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PubMed2026

Seed shattering habit in millets and the secrets of the abscission layer - a comprehensive review.

Though seed shattering continues to be a significant barrier affecting yield stability and harvesting efficiency in millets and other grasses, millets are increasingly acknowledged as climate-resilient, nutrient-rich 2007cereal crops with the potential to strengthen global nutritional and food security under the combined pressures of climate change, population growth, and limited natural resources. Since strong artificial selection favoured non-shattering phenotypes during domestication, seed shattering, an adaptive trait in wild species that promotes seed dispersal through the formation and activation of specialised abscission layers, became a distinguishing feature of cultivated cereals. With a focus on the morphological, physiological, hormonal, and genetic modulation of the abscission zone, this article summarizes the state of the art regarding seed shattering in millets. Abscission layer morphology, location, and lignification vary greatly among grasses, from well-defined lignified zones in rice and sorghum to non-lignified and anatomically subtle zones in Setaria and Panicum species. Cell wall-modifying enzymes like polygalacturonases, cellulases, expansins, and pectin methylesterases that mediate middle lamella degradation are modulated by coordinated hormonal signalling involving auxin, ethylene, and abscisic acid, which controls the timing and progression of cell separation at the physiological level. Domestication-related genes, including SH1, qSH1, SH4, and LES1, demonstrate convergent evolutionary mechanisms controlling abscission layer development in a variety of grass lineages at the molecular level. Understanding these regulatory networks has been greatly enhanced by recent developments in transcriptomics, functional genomics, and genome sequencing in both model species and underused millets. The role of millets as climate-smart cereals for sustainable future agriculture is reinforced by the integration of anatomical, physiological, and genetic insights, which offer a solid basis for targeted breeding and genome-editing strategies intended to improve seed retention, enhance yield stability, and increase harvest efficiency.

Abscission Layer↗

PubMed1975

Presynaptic events in meiocytes of Lilium longiflorum and their relation to crossing-over: a preselection hypothesis.

We are proposing a "Preselection Hypothesis" to account for the regulation of crossing-over in eukaryotic organisms. The hypothesis characterized meiosis in terms of three major physiological stages: (1) a presynaptic stage when pairs of homologous DNA stretches are selected so as to become trapped within the synaptinemal complex during synapsis, (2) an alignment of homologous chromosomes and stabilization of paired bivalents via the synaptinemal complex, and (3) a scission and rejoining of DNA stretches leading to the formation of chiasmata and crossovers. The hypothesis centers on the first stage and is based on evidence for the occurrence of significant cytological and biochemical changes prior to synapsis. The major feature of the hypothesis is that crossing-over occurs only in trapped DNA stretches. Thus, potential crossing-over sites, though not crossing-over itself, are determined well before chromosomes pair. Since, to a large degree, crossovers are distributed randomly along the length of each chromosome, the preselection process must result in a random assortment of trapped DNA stretches, the assortment differing from one meiocyte to another.

Chromosomes↗

PubMed2026

DHX9 Inhibition Enhances Paclitaxel Sensitivity by Inducing Mitotic Failure in Ovarian and Endometrial Cancers.

Recurrent high-grade serous ovarian carcinoma (HGSOC) and endometrial cancer remain major clinical challenges with limited effective treatment options. DExH-box helicase 9 (DHX9), a DNA/RNA helicase essential for genomic stability, has not yet been explored as a therapeutic target in gynecologic cancers. In this study, we show that a selective DHX9 inhibitor (DHX9i) suppresses proliferation in a subset of HGSOC and endometrial cancer cell lines by inducing DNA damage, chromosomal instability, and mitotic failure. This effect was independent of microsatellite instability status and prior resistance to platinum or PARP inhibitors. Genomic analysis indicated that DHX9i resistance was unlikely to be driven by single-gene mutations but was instead associated with copy-number alterations in mitotic spindle and microtubule-regulating genes in both HGSOC and endometrial cancer. Transcriptomic profiling further revealed consistent alterations in microtubule- and spindle-associated pathways in DHX9i-resistant models following DHX9i treatment. Mechanistically, DHX9i induced mitotic defects in DHX9i-sensitive models, whereas resistant lines maintained mitotic integrity. Given the convergence of resistance-associated features on microtubule-related pathways, we combined DHX9i with the microtubule-stabilizing agent paclitaxel to enhance mitotic stress. This combination triggered mitotic disruption and enhanced cytotoxicity in DHX9i-resistant cells. In vivo, the combination led to sustained tumor regression and prolonged survival in both DHX9i-sensitive and DHX9i-resistant models without notable toxicity. Overall, our findings define genomic, transcriptomic, and phenotypic characteristics associated with differential responses to DHX9i and support the clinical evaluation of the DHX9i-paclitaxel combination as a therapeutic strategy in recurrent gynecologic cancers.

Female↗

PubMed2026

Bacteriophages Control Epiphytic Pseudomonas syringae Populations in Highbush Blueberry Leaves.

The Pseudomonas syringae complex (Psc) is a group of globally distributed phytopathogens responsible for substantial agricultural losses. Although bacteriophage-based biocontrol has shown promise against Psc, no studies have examined phages targeting blueberry-tropic Psc lineages. Here, we isolated phages infecting Psc strains from diseased highbush blueberry (Vaccinium corymbosum), and evaluated their suitability for biocontrol using a multi-stage screening pipeline incorporating host-range analysis, comparative genomics, environmental stability testing, in vitro antibacterial efficacy assays and ex planta validation. Twelve of the isolated phages exhibited favourable host-range characteristics. Genomic analyses revealed substantial phylogenetic diversity among these candidates but simultaneously identified multiple clonal groups, reducing the collection to eight non-redundant phages spanning five distinct genera. Candidate phages generally retained infectivity under environmentally relevant conditions and exhibited heterogeneous but largely favourable stability profiles. Planktonic killing assays uncovered considerable variation in antibacterial efficacy, but phage performance appeared to be driven by infection compatibility and host-specific factors rather than properties intrinsic to individual phages. Notably, the jumbo phageCB10 emerged as a particularly promising candidate due to its strong antibacterial activity (median GRC = 0.943), favourable environmental stability and unique genomic features. Cocktails containing the most effective candidates produced substantial and longitudinally sustained reductions in epiphytic colonization of detached blueberry leaves by Psc, exceeding five orders of magnitude at peak efficacy and demonstrating robust activity in a biologically relevant ex planta system. Importantly, in vitro antibacterial efficacy was predictive of performance in our ex planta model (r = 0.67; p = 0.0003), supporting the utility of tiered screening approaches for candidate selection. Taken together, these findings establish a framework for the systematic identification and evaluation of phages targeting Psc, and support the development of phage-based interventions for managing plant diseases.

Pseudomonas syringae↗

PubMedDate not supplied

[Conformational transitions of DNA in concentrated neutral salt solutions].

Salt anions can be arranged in lyotropic series of the action of conformational stability of DNA. This effect is universal for proteins and DNA. It is explained by the salt changes of transfer free energy of macromolecular inner groups to the solvent. Effect mechanism is the combination of anion direct interaction with the exposed inner groups and in indirect way through the changes of water structure. Individual features of the salt effect on DNA are the induced transitions in DNA duplex and the changes of differential stability of AT- and GC-base pairs. An important role in these phenomena plays the dehydration of DNA in the reduction of water activity in concentrated salt solutions. Local changes in medium polarity, hydration level of DNA molecule at different stages of their functioning can explain the regulatory role in intracellular processes, as well as selectivity and specificity of the action of individual ions in the cell.

Circular Dichroism↗

PubMed2026

Yeast Rad55-Rad57-SHU paralog complex dynamically promotes Rad51 filament formation.

Homologous recombination (HR) is an important DNA repair pathway that safeguards genome integrity. During HR, the Rad51 nucleoprotein filaments catalyze strand invasion into a homologous duplex DNA. Filament formation requires a conserved family of Rad51 paralogs that act as tumor suppressors in humans. By capturing six distinct states using cryo-electron microscopy, we reveal that the Saccharomyces cerevisiae Rad51 paralog complex, composed of the Rad55-Rad57 heterodimer and the SHU (Psy3-Csm2-Shu1-Shu2) complex, selectively brings Rad51 to single-stranded DNA to seed filament formation. Rad51 itself is a transient yet integral component of this machinery which binds along the Rad57 subunit to complete a high-affinity DNA-binding site. We also uncover a dual-nucleotide regulatory mechanism: a structural ADP molecule stabilizes the complex, while a second, catalytic ATPase site at the Rad57-Rad51 interface promotes the release of the paralog complex. These structural and mechanistic features provide a blueprint for understanding the function of Rad51 paralogs across eukaryotes.

Saccharomyces cerevisiae Proteins↗

PubMed2026

NCBoost v2: a classifier for non-coding single-nucleotide variants in Mendelian diseases.

MOTIVATION: The current diagnostic rate of rare diseases through whole-genome sequencing has stabilized at around 30% on average, highlighting the need for improved computational scores to identify pathogenic variants. In 2019, we developed NCBoost, a supervised-learning approach that mined a comprehensive set of sequence constraint features and proved particularly well suited to identifying high-effect pathogenic non-coding variants in genetic diseases. Since its first release, the substantial increase in the number of variants available for training, as well as the enhanced capacity to detect purifying selection signals from large-scale genome sequencing projects, motivated an update of NCBoost. RESULTS: We implemented NCBoost v2, a pathogenicity score for non-coding single-nucleotide variants, trained on the largest set of curated pathogenic variants in monogenic Mendelian diseases available to date. It leverages conservation features computed from recent large-scale genomic consortia such as Zoonomia and gnomAD, and incorporates recent splice-altering predictive scores. NCBoost v2 outperformed alternative state-of-the-art methods in a variety of scenarii, providing more consistent scores across non-coding genomic regions and fine-tuning the scoring of pathogenic splice-altering variants in Mendelian disease genes. AVAILABILITY AND IMPLEMENTATION: NCBoost v2 software is implemented in Python 3.10 and is freely available under the GNU General Public License Version 3 at https://doi.org/10.5281/zenodo.16029049 and https://github.com/RausellLab/NCBoost-2, together with precomputed scores for the human genome assembly GRCh38.

Polymorphism, Single Nucleotide↗

PubMed1992

New IS10 transposition vectors based on a gram-positive replication origin.

We describe below a set of plasmid-based vehicles which can be used for delivery of IS10-derived transposons into Gram- bacteria. These vehicles replicate via a Gram+ plasmid origin that is inactive in Escherichia coli; they are easily maintained in Bacillus subtilis. Transposons are introduced by electroporation or transformation with the plasmid, and as in previous delivery systems, transpositions are selected with the appropriate antibiotic. This system should be particularly useful in situations where the standard delivery vehicles, based on bacteriophage lambda, are inappropriate. The system described incorporates a number of useful features: a variety of antibiotic markers (Er, Cm, Km or Tc), a polylinker containing restriction sites for rare-cutting endonucleases to facilitate physical mapping of chromosomal insertions, a mutant transposase that confers a relaxation in insertion specificity and positioning of the transposase-encoding gene outside of the transposing segment to ensure the stability of insertions once isolated.

Bacillus subtilis↗

PubMed1979

Electrophrenic respiration: report of six cases.

The development of electrophrenic respiration has permitted freedom from mechanical ventilation for patients who have irreversible respiratory failure in association with high-cervical spinal cord or brainstem lesions. There are three basic criteria for successful diaphragm pacing: (1) the need for long-term mechanical ventilatory assistance, (2) a functionally intact phrenic nerve-diaphragm axis, and (3) chest wall stability. Inability to achieve satisfactory pacing can be due to malfunction of equipment, instability of the chest wall, or inadequate neuromuscular responsiveness. These features of diaphragm pacing are exemplified in a series of six patients. Three achieved independence from mechanical ventilatory assistance with full-time phrenic pacing. In one patient, only limited electrophrenic respiration was achieved, and in another the method was entirely unsuccessful. Although functioning well, pacing systems were removed from the sixth patient because of infection. Diaphragm pacing can be a valuable form of respiratory support for carefully selected patients.

Adolescent↗

PubMed2000

DNA replication fidelity.

DNA replication fidelity is a key determinant of genome stability and is central to the evolution of species and to the origins of human diseases. Here we review our current understanding of replication fidelity, with emphasis on structural and biochemical studies of DNA polymerases that provide new insights into the importance of hydrogen bonding, base pair geometry, and substrate-induced conformational changes to fidelity. These studies also reveal polymerase interactions with the DNA minor groove at and upstream of the active site that influence nucleotide selectivity, the efficiency of exonucleolytic proofreading, and the rate of forming errors via strand misalignments. We highlight common features that are relevant to the fidelity of any DNA synthesis reaction, and consider why fidelity varies depending on the enzymes, the error, and the local sequence environment.

Base Pair Mismatch↗

PubMed1992

Stability of septohippocampal neurons following excitotoxic lesions of the rat hippocampus.

The present study examined the effects of removing hippocampal nerve growth factor (NGF)-producing neurons upon cholinergic and noncholinergic septohippocampal projecting neurons. To deplete septal/diagonal band neurons of their intrinsic source of NGF, rats received unilateral intrahippocampal injections of ibotenic acid and were sacrificed 2-24 weeks later. Choline acetyltransferase and parvalbumin immunohistochemistry failed to reveal changes in the number of cholinergic or gamma-aminobutyric acid-containing neurons, respectively, within the septal/diagonal band region ipsilateral to the hippocampal lesion at any time point examined. Additionally, immunocytochemical localization of nonphosphorylated and phosphorylated neurofilament proteins did not reveal abnormal staining characteristics within the septal/diagonal band complex, suggesting that this lesion does not alter cytoskeletal features of neurons which project to the hippocampus. Selected rats received unilateral hippocampal lesions and 3 months later were injected with fluorogold into the remaining hippocampal remnant and with wheat germ agglutinin conjugated to horse radish peroxidase into the intact contralateral hippocampus. Both retrograde tracers were predominantly transported to their respective ipsilateral septum and vertical limb of the diagonal band. This indicates that following the lesion, septal/diagonal band neurons still project ipsilaterally and sprouting to the NGF-rich contralateral side does not occur. RNA blot analysis revealed a decrease in NGF mRNA expression within the lesioned hippocampus with a maximum reduction of approximately 70%. In contrast, no change in NGF mRNA expression was observed within the ipsilateral septum relative to the contralateral side. The present study demonstrates that removal of hippocampal target neurons does not alter the number, morphology, or projections of both cholinergic and noncholinergic septal/diagonal band neurons.

Animals↗

PubMed2026

Megamimivirus double-stranded DNA linear genomes flanked by highly diverse terminal inverted repeats.

UNLABELLED: Giant viruses have fundamentally expanded our understanding of virology by challenging the conventional boundaries of both virion size and genome complexity. However, the scarcity of isolates has left many of their unique biological features unexplored. Here, we report the isolation and characterization of four new giant virus species belonging to the subfamily Megamimivirinae, sampled from distinct environments across China. Among these, Megavirus daqingense is the first giant virus isolated from an oil reservoir; it exhibits virion stability under high salinity, chloroform exposure, and elevated temperatures, suggesting fitness adaptations to subsurface conditions. Using a hybrid sequencing approach that integrates short- and long-read technologies, we assembled complete linear genomes for all four isolates, each flanked by long terminal inverted repeats (TIRs). Comparative genomic and synteny analyses identified 29 distinct TIRs from 46 megamimivirus genomes. Gene content within these TIRs was highly diverse, with no orthologous proteins conserved across all repeats. Furthermore, TIR genes experienced weaker purifying selection than those in non-TIR regions (i.e., the genomic regions excluding the TIRs), consistent with their role as drivers of genome plasticity. Notably, we discovered for the first time that identical tRNA genes are shared between TIRs and non-TIR regions of eukaryotic viruses. Collectively, our work provides insights into the structural and evolutionary complexity of megamimiviruses, revealing TIRs as reservoirs of genetic diversity and hotspots for gene transfer, thereby playing a pivotal role in shaping the dynamic architecture of giant virus genomes. IMPORTANCE: Terminal inverted repeats (TIRs) are critical structural elements at the termini of linear genomes essential for fundamental processes such as recombination, replication, and integration across diverse organisms. However, the inherent limitations of short-read sequencing technologies have left the complete structure, diversity, and evolutionary significance of long TIRs in giant viruses unexplored. In this study, we leverage hybrid sequencing and comparative genomic analyses to unveil the complexity of TIRs across the subfamily Megamimivirinae. We demonstrate that TIRs are dynamic genomic hotspots characterized by remarkable gene diversity and unexpected conservation of specific tRNA genes. These findings establish TIRs as key drivers of genome plasticity, serving as hotspots for horizontal gene transfer and genetic innovation. By resolving the long-hidden terminal structures of megamimivirus genomes, this work provides a foundational framework for understanding how TIRs shape the evolution of giant viruses and, more broadly, advances our understanding of genome architecture in large DNA viruses.

Megavirus↗

PubMed1992

Conformational study of a nine residue fragment of the antigenic loop of foot-and-mouth disease virus.

The nine-residue peptide Ac-TASARGDLA-NHMe was selected as model peptide in order to understand the conformational features of the antigenic loop of foot-and-mouth disease virus (FMDV). A throughout exploration of the conformational space has been carried out by means of molecular dynamics (MD) and energy minimization. The calculations have been carried out using the AMBER force field. Solvent effects have been included by an effective dielectric constant of epsilon = 4r. The lowest energy conformation presents a secondary structure constituted by an alpha-helix at the N-terminal end followed by two gamma-turns in the central region. The rest of the accessible minima found present also a high tendency to form gamma-turns. Finally, a 100 ps MD trajectory calculation at 298 K suggest a stability of the secondary structure elements of the lowest energy conformation.

Amino Acid Sequence↗

PubMed1975

Variation in spotting among the close relatives of the butterfly, Maniola jurtina.

A study of spotting in seven related butterfly species in the genera Maniola and Pyronia has been initiated, in the hope of complementing previous work on Maniola jurtina. Marked individual variability has been found in six of the species. Stability of spotting over large areas has not been prominent, but a high degree of apparent geographical variability has been found in four species. Sometimes this has taken the form of clines and sometimes of quantal steps. Some of the quantal changes coincide with the appearance of different "subspecies". Among the incomplete data presented, parallel geographical variation in different species has not been an obvious feature. There have not been enough samples to test for temporal variation in spotting.

Animals↗

PubMed2022

High early death rates, treatment resistance, and short survival of Black adolescents and young adults with AML.

Survival of patients with acute myeloid leukemia (AML) is inversely associated with age, but the impact of race on outcomes of adolescent and young adult (AYA; range, 18-39 years) patients is unknown. We compared survival of 89 non-Hispanic Black and 566 non-Hispanic White AYA patients with AML treated on frontline Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology protocols. Samples of 327 patients (50 Black and 277 White) were analyzed via targeted sequencing. Integrated genomic profiling was performed on select longitudinal samples. Black patients had worse outcomes, especially those aged 18 to 29 years, who had a higher early death rate (16% vs 3%; P=.002), lower complete remission rate (66% vs 83%; P=.01), and decreased overall survival (OS; 5-year rates: 22% vs 51%; P<.001) compared with White patients. Survival disparities persisted across cytogenetic groups: Black patients aged 18 to 29 years with non-core-binding factor (CBF)-AML had worse OS than White patients (5-year rates: 12% vs 44%; P<.001), including patients with cytogenetically normal AML (13% vs 50%; P<.003). Genetic features differed, including lower frequencies of normal karyotypes and NPM1 and biallelic CEBPA mutations, and higher frequencies of CBF rearrangements and ASXL1, BCOR, and KRAS mutations in Black patients. Integrated genomic analysis identified both known and novel somatic variants, and relative clonal stability at relapse. Reduced response rates to induction chemotherapy and leukemic clone persistence suggest a need for different treatment intensities and/or modalities in Black AYA patients with AML. Higher early death rates suggest a delay in diagnosis and treatment, calling for systematic changes to patient care.

Adolescent↗

PubMed2025

Genomic Insights Into Convergent Evolution: Adaptation to Rocky Habitats in Rock-Inhabiting Fungi.

Rock-inhabiting fungi (RIF), obligate colonizers of bare rocks, are primarily distributed across two major phylogenetic classes: Dothideomycetes and Eurotiomycetes. These fungi display striking convergence in morphology and physiology, characterized by meristematic growth, melanized cell walls, and extreme stress tolerance. However, the genomic underpinnings of this adaptive convergence remain poorly understood. Here, through comparative genomic analysis of 9 RIF and 18 non-RIF fungi, we revealed that RIF possess compact, gene-dense genomes marked by contraction of genes involved in nutrient uptake and secondary metabolism, alongside expansions in cell wall biosynthesis, lipid metabolism, and stress-responsive pathways. We identified two genes under positive selection across multiple RIF lineages: Ino80 ATPase (chromatin remodeling) and the ER chaperone BiP (protein folding). Further evidence of convergence was found in the mannosyltransferase Mnn9, a key enzyme in cell wall assembly, where two RIF-specific amino acid substitutions were predicted to enhance protein stability. Additionally, a unique Mnn9-like clade has expanded exclusively in RIF. RNAi-mediated knockdown of an Mnn9-like gene in Rachicladosporium sp. confirmed its role in cell wall mannosylation, osmotic stress response, and the transition from meristematic to filamentous growth. Our findings elucidate a set of common genomic adaptations and highlight the specialized evolution of the Mnn9 family in driving the convergent success of phylogenetically diverse RIF in rocky environments.

Phylogeny↗

PubMed2026

Discovery and validation of a multi-protein panel for predicting non-fatal major adverse cardiovascular events in diabetic kidney disease.

OBJECTIVE: To identify plasma protein biomarkers associated with incident non-fatal major adverse cardiovascular events (MACE) in diabetic kidney disease (DKD) patients. RESEARCH DESIGN AND METHODS: We analyzed 317 DKD patients from the UK Biobank. Plasma proteomics and clinical data (demographics, metabolism, renal function) were integrated. In an exploratory discovery phase, three sequential Cox regression models (crude, socio-demographic-adjusted, socio-demographic-metabolic adjusted) screened non-fatal MACE-associated proteins. To prevent information leakage, the cohort was then randomly split into training (70%) and testing (30%) sets; machine-learning feature selection, hyperparameter optimization, and final model development were performed exclusively within the training set. The associated proteins were input into the four-step machine-learning pipeline (LASSO-Cox, random survival forest, Boruta, XGBoost-Cox). Predictive performance was validated using Kaplan-Meier survival analyses, longitudinal trajectory modeling, and ROC benchmarking. An interactive web application was deployed for clinical implementation. RESULTS: Of 1,463 plasma proteins, 561 were associated with non-fatal MACE across Cox models, with 14 overlapping proteins. Nine core proteins (ANG, IL1R1, CXCL14, ESAM, PTGDS, HAVCR1, FGFR2, IGSF8, CCL3) were validated: ANG showed the strongest non-fatal MACE association (HR = 3.88, 95%CI 2.33-6.48, p<0.001), and all high-expression groups had elevated non-fatal MACE risk. GO/KEGG enrichment highlighted inflammatory-immune pathways like positive regulation of MAPK cascade, Cytokine-cytokine receptor interaction and PI3K-Akt signaling pathway as key mechanisms. The model integrating proteins, demographic factors, and clinical variables achieved the highest predictive performance across non-fatal MACE (AUC = 0.768), myocardial infarction (MI) (0.808), and stroke (0.816) outcomes, with superior stability in cross-validation. CoxBoost + Elastic Net framework was selected as the optimal framework via benchmarking of 101 algorithms. The model demonstrated favorable calibration in high-risk patients and yielded positive net clinical benefit across decision thresholds of 5% to 45%. The web tool (https://jiangli2941.github.io/MACE-prediction-v2/) enables input of 28 variables, outputs non-fatal MACE risk status, risk probability, and highlights abnormal indicators. CONCLUSION: Plasma proteomics combined with machine learning identifies robust non-fatal MACE predictors in DKD.

Humans↗

PubMed1992

Features of cholera and Vibrio parahaemolyticus diarrhoea endemicity in Calabar, Nigeria.

The clinical and epidemiological features of acute vibrio diarrhoeal disease were studied in 881 patients seen at the University of Calabar Teaching Hospital (UCTH), Calabar, Nigeria, between January and December 1989. Stools and rectal swabs of patients and randomly-selected control subjects were microscopically and culturally examined for the presence of enteric pathogens. Households of vibrio diarrhoea cases and matched controls were visited for ecologic studies. Of a total of 108 (12.3%) culturally-confirmed bacterial diarrhoeas, 47 (43.5%) were due to Escherichia coli, 33 (30.6%) to Vibrio cholerae-01 (classical and El Tor biotypes) and V. parahaemolyticus, while shigellae and salmonellae accounted for 29 (26.9%) and 9 (8.3%) cases, respectively. Most cholera case households clustered within the ancient neighbourhood of the inner city, characterized by poorly developed water and sewage disposal systems. A preponderance of vibrio diarrhoea patients were children < or = 10 years. Adult cases involved mostly females. The only case of diarrhoea-related death involved an eight-month old child with kwashiorkor and V. parahaemolyticus infection. Incidence of vibrio diarrhoeas was seasonal, with most cases occurring during the dry season followed by subsidence at the onset of rainy season. Bimodal peaks of vibrio diarrhoeal episodes observed over the period appeared to coincide with periods of acute water scarcity, high temperature, increased fishing activities and trade traffic on the Calabar River estuary. Of the environments sampled, only clam shells from a case household and river sediments yielded vibrio pathogens on culture. Ecological factors that are capable of stabilizing a focus of vibrio diarrhoea endemicity in this area are highlighted.

Adolescent↗