Anna Malm

Candida species have emerged as a global threat due to their rapid worldwide spread and multidrug-resistant properties. Therefore, novel and more effective antifungal agents, including natural-based preparations, are being actively sought. Essential oil (EO) components, including α-bisabolol, carvacrol, eugenol, linalool, menthol, and thymol, were evaluated in vitro for their antifungal, antioxidant, and anti-inflammatory activities. The aim of this study was to select EO compounds demonstrating the highest anticandidal activity together with promising antioxidant and anti-inflammatory properties for potential use as active ingredients in topical preparations. The activity of the tested EO compounds against five reference yeast strains belonging to Candida spp. was assessed in vitro using the broth microdilution method according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI). All EO compounds demonstrated potential anticandidal activity, with minimum inhibitory concentrations (MICs) ranging from 0.25 to 4 mg/mL, and exhibited fungicidal properties (MFC/MIC = 1–4). The highest activity was observed for α-bisabolol (MIC = 0.25–1 mg/mL), followed by carvacrol (MIC = 0.25–2 mg/mL), thymol (MIC = 0.5–2 mg/mL), and eugenol (MIC = 0.5–2 mg/mL). Eugenol exhibited the strongest antioxidant properties, even at a concentration of 0.1 mg/mL, as demonstrated by the DPPH assay. Moreover, this compound showed the highest anti-inflammatory activity, reflected by cyclooxygenase-2 (COX-2) inhibition of approximately 45% at a concentration of 0.5 mg/mL. Based on the obtained results, eugenol appears to be the most promising candidate for the development of topical preparations intended for the treatment of superficial infections caused by Candida spp.

Essential oils (EOs) are widely investigated as multifunctional agents for cosmetic applications due to antimicrobial and antioxidant properties; however, their efficacy and safety depend on chemical composition and microbiological selectivity. This study characterized ten commercially available EOs (basil, lavender, melissa, mint, oregano, rosemary, sage, thyme, clove, tea tree) and evaluated their antistaphylococcal and antioxidant activities. Chemical composition was analyzed using GC-MS and ATR-FTIR spectroscopy, while antistaphylococcal activity was assessed against Staphylococcus spp. isolated from skin microbiota using the microbroth dilution method. Antioxidant capacity was determined by the DPPH assay. Multivariate statistical analyses were applied to explore chemical composition–activity relationships. The EOs showed distinct chemical profiles dominated by phenolic compounds (eugenol, carvacrol, thymol), oxygenated monoterpenes (linalool, menthol, 1,8-cineole), and terpenoids. Clove, oregano, and thyme EOs exhibited the strongest antistaphylococcal activity (MIC 0.5–2 mg/mL) and highest antioxidant capacity (>80%), whereas lavender, mint, and sage EOs showed weak effects. All EOs demonstrated bactericidal activity with consistent susceptibility patterns among Staphylococcus spp. PCA and FTIR confirmed an association between phenolic content and bioactivity. In conclusion, antimicrobial efficacy is primarily driven by phenolic composition, supporting targeted cosmetic use while acknowledging possible effects on skin Staphylococcus spp. populations.

Staphylococcus aureus is a high-priority pathogen causing skin and soft tissue infections (SSTIs). The frequent resistance to anti-staphylococcal agents exhibited by this underscores the need for accurate diagnostics to guide effective therapy. Therefore, this study aimed to compare phenotypic and genotypic resistance in S. aureus isolates from nasal carriers and SSTIs and to elucidate gene-silencing mechanisms. In total, 355 S. aureus isolates (256 isolated from carriers and 79 from SSTIs) were studied for their phenotypic and genotypic resistance to β-lactams, macrolides, tetracyclines, aminoglycosides, and mupirocin. The silenced mupA gene (low prevalence: 0.6%; 2/335), linked to mupirocin resistance, was sequenced, and expression was assessed via reverse transcription qualitative PCR (RT-qPCR) in all mupA-positive isolates. SSTI isolates showed significantly higher resistance to erythromycin, gentamicin, and mupirocin, along with a higher prevalence of multidrug-resistant strains and ermC and tetM genes. Sequencing revealed multiple mutations in silent mupA, including a critical frameshift (c.372 delA) in a poly(A) tract that brings about premature truncation. RT-qPCR indicated upregulation of silent mupA variants and high variability in functional strains, suggesting that frameshift alone prevents resistance. These findings highlight silent resistance genes as key targets for advancing S. aureus surveillance and for combating emerging threats.

Geum aleppicum Jacq. (yellow avens), a species traditionally used in folk medicine, remains understudied in the ethnopharmacological aspects. In this study, we comprehensively evaluated the phytochemical composition and biological activity of a hydroethanolic (50:50, v/v) extract from the aerial parts of G. aleppicum collected in Kazakhstan. Using the high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS), we identified 24 compounds, predominantly phenolic acids, flavonoids, tannins, and triterpenoids. The major compound was ellagic acid (2.28 mg/g dry extract) as revealed by the reverse phase high-performance liquid chromatography–diode array detector (RP-HPLC-DAD). The extract exhibited a high polyphenol content (131.45 mg GAE/g) and strong antioxidant activity in Ferric Reducing Antioxidant Power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay (3.82 ± 0.07 mmol Fe²⁺/g and 106.61 ± 0.89 mg GAE/g, respectively). Antimicrobial assay of the extract revealed notable antifungal activity against Candida spp., especially against C. glabrata and C. tropicalis with minimum inhibitory concentration (MIC) of as low as 0.125 mg/mL, showing fungistatic effect. Although the extract inhibited the cytopathic effect induced by Human Herpesvirus 1 (HHV-1) in VERO cells, it did not significantly reduce viral replication. Moreover, among human cancer cell lines studied, the extract exerted moderate and selective cytotoxicity against A549 lung cancer cells (CC₅₀ = 75.51 µg/mL, SI = 9). These findings highlight G. aleppicum as a rich source of bioactive compounds, especially phenolics, supporting its potential for development of pharmaceutical and cosmetic applications.

Introduction and objective: Milking wastewater (MW) is an under-recognised reservoir of antibiotic resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). The aim of the study is to evaluate MW as a point source pollutant for the presence of ARB and ARGs, to develop a treatment...

Artemisia serotina Bunge represents one of the endemic Artemisia L. species in flora of Central Asia. There is scant information on the phytochemistry and biological activity of this species. The aim of the present study was to analyze the chemical composition of essential oil from A. serotina (ASEO) growing in south Kazakhstan, together with the determination of its biological activity. ASEO isolation was carried out by hydrodistillation according to the State Pharmacopoeia of the Republic of Kazakhstan. Analysis of GC/MS data revealed that the most characteristic components of ASEO were irregular monoterpenes from three families: santolinane, artemisane, and lavandulane. The major compound was santolina alcohol (34.6%). Antimicrobial activity was studied against the reference bacterial and fungal strains using the recommended methods, allowing for an estimation of MIC (minimum inhibitory concentration). ASEO was most effective against Candida albicans (MIC = 2 mg/mL), exerting fungicidal activity. Thw MIC for bacterial species was higher, i.e., 4–16 mg/mL. Antiviral activity was tested against Coxsackievirus B3 (CVB3) and Human Herpesvirus type 1 (HHV-1) propagated in VERO cells. No antiviral effect against either virus was found at an ASEO concentration of 0.25 mg/mL, but a noticeable decrease in the intensity of HHV-1-related cytopathic effects was observed. Anticancer activity studies included several cancer cell lines. Cytotoxicity, cell cycle, thiol levels, and cell vitality were analyzed. Among the cancer cell lines tested, the breast cancer T47-D cell line exhibited the highest sensitivity to ASEO (IC₅₀ = 40.81 ± 4.21 µg/mL at 24 h; IC₅₀ = 33.17 ± 2.11 µg/mL at 48 h). The anticancer effect was suggested to be mainly due to the induction of cytostatic effects, accompanied by a disturbance of the intracellular redox balance. The obtained data provide novel information on the unique chemical composition of ASEO from south Kazakhstan, representing a new chemotype. Its bioactivity, including promising antifungal and anticancer properties, was demonstrated for the first time.

The genus Inula has been used in folk medicine for centuries; however, the data concerning Inula britannica L. are scarce. This study aimed at investigating the chemical composition of methanolic and ethanolic extracts from the aerial parts of I. britannica collected in Kazakhstan and evaluating their antimicrobial and antioxidant properties, with special attention being paid to polyphenols. The total content of polyphenols and flavonoids in the extracts was determined colorimetrically, while their qualitative and quantitative analyses were conducted using HPLC/ESI-QTOF-MS and RP-HPLC/DAD. Their antioxidant potential was determined using the FRAP and DPPH methods, whereas their antimicrobial activity was determined by the microdilution method towards a panel of reference microorganisms, including pathogens of the human gastrointestinal tract. Chemical analysis demonstrated that the methanolic extract had a higher content of polyphenols (58.02 vs. 43.44 mg GAE/g) and flavonoids (21.69 vs. 13.91 mg QUE/g) than the ethanolic extract. In both extracts, 15 compounds were identified, with the highest contents being those of cynarine (13.96 and 11.68 mg/g) and chlorogenic acid (9.22 and 5.09 mg/g). The DPPH assay showed a higher antioxidant activity of the methanolic extract (19.78 ± 0.12 mg GAE/g) in comparison to that of the ethanolic extract (15.56 ± 0.24 mg GAE/g). Similarly, the FRAP method showed that the methanolic extract exerted a much higher antioxidant activity (5.07 ± 0.18 mmol Fe²⁺/g) than the ethanolic extract (0.39 ± 0.01 mmol Fe²⁺/g). In contrast, both extracts showed similar antimicrobial properties, with the highest activity being that against Helicobacter pylori ATCC 43504 (MIC = 0.125–0.25 mg/mL). This paper presents novel data on I. britannica L., implying its significance as a source of valuable active compounds and being a prerequisite for further biological studies.

The colonization of microbes and the resulting formation of biofilms on dental implants are significant contributors to peri-implantitis and the failure of these implants. The aim of the research was to analyze the impact of density and depth of laser texturing of the Ti-6Al-7Nb alloy surface on the colonization of selected microorganisms and biofilm formation. Standard strains of Gram-negative and Gram-positive bacteria and yeasts from the American Type Culture Collection—ATCC—were used to demonstrate the ability to form single-species biofilms in vitro. The study evaluated three types of titanium samples with different texture density and depth. The colonization and biofilm formation abilities of the tested microorganisms were assessed. The obtained results were subjected to statistical analysis. Among the analyzed strains, L. rhamnosus showed the highest colonization of the tested surfaces. It was found that there is no relationship between the texture parameters and the number of colony-forming units (CFU/mL) for C. albicans, S. mutans, and L. rhamnosus. For the F. nucleatum strain, it was shown that the number of colony-forming bacteria is related to the texture density.

Antimicrobial resistance (AMR) is a global public health problem, and the rapid rise in AMR is attributed to the inappropriate and/or overuse of antibiotics. Therefore, alternative antimicrobial agents, including those of natural origin, are being sought for the development of new drugs. The purpose of our study was to analyze the chemical composition, and antimicrobial and antioxidant activities of four oregano essential oils (OEOs) from Poland, Europe, Turkey and the USA. The antimicrobial activity (AMA) was evaluated using 23 strains, including Gram-positive bacteria, Gram-negative bacteria and Candida species. The antioxidant activity (AA) of essential oils (EOs) was determined by the DPPH method. The main component of the EOs tested was carvacrol (76.64–85.70%). The highest amount of this compound was determined in the Polish OEO. The OEOs we tested showed antimicrobial resistance, which was especially strong against fungi (MIC = 0.06–0.25 mg/mL⁻¹). These products also showed high AA (71.42–80.44%). OEOs high in carvacrol should be the subject of further research as potential antimicrobial and antioxidant agents.