Explore the vast range of titles available.

Oregano oil (OrO) possesses well-pronounced antimicrobial properties but its application is limited due to low water solubility and possible instability. The aim of this study was to evaluate the possibility to incorporate OrO in an aqueous dispersion of chitosan—alginate nanoparticles and how this will affect its antimicrobial activity. The encapsulation of OrO was performed by emulsification and consequent electrostatic gelation of both polysaccharides. OrO-loaded nanoparticles (OrO-NP) have small size (320 nm) and negative charge (−25 mV). The data from FTIR spectroscopy and XRD analyses reveal successful encapsulation of the oil into the nanoparticles. The results of thermogravimetry suggest improved thermal stability of the encapsulated oil. The minimal inhibitory concentrations of OrO-NP determined on a panel of Gram-positive and Gram-negative pathogens (ISO 20776-1:2006) are 4–32-fold lower than those of OrO. OrO-NP inhibit the respiratory activity of the bacteria (MTT assay) to a lower extent than OrO; however, the minimal bactericidal concentrations still remain significantly lower. OrO-NP exhibit significantly lower in vitro cytotoxicity than pure OrO on the HaCaT cell line as determined by ISO 10993-5:2009. The irritation test (ISO 10993-10) shows no signs of irritation or edema on the application site. In conclusion, the nanodelivery system of oregano oil possesses strong antimicrobial activity and is promising for development of food additives.

Oregano oil was successfully encapsulated into chitosan–albumin nanogel via emulsification and electrostatic gelation. The system was characterized with a mean diameter around 26 nm, narrow size distribution (PDI = 0.242) and approximately 40% encapsulation efficiency. The incorporation of the oil into the nanogel was confirmed by XRD and FTIR analyses, and the dissolution of the oil was enhanced after the encapsulation. Furthermore, the treatment of Betacoronavirus 1 infected bovine kidney MDBK cells with the oregano oil-loaded nanogel (25 µg/mL) showed more than 50% protection against the infection, as compared to the non-treated virus infected control. The cytopathic effect (CPE) of the virus was inhibited in a concentration-dependent manner. The system inhibited the virus replication, resulting in a decrease of the viral particles by more than half, as shown by the cytotoxicity and CPE assays. The virus titer in treated and non-treated samples was determined by digital droplet PCR and revealed Δ3 log diminishment of the virus particles in samples treated with 25 µg/mL encapsulated oregano oil. This study is a basis for further investigations on the pharmacodynamics of the nanogel and its possible combinations with clinically applied chemotherapeutics.

Antibiotic resistance (ABR) is a significant threat to human and animal health, as well as to the environment. Antibiotic residues, antibiotic-resistant bacteria and antibiotic resistance genes are emerging contaminants of water resources. The present study aimed to assess the prevalence of ABR among waterborne enterococci in an anthropogenic-affected section of the Yantra River (Bulgaria). The susceptibility of 426 strains to 13 antibiotics (ABs) was tested by the disk diffusion method, and the genes encoding resistance by PCR analyses. A total of 39% of isolates were found to be antibiotic-resistant, with 9% mainly being multidrug-resistant to three AB classes. The most common resistance was to erythromycin (19%), tetracycline (18%) and ampicillin (14%), encoded by the ermB, tetM and blaTEM genes. A total of 3% of isolates were ciprofloxacin-resistant and only 1% was resistant to vancomycin or high-level gentamicin. All isolates were susceptible to teicoplanin and linezolid. Spatial variations in ABR levels were found, with the lowest abundance of antibiotic-resistant enterococci occurring in upstream river waters, away from urban areas, and the highest in urban areas. The spread of waterborne antibiotic-resistant enterococci highlights the need for water pollution management, monitoring and control to limit anthropogenic pressures through wastewater discharges and diffuse fecal pollution, and to ensure the ecological well-being of receiving waters.

Juniper representatives are natural sources of plenty of bioactive metabolites and have been used since ancient times as folk remedies against tapeworms, warts, cancer, etc. The antiproliferative activities of junipers are attributed to podophyllotoxin (PPT), which is a precursor for the synthesis of efficient anticancer drugs. However, the natural sources of PPT, Sinopodophyllum hexandrum (Royle) T. S. Ying and Podophyllum peltatum L., are already endangered species because of their intensive industrial exploitation. Therefore, identification of other sources of PPT is necessary. This study is a broad comparative investigation of junipers, for which original sources have been accessed from different continents of the world. The present research is aimed at the identification of species, producing PPT and other lignans at concentrations that are sufficient for the high antiproliferative activity of the corresponding extracts. Cytotoxic juniper leaf extracts demonstrated a broad spectrum of activity on a panel of cancer cell lines. The antiproliferative properties of junipers were attributed to the combined activity of great diversity of lignans (podophyllotoxin, deoxypodophyllotoxin, β-peltatin, yatein, matairesinol, anhydropodorhizol, etc.), detected by UHPLC-HRMS and LC-ESI-MS/MS in the corresponding extracts. Several species of the genus Juniperus L. were outlined as perspective sources of drug precursors with potential pharmaceutical applications.

Plants from the Rosacea family are rich in natural molecules with beneficial biological properties, and they are widely appreciated and used in the food industry, perfumery, and cosmetics. In this review, we are considering Rosa damascena Mill., Rosa alba L., Rosa centifolia L., and Rosa gallica L. as raw materials important for producing commercial products, analyzing and comparing the main biological activities of their essential oils, hydrolates, and extracts. A literature search was performed to find materials describing (i) botanical characteristics; (ii) the phytochemical profile; and (iii) biological properties of the essential oil sand extracts of these so called “old roses” that are cultivated in Bulgaria, Turkey, India, and the Middle East. The information used is from databases PubMed, Science Direct, and Google Scholar. Roses have beneficial healing properties due to their richness of beneficial components, the secondary metabolites as flavonoids (e.g., flavones, flavonols, anthocyanins), fragrant components (essential oils, e.g., monoterpenes, sesquiterpenes), and hydrolysable and condensed tannins. Rose essential oils and extracts with their therapeutic properties—as respiratory antiseptics, anti-inflammatories, mucolytics, expectorants, decongestants, and antioxidants—are able to act as symptomatic prophylactics and drugs, and in this way alleviate dramatic sufferings during severe diseases.

Propolis produced by the stingless bee Lisotrigona cacciae was studied for the first time. Using different chromatographic procedures, a total of eighteen constituents (phenols and triterpenes) were isolated, among which flavane 1, homoisoflavanes 2-4, and xanthones 5 and 6 were new for propolis. Propolis extract was also characterized by gas chromatography/mass spectrometry and other fifteen constituents were identified. The xanthone α-mangostin (8) demonstrated significant activity against Staphylococcus aureus with MIC and MBC 0.31 μg/ml, followed by 7,4'-dihydroxy-5-methoxy-8-methylflavane (1) with MIC 78 μg/ml and MBC 156 μg/ml. 10,11- Dihydroxydracaenone C (4), a component bearing ortho-hydroxyl groups, was the only compound displaying radical scavenging ability. Triple botanical origin of the sample was defined, consisting of Dracaena cochinchinensis, Cratoxylum cochinchinense and Mangifera indica. D. cochinchinensis is a new resin source of propolis.

According to the EFSA Report on Zoonoses (2024), yersiniosis was classified as the fourth most commonly reported zoonosis in humans in 2023, with a 13.5% increase in yersiniosis infections compared to 2022. In 2024, the findings were consistent with the 2020–2023 trend. Isolation and identification of enteropathogenic Yersinia is difficult and time consuming, especially when examining food and environmental samples. Among them, Y. pseudoturbeculosis poses a challenge due to the lack of a single selective medium for all bioserotypes. Therefore, faster methods for the detection of Yersinia spp. need to be implemented into the praxis. Rapid identification of pathogens in food or at the time and location of the epidemiological outbreak (point-of-care testing) enables either prevention of the outbreak or early stage diagnosis and prompt decisions. The loop-mediated isothermal amplification (LAMP) is increasingly coming to scientists’ attention as a robust and rapid methodology for pathogen detection in laboratories with limited resources and equipment. The aim of current study is to evaluate, for the first time, the sensitivity of the LAMP protocol based on colorimetric detection in the visible spectrum in comparison with that of the digital droplet PCR (ddPCR). For this aim, a series of decimal logarithmic dilutions of the pathogen Y. pseudotuberculosis in artificially contaminated raw goat milk was used. One commercial LAMP kit with two different dyes (one dsDNA-binding and one Mg2+-sensitive) was compared to the sensitivity of the detection to ddPCR. The results obtained revealed a high sensitivity of the kit for detection of DNA isolated from artificially contaminated milk samples in the following range: visible detection based on visible color change—3.1 × 104 mL (violet dye) and 3.4 × 103/mL (blue dye); detection with gel electrophoresis—2.0 × 101/mL (violet dye) and 3.4 × 102/mL (blue dye). The enumeration of the DNA copies in the same samples was performed with ddPCR, with a detection limit of 2.0 × 101/mL. Our results indicate the potential and the possible applicability of the LAMP method for rapid and sensitive visual detection of Y. pseudotuberculosis in raw goat milk. The presented ddPCR protocol can be used for highly sensitive identification and enumeration of Y. pseudtuberculosis in raw goat milk. In conclusion, the conducted comparison is of importance for future implementation of LAMP protocols for on-field analysis near the sampling site and point-of-care or laboratory diagnostics of Y. pseudtuberculosis after the successful validation procedure of an appropriate LAMP protocol.

Given the medical and social significance of Helicobacter pylori infection, timely and reliable diagnosis of the disease is required. The traditional invasive and non-invasive conventional diagnostic techniques have several limitations. Recently, opportunities for new diagnostic methods have appeared based on the recent advance in the study of H. pylori outer membrane proteins and their identified receptors. In the present study we assess the way in which outer membrane protein–cell receptor reactions are applicable in establishing a reliable diagnosis. Herein, as well as in other previous studies of ours, we explore the reliability of the binding reaction between the best characterized H. pylori adhesin BabA and its receptor, the blood antigen Leb. For the purpose we developed surface plasmon resonance (SPR) and double resonance long period grating (DR LPG) biosensors based on the BabA–Leb binding reaction for diagnosing H. pylori infection. In SPR detection, the sensitivity was estimated at 3000 CFU/mL—a much higher sensitivity than that of the RUT test. The DR LPG biosensor proved to be superior in terms of accuracy and sensitivity—concentrations as low as 102 CFU/mL were detected.

In this study, doxorubicin was loaded in a chitosan–albumin nanogel with the aim of improving its stability and exploring the potential of the system in the treatment of skin cancer. Infrared spectroscopy and X-ray diffraction confirmed the encapsulation of the drug. Transmission electron microscopy revealed the spherical shape of the nanogel particles. The drug-loaded nanogel was characterized with a small diameter of 29 nm, narrow polydispersity (0.223) and positive zeta potential (+34 mV). The exposure of encapsulated doxorubicin to light (including UV irradiation and daylight) did not provoke any degradation, whereas the nonencapsulated drug was significantly degraded. In vitro studies on keratinocytes (HaCaT) and epidermoid squamous skin carcinoma cells (A-431) disclosed that the encapsulated doxorubicin was more cytotoxic on both cell lines than the pure drug was. More importantly, the cytotoxic concentration of encapsulated doxorubicin in carcinoma cells was approximately two times lower than that in keratinocytes, indicating that it would not affect them. Thus, the loading of doxorubicin into the developed chitosan–albumin nanogel definitely stabilized the drug against photodegradation and increased its antineoplastic effect on the skin cancer cell line.

A complex evaluation of antimicrobial activities of microalgae, including those relevant to wastewater treatment (WWT), in light of the integrated biorefinery concept, is performed. An example of this concept is linking a commercial microalgal system to plants, factories, or farms that emit polluted wastewater (WW). The microalgae would not only metabolize the pollutants—such as nitrogen (N) and phosphorus (P)—from the WW, thus fueling their biomass, but they would exert an antibacterial effect against the pathogenic bacteria there. The biomass then could be harvested and used for biofertilizers, biofuels, and bioplastics and might possibly be utilized as animal feed, antimicrobial and other pharmaceutical agents. A large amount of the research on the antimicrobial activity and WWT potential focuses on the families Chlorellaceae and Scenedesmaceae, which are also some of the most commercially used strains of microalgae. For that reason, they are the species chosen for the current review. Furthermore, the increasing antimicrobial resistance necessitates the search for antibiotic alternatives, and the antibacterial and antifungal activity of Chlorellaceae and Scenedesmaceae is very promising. Microalgae are rich in antibacterial compounds like polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, proteins, etc., and for that reason, their extracts possess antimicrobial effects. The in vitro antimicrobial activity of Chlorellaceae and Scenedesmaceae families has varied in a broad range from low to strong activity or no effect. Several strains have fulfilled the criteria for outstanding and high activity, especially C. vulgaris and other Chlorellaceae spp., with an effect equal to or better than the control antibiotics. There were several strains with minimum inhibitory concentrations (MIC) below 80 µg/mL and even 10 and 1.5 µg/mL; some species also had inhibition zones (IZ) over 30 mm, even as high as 48 mm. In vivo results are also promising but scarce, and all this warrants further in vivo and in situ studies—from animal models to clinical and environmental trials. Altogether, important data in the light of the circle economy, the urgent necessity to decrease CO2 emissions to fight climate change, and to curb the harmful influence of future pandemics are presented. This review paves the way for further utilizing the total potential of a microalgal system.