Samah Omar Noor

Oral fungal infections resulting from non-albicans Candida species and new opportunistic yeasts are increasingly linked to antifungal resistance, especially in individuals with periodontal disease. Bioactive compounds may serve as potential alternatives; nevertheless, there is a paucity of research that has comprehensively assessed their antifungal and antibiofilm efficacy against clinically defined oral yeast isolates. This study aimed to (i) describe the variety and antifungal resistance profiles of oral yeasts isolated from women with various periodontal diseases; (ii) assess four ethanolic extracts of Aseer medicinal plants (Foeniculum vulgare, Solanum incanum, Forsskaolea tenacissima, and Abutilon pannosum) for their antifungal and antibiofilm properties; and (iii) correlate phytochemical composition determined by GC–MS with biological activity. Oral samples (saliva and subgingival plaque) were collected from 50 female participants with documented periodontal parameters. Fungal isolates were identified using morphological, biochemical (VITEK 2), and molecular (ITS rDNA sequencing) methods. Testing for antifungal susceptibility was performed according to CLSI guidelines. Plant extracts were evaluated for antifungal activity (disk diffusion, MIC, MFC), antibiofilm activity (crystal violet assay and light microscopy), and phytochemical profiling (GC–MS). Fungal growth was detected in 37 of 50 samples (74%), yielding six yeast species: Nakaseomyces glabratus (40.5%), Candida tropicalis (18.9%), C. parapsilosis (13.5%), Pichia kudriavzevii (10.8%), Rhodotorula mucilaginosa (8.1%), and Aureobasidium melanogenum (8.1%). N. glabratus demonstrated reduced susceptibility to fluconazole. A. pannosum and F. vulgare exhibited the strongest in vitro antifungal activity (inhibition zones up to 19.2 mm; MIC 0.19–0.78 mg/mL; MFC 0.39–1.56 mg/mL), significantly greater than F. tenacissima (p < 0.0001). Sub-MIC concentrations of A. pannosum reduced C. tropicalis biofilm biomass by 59.6%. GC–MS analysis identified methyl salicylate (20.3–40.2%) and cyclohexanol derivatives (8.0–23.2%) as major constituents. Antifungal activity showed a trend in relation to methyl salicylate content (R² = 0.78). However, because only four plant extracts were included, this relationship should be interpreted as a descriptive observation rather than a statistically testable association. Ethanolic extracts of Abutilon pannosum and Foeniculum vulgare demonstrated significant in vitro antifungal and antibiofilm activity against clinically relevant oral yeasts, including azole-tolerant Nakaseomyces glabratus. The observed trends between phytochemical composition and biological activity warrant further investigation into their potential as adjunct therapeutic agents for oral fungal infections. Further studies are required to confirm these results and see if they can be used in therapeutic settings.

This work provides an in vitro assessment of the antibacterial efficacy of ethanolic extracts derived from four medicinal plants historically utilized in the Aseer region (Foeniculum vulgare, Solanum incanum, Forsskaolea tenacissima, and Abutilon pannosum) against cultured oral bacterial isolates obtained from healthy volunteers. Oral samples from a subset of 50 healthy female participants were included in this analysis, yielding independent cultured bacterial isolates. Isolates were identified using morphological and biochemical characterization combined with partial 16S rRNA gene sequencing and included representatives of common oral-associated genera. Antibacterial activity was assessed using agar disk diffusion and broth microdilution assays. Abutilon pannosum and Solanum incanum had lower values of MIC (range of 16–128 µg/mL), whereas Forsskaolea tenacissima had higher values of MIC (maximum to >512 µg/mL) with the tested isolates. Qualitative microscopic observations and crystal violet biofilm staining showed extract-associated varying cellular morphology, aggregation patterns and surface coverage under sub-inhibitory conditions. Representative isolate scanning electron microscopy (SEM) qualitatively validated descriptive cell surface morphology and organization changes. The research presents preliminary in vitro results of inconsistent antibacterial and antibiofilm effects of crude ethanolic extracts of four plants in the Aseer region on a small (n = 13) group of cultured oral bacteria isolates in healthy volunteers, which requires fractionation and further testing.

Acinetobacter baumannii (A. baumannii), a common hospital-associated pathogen, is known for its rapid ability to develop antibacterial drug resistance. The HIS-C enzyme in this pathogen is essential for histidine biosynthesis, making this a prominent drug target for antimicrobial therapy. This experimental investigation analyzes the inhibitory function of quercetin, a well-known antibacterial flavonoid, on HIS-C enzyme through the in vitro and in silico approaches. The binding affinity between quercetin and HIS-C was further examined through in vitro assays. Further, the surface plasmon resonance (SPR) experiments confirmed the strong binding affinity, with a dissociation constant (KD) of 3.3 × 10^-6 M. Antibacterial assays proved the inhibitory potential of quercetin against A. baumannii growth, with a minimum inhibitory concentration (MIC) of 15 µg/mL. In silico analyses were performed to support these experimental results by providing additional insights into the binding interactions. Altogether, these in vitro and in silico findings have significantly proven the potential of quercetin as an HIS-C inhibitor. Further in vivo studies, particularly on toxicity and pharmacokinetics, are essential before it can be considered for therapeutic application against A. baumannii infections.

Salinization induced by salt stress is a critical environmental factor, and limits the expansion of agricultural areas and population distribution in continental regions, including Saudi Arabia. Common beans, a vital source of protein, energy, and dietary fibers, are negatively affected by salt stress. In this research, the endophytic fungus Cladosporium halotolerans was utilized to remediate saline soils and enhance common bean growth and resilience. The results of this study demonstrated that soil treatment with C. halotolerans enhances the soil properties by decreasing soil pH and increasing soil organic matter content under saline conditions. Inoculation by C. halotolerans also significantly improved plant growth parameters, induced systemic resistance to salinity, and increased the levels of chlorophyll b and carotenoids. Fungal inoculation also causes stress relief as indicated by reducing malondialdehyde concentration by 27.4% lower than stressed plants. Microscopic images revealed the active association and colonization of C. halotolerans within the roots of the Phaseolus vulgaris both under control and saline conditions. Therefore, utilizing endophytic fungi C. halotolerans for saline soil remediation appears to be a promising alternative in plant treatments, highlighting their potential as valuable resources for both research and commercial applications under salinity stress.

In vitro fertilization (IVF) is the most advanced technique of assisted reproductive where the sperm reach the eggs for fertilization in a laboratory tube. Seminal fluid often contains bacterial contaminants that decrease the quality and quantity of seminal fluids. Aim: In this study we investigated the presence of bacteria in semen before IVF procedure. Methodology: All samples were identified according to the morphological, biochemical, molecular, and antimicrobial tests. Results: Microbial species were detected in 28% of semen samples, while 72% did not show any bacterial growth. The prevalent bacterial isolates were Staphylococcus spp., Enterococcus spp., Catellicoccus spp., and Pseudomonas spp. Conclusion: The use of microbiological analysis to identify resistant bacterial isolates is considered an effective method to reduce infertility in men by changing the contaminated semen.

Rhazya stricta is an important medicinal plant used as native herbal drug to cure various diseases across Asia. Plant-microbe interactions represented by different environment abiotic stress factors that shows effects also on the host plants or on the associated microbial communities. Soil microorganism can be adapted to specific stress conditions and evolve tolerance to this stress. The adjustment of the plant microbiome can productively improve the yield production of essential crops. In the present study, metagenomics analysis of bacterial communities associated with five desert plants (Rhazya stricta, Enneapogon desvauxii, Citrullus colocynthis, Senna italica, and Zygophyllum simplex) was used to highlights the bacterial diversity in the communities of these desert plants, as they also have an importance as folkloric medicinal plants, in addition to their important roles in the ecological and agricultural applications. The results of the bacterial community's taxonomy showed eleven phyla in each sample, and the most abundant were highlighted for further analysis as it was unassigned phyla. Results indicated that the most commonlyknownphylawere; Actinobacteria, Proteobacteria, Chloroflexi, Firmicutes, Acidobacteria, Gemmatimonadetes, and Bacteroidetes. Further bioinformatics and functional analysis of bacteria are needed to investigate their effectiveness in promoting plant growth and understanding symbiotic relationships under drought-stress conditions, meanwhile, introducing the pinpointed ones in this study will help in achieving this task.