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Targeted sequencing reveals a distinct genetic alteration landscape in oral multiple primary squamous cell carcinomas.

OBJECTIVE: Oral multiple primary cancers (MPCs) are associated with poor clinical outcomes, yet their genomic characteristics remain insufficiently understood. DESIGN: Fifty-four formalin-fixed paraffin-embedded (FFPE) tumor samples from 30 patients with oral MPCs were analyzed using high-depth targeted sequencing of a customized 14-gene panel derived from prior whole-exome sequencing data. Detected alterations were analyzed after removal of synonymous mutations. RESULTS: Non-silent genomic alterations were identified in 59.3% (32/54) of samples, involving 19 patients. A total of 70 variant loci across 13 genes were detected. AKAP13 was the most frequently mutated gene at both the sample (22.2%, 12/54), with recurrent mutations observed across multiple patients. In contrast, TP53 mutations occurred at a substantially lower frequency (11.1%, 6/54). Marked inter- and intra-patient mutational heterogeneity was observed. CONCLUSIONS: FFPE-based targeted sequencing enabled an initial characterization of genomic alterations in oral MPCs. Recurrent alterations in AKAP13, GLI2, JMJD1C, and DNAH8, together with the relatively low frequency of TP53 alterations, identify candidate genomic features for further investigation and provide a basis for future studies of the molecular basis of oral MPCs.

Humans

Genome-wide identification, structural characterization, and evolutionary analysis of growth-related gene families in African catfish (Clarias gariepinus).

The somatotropic axis encompassing growth hormone (GH), insulin-like growth factor (IGF), myostatin (MSTN), and prolactin (PRL) signalling cascades is the master regulator of somatic growth, metabolism, and development in vertebrates. African catfish (Clarias gariepinus), a commercially pivotal aquaculture species, now possesses a chromosome-level reference genome (CGAR_prim_01v2); however, a systematic, genome-wide characterization spanning all five interconnected growth-related gene families has not previously been undertaken in this species. Here, we identified and characterized 15 growth-related genes spanning gh1, ghra, ghrb, Igf1, Igf2a, Igf2b, igf1ra, Igf1rb, Igf2r, Mstna, Mstnb, prl, prlra, prlrb, and smtlb distributed across 13 chromosomes. Complete one-to-one orthology with zebrafish confirmed strong dosage-balance conservation across >120 million years of teleost divergence. Physicochemical analysis resolved a clear biochemical dichotomy between compact, basic secreted ligands (19.88-45.81 kDa; pI up to 10.02) and large, acidic, heavily glycosylated membrane receptors (56.82-270.80 kDa; pI 4.85-5.97). Phylogenetic analysis confirmed 3R whole-genome duplication origins for all paralog pairs, while synteny analysis revealed a disruption of the ancestral gh1-prl chromosomal block in C. gariepinus, a finding that warrants further comparative and functional investigation. This genomic atlas provides the sequence and structural information including exon-intron boundaries, domain architecture, and chromosomal coordinates needed as a prerequisite for future marker-assisted selection and CRISPR-based myostatin-editing efforts in African catfish aquaculture, though translation into applied breeding outcomes will require subsequent functional and expression studies.

Animals

S-layer-phage interaction in Clostridioides difficile.

Successful infection by a bacteriophage requires the injection of the phage genome into the cytoplasm of the host bacterium. To achieve this, an infecting phage must traverse the layers of the host cell envelope, including the membrane(s) and the cell wall. This process is further complicated in bacterial species that produce a proteinaceous S-layer on the outermost surface of the cell. Surprisingly little is known about the mechanistic basis of these early stages in the phage lifecycle, and even less is known about infection of S-layer producing bacteria. Recent advances in structural biology, particularly in cryoEM, have dramatically improved our understanding of the structures of both bacterial S-layers and phage virions separately, but we still lack a molecular view combining both phage and S-layer in the process of infection. Here, we review our current understanding of phage-S-layer interactions, using the human pathogen Clostridioides difficile as an example host.

Clostridioides difficile

Gut microbial diversity at baseline conditions the clinical, microbiome, and metabolic response to paraprobiotic Lactiplantibacillus plantarum LRCC5282 in overweight adults.

The gut microbiota is increasingly recognized as a target for obesity management; however, whether baseline gut microbial diversity conditions responsiveness to microbiota-targeted interventions remains unclear. We aimed to investigate whether baseline gut microbial diversity is associated with responsiveness to a paraprobiotic derived from Lactiplantibacillus plantarum LRCC5282 (LP5282-P) in overweight adults. In a 12-week, randomized, double-blind, placebo-controlled, multicenter trial of 120 overweight adults, LP5282-P produced no significant between-group differences in any clinical outcome across the overall per-protocol population. However, in the low-diversity subgroup, LP5282-P was associated with significant reductions in body weight, body mass index, and circulating leptin levels. These clinical changes were accompanied by compositional shifts in the gut microbiota, including higher relative abundances of Christensenellaceae, Faecalibacterium, and Alistipes. Fecal metabolite profiles showed elevated acetate and butyrate concentrations and altered bile acid composition. Within the low-diversity subgroup, changes in the relative abundances of Akkermansia and Eubacterium were inversely correlated with changes in body weight, body fat mass, and leptin levels. In contrast, the high-diversity subgroup exhibited no consistent response across the outcome domains examined. Overall, baseline gut microbial diversity was associated with differential responsiveness to LP5282-P, supporting its potential use as a stratification variable in future microbiota-targeted intervention trials. Further studies integrating direct measures of microbial activity and host response are warranted to elucidate the biological pathways underlying this diversity-dependent responsiveness. Trial registration: Clinical Research Information Service (CRIS), KCT0008119.

Humans

Comparative profiling of microbial community structure, enzyme potential, metabolic features, and volatile composition in craft and Jiafan Huangjiu processes.

Craft Huangjiu and Jiafan Huangjiu represent two distinct industrial Huangjiu product outcomes with contrasting volatile profiles. This study compared craft Huangjiu (L70) and Jiafan Huangjiu (L79) to characterize their physicochemical, microbial, gene-level functional, metabolic, and volatile features. Because L70 involved mid-fermentation addition of finished Huangjiu, this comparison was not intended to isolate the sole effect of fermentation interruption versus continued fermentation. L79 showed more extensive carbon and nitrogen utilization, with lower residual substrates and higher ethanol and acetic acid contents than L70, whereas L70 retained a less complete fermentation state. At the volatile level, GC-MS and volatile metabolomics consistently showed an ester-enriched profile in L79 and a more alcohol-dominant profile in L70. FlavorDB-based putative annotation and threshold-based OAV analysis further indicated distinct database-assigned descriptor distributions and potential odor-active compounds, with more OAV > 1 ester-related compounds in L79. Metagenomic analysis showed that L70 was dominated by Lactobacillus acetotolerans, whereas L79 contained higher relative abundances of Saccharomyces cerevisiae, Aspergillus oryzae, Aspergillus flavus, and Fructilactobacillus fructivorans. Metagenomic functional annotation showed higher representation of hydrolysis-related CAZy genes and ester-related enzyme annotations in L79. KEGG-based pathway mapping further indicated greater gene-level potential for ethanol-, acetate-, and acetyl-CoA-related metabolism in L79. Accordingly, the L70 profile should be interpreted as the integrated final-product outcome of process intervention, exogenous input, and subsequent fermentation. The findings provide a comparative basis for future flavor regulation and process optimization in Huangjiu and other fermented alcoholic beverages.

Volatile Organic Compounds

Integrated electronic nose, GC-MS, and metagenomic analyses reveal volatile flavor and microbial community differences in heap-fermented grains of Jiangxiangxing Baijiu across different fermentation degrees.

The fermentation degree of heap-fermented grains in Jiangxiangxing Baijiu production is a critical factor influencing base Baijiu quality. However, conventional assessment methods largely rely on empirical experience and therefore suffer from limited objectivity and accuracy. In this study, integrated volatile profiling and metagenomic approaches were employed to investigate volatile characteristics and microbial functional potential differentiation in fermented grains with different fermentation degrees (under-fermented, normally fermented, and over-fermented). Significant differences in physicochemical properties were observed among fermentation degrees, particularly in acidity and reducing sugar content. Electronic nose analysis revealed distinct sensor response patterns among different fermentation degrees, indicating differences in overall volatile odor fingerprint patterns. A total of 81 volatile compounds were identified by HS-SPME-GC-MS, with aldehydes, ketones, and pyrazines showing pronounced variations among fermentation degrees, and acetaldehyde exhibiting strong discriminatory potential. LEfSe analysis identified 18 microbial taxa as potential biomarkers associated with different fermentation degrees, including Pichia kudriavzevii, Lentibacillus daiqui, and Acetobacter pasteurianus. Correlation analysis revealed significant positive associations between acetaldehyde levels and Acetobacter abundance. Furthermore, KEGG, CAZy, and eggNOG analyses revealed differentiated functional potentials among fermentation degrees, providing insights into the potential metabolic basis associated with flavor differentiation. Overall, these findings highlight that fermentation degree differentiation is closely associated with coordinated changes in physicochemical conditions, microbial communities, and functional potentials, providing ecological insights into flavor differentiation and theoretical support for objective fermentation degree evaluation and quality control of Jiangxiangxing Baijiu production.

Fermentation

Depth-dependent microbial succession and interspecies hydrogen transfer drive pit mud maturation in Chinese strong-flavor baijiu fermentation.

Microbial communities in fermentation pit mud play a key role in determining the quality of Chinese strong-flavor baijiu (CSFB). However, the ecological processes underlying pit mud maturation across spatial and temporal scales remain unclear. In this study, amplicon sequencing and metagenomic analyses were employed to investigate the taxonomic succession, community assembly, and metabolic functions of bacterial and archaeal communities during the transition from fresh pit mud (FPM) to new pit mud (NPM) and old pit mud (OPM). A pronounced depth-dependent succession pattern was observed, with 4 cm representing a critical ecological boundary separating distinct community structures and maturation trajectories. During surface-layer maturation, community assembly shifted from stochastic to deterministic processes, accompanied by homogeneous selection and increasing network complexity. In contrast, stochastic processes remained dominant throughout deep-layer maturation. Metagenomic analyses revealed a functional transition from lactate and acetate production, primarily associated with Lactobacillus in FPM and NPM, to butyrate and caproate production associated with Clostridium and Caproiciproducens in OPM. This functional transition was accompanied by enhanced amino acid metabolism, which was associated with the enrichment of Proteiniphilum and Aminobacterium. Notably, methanogen-mediated interspecies hydrogen transfer (IHT) emerged as a key ecological feature during pit mud maturation. In OPM, IHT networks primarily involving Methanobacterium and Methanosarcina linked methanogenesis with reverse β-oxidation through diverse hydrogen-transfer pathways, reinforcing metabolic interactions underlying caproate production. These findings provide new insights into the ecological mechanisms underlying pit mud maturation and offer a theoretical basis for the directed cultivation of high-quality pit mud in CSFB production.

Hydrogen

Microbial signal profiles and organism-level concordance between plasma metagenomic sequencing and blood culture in suspected bloodstream infection.

Plasma metagenomic next-generation sequencing (mNGS) and blood culture detect different components of the microbial signal and frequently produce discordant organism reports. We characterized microbial signal class, report-derived burden, organism-level concordance, and independent clinical attribution in a retrospective, single-center, episode-level cohort. Among 329 episodes with evaluable plasma mNGS reports, 315 had blood culture performed; 232 were mNGS positive/culture negative and 53 were positive by both methods. In the 232 discordant episodes, the recorded routine-care diagnosis classified 124 as bloodstream infection (BSI) and 108 as non-BSI. Nonviral signals were present in 78.2% and 42.6%, respectively (P&#x2009;<&#x2009;0.001), and median maximum report-derived sequence counts were 98.5 and 11.5 (P&#x2009;<&#x2009;0.001). Two laboratory physicians then independently reviewed source records using structured criteria while masked to the recorded BSI label and mNGS organism and sequence-count information. Initial agreement for the five-category BSI assessment was 97.6% (Cohen's kappa, 0.960). Within the mNGS-positive/culture-negative subgroup, adjudicated BSI likelihood showed a modest ordinal association with report burden (Spearman rho&#x2009;=&#x2009;0.190; P&#x2009;=&#x2009;0.004), while mNGS organisms were considered supported in 1 episode, plausible in 158, unlikely or contaminant in 72, and unresolved in 1. Among 53 dual-positive episodes, 33 (62.3%) shared at least one species, but only 5 (9.4%) had complete species-set concordance. Plasma mNGS and blood culture therefore frequently generated non-equivalent organism sets. Signal class and report burden contributed graded contextual evidence, but organism-level attribution required clinical review and orthogonal microbiology rather than binary positivity alone.

Humans

Exploratory proteomic and metabolomic profiling of pleural effusions identifies histone H4 and alanine as promising complementary markers for pleural tuberculosis.

The diagnosis of pleural tuberculosis (Pl-TB) remains challenging. Histopathological analysis and pathogen detection in pleural biopsies are informative but limited. We investigated differentially expressed proteins and metabolites in pleural effusions from patients with Pl-TB, malignancies, and other pathologies. A proteomic analysis of pooled pleural effusions identified 45 proteins exclusively detected or upregulated in Pl-TB samples, many linked to infectious processes. Conversely, 18 proteins were uniquely found or upregulated in malignant pleural effusions, mainly associated with detoxification and hemostasis. To validate these findings, we employed targeted proteomics in individual samples. Eight proteins were validated: S100-A9, histone H4, insulin-like growth factor-binding protein 2, fibrinogen beta chain, ficolin-3, immunoglobulin heavy constant alpha 1, sulfhydryl oxidase 1, and histidine-rich glycoprotein. Additionally, NMR-based metabolomics identified 13 metabolites with differential abundance between Pl-TB and non-TB samples. Notably, N-acetyl-glycoprotein and the branched-chain amino acids, alanine and lysine differed between groups. Proteomic and metabolomic analyses revealed distinct molecular profiles between Pl-TB and non-TB patients, despite intra-group variability. To address this, we applied classification models. Histone H4 and alanine consistently emerged as discriminative features. Overall, this study provides novel insights into the molecular landscape of Pl-TB. The combined quantification of proteins and metabolites may improve differential diagnosis, although should be further validated in larger, independent cohorts before clinical application.

Humans

Genome-wide analysis of the plant-specific PLATZ gene family in Taraxacum kok-saghyz and its roles in response to drought and salt tolerance.

Abiotic stress severely limits plant growth and productivity. Taraxacum kok-saghyz Rodin (TKS), known for its environmental resilience, represents a valuable resource for identifying stress-tolerant genes to improve stress-adaptive crops. Plant AT-rich protein and zinc-binding protein (PLATZ) transcription factors serve as core regulators of plant growth, developmental processes, and adaptive responses to various stress conditions; however, they remain uncharacterized in TKS. Here, we identified 10 TksPLATZ genes through a whole-genome analysis. Phylogenetically, these genes were grouped into five distinct evolutionary branches. Promoter sequence analysis revealed multiple types of cis-acting regulatory elements that are connected with hormonal signal responses and environmental stress adaptation. Integrated analysis of transcriptome datasets and RT-qPCR validation demonstrated that TksPLATZ genes display tissue-specific expression profiles and show distinct responsive patterns to drought and salt stress treatments. Among them, TksPLATZ1, TksPLATZ2 and TksPLATZ7 were markedly induced under both stressors and were selected for further functional study. We demonstrated that TksPLATZ1, TksPLATZ2 and TksPLATZ7 localize to the cell nucleus and act as transcriptional activators and repressors, respectively. Phenotypic data from overexpression experiments in plants confirm that heterologous expression of TksPLATZ1, TksPLATZ2, and TksPLATZ7 enhances the tolerance of Arabidopsis to salt and osmotic stress. These findings provide valuable genetic resources for improving plant tolerance to environmental stresses.

Salt Tolerance

Integrated assessment of biocontrol potential and genome analysis of endophytic Bacillus velezensis MGL-B1 against mango stem-end rot.

Mango stem-end rot is a globally significant postharvest disease that severely threatens the mango industry, primarily caused by Botryosphaeria dothidea. However, information on biocontrol agents targeting this pathogen in mango remains limited. In this study, we isolated and identified a strain of Bacillus velezensis MGL-B1 from mango leaf tissues for the first time, which exhibited broad-spectrum antifungal activity. Both in vitro and in vivo assays demonstrated that MGL-B1 effectively inhibited the growth of B. dothidea, with an in vivo biocontrol efficacy reaching 83.72&#xa0;&#xb1;&#xa0;5.10%, comparable to that of the commonly used chemical fungicide thiabendazole. Further mechanistic analysis revealed that MGL-B1 acts by directly disrupting the integrity of the pathogen's mycelial cell membrane. In addition, its released volatile organic compounds (VOCs) also displayed significant antifungal activity, with components such as 2-nonanone, 2-nonanol, and phenylethyl alcohol being confirmed to exert antifungal effects in in vitro fumigation assays. qPCR analysis showed that MGL-B1 treatment significantly upregulated the transcriptional levels of genes involved in plant-pathogen interaction, phenylpropanoid biosynthesis, and antioxidant defense pathways in mango fruits, with upregulation folds of 16.32, 37.19, and 75.93, respectively; meanwhile, the expression of browning-related genes such as polyphenol oxidase (PPO) was markedly suppressed. Whole-genome sequencing further revealed 14 biosynthetic gene clusters for antimicrobial compounds, including five unknown gene clusters. Collectively, B. velezensis MGL-B1 represents a promising biocandidate strain with multiple antifungal mechanisms and excellent control efficacy, providing a valuable resource for green and sustainable management of mango diseases.

Mangifera

Integrated exome and mitochondrial genome sequencing reveals the genetic landscape of primary mitochondrial diseases: findings from a large Tunisian cohort.

Primary mitochondrial diseases are a heterogeneous group of neurometabolic disorders recognized as the most common metabolic genetic diseases. They manifest at any age, affecting any tissue or organ, especially those with high energy demands, and are caused by pathogenic variants in both mitochondrial and nuclear genomes. Here, we aimed to describe the genetic spectrum of a Tunisian pediatric cohort with suspected mitochondrial diseases. We recruited 47 unrelated families who underwent exome sequencing as a first-tier test followed by whole mitochondrial genome sequencing for unsolved cases. Dedicated bioinformatic pipelines and prediction tools were used to determine the potential disease-causing variants. Sanger sequencing confirmed the presence and segregation within parents. For the newly identified variants, structural modeling was conducted to study the impact of these variants on protein structure and motions. Dual genome sequencing yielded a molecular diagnosis in 33/47 families (70%) and 18/47 (38%) showed disease-causing variants in genes encoding mitochondrial proteins. Among them, four families disclosed novel variants in FASTKD2, SERAC1 and GATB, which were supported by in-depth in silico and structural analyses demonstrating their deleterious effect. The remaining families (32%, 15/47) disclosed other metabolic and neurological disorders. An exome-first strategy delivers a high diagnostic yield in Tunisia, where consanguinity remains high and simultaneously captures mitochondrial and non-mitochondrial etiologies. Mitochondrial sequencing remains indispensable in the case of an inconclusive exome. Thus, our data expand the clinical and genetic spectrum of primary mitochondrial diseases in Tunisia, an underrepresented and admixed population.

Humans

Climate and soil shape Daqu wheat quality and seed microbiome via rhizosphere taxa and microbial assembly.

The grain quality and seed microbiome of Daqu wheat are fundamental determinants of Daqu fermentation performance; however, the mechanisms by which cultivation environments influence these traits via rhizosphere microbial communities remain unclear. Bacterial and fungal communities across the bulk soil-rhizosphere-seed continuum of three wheat cultivars grown in four ecoregions were characterized using absolute quantitative amplicon sequencing. The rhizosphere microbiome was treated as a central intermediary, while the response variables were seed microbial diversity and grain-quality traits, including starch content, protein content, and grain hardness. Twelve physicochemical properties of soil and 11 climatic factors were integrated into a multidimensional association framework. Environmental conditions exerted stronger influences on both seed quality traits and microbial diversity than cultivar identity. Distinct regional signatures were also evident in rhizosphere microbiomes, with environmental gradients explaining community variation more effectively than geographic distance. Bacterial communities exhibited greater sensitivity to environmental fluctuations than fungi. Mantel analyses identified available nitrogen, precipitation, and atmospheric pressure as significant drivers of core rhizosphere taxa (P&#xa0;<&#xa0;0.05). iCAMP revealed that stochastic processes predominantly governed rhizosphere bacterial assembly, whereas stochastic and deterministic mechanisms jointly shaped fungal assembly. Partial least squares path modeling further uncovered a rhizosphere-mediated environment-seed cascade, wherein sunlight intensity and duration, atmospheric pressure, and soil nitrogen directly or indirectly affected seed wet gluten content, grain hardness, and seed microbial diversity through their influences on rhizosphere microbiota. Rhizosphere bacterial diversity was negatively associated with seed bacterial diversity (path coefficient&#xa0;=&#xa0;-0.118, P&#xa0;<&#xa0;0.05), indicating that rhizosphere communities may shape seed endophytic bacterial assemblages via environmental filtering and competitive interactions. Collectively, these findings elucidate how environments shape the quality and seed microbiomes of Daqu wheat, providing scientific guidance for optimal site selection and the standardized production of high-quality brewing wheat for industrial Baijiu.

Triticum

Divergent evolutionary strategies in spider venoms: A comparative proteomic profiling of four sympatric species from Yunnan.

Spider venoms comprise complex cocktails of bioactive molecules evolved for predation and defense, representing a valuable resource for biological research and pharmaceutical discovery. In this study, we performed a systematic analysis of venom gland extracts from four common spider species indigenous to Yunnan, China: Agelena limbata, Hippasa lycosina, Lycosa grahami, and Sinopoda pengi. Using an integrated transcriptomic and proteomic targeted profiling approach, we successfully annotated 141 distinct toxins. Comparative analysis revealed significant interspecific heterogeneity, suggesting distinct evolutionary trajectories and "weapon system economics." Both A. limbata and L. grahami exhibited a "peptide-dominant" profile anchored by neurotoxic peptides and isomerases, optimized for rapid chemical paralysis. In contrast, S. pengi displayed a distinct "protein-dominant" signature enriched with high-molecular-weight enzymes and CAP superfamily proteins, likely functioning to facilitate tissue degradation and toxin diffusion. Occupying an intermediate position, H. lycosina demonstrated a hybrid composition. These findings suggest that although these species share the same geographical range, their venom systems have undergone divergent evolutionary adaptations driven by specific ecological niches and hunting strategies. This study represents the first systematic proteomic characterization of these venom components, providing a valuable reservoir of molecular candidates while highlighting the bioinformatic nuances of analyzing whole-gland homogenates.

Animals

Long-term microbiome and clinical effects of a microbiome-guided personalized diet versus low-FODMAP diet in irritable bowel syndrome: A 12-month follow-up randomized controlled trial.

Dietary therapy is central to irritable bowel syndrome (IBS) management, yet the long-term durability of the low-FODMAP diet (LFD), and of microbiome-guided personalization, remains unclear. We assessed the long-term clinical and gut-microbiome effects of a microbiome-guided personalized diet (PD) compared with a standard LFD in adults meeting Rome IV criteria for IBS. In this multicenter, open-label randomized controlled trial with blinded outcome assessment, participants who completed a 6-week dietary intervention (PD or LFD) were followed at 6 and 12 months without further dietary intervention. Outcomes included the IBS Severity Scoring System (IBS-SSS), IBS Quality of Life (IBS-QOL), and the Hospital Anxiety and Depression Scale (HADS); gut microbiota were profiled by 16S rRNA sequencing. Longitudinal changes were evaluated using linear mixed-effects models, responder analyses, PERMANOVA, and PERMDISP. Both diets reduced IBS-SSS at 6 weeks. PD maintained symptom improvement at 6 and 12 months (-82.0 and -78.3 points from baseline), whereas LFD benefits regressed by 12 months (+29.3 points; between-group p&#x2009;=&#x2009;0.001). At 12 months, IBS-SSS responder rates were higher with PD than LFD (62.5% vs 34.5%; absolute risk difference&#x2009;+28.0%, 95% CI 4.2-47.7; Fisher p&#x2009;=&#x2009;0.029), and IBS-QOL, HADS-anxiety, and HADS-depression showed more favourable trajectories with PD. PD was associated with sustained Shannon alpha-diversity gains (+0.488 at 6 weeks;&#x2009;+0.205 at 12 months; both p&#x2009;<&#x2009;0.01). A modest between-group beta-diversity difference at 6 months (R2&#x2009;=&#x2009;0.035; p&#x2009;=&#x2009;0.011) was not significant at 12 months. This hypothesis-generating follow-up suggests more durable benefit with PD; larger trials powered for long-term clinical and microbiome outcomes are warranted.

Humans

Genomic epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli across humans, poultry and wastewater sectors in Douala, Cameroon.

BACKGROUND: The global health threat of antimicrobial resistance involves the human, animal and environmental sectors. Data from Cameroon are scarce. OBJECTIVES: This study aimed to define extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) rates and associated risk factors across the three sectors in Douala, Cameroon, and to define molecular characteristics of isolates. METHODS: From June 2022 to May 2023, we collected blood cultures from hospitalized patients, rectal swabs from healthy pregnant women, caeca from broiler chickens and environmental wastewater. Samples were screened for ESBL-Ec using CHROMAgar&#x2122; ESBL and cefotaxime-supplemented Tryptone Bile X-glucuronide agar. Antimicrobial susceptibility testing was performed by disk diffusion following EUCAST guidelines. Whole-genome sequencing was carried out using Illumina technology. RESULTS: Of 628 samples, 374 yielded ESBL-Ec. Prevalence was 54.6% (131/240) in pregnant women, 70.4% (169/240) in chickens and 93.1% (67/72) in wastewater. The proportion of ESBL-Ec among E. coli-positive-blood cultures was 9.2% (7/76). Multi-family household living was independently associated with ESBL-Ec carriage among pregnant women (adjusted odds ratio&#x200a;=&#x200a;1.7, 95% CI 1.0-3.1, P&#x200a;=&#x200a;0.03). High co-resistance (>70%) was observed for tetracycline, ciprofloxacin and trimethoprim/sulfamethoxazole. Sequencing of 32 isolates revealed 45 distinct resistance genes, including blaCTX-M-15 (n&#x200a;=&#x200a;13, 40.6%), blaCTX-M-55 (n&#x200a;=&#x200a;11, 34.4%) and last-resort antibiotic resistance genes mcr-1 and bla OXA-181. High-risk sequence types included ST131 (pregnant women) and ST10 (chickens). Notably, ST48 was shared between pregnant women and chickens, and ST155 between pregnant women and wastewater. CONCLUSION: Cross-sectoral ESBL-Ec in Douala exhibits high genomic diversity and alarming resistance. The occurrence of last-resort genes requires immediate One Health surveillance and coordinated interventions.

Journal Article

Comparative assessment of post-transport disease susceptibility in Asian seabass (Lates calcarifer): Associations with oxidative stress, immune responses, gut microbiota, and tissue pathology.

Stress is a crucial factor that affects aquaculture systems, particularly during transportation, which often leads to deteriorated fish health and reduced survival rates. This study aimed to investigate the comparative differences in physiological changes, oxidative stress parameters, and immune responses between clinically healthy and diseased Asian seabass (Lates calcarifer) following commercial transportation. The study compared the health status of fish after transportation, categorized into healthy (Healthy) and diseased (Disease) groups. Assessments were conducted on oxidative stress parameters, immune responses, gut microbiota composition, and tissue pathology. The results showed that diseased fish exhibited significantly higher oxidative stress levels (P&#xa0;<&#xa0;0.05), as indicated by an increase in malondialdehyde (MDA) levels and altered antioxidant and redox-related markers, including superoxide dismutase (SOD), nitric oxide (NO), catalase (CAT), glutathione (GSH), glutathione reductase (GR), and glutathione peroxidase (GPx), measured across multiple target tissues (head kidney, gills, liver, intestine, and brain), compared with healthy fish. Furthermore, the expression of immune-related genes was significantly downregulated in diseased fish after transportation, indicating immune suppression. In contrast, healthy fish maintained a more balanced immune response, which may partially mitigate the adverse effects of transport-induced stress. Gut microbiota analysis revealed that diseased fish had a significant reduction in beneficial bacteria such as Cetobacterium somerae and Bacillus spp., accompanied by a significant (P&#xa0;<&#xa0;0.05) increase in opportunistic pathogens including Aeromonas spp., Photobacterium spp., and Vibrio spp. Histopathological examination showed severe damage in the gills, liver, and intestines of diseased fish (P&#xa0;<&#xa0;0.05), while only minor tissue alterations were observed in healthy fish. Overall, the findings indicate that post-transport diseased Asian seabass exhibit marked oxidative stress, impaired antioxidant defense, altered immune responses, gut microbial dysbiosis, and multi-organ tissue damage compared with clinically healthy post-transport fish. These results suggest that deterioration of transport conditions may contribute to post-transport morbidity and disease susceptibility.

Animals

Impaired adaptation to smoke-derived phenolic compounds in Listeria monocytogenes CC204 from smoked salmon and trout.

Listeria monocytogenes is a major foodborne pathogen in ready-to-eat smoked fish products. This study evaluated whether clonal complex affiliation contributes to variability in growth responses to stresses representative of smoked salmon and trout processing. Ten strains were studied, including strains from CC121, CC26 and CC204, the three major clonal complexes reported in the French smoked salmon and trout sectors, together with the EGDe reference strain. Strains were exposed to salt, cold, smoke-derived phenolic compounds and combined stress conditions. Growth responses were compared with whole-genome-based phylogeny, and the impaired phenotype observed under phenolic exposure was further investigated using viable counts, live/dead microscopy and comparative genomics. Growth profiles were partly structured by clonal complex, with strains from the same clonal complex showing similar behaviour across stress conditions. Salt and cold reduced growth globally, while smoke-derived phenolic compounds were the most discriminating conditions. CC204 strains showed markedly lower growth rates under phenolic exposure than CC121, CC26 and EGDe. This phenotype was not associated with loss of cultivability or significant loss of membrane integrity. Comparative genomics did not identify a clear gene-content determinant explaining the CC204 phenotype. These results suggest that CC204 has an impaired adaptive response to smoke-derived compounds, likely involving regulatory or physiological mechanisms.

Listeria monocytogenes