. Five compounds (cannabigerol, cannabidiol, cannabigerolic acid, moracin M, and moracin C) were selected for further investigation in MRSA 7112 cultures. The spent media from MRSA 7112 cultures treated with moracin M (16, 32, 64 μg/mL) and cannabigerolic acid (16 μg/mL) showed significant inhibition of AI-2 production when transferred to V. harveyi MM30 cultures. Moracin M and cannabigerolic acid demonstrated potential as quorum-sensing inhibitors by targeting AI-2 production and signalling pathways in MRSA 7112 and V. harveyi. These findings suggest their potential for further development as antibacterial agents targeting quorum-sensing mechanisms.
- Publication type
- Journal Article MeSH
BACKGROUND: Antimicrobial lock therapy is recommended for preventing and treating catheter-related bloodstream infections, but different solutions have uncertain efficacy. METHODS: Two locks, 1.35% taurolidine and 4% ethylenediaminetetraacetic acid (EDTA), were tested on Staphylococcus epidermidis, Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, multidrug-resistant P. aeruginosa, vancomycin-resistant Enterococcus faecium, Klebsiella oxytoca (carbapenemase producing), K. pneumoniae (extended-spectrum β-lactamase producing), Candida albicans, and Candida glabrata. Broviac catheter segments were incubated with these organisms and then exposed to various lock solutions. Colony-forming units (CFUs) were counted after 2, 4, and 24 h of incubation. RESULTS: Taurolidine showed a significant decrease in CFUs after 2 h in S. aureus, S. epidermidis, methicillin-resistant S. aureus, vancomycin-resistant E. faecium, P. aeruginosa (both sensitive and multidrug-resistant strains), K. oxytoca, C. albicans, and C. glabrata. After 4 h, significant reductions were noted in S. aureus, S. epidermidis, methicillin-resistant S. aureus, P. aeruginosa, multidrug-resistant P. aeruginosa, K. pneumoniae, K. oxytoca, and C. albicans. Taurolidine was also effective after 24 h, especially against methicillin-resistant S. aureus and multidrug-resistant P. aeruginosa. Four percent EDTA acid showed a significant reduction in CFUs after 2 h in S. aureus, vancomycin-resistant E. faecium, P. aeruginosa, K. oxytoca, C. albicans, and C. glabrata. After 4 h, reductions occurred in P. aeruginosa, multidrug-resistant P. aeruginosa, K. oxytoca, and C. albicans and after 24 h in methicillin-resistant S. aureus, P. aeruginosa, and K. oxytoca. CONCLUSION: Taurolidine is more effective than 4% EDTA acid in eradicating Gram-positive and Gram-negative microorganisms and fungi.
- MeSH
- Anti-Infective Agents * pharmacology MeSH
- Candida albicans drug effects MeSH
- Edetic Acid * pharmacology MeSH
- Catheter-Related Infections * prevention & control microbiology MeSH
- Humans MeSH
- Methicillin-Resistant Staphylococcus aureus drug effects MeSH
- Microbial Sensitivity Tests MeSH
- Colony Count, Microbial MeSH
- Pseudomonas aeruginosa drug effects MeSH
- Staphylococcus aureus drug effects MeSH
- Staphylococcus epidermidis drug effects MeSH
- Taurine * analogs & derivatives pharmacology MeSH
- Thiadiazines * pharmacology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
Infections caused by antibiotic-drug-resistant microorganisms are a major global health concern, and they result in millions of deaths every year. Methicillin-resistant Staphylococcus aureus (MRSA) is one of such drug-resistant microbial strains, and new and effective antimicrobial agents are desperately needed to combat infections caused by MRSA. In the search for effective anti-MRSA agents, the leaves of Citrus grandis (Rutaceae), also known as C. maxima, were investigated. Implementing a bioassay-guided approach, sinensetin (2), which is a polymethoxyflavone, was isolated as a promising anti-MRSA compound, showing inhibitory activity against three (EMRSA-15, MRSA340802 and MRSA274819; MIC values 128-256 μg/mL) of five MRSA strains tested in the present study. Five other flavonoids 6,7,8,3',4'-pentamethoxyflavone (1), cirsilineol (3), nobiletin (4), 5-desmethylsinensetin (5) and hesperidin (6) were isolated from the dichloromethane extract of this plant. They displayed varied levels of antimicrobial activities against the tested microbial strains, Micrococcus luteus NCTC 7508, Escherichia coli NCTC 12241 and Pseudomonas aeruginosa NCTC 12903, and a fungal strain, Candida albicans ATCC 90028, but not against Staphylococcus aureus NCTC 12981. Sinensetin (2) also exhibited strong antimicrobial activity against the fungal strain C. albicans with an MIC value of 0.0625 mg/mL. The chemical structures of all isolated compounds were unequivocally elucidated by spectroscopic means (1D and 2D NMR and HR-ESIMS). The present study revealed sinensetin (2) as a potential structural template for generating structural analogues and developing anti-MRSA agents and provided scientific evidence supporting the traditional uses of C. grandis in the treatment of microbial infections.
- MeSH
- Anti-Bacterial Agents pharmacology isolation & purification chemistry MeSH
- Candida albicans drug effects MeSH
- Citrus * chemistry MeSH
- Flavonoids * pharmacology isolation & purification MeSH
- Phytochemicals pharmacology isolation & purification MeSH
- Plant Leaves * chemistry MeSH
- Methicillin-Resistant Staphylococcus aureus * drug effects MeSH
- Microbial Sensitivity Tests * MeSH
- Molecular Structure MeSH
- Plant Extracts pharmacology chemistry MeSH
- Publication type
- Journal Article MeSH
Background: In recent years, significant resistance of microorganisms to antibiotics has been observed. A biofilm is a structure that significantly aids the survival of the microbial population and also significantly affects its resistance. Methods: Thyme and clove essential oils (EOs) were subjected to chemical analysis using gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). Furthermore, the antimicrobial effect of these EOs was tested in both the liquid and vapor phases using the volatilization method. The effect of the EOs on growth parameters was monitored using an RTS-8 bioreactor. However, the effect of the EOs on the biofilm formation of commonly occurring bacteria with pathogenic potential was also monitored, but for less described and yet clinically important strains of Arcobacter spp. Results: In total, 37 and 28 compounds were identified in the thyme and clove EO samples, respectively. The most common were terpenes and also derivatives of phenolic substances. Both EOs exhibited antimicrobial activity in the liquid and/or vapor phase against at least some strains. The determined antimicrobial activity of thyme and clove oil was in the range of 32-1024 μg/mL in the liquid phase and 512-1024 μg/mL in the vapor phase, respectively. The results of the antimicrobial effect are also supported by similar conclusions from monitoring growth curves using the RTS bioreactor. The effect of EOs on biofilm formation differed between strains. Biofilm formation of Pseudomonas aeruginosa was completely suppressed in an environment with a thyme EO concentration of 1024 μg/mL. On the other hand, increased biofilm formation was found, e.g., in an environment of low concentration (1-32 μg/mL). Conclusions: The potential of using natural matrices as antimicrobials or preservatives is evident. The effect of these EOs on biofilm formation, especially Arcobacter strains, is described for the first time.
- Publication type
- Journal Article MeSH
