Search Results (304)

In this study, we investigated the presence and diversity of FLA in 62 environmental samples collected across Tenerife, Canary Islands, Spain including agricultural and playground soils, and on double treated water from public refrigerated fountains. Amoebae were isolated by culturing processed samples onto 2% Non-Nutrient Agar plates (NNA) which were checked daily for further processing up to molecular characterization. In this case, two approaches for molecular identification were assessed: direct multiplex qPCR targeting four potentially pathogenic FLA (Acanthamoeba spp., Vermamoeba vermiformis, Naegleria fowleri, and Balamuthia mandrillaris) DNA, and culture-based isolation followed by standard PCR and sequence analysis. Regarding qPCR results, 72.6% (45/62) of the samples were positive for at least one FLA, with V. vermiformis (37/62) and Acanthamoeba spp. (34/62) being the most frequent. Moreover, B. mandrillaris was detected for the first time in the Canary Islands in 6 out of 62 samples. Results from standard PCR from cultured isolates confirmed the presence of Acanthamoeba (mainly genotype T4) and Vermamoeba and also allowed the identification of Vahlkampfia and Vannella genera, as well as the genus Rhogostoma—its first report in the Canary Islands. Thermotolerance and osmotolerance assays were performed on Acanthamoeba spp. and, innovatively, on V. vermiformis isolates. Both were capable of surviving at 37 °C and during incubation with 0.5 M mannitol, suggesting potential pathogenicity. However, growth was significantly impaired under harsher conditions (42 °C and 1 M mannitol). These findings underscore the widespread occurrence of FLA in public and agricultural environments in Tenerife and highlight their potential risk to public health. Their ability to act as carriers of pathogenic bacteria/viruses further reinforces the need for routine surveillance and preventive measures in the environment. Full article

Two Gram-negative aerobic halophilic bacteria, designated KMM 9989^T and KMM 9879, were isolated from a bottom sediment sample of the Okhotsk Sea, Russia. The novel strains grew in 0.5–4% NaCl, at 5–35 °C and pH 5.5–10.0. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences placed strains KMM 9989^T and KMM 9879 within the family Roseobacteraceae, where they were clustered with their closest relative Marinovum algicola KCTC 22095^T. The average nucleotide identity (ANI) between strain KMM 9989^T and Marinovum algicola KCTC 22095^T was 81.4%. The level of digital DNA–DNA hybridization (dDDH) between the novel isolates KMM 9989^T and KMM 9879 was 97%, while between strain KMM 9989^T and Marinovum algicola KCTC 22095^T, it was 27%. Strains KMM 9989^T and KMM 9879 contained Q-10 as the predominant ubiquinone and C_18:1ω7c as the major fatty acid. The polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unidentified aminolipid, two unidentified phospholipids, and three unidentified lipids. The genomic size of strains KMM 9989^T and KMM 9879 was determined to be 4,040,543 bp and 3,969,839 bp with a DNA GC content of 61.3 and 61.4 mol%, respectively. Both strains contained a common plasmid of 238,277 bp and a strain-specific plasmid (188,734 bp for KMM 9989^T and 118,029 bp for KMM 9879). It is suggested that the motility of KMM 9879 may be mediated by the presence of a complete fla2-type operon in the strain-specific chromid. Thus, based on the phylogenetic analyses and distinctive phenotypic characteristics, the novel marine strains KMM 9989^T and KMM 9879 are proposed to be classified as a novel species Marinovum sedimenti sp. nov. with the strain KMM 9989^T (=KCTC 8835^T) as the type strain of the species. Full article

Free-living amoebae (FLA) are protozoa ubiquitous in nature, isolated from a variety of environments worldwide. In addition to their natural distribution, some species have been found to be pathogenic to humans. In the present study, FLA presence was evaluated and characterized at the molecular level from different water and soil samples in Fuerteventura Island, Canary Islands, Spain. A total of 31 samples were analyzed by culture and molecular assays (q-PCR and PCR). Moreover, the microbiological quality of the water samples was examined as required by current legislation and international standards. The obtained data revealed that the genus Acanthamoeba was the most prevalent genus of FLA in soil samples and the species Vermamoeba vermiformis was the most isolated in water samples collected from Fuerteventura by culture and molecular assays, q-PCR, and conventional PCR/Sanger sequencing. On the other hand, a microbiological analysis revealed heterogeneous contamination patterns. Escherichia coli was detected in several samples, with some exhibiting high counts while others showed no presence. Salmonella spp. appeared in multiple samples, particularly FTVW1, FTVW9, and FTVW13, whereas Shigella spp. was only found in one sample (FTVW1). Moreover, q-PCR detection offers advantages such as reduced detection time and cost. In addition, culture was proven to be more effective for confirming FLA viability and isolating a greater variety of FLA. Overall, the occurrence of potentially pathogenic free-living amoebae in habitats related to the human population, as reported in the present study, supports the relevance of FLA as a potential health threat to humans. Full article

Arcobacter butzleri and Arcobacter cryaerophilus are emerging foodborne and waterborne pathogens associated with enteritis and extraintestinal infections in humans. Their persistence in the environment and resistance to antimicrobial treatment are closely related to their ability to form biofilms, which provide protection against adverse conditions and support survival on food contact surfaces. This study evaluated both the genotypic and phenotypic aspects of biofilm formation among A. butzleri and A. cryaerophilus isolates from food and environmental sources. Six biofilm-associated genes (flaA, flaB, fliS, luxS, pta, and spoT) were detected by multiplex PCR, and biofilm production was assessed using the Christensen microtiter plate assay and Congo Red Agar (CRA) test. All A. cryaerophilus isolates carried the same gene set as A. butzleri, suggesting conserved genetic determinants of motility and Quorum sensing. However, phenotypic assays revealed interspecific variability: while most A. butzleri isolates formed strong biofilms, 70% of A. cryaerophilus strains showed moderate to strong formation despite all being CRA-negative. No direct correlation between gene presence and biofilm intensity was observed, indicating complex regulation of biofilm development. This study provides a comparative overview of biofilm formation in A. butzleri and A. cryaerophilus and highlights their adaptive potential and persistence in food-related environments. Full article

This study evaluated the antagonistic activity of the cell-free supernatant of Lacticaseibacillus rhamnosus ATCC 9595 (Lcr-CFS) against Listeria monocytogenes, a major foodborne pathogen, that represents a challenge to food safety, due to its remarkable tolerance to environmental stresses and strong biofilm-forming ability. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Lcr-CFS against L. monocytogenes were defined as 31.25 and 62.5 mg/mL, respectively. Time-kill assays revealed dose- and time-dependent bactericidal effects. At sub-MICs, Lcr-CFS significantly reduced L. monocytogenes biofilm formation, disrupted preformed biofilms and decreased cell viability (80.3–96.7%), effects that were confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and fluorescence microscopy. Transmission electron microscopy showed L. monocytogenes cell wall damage, cytoplasmic leakage, and morphological alterations consistent with bactericidal effects. Additionally, exposure to 1x and 2x MIC of Lcr-CFS induced reactive oxygen species (ROS) accumulation, indicating oxidative stress as part of the mechanism by which Lcr-CFS exerts its antimicrobial activity. Gene expression analysis revealed upregulation of stress and virulence-associated genes (sigB, prfA, degU, flaA, motA, hlyA, pclA, and actA) upon exposure to 0.5x MIC suggesting a complex cross-talk network between adaptive mechanisms and environmental stresses. Although L. monocytogenes initiates a stress response, it appears unable to counteract the damage induced by Lcr-CFS, resulting in cell death. These findings highlight the antimicrobial and anti-biofilm properties of Lcr-CFS against L. monocytogenes. Given its in vitro efficacy, Lcr-CFS emerges as a promising biocontrol agent to improve food safety by mitigating the persistence of L. monocytogenes in food processing settings. Full article

Monitoring the occurrence of Borreliaceae spirochetes in ticks may provide an indication of the risks of acquiring Lyme borreliosis (LB) and Borrelia miyamotoi disease (BMD). All ticks obtained in our study from humans in the years 2018–2022 (n = 1232) were identified morphologically for species, sex and developmental stage. The detection of Borreliaceae spirochetes and species identification were performed by nested PCR based on the flaB gene fragment and the region between the mag and trnI genes. Two species of ticks were identified: Ixodes ricinus (96.9%) and Dermacentor reticulatus (3.1%). The infection of I. ricinus ticks with Borreliaceae spirochetes was found to reach 18.3%, including B. miyamotoi (2.5%). Among Borreliella species, Bl. afzelii was the most frequent, followed by Bl. burgdorferi, Bl. spielmanii, Bl. valaisiana, Bl. garinii, Bl. bissettiae, Bl. californiensis and Bl. carolinensis. Borreliaceae spirochetes were also found in D. reticulatus ticks, of which Bl. afzelii and B. miyamotoi were the most common. In conclusion, ticks affecting humans in Poland represent a real risk of infection with Borreliaceae spirochetes, and knowledge of the prevalence and distribution of these bacteria is an important tool in assessing the risks of LB and BMD. Full article

Background/Objectives: Fasciclin-like arabinogalactan proteins (FLAs) are critical components of the plant cell wall, playing vital roles in development and abiotic stress responses. However, a systematic genome-wide analysis of the FLA family in soybean (Glycine max L.), a major legume crop susceptible to drought, is lacking. This study aimed to comprehensively identify GmFLA members and investigate their potential functions in drought tolerance. Methods: We identified GmFLA genes via BLASTP (v2.16.0) and Hidden Markov Model (HMM) searches against the soybean genome. Subsequent analyses encompassed their physicochemical properties, chromosomal distribution, gene structure, phylogenetic relationships, conserved domains, cis-acting elements, and subcellular localization. Drought-responsive candidates were screened using a Gene Expression Omnibus (GEO) dataset, and their expression profiles were validated under drought stress using quantitative real-time PCR (qRT-PCR). Results: A total of 55 GmFLA genes were identified and unevenly distributed across 14 chromosomes. Most genes featured a single-exon structure and contained a conserved Fasciclin domain, with predicted localization primarily to the chloroplast. Phylogenetic analysis grouped them into three distinct subclasses with Arabidopsis homologs, suggesting lineage-specific expansion. Promoter analysis revealed an abundance of stress- and hormone-related cis-elements. Expression analysis identified five candidate genes (GmFLA5, GmFLA15, GmFLA40, GmFLA47, and GmFLA54) that showed tissue-specific expression changes under drought treatment. Conclusions: This study provides the first comprehensive genomic characterization of the GmFLA gene family and identifies candidate GmFLAs with drought-responsive expression patterns. Our findings establish a foundation for future functional research to investigate their potential roles in soybean drought response. Furthermore, these candidates serve as potential targets for further investigation in strategies aimed at improving soybean drought tolerance. Full article

This study examines the efficacy of virtual reality exposure therapy (VRET) in alleviating foreign language anxiety (FLA) among university students. Although research exists on FLA, interventions have relied on self-reporting measures, leaving a gap in understanding physiological indicators and anxiety reduction. While previous research has explored either the therapeutic potential of virtual reality or the neurophysiological correlations of anxiety through electroencephalography (EEG), few have integrated these methodologies within a single experimental framework. This study combined the foreign language classroom anxiety scale (FLCAS) with (EEG) data to capture subjective and neural responses to anxiety in second language (L2) speaking. The participants (n = 20) completed language speaking tasks both before and after VR intervention, which exposed them to anxiety-inducing conditions replicating language challenges. During these tasks, brainwave signals were recorded, focusing on frontal alpha asymmetry (FAA) and alpha power (F3, F4), indicating neural activity associated with stress and emotional regulation. Results showed participants experienced a significant decrease (p = 0.017 < 0.05) in self-reported FLCAS scores after VRET. The reduction in FLA showed a negative correlation with increased alpha power at F3 (r = −0.55, p = 0.012), suggesting a link between left frontal neural regulation and anxiety reduction. These findings underscored VRET’s effectiveness in influencing emotional responses during L2-speaking tasks. Full article

Artemisia dracunculus L., commonly known as tarragon, is a popular culinary herb and a valuable source of bioactive extracts and phytocompounds. Its wide distribution across regions of the Northern Hemisphere demonstrates the species’ high adaptability to diverse growing conditions and has led to the development of chemoraces that differ in chemical composition. North Asian populations of A. dracunculus remain poorly studied, and plants growing in Siberia have not yet been examined. Given the vast areas occupied by tarragon, the species is a promising candidate for industrial use. Liquid chromatography–mass spectrometry (LC–MS) profiling identified 80 compounds in Siberian tarragon samples, including hydroxycinnamates (HCys), coumarins, flavonoid aglycones (FlAs), and glycosides (FlGs). Among these, 62 phenolics were reported for the first time as A. dracunculus metabolites, highlighting the uniqueness of the North Asian accessions, particularly in their diversity of flavone O-glycosides and methylated flavanone aglycones. The highest levels of HCy, FlA, and FlG were 21.84, 52.53, and 54.44 mg/g, respectively, yielding a total phenolic content of 128.81 mg/g in the dry plant material—a high value. The concentrations of certain compounds exceeded 1%, making tarragon a noteworthy source of rare metabolites, including naringenin 7-O-methyl ester, thermopsoside, tilianin, and naringenin 7,4′-di-O-methyl ester. Thus, the existing knowledge of the chemical profile of tarragon has been expanded by new data on phenolic compounds from the North Asian populations of the species, which may be used to develop new A. dracunculus varieties with improved metabolic profiles and bioactive properties. Full article

This study was conducted to assess the involvement of two lizard species: the sand lizard (Lacerta agilis) and the common lizard (Zootoca vivipara), and their Ixodes ricinus ticks, in the circulation spirochetes of the Borrelia burgdorferi s.l. complex. Lizards were captured at three study sites in suburban areas of western Poland. Common lizards were less abundant and occurred only at one site. A total of 1129 ticks were collected from 167 sand lizards and 164 individuals from 42 common lizards. Biopsies of the distal part of the lizard tail were taken from 172 animals. All samples that tested positive by real-time PCR underwent subsequent nested PCR targeting the flaB gene, followed by sequencing. At least 6.3% of I. ricinus ticks (MIR) from L. agilis, and 6.1% from Z. vivipara, were infected. Borrelia lusitaniae was the most prevalent genospecies in L. agilis-derived ticks, accounting for 73.2% of all infected samples, followed by B. burgdorferi s.s. (23.0%). Conversely, this latter species prevailed (90%) over B. lusitaniae (10%) in tick samples from Z. vivipara. Therefore, we believe that sand lizards are competent reservoir hosts for B. lusitaniae, while the role of Z. vivipara for this species is unclear. The high prevalence of B. burgdorferi s.s. was also found in infected larval samples (40.7%) and biopsies (60%) of L. agilis. Thus, in our opinion, these two lizard species could be another group of reservoir hosts for this human pathogen, along with birds and rodents. Full article

Listeria monocytogenes is a foodborne pathogen of significant public health concern due to its high environmental resilience and ability to cause severe infections in vulnerable populations. The objective of the present study is to characterize foodborne strains of Listeria monocytogenes isolated between 2020 and 2024 in northwestern Italy. Lm was detected through isolation, biochemical confirmation and molecular serogrouping. Next generation sequencing (NGS) analysis was used to characterize the strains in terms of virulence and antibiotic resistance. A total of 39 positive samples were identified from various food matrices, including meat products, fish, cheeses and ready-to-eat foods. The most frequently detected serogroups were IIc and IIa, with a notable presence of the highly virulent IVb group. Next-generation sequencing (NGS) was applied to all isolates, revealing the presence of virulence genes associated with the LIPI-1 island and internalins. In addition to pathogenicity islands, genes related to stress resistance (clpCEP, Gad A, GadB, GadC), biofilm production (agrA, flaA, degU, hfq) and sortase-mediated anchoring of surface protein (strA, strB) have been identified. The presence of antibiotic resistance genes was confirmed, with all isolates harboring the fosX gene. Moreover, four isolates exhibited resistance determinants against antibiotics belonging to two different classes: tetracyclines (tetM) and lincosamides (lsa(A)). Multilocus sequence typing (MLST) showed that clonal complex CC9 was the most prevalent among the isolates. Further, cgMLST and SNP analyses identified a principal cluster of closely related strains, which were isolated from meat products. These findings highlight the need for continuous surveillance of L. monocytogenes. Full article

The increasing global incidence of infections caused by free-living amoebae (FLA) and the lack of effective, safe, and approved treatments highlight the urgent need for novel amoebicidal compounds with pharmacological potential. Despite a growing body of literature on the anti-FLA properties of various compounds, comprehensive reviews summarizing this progress remain scarce. This study aimed to identify the most promising compounds tested in vitro and/or in vivo for anti-FLA activity. A systematic review was conducted, analyzing 108 studies published between 1986 and 2024, selected from an initial pool of 23,653 database results. A total of 537 compounds were evaluated for their in vitro anti-FLA activity. Compounds exhibiting ≥50% reduction in amoeba viability relative to untreated controls were classified as promising if they showed low toxicity in mammalian cell models, particularly when active at concentrations ≤ 10 µM, consistent with predicted favorable pharmacokinetic and pharmacodynamic profiles. The most promising compounds for drug and disinfectant development include ten trophocidal agents against B. mandrillaris, thirty-two trophocidal and four cysticidal agents against N. fowleri, and sixty-two trophocidal and nineteen cysticidal agents against Acanthamoeba spp. Compounds active at low concentrations (≤10 µM or <0.014 mg/mL) prioritized for in vivo drug development studies include: against Balamuthia mandrillaris, trophocidal 515, 531, 533; against Naegleria fowleri, trophocidal 421, 416, 518, 46, 254, 522, 111–120 and cysticidal 16; and against Acanthamoeba spp., trophocidal 498, 499, 500, 535, 107, 347, 348, and 340. Future studies should evaluate their efficacy, safety, pharmacokinetics, and pharmacodynamics toward developing effective drugs, antiseptics, and disinfectants. Full article

Helicobacter pylori infects the human stomach and causes various gastrointestinal diseases. Saucerneol D is a type of lignan, which is a polyphenol compound that exists naturally in plants, and it is abundant in flaxseed, sesame seeds, whole grains, vegetables, and fruits. Saucerneol D is found in Saurus chinensis extract and has been reported to exert a variety of effects, such as antioxidant and anti-inflammatory abilities. However, its antibacterial effect against H. pylori has not been reported; therefore, we analyzed the effect of saucerneol D on H. pylori in the present study. Changes in the expression of pathogenic factors and gene transcription in H. pylori were observed after treatment with saucerneol D using Western blotting and RT-PCR. It was confirmed that saucerneol D suppressed the growth of H. pylori by decreasing the expression of the genes dnaN and polA, which are required for bacterial replication. Saucerneol D also reduced the secretion of the major pathogenic toxin protein, CagA, by downregulating the expression of type IV secretion system-composing proteins. Furthermore, saucerneol D reduced ammonia production by inhibiting the expression of urease proteins, which are essential for the survival of H. pylori in the acidic gastric environment. Additionally, saucerneol D decreased the expression of flaB, potentially reducing motility. Finally, it was confirmed that the expression of the sabA gene, associated with cell adhesion, was reduced. These results suggest that saucerneol D inhibits the growth of H. pylori and the expression of several pathogenic factors, indicating that saucerneol D has an antimicrobial effect against H. pylori. Full article

Ficus lindsayana is recognized for its medicinal properties, with previous studies highlighting the antioxidant and anti-inflammatory effects of its latex (FLtA) and root (FRE) extracts. Harvesting these plant parts, however, raises ecological concerns. This study evaluates the phytochemical profiles, safety, and biological activities of F. lindsayana leaf (FL) extracts as more sustainable alternatives. Leaves were extracted using hot water (FLA) and 80% ethanol (FLE), yielding 32.9% and 11.4%, respectively. Metabolomic and targeted HPLC-MS/MS analyses revealed distinct phytochemical compositions. FLE was enriched in flavonoid aglycones and lipophilic compounds, while FLA contained higher levels of polar phenolics. FLA showed greater total phenolic and flavonoid contents and stronger antioxidant activity, with an SC₅₀ of 159 μg/mL for the DPPH assay. In contrast, FLE demonstrated more pronounced anti-inflammatory activity. In LPS-stimulated RAW 264.7 macrophages, FLE significantly reduced nitric oxide production and iNOS expression at both the protein and mRNA levels. FLE also reduced IL-6 secretion in a dose-dependent manner without affecting TNF-α, suggesting selective cytokine modulation. Both extracts exhibited low cytotoxicity (IC₂₀ > 800 µg/mL in most cell types), non-hemolytic properties, and no mutagenic activity in the Drosophila wing spot assay. Compared to root and latex extracts, FLE ranked second in anti-inflammatory potency (FRE > FLE > FLA = FLtA). FLE, therefore represents a promising candidate, combining potent bioactivity with environmental responsibility and supporting the further development of F. lindsayana leaf-derived products for use in functional foods or botanical therapeutics. Full article

The mother’s love is vital for adolescent development, yet there is a lack of specific tools to measure its psychological absence. This study aimed to develop the Mother-Love Absence Scale (MLAS) by revising the Father-Love Absence Scale (FLAS) and verify its reliability and validity among adolescents. Study 1 included 2700 junior and senior high school adolescents. The junior and senior high school samples were each randomly split into two subsamples. One subsample was used for Exploratory Factor Analysis (EFA), while the other was used for Confirmatory Factor Analysis (CFA), internal consistency reliability tests, and cross-gender measurement invariance tests. The results indicated that the factor structure of the MLAS was consistent with that of the FLAS, both comprising four factors: emotional absence, cognitive absence, behavioral absence, and volitional absence. Furthermore, multi-group confirmatory factor analysis verified the gender invariance of the scale. In Study 2, 193 adolescents were surveyed to conduct a CFA and a criterion-related validity analysis. The results of the CFA again demonstrated a good model fit for the four-factor structure. The criterion-related validity analysis indicated that the mother-love absence was negatively connected with parent–child interaction and positively correlated with parental phubbing. Therefore, the revised MLAS has well reliability and validity and can be a reliable instrument for measuring mother-love absence in adolescents. Full article