Microbial symbionts associated with herbivorous insects can modulate plant hormone networks and reconfigure induced defenses during feeding. This review synthesizes current knowledge on how symbiont effectors converge on conserved jasmonic acid (JA)/salicylic acid (SA)/ethylene (ET) signaling hubs to suppress or reprogram plant immunity. These microbial partners secrete a diverse arsenal of bioactive molecules, including effector proteins (e.g., the histidine-rich Ca2+-binding protein ApHRC from Serratia symbiotica in pea aphids), enzymes (e.g., gut microbiome-derived proteases in Anticarsia gemmatalis larvae), and host metabolite mimics (e.g., cytokinin production induced by Wolbachia in the apple leaf-mining moth). Through these mechanisms, symbionts selectively manipulate plant hormonal pathways, a form of molecular interference that often enhances herbivore performance by increasing feeding efficiency, fecundity, and host plant range, thereby increasing plant susceptibility to biotic stress. These physiological alterations trigger cascading ecological effects, reshaping multitrophic interactions: symbiont-mediated changes in herbivore-induced plant volatiles (HIPVs) and secondary metabolites influence the behavior of natural enemies, alter competitive outcomes among herbivores, and disrupt plant-insect communication. Consequently, microbial symbionts act as hidden ecological engineers, driving community dynamics and evolutionary trajectories. By integrating molecular, ecological, and evolutionary perspectives, we propose a unified framework that explicitly links symbiont effector function to plant immune modulation and its ecosystem-level consequences. Ultimately, this synthesis underscores the potential of targeting insect-microbe partnerships through approaches such as effector blocking, microbiome augmentation, or symbiont disruption, for developing sustainable pest management strategies and advancing the field of plant defense ecology. © 2026 Society of Chemical Industry.
Methicillin-resistant Staphylococcus aureus (MRSA) is a major antimicrobial-resistant pathogen affecting both human and animal health. Although historically associated with healthcare settings, MRSA is now established in livestock production and throughout the production chain. Its detection in animals, food products, and processing environments reflects the complex ecology of antimicrobial resistance (AMR) in modern food systems. This narrative review synthesizes current evidence on the molecular basis of methicillin resistance and multidrug resistance determinants, as well as the epidemiology of MRSA in food-associated settings. Particular emphasis is placed on its occurrence in animal-derived foods and key reservoirs within farms, slaughterhouses, and processing environments. Livestock-associated populations are dominated by clonal complex CC398. In contrast, CC9 is prevalent in pig production systems in Asia, while CC5-related lineages occur at the human and animal interface. MRSA has been detected in retail meat and animal-derived foods at low but measurable prevalence, indicating contamination during slaughter and processing. Virulence determinants include staphylococcal enterotoxins linked to food poisoning and Panton-Valentine leukocidin associated with severe infections. Biofilm formation and adhesins further support persistence and colonization. Epidemiological and molecular evidence indicates that livestock, processing environments, and food-contact surfaces act as interconnected reservoirs sustaining MRSA circulation. Human exposure occurs primarily through occupational contact and environmental pathways, whereas foodborne transmission appears less common. Effective control requires integrated surveillance, responsible antimicrobial use in livestock production, and strict hygiene practices throughout the production chain within a One Health framework.
The Taiwanese loach (Paramisgurnus dabryanus ssp. Taiwanese), known for its nutritional and ornamental qualities, exhibits a rare form of albinism. Specifically, certain individuals display golden-pink eyes and a golden-red body color devoid of blotches, thereby attracting consumers. However, the principal genes regulating this phenotype remain unidentified. Consequently, this study conducted a transcriptome comparative analysis of the skin between wild-type (M) and mutant (N) Taiwanese loaches. A total of 6,152 differentially expressed genes (DEGs) were identified, comprising 2,467 down-regulated and 3,685 up-regulated DEGs in mutant individuals. Additionally, several pigmentation-related genes (mitf, wnt3, mc1r, wnt1, dct, tyrp1, and tyr) were identified. KEGG enrichment analysis of DEGs revealed pathways associated with melanin deposition, including the melanogenesis, tyrosine metabolism, and folate biosynthesis pathways. Eleven DEGs were randomly selected to validate RNA-seq results through qPCR. Furthermore, key genes (tyr, mc1r) were validated through gene knockout, accurately identifying the main gene responsible for color mutation in the Taiwanese loach. This study not only offers new insights into the molecular mechanism underlying abnormal body color in the Taiwanese loach but also demonstrates that gene knockout technology can rapidly produce a large quantity of golden-red loaches, significantly enhancing their economic value.
Aphelenchoides bicaudatus is widely reported yet frequently confused with morphologically similar congeners. We redescribe A. bicaudatus recovered from declining Pinus massoniana and associated Monochamus alternatus in eastern China using integrated light microscopy, SEM, and rDNA markers (ITS and SSU). Key diagnostic characters, particularly the bifurcated female tail terminus and SEM-resolved lip annulation, matched prior descriptions and were supported by congruent maximum-likelihood phylogenetic placement with reference sequences. We further document embryogenesis under controlled conditions and provide a time-resolved staging series from oviposition to hatching (approximately 60 h) in a parthenogenetic line, highlighting an extended one-cell phase relative to related aphelenchoids. These data expand the currently limited baseline of developmental information for Aphelenchoides and provide practical morphological and molecular references for identification. Our field sampling records co-occurrence with pine decline and beetles, but does not establish causality or vectoring.
Fittonia Coem. is a widely cultivated ornamental foliage genus, but the taxonomy and relationships of cultivated forms remain poorly resolved because traditional classifications rely heavily on variable foliar traits. In this study, we investigated the genetic relationships and phenotypic variation among 14 commercially available Fittonia cultivars using amplified fragment length polymorphism (AFLP), methylation-sensitive amplified fragment length polymorphism (MSAP), DNA flow cytometry, chromosome counting, and comparative morphological and anatomical analyses. Morphological character states were further mapped onto AFLP- and MSAP-derived phylograms to assess their evolutionary patterns and taxonomic relevance. AFLP and MSAP analyses consistently recovered two well-supported clusters within the cultivated material examined: Clade I, comprising 'Titanic' and 'Angel Snow', and Clade II, comprising the remaining 12 cultivars. These clades were independently supported by stable differences in trichome morphology, cystolith distribution, epidermal cell form, leaf venation architecture, and stem anatomy. In contrast, several traditionally used diagnostic characters, including leaf vein color and petiole length, were found to be homoplastic or continuously variable. Chromosome counts and flow cytometry indicated that all cultivars were diploid (2n = 36) and exhibited limited variation in genome size. Together, these results provide integrative evidence for two distinct clusters within cultivated Fittonia. However, because sampling was limited to commercially available cultivars, the relationship of these clusters to currently recognized species remains unresolved. Our findings highlight the limitations of traditional trait-based classifications and underscore the need for broader sampling, including wild populations, to reassess species boundaries in the genus.
The gene-centric view of cancer has provided important mechanistic insights, but does not fully account for the clinical heterogeneity observed in complex cases. An eco-evolutionary framework instead conceptualizes tumors as dynamic systems shaped by interactions among malignant clones, stromal components, immune populations and the surrounding microenvironment. Multicentric/multifocal breast cancer (MMBC) provides a relevant context in which to explore this biological complexity. Using patient-derived organoids, we observed that organoids derived from histologically tumor-free margins can display stem-like and basal-like features under defined culture conditions, whereas those from primary tumor regions may exhibit more differentiated phenotypes. These observations suggest that histological margin status alone may not fully capture the functional heterogeneity of peritumoral tissue. Our findings support the hypothesis that biological influences within the margin region may contribute to shaping cellular phenotypes beyond the presence of overt malignant cells. Overall, this study highlights the potential value of integrating organoid-based functional approaches with eco-evolutionary concepts to further investigate the biological landscape of the peritumoral field in MMBC.
Climate change and environmental pollution are two primary challenges facing biodiversity and ecosystem stability. Earthworms are key contributors to soil structure and nutrient cycling, and their molecular stress responses can provide an early indication of soil health impairment. Heat shock proteins are central to the stress response, and small heat shock proteins (sHSPs) are ATP-independent chaperones that limit stress-induced protein aggregation. Because their expression is stress-sensitive, sHSPs are promising molecular markers for soil stress and contributors to thermotolerance. Eisenia fetida, a widely used ecotoxicology model, relies on molecular chaperones like small heat shock proteins (sHSPs) for stress tolerance. We previously characterized sHSPs containing a single α-crystallin domain (ACD) in E. fetida. Here, we report the first identification of sHSPs containing two α-crystallin domains (ACDs) in annelid species. These genes were identified from an E. fetida transcriptome, their domain architecture was defined, and their transcriptional responses were quantified under heat stress, desiccation, and exposure to two pollutants (bisphenol A and endosulfan), including combined exposure with elevated temperature. Double-ACD sHSPs showed stimulus- and time-dependent transcriptional patterns. Moderate heat and desiccation primarily induced late (24 h) upregulation of several sHSP genes, whereas bisphenol A at optimal temperature did not result in significant transcriptional change and endosulfan produced only limited changes under single-stressor exposure. In contrast, combined exposure to endosulfan and elevated temperature triggered a significant upregulation of multiple sHSP genes, consistent with an additive stress effect. These results expand this protein family diversity in annelids and support a staged sHSP response in which structurally distinct sHSPs may contribute to resilience under prolonged or combined environmental stress.
The zoonotic Lassa virus (LASV), killing thousands of people annually, is maintained majorly by the multimammate mice Mastomys natalensis and M. erythroleucus; but other rodent reservoirs exist. Knowledge regarding LASV ecology remains limited in certain areas where Lassa fever continues to be incident and even recently emergent. Here, we assess community composition and LASV infection-status of small mammals in key localities across the Guinea savanna belt that spans the countries of Benin and Nigeria. Active LASV infection was determined by conventional (gel based)- and quantitative-PCR screening, while previous infection was determined by an immunofluorescent assay on IgG antibodies. Surprisingly, M. natalensis and M. erythroleucus, known to be sympatric across the Guinea savanna, co-occurred in only one locality and were PCR-negative for the virus; but showed IgG antibodies in localities endemic for Lassa fever within Nigeria. Viremia, alternately, was detected in Mus (Nannomys) baoulei and (a newly-discovered reservoir) Lemniscomys striatus, carrying relatively ancient LASV lineages, VIII & IX respectively, within Benin. Our results suggest non-Mastomys rodents assume an increased role in LASV ecology within the Guinea savanna belt of Benin and Nigeria; especially in central Benin, which turns out to be a long-overlooked hotbed of early evolution, host-switching and contemporary emergence.
Rhoptroceros cyatheae (Hymenoptera: Selandriidae) is a dominant herbivorous pest of Alsophila spinulosa in southwestern China, including Guizhou and Sichuan provinces. Infestation by this pest impairs spore reproduction of A. spinulosa and reduces the photosynthetic capacity of host plants. However, the chemosensory genes of R. cyatheae have not been reported, and the molecular basis of antennal detection of host volatile organic compounds (VOCs) is poorly understood. This study aims to screen and identify bioactive VOCs potentially involved in host searching behavior of R. cyatheae, analyze antennal VOC detection patterns, and explore the in vitro binding characteristics of an odorant-binding protein (OBP) involved in olfactory recognition, thereby providing a preliminary theoretical basis for the green management of R. cyatheae. Dynamic headspace sampling, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-electroantennography (GC-EAD) were used to measure antennal electrophysiological responses of R. cyatheae to volatiles from its host A. spinulosa. Y-tube olfactometer assays were conducted to evaluate behavioral responses. For RcyaOBP7, fluorescence competitive binding assays, structural modeling, and molecular docking were integrated to investigate its in vitro binding characteristics with nine selected bioactive VOCs. Nine A. spinulosa volatiles were identified that elicited antennal electrophysiological responses in R. cyatheae, and the sawfly showed behavioral orientation to these VOCs, confirming that its antennae can detect host VOCs. In vitro binding assays showed that RcyaOBP7 exhibited strong binding affinity to p-ethylacetophenone, suggesting its potential involvement in antennal olfactory recognition of this volatile. Specific VOCs released by A. spinulosa are among the signaling molecules detected by the antennae of R. cyatheae. In vitro findings indicate that RcyaOBP7 binds specifically to p-ethylacetophenone, suggesting a possible role in antennal olfactory recognition and behaviors such as host location. However, in vivo functional validation and field trials under ecologically relevant conditions are needed to confirm these roles. This study characterizes the in vitro binding properties of RcyaOBP7 and provides a basis for further research on green management strategies for R. cyatheae based on antennal olfactory signals.
Glyphosate is one of the most widely used herbicides worldwide and has been increasingly reported in aquatic environments, including riverine, estuarine, and coastal systems. However, information on its intestinal effects in benthic marine invertebrates remains limited. In this study, we investigated dose-dependent intestinal responses of the sea cucumber Apostichopus japonicus following acute waterborne glyphosate exposure using integrated transcriptomic and metabolomic analyses. Sea cucumbers were exposed for 24 h to four nominal glyphosate concentrations: 0, 9.23, 46.15, and 230.77 mg/L. Mortality occurred only in the highest-concentration group, allowing phenotypic stratification of this group into high-dose survivors (HL) and high-dose dead individuals (HD) for downstream multi-omics comparisons. Principal component analysis and orthogonal partial least-squares discriminant analysis indicated clear exposure- and phenotype-associated shifts in intestinal molecular profiles. Differential expression analysis and pathway enrichment showed that low-dose exposure was mainly associated with metabolic and digestion-related adjustments, whereas higher exposure levels were characterized by broader perturbation of immune regulation, stress-response signaling, proteostasis-related processes, and cell fate-associated pathways. Metabolomic profiling further revealed progressive remodeling of lipid, amino acid, energy, redox, and transport-related pathways, with the most extensive alterations observed in HD. Integrated transcriptome-metabolome analysis supported increasingly structured cross-omics covariation with rising exposure severity, highlighting coordinated intestinal system disruption under high-dose glyphosate stress. Overall, these findings demonstrate that acute waterborne glyphosate exposure induces dose-dependent intestinal molecular reprogramming in A. japonicus, with marked divergence between surviving and dead individuals at the highest exposure level. This study provides mechanistic evidence for early intestinal responses to glyphosate in a representative marine deposit-feeding invertebrate and offers a basis for future studies linking controlled exposure experiments with environmentally relevant marine risk scenarios.
Clinacanthus nutans is a traditional medicinal plant widely used in Southeast Asia for treating inflammation, viral infections, and cancer. However, its molecular basis remains poorly understood. In this study, the first chromosome-scale genome of C. nutans (731.61 Mbp) was assembled, with 93.76% anchored to 18 pseudochromosomes. Repetitive elements constituted 69.05% of the genome, predominantly long terminal repeat retrotransposons. Phylogenomic and synonymous substitution rate analyses revealed a Lamiales-wide whole-genome duplication event, followed by extensive chromosomal rearrangements. Gene family expansion analysis showed that segmental and dispersed duplications were the primary drivers of enzyme-coding genes (EGs) expansion involved in the flavonoid and triterpenoid pathways. Integrated transcriptomic and metabolomic analyses across five organs revealed distinct organ-specific expression and metabolite profiles. Genes exhibited pronounced differential expression between leaves and roots, with enrichment in flavonoid and triterpenoid biosynthetic pathways, highlighting functional divergence and metabolic specialization. Flavonoids were enriched in aerial tissues, whereas triterpenoids accumulated in roots. Weighted gene co-expression network analysis identified key EGs (e.g. CHS, CHI, OSC) and core transcription factors (e.g. MYB, bHLH, WRKY) potentially involved in organ-specific metabolic regulation. These findings suggest a coordinated transcriptional-metabolic regulatory framework underlying the specialized functions of different tissues. This work provides valuable genomic resources and mechanistic insights into the biosynthesis and regulation of bioactive compounds in C. nutans, thereby facilitating future research and molecular breeding of this important ethnomedicinal plant.
The common pine sawfly, Diprion pini, is a widespread defoliator of pine forests across Europe and Asia, with outbreaks causing substantial ecological and economic damages. However, genomic resources for this species have been limited, hindering advances in molecular ecology or pest management. Here, we present a near chromosome-level reference genome for D.pini, generated using PacBio HiFi reads, Oxford Nanopore MionION long reads, and 10× Genomics linked reads. The final assembly is organized into mostly chromosome-sized scaffolds. It spans a length of 268 Mb, comprises 81 scaffolds, and has a scaffold N50 of 18.7 Mb. BUSCO analysis (hymenoptera_odb10) indicates a high genome completeness of 97.2%. With 22,7 kb the mitochondrial genome is unusually large due to an extended non-coding control region (6874 bp). Gene prediction identified 26,335 protein-coding genes, of which 12,769 were functionally annotated. Comparative analyses with other sawflies and Apocrita identified 2472 proteins unique to D. pini, some of which are putatively associated with the processing of plant secondary metabolites. Notably, our genome assembly highlights that, when a closely related, high-quality reference genome is available, chromosome-scale assemblies can be generated without the need of Hi-C sequencing. The genome provides a valuable foundation for the development of improved monitoring and management strategies for D. pini outbreaks and contributes to advancing fundamental research on Hymenoptera evolution.
Maize is one of the most widely cultivated crops worldwide and is extensively used for animal feed and industrial applications. Plant height (PH) and ear height (EH) are critical determinants of lodging resistance and tolerance to high planting density, and coordinated regulation of these traits is essential for yield improvement. In this study, 479 maize inbred lines from Northeast and North China were genotyped using 7861 single-nucleotide polymorphism (SNP) markers to perform a genome-wide association study (GWAS). After controlling for population structure and relatedness, the mixed linear model (MLM) identified 20 loci significantly associated with PH on chromosomes 2, 4, 5, 6, 7, and 8, and 8 loci associated with EH on chromosomes 2, 3, 4, and 7. A total of 23 candidate genes were identified, including PLATZ8, pectin methylesterase 36, and leucine-rich repeat extensin 14. Gene Ontology (GO) enrichment analysis revealed significant enrichment in biological and molecular functions such as DNA binding, pectinesterase activity, zinc ion binding, ATP binding, and uniporter activity. Bioinformatic characterization of the two most likely candidate genes, Zm00001d002726 and Zm00001d015394, showed that both possess a typical compact four-exon structure. Functional prediction indicated that Zm00001d002726 encodes a pectinesterase/pectinase, potentially regulating cell elongation through pectin degradation and remodeling of the cell wall. Pectinesterase activity may influence PH and EH by mediating pectin demethylation within the cell wall. In contrast, Zm00001d015394 encodes a PLATZ family transcription factor that may regulate downstream gene expression through DNA-binding activity. These findings provide insight into the genetic architecture and potential molecular mechanisms underlying PH and EH in maize and offer a foundation for future breeding efforts.
Honey bee health is increasingly compromised by multiple interacting stressors, including pathogens whose epidemiology is shaped by environmental and temporal variables. Among them, highly prevalent and impactful are the microsporidian Nosema (=Vairimorpha) ceranae and the black queen cell virus (BQCV). This study presents a large-scale, longitudinal assessment of the two pathogens in managed Apis mellifera colonies across all Italian regions, conducted between the years 2021 and 2024 and involving 12028 samples from 398 apiaries. Molecular qPCR diagnostics revealed N. ceranae in 50.9% of the samples, with significant peaks of prevalence and abundance in northwestern regions and during spring (March and June). BQCV, analysed in the third year only, showed a markedly higher prevalence (77.6%). Co-infection was frequently observed, and a weak positive correlation was found between the pathogens' abundances. Land use also emerged as a relevant factor: N. ceranae prevalence was significantly lower in arable lands, while BQCV presence and viral loads were reduced in forest and semi-natural habitats. The complete absence of N. apis suggested the hypothesised replacement by N. ceranae, as verified in other Mediterranean Countries. Overall, the results highlight the multifactorial nature of honey bee disease ecology and the importance of integrating spatial, seasonal, and land-use data into pathogen surveillance systems. Understanding these patterns is essential for designing regionally adapted management practices and improving colony resilience.
Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease in which host-microbiota crosstalk plays a pivotal role in immune dysregulation. Recent metagenomic studies have revealed that disease-specific dysbiosis--characterized by the expansion of pathobionts and depletion of immunoregulatory commensals--occurs across the gut, oral cavity, skin, and genital tract. Integrative multi-omics analyses have identified three mechanistic pathways linking microbial imbalance to autoimmunity: (1) microbial peptides trigger molecular mimicry and epitope spreading, activating autoreactive lymphocytes: (2) microbial metabolites disrupt redox homeostasis, impair epithelial barriers, and skew the AhR-mediated Th17/Treg balance; and (3) dysbiosis alters epigenetic regulation by inhibiting DNA methyltransferases, leading to hypomethylation of SLE-risk genes. Translational studies have shown that microbiome-targeted interventions, including probiotics, prebiotics, fecal microbiota transplantation, and even B cell-depleting chimeric antigen receptor T-cell (CAR-T) therapy, can restore microbial balance, reduce autoantibody levels, and modulate the gut-immune axis. Furthermore, microbial signatures are emerging as potential biomarkers for disease activity and treatment response. Despite this promise, challenges remain, such as the impact of immunosuppressants on the microbiota, spatial heterogeneity in host-microbe interactions, and limitations in causal inference. Looking forward, integrating single-cell metagenomics, microbiota-directed diets, and engineered microbial consortia may pave the way for personalized microbiome-based therapies. Reframing SLE as a "meta-organismal imbalance" positions microbial ecology at the forefront of precision medicine.
The genetic variability of Plasmodium falciparum serves as an important marker of the parasite's ability to adapt and develop resistance to antimalarial treatments. This study sought to evaluate the diversity of the P. falciparum merozoite surface protein 2 (msp2) gene among patients receiving care in four health centers in the Mbouda Health District, Cameroon. Blood samples were obtained from 481 individuals who came for diagnostic testing with symptoms suggestive of malaria. Rapid diagnostic tests and thick blood smears were performed to confirm P. falciparum infection and determine parasite density, respectively. Positive samples were spotted onto Whatman filter paper for molecular testing. DNA was extracted using the Chelex-100 technique, and msp2 fragments were amplified via nested PCR. Amplicons were separated on 1.3% agarose gels and visualized under UV light. Phylogenetic analysis was performed in R, and statistical analyses were conducted using SPSS version 23. Out of the 481 samples analyzed, 137 (28.48%) tested positive for P. falciparum, with a mean parasite density of 2196.77 ± 1344.36 parasites/µL. Female participants showed a weakly significant association with malaria infection, while children aged 0-5 years, despite having an odds ratio above 1, did not show a statistically significant association. The msp2 gene was successfully amplified in 64% of positive samples, revealing 15 distinct alleles. The overall genetic diversity was 14.15%, with a mean multiplicity of infection (MOI) of 1.20. The proportions of mono-, double-, and triple-genotype infections were 81.68%, 18.18%, and 1.33%, respectively. Phylogenetic analysis identified 13 distinct clades, indicating genetic relatedness among circulating P. falciparum strains. A considerable level of genetic diversity and multiple infections was detected among P. falciparum isolates in the Mbouda Health District, suggesting high transmission intensity. Further studies incorporating additional molecular markers such as msp1 and GLURP are recommended to provide a more comprehensive picture of P. falciparum genetic variation in the region.
Alhagi camelorum is a dominant leguminous shrub distributed in the Taklamakan Desert, an area characterized by extreme drought and high soil salinization, which can complete its life cycle normally in salt-affected soils. However, the underlying molecular regulatory mechanism of its salt tolerance remains largely unclear. The AcABI5 gene was successfully cloned and characterized, and it encodes a typical nuclear-localized bZIP transcription factor. Functional characterization demonstrated that overexpression of AcABI5 markedly improved the salt stress tolerance of A. camelorum calli, whereas silencing of AcABI5 via virus-induced gene silencing (VIGS) rendered the plant more sensitive to salt stress. Further mechanistic investigations revealed that AcABI5 enhanced salt tolerance by regulating the expression of superoxide dismutase (SOD)- and peroxidase (POD)-related antioxidant genes. Compared with the wild type, AcABI5-overexpressing calli exhibited significantly increased SOD and POD activities and remarkably reduced malondialdehyde (MDA) content under salt treatment, whereas AcABI5-silenced lines exhibited the opposite physiological phenotypes. Furthermore, heterologous silencing of AcABI5 in Nicotiana benthamiana via virus-induced gene silencing (VIGS) produced comparable salt-sensitive phenotypes, similar to those observed in A. camelorum AcABI5-silenced lines. Collectively, these results provide insights into the molecular mechanism by which AcABI5 enhances salt tolerance in A. camelorum, and lay a solid theoretical foundation for the optimization of the A. camelorum genetic transformation system and the expansion of related salt-tolerant crop research.
Clostridioides difficile is a well-recognized cause of antibiotic-associated colitis. The highly pathogenic PCR ribotype(RT)027/sequence type(ST)1 strain has been prevalent since 2002, particularly in Europe and the United States, whereas strains detected in Japan primarily comprise RT018/ST17, RT369/ST81, and RT002/ST8. Community-associated C. difficile infection (CA-CDI) has increased in recent years, and an association with livestock, food, and companion animals has been suggested. This study investigated the molecular epidemiology of C. difficile in Japan, focusing on isolates from diarrheal outpatients in comparison with animal and environmental sources. A total of 401 samples were collected, including park soil and fecal samples from livestock, companion animals, wild animals, and outpatients. Overall, 63 strains were isolated. High isolation rates were observed in soil samples (19/37, 51%) and companion animals (19/64, 30%), of which 68% and 37% were toxigenic, respectively. Whole-genome sequencing revealed ST2 as the most common sequence type, followed by ST42 and ST15. No single sequence type predominated among isolates from diarrheal outpatients, and six patients met the epidemiological definition of CA-CDI. Core-genome single-nucleotide polymorphism (SNP) analysis identified close genetic relationships in two pairs of ST42 strains-one between a patient-derived isolate and park soil, and another between a canine-derived isolate and soil from a different park-using a hypothetical transmission-exclusion cutoff of <13 SNPs. These findings suggest the presence of shared environmental reservoirs linking humans, animals, and soil, rather than indicating the direction of transmission. The study highlights the importance of considering environmental reservoirs within a One Health framework for CA-CDI in Japan.IMPORTANCEClostridioides difficile infection (CDI) is a widely recognized cause of antibiotic-associated diarrhea, and reports of community-associated CDI (CA-CDI) have risen in recent years. Understanding how C. difficile circulates outside healthcare settings is, therefore, an important public health challenge. In this study, we analyzed C. difficile isolates from outpatients with diarrhea, companion animals, and environmental sources, including soil from public parks. The organism was frequently detected in soil and pets, and genomic analyses identified closely related strains across human, animal, and soil samples. Although these findings do not indicate transmission direction, they suggest that environmental reservoirs may contribute to the broader ecology of C. difficile in the community. Our results underscore the importance of a One Health perspective integrating human, animal, and environment together when studying CA-CDI and highlight the need for further research to better understand how C. difficile persists and spreads outside hospital settings.
Photosynthetic protists, known as microalgae, face increasing temperatures due to climate change. The green biflagellate alga Chlamydomonas reinhardtii (Chlamydomonas) serves as a model for thermoregulation. While responses to thermal stress are well characterized, much less is known about the impact of ambient temperature shifts. Understanding microalgal responses to environmental temperature changes is critical, as these primary producers drive ecosystem productivity and food web dynamics. Here, Chlamydomonas grew mixotrophically at ambient temperatures from 18 °C to 33 °C. Transcriptomic profiling revealed extensive reorganization, with over 5,000 transcripts significantly affected, including those involved in algal-bacterial interactions, photoreception, lipid metabolism, photosynthesis, cilia formation, and the secretome. CO2 transfer rates and acetate levels measured at 18 °C and 28 °C suggest decreased photoautotrophic algal growth at 28 °C at first. Antagonistic bacterial activity was sustained longer at lower temperatures. Proteomic analyses of isolated cilia and secreted proteins corroborate major abundance changes within these sub-proteomes, particularly in ciliary intraflagellar transport complexes and mating-related proteins in the secretome. Together, these molecular alterations resulted in pronounced changes in growth, the lengths of cells and cilia swimming behavior, mating ability and bacterial antagonism. These data reveal major cellular responses caused by ambient, even short-term temperature shifts.
Cadmium (Cd) is a pervasive environmental contaminant with potent cytotoxic effects in a wide range of organisms. Although autophagy and apoptosis are recognized as major cellular responses to heavy metal stress, the molecular basis of Cd-induced cell death in insects remains insufficiently understood. In this study, we used fifth-instar day-4 (5L4D) larvae of Bombyx mori and the silkworm-derived Bm-12 cell line to investigate the involvement of three core autophagy-related proteins, Bombyx mori Autophagy-related protein 5(BmATG5), Bombyx mori Autophagy-related protein 6(BmATG6), and Autophagy-related protein 8(BmATG8), in Cd-induced autophagy and apoptosis. Exposure to CdCl2 markedly induced autophagic and apoptotic responses in both larval midgut tissue and Bm-12 cells, as demonstrated by monodansylcadaverine(MDC) staining, Lyso-Tracker Red staining, DAPI and Hoechst 33258 staining, and DNA fragmentation assays. qPCR and Western blot analyses showed significant upregulation of BmATG5, BmATG6, and BmATG8 following Cd exposure. Notably, the cleaved forms tBmATG5-N (24 kDa) and tBmATG6-C (35 and 37 kDa), as well as the lipidated form BmATG8-PE (12 kDa), accumulated substantially under Cd stress. In parallel, intracellular Ca2+ levels and calpain activity were significantly increased, suggesting activation of a calcium-dependent regulatory pathway. Pharmacological inhibition experiments further indicated that autophagy and apoptosis are functionally interconnected during the Cd response. Collectively, these findings demonstrate that BmATG5, BmATG6, and BmATG8, together with their processed forms, play central roles in coordinating autophagy-apoptosis crosstalk during Cd-induced cytotoxicity in Bombyx mori. This study provides new mechanistic insight into heavy metal toxicity in insects and expands our understanding of stress-induced programmed cell death during silkworm metamorphosis.