Bloodsucking Parasites
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Science bulletin on bloodsucking arthropod vectors: flies, ticks, mosquitoes, mites, fleas, lice spreading dengue, malaria, WNV, Lyme, Rickettsia, Babesia, Bartonella -- MF
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The First Chromosome-Scale Genome Assembly for Dermacentor reticulatus: A Key Vector of Tick-Borne Pathogens of Public and Veterinary Health Importance in Europe bioRxivpreprint
The First Chromosome-Scale Genome Assembly for Dermacentor reticulatus: A Key Vector of Tick-Borne Pathogens of Public and Veterinary Health Importance in Europe
Background Dermacentor reticulatus is a key tick species across Europe and an established vector of multiple pathogens that affect both human and animal health. Despite its significant role in disease transmission, genomic data for this species remain limited. Here, we present the first chromosome-scale genome assembly of D. reticulatus, constructed using Oxford Nanopore long-read sequencing data. Methods High molecular weight DNA was extracted from a female Dermacentor reticulatus collected in Devon, UK, and sequenced using Oxford Nanopore long-read technology. Genome assemblies were generated using both guided and unguided approaches, followed by repeat masking, gene prediction, and functional annotation. Genome completeness was assessed using BUSCO, and comparative, phylogenetic, and functional analyses were performed against other Dermacentor and tick species. Results This chromosome-scale genome assembly revealed a repeat-rich genome, with approximately 61.9% of the total sequence consisting of repetitive elements. Benchmarking universal single-copy ortholog (BUSCO) analysis demonstrated strong genome completeness, with guided assembly (chromosome) achieving a score of 97.1%, closely matching those of related Dermacentor species. For comparison, unguided assembly (scaffold) yielded a BUSCO score of 96.7%. Gene annotation following repeat masking resulted in BUSCO completeness scores of 95.1% (guided) and 95.0% (unguided). Functional characterisation included Pfam domain assignment and Gene Ontology analysis. Additionally, we assembled the mitochondrial genome (15,103 bp), comprising 38 genes, providing further insight into D. reticulatus phylogenetic placement. Conclusions This genomic resource establishes a foundation for functional genomics, evolutionary studies and supports future research in vector biology and the control of tick-borne diseases.
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Pathogens, Vol. 14, Pages 1035: Characterization of the Pepper Virome in Oklahoma Reveals Emerging RNA and DNA Viruses Pathogens
Pathogens, Vol. 14, Pages 1035: Characterization of the Pepper Virome in Oklahoma Reveals Emerging RNA and DNA Viruses
Pepper (Capsicum spp.) is an economically valuable crop worldwide including in the United States due to its nutritional benefits in human health and widespread use as a spice or vegetable. Although numerous viruses have been reported infecting peppers in the USA, little is known about the diversity and distribution of pepper-infecting viruses in Oklahoma. To address this knowledge gap, we conducted a comprehensive pepper virome study to identify viruses infecting pepper and their incidence across six different counties in Oklahoma. A total of 310 plant samples including pepper and other potential hosts were collected during the 2021 and 2022 growing seasons. Samples were analyzed using high-throughput sequencing (HTS) and/or reverse transcription-polymerase chain reaction (RT-PCR) assays. Viral contigs identified via HTS were further validated through RT-PCR or PCR assays followed by Sanger sequencing. In total, 17 distinct viruses were detected, including 15 RNA and two DNA viruses, with several representing putatively novel findings. The most prevalent virus was beet curly top virus (BCTV), followed by tomato yellow leaf curl virus (TYLCV), potato yellow dwarf virus/constricta yellow dwarf virus (PYDV/CYDV), and pepper mild mottle virus (PMMoV). Virus incidence varied by season and location, with some surveys showing infection rates exceeding 80%. This study provides the first in-depth characterization of the pepper virome in Oklahoma and valuable insights into the prevalence and distribution of pepper-infecting viruses. These findings will support the development of informed, targeted strategies for virus detection and management in pepper production systems.
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bloodsparasites.bsky.social
Defining the transmission parameters of lumpy skin disease virus by the three model insect vector species Aedes aegypti, Stomoxys calcitrans and Culicoides nubeculosus reveals important differences in their likely role in transmission bioRxivpreprint
Defining the transmission parameters of lumpy skin disease virus by the three model insect vector species Aedes aegypti, Stomoxys calcitrans and Culicoides nubeculosus reveals important differences in their likely role in transmission
Lumpy skin disease virus (LSDV) is a poxvirus that can cause severe, systemic disease in cattle. By far the most important route of transmission of LSDV is mechanical transmission via haematophagous arthropod vectors. However we lack detailed information on this process including the likelihood of transmission by different vector species. This study used an experimental bovine model of LSDV transmission to quantify the transmission of LSDV from an infected donor to a naive recipient calf. Three species of Diptera representing different vector groups were included (Stomoxys calcitrans, Aedes aegypti and Culicoides nubeculosus, respectively a large biting fly, a mosquito and a midge), and the clinical, virological and immunological outcomes in the recipient calves studied. The ability of Ae. aegypti to mechanically transmit LSDV following feeding on an artificial membrane feeding system was also examined. Both Ae. aegypti and S. calcitrans were able to transmit LSDV, resulting in disease in recipient calves. Bites from virus-positive C. nubeculosus did not result in disease in recipient calves, though the presence of neutralising antibodies in these recipients indicated exposure to virus or virus components. Ae. aegypti successfully transmitted LSDV following feeding on LSDV-spiked blood through an artificial membrane feeding system, validating this laboratory model as a future replacement for donor cattle. Mathematical models of the data were generated and predicted S. calcitrans to be the most efficient vector of LSDV of the insects tested with a reproduction number (R0) of 5.8.
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Trends in insecticide resistance in #Anopheles #mosquitoes (Diptera: Culicidae) in Ghana: a systematic review JMedEnt
Trends in insecticide resistance in #Anopheles #mosquitoes (Diptera: Culicidae) in Ghana: a systematic review
AbstractMalaria continues to be a major public health issue in Ghana, contributing significantly to hospital outpatient visits. Vector control remains central to malaria prevention; however, the growing resistance of malaria vectors to insecticides presents a major obstacle to control and elimination efforts. This review examined the evolution of insecticide resistance in Ghana from 2001 to 2024, summarising resistance mechanisms across the country’s bioclimatic zones to inform evidence-based vector control strategies aligned with Ghana’s malaria elimination goals. A systematic literature search was conducted using PubMed, Google Scholar, and Scopus databases to identify studies on insecticide resistance in major malaria vectors. A total of 41 articles were retrieved, and data were analysed using Microsoft Excel 365 and GraphPad Prism v.9.1.2. Pyrethroids were the most frequently studied insecticides, particularly in the Coastal (48%, n = 17), Forest (37.1%, n = 13), and Sahel (14.3%, n = 5) zones. An increasing trend of pyrethroid resistance in #Anopheles gambiae s.l. was observed across all transmission zones, with the vgsc-L995F mutation being the most reported resistance mechanism. Temporal analysis revealed significant differences in resistance levels over time across all zones. Resistance to dual-active ingredients (piperonyl butoxide + pyrethroid) was also detected nationwide. Notably, there are limited studies on An. funestus susceptibility and metabolic resistance driven by copy number polymorphisms or vgsc variants. Given these gaps, the application of genomic surveillance and whole genome sequencing is essential for identifying locally relevant resistance mechanisms to guide future vector control interventions in support of Ghana’s malaria elimination efforts.
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ICYMI: Visualization of Trypanosoma brucei flagellar pocket collar biogenesis identifies two new cytoskeletal structures @plosbiology.org
Visualization of Trypanosoma brucei flagellar pocket collar biogenesis identifies two new cytoskeletal structures
by Marie Zelená, Elina Casas, Chloé Lambert, Nicolas Landrein, Denis Dacheux, Eloïse Bertiaux, Kim Ivan Abesamis, Gang Dong, Vladimir Varga, Derrick Roy Robinson, Mélanie Bonhivers Understanding how cells assemble internal structures is central to cell biology. In Trypanosoma brucei, the flagellar pocket (FP) is essential for nutrient uptake, and immune evasion, and its formation depends on a cytoskeletal structure called the flagellar pocket collar (FPC). However, the mechanisms underlying FPC assembly remain poorly understood. In this study, we used cutting-edge ultrastructure expansion microscopy (U-ExM) to investigate FPC biogenesis in T. brucei. We mapped the formation of the proximal part of the new microtubule quartet (nMtQ) alongside flagellum growth, providing new insights into its assembly. Additionally, we tracked the localization dynamics of key structural proteins—BILBO1, MORN1, and BILBO2—during the biogenesis of the FPC and the hook complex (HC). Notably, we identified two previously undetected structures: the proFPC and the transient FPC-interconnecting fiber (FPC-IF), both of which appear to play crucial roles in linking and organizing cellular components during cell division. By uncovering these novel aspects of FPC biogenesis, our study significantly advances the understanding of cytoskeletal organization in trypanosomes and opens new avenues for exploring the functional significance of these structures.
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Temperature is the key weather determinant of Aedes albopictus seasonal activity in southern France bioRxivpreprint
Temperature is the key weather determinant of Aedes albopictus seasonal activity in southern France
The presence and the activity of Aedes albopictus are a growing concern for nuisance and public health in Europe. Vector control operators, public health officers, and communities look for weather-based decision support systems to inform mosquito management policies. Despite an increasing number of entomological and modelling studies, our incomplete understanding of mosquito population response to weather drivers in natural conditions restricts the development of sound vector management policies. Here, we aim to clarify the role of weather conditions on Ae. albopictus presence and abundance in four sites in southwestern France. We rely on ovitrap longitudinal records collected on a 1-2 weeks basis and weather time series over 2023 and 2024 to model oviposition activity. Our analysis combines a mechanistic model from literature and a new machine learning model fitted on cross-correlated lagged weather predictors. Both models satisfactorily reproduce the observed oviposition dynamics, correctly predicting the onset and the end of the activity - periods that existing models have often inadequately captured. Temperature plays a major role in triggering the presence of Ae. albopictus, explaining the interannual variation of oviposition in all sites, especially in spring and autumn. In fact, warm springs and autumns extend the periods in which Ae. albopictus life-history traits (fertility, development, survival) approach their thermal optima. In summer, a more prominent role of rain and humidity emerges among secondary drivers of oviposition intensity. This work contributes to the development of operational weather-driven forecasting tools for Ae. albopictus activity to support vector control operations in different biogeographical contexts.
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Pathogens, Vol. 14, Pages 1034: Application of Machine Learning Algorithms in Urinary Tract Infections Diagnosis Based on Non-Microbiological Parameters Pathogens
Pathogens, Vol. 14, Pages 1034: Application of Machine Learning Algorithms in Urinary Tract Infections Diagnosis Based on Non-Microbiological Parameters
Urinary tract infections (UTIs) are among the most common pathologies, with a high incidence in women and hospitalized patients. Their diagnosis is based on the presence of clinical symptoms and signs in addition to the detection of microorganisms in urine trough urine cultures, a time-consuming and resource-intensive test. The goal was to optimize UTI detection through artificial intelligence (machine learning) using non-microbiological laboratory parameters, thereby reducing unnecessary cultures and expediting diagnosis. A total of 4283 urine cultures from patients with suspected UTIs were analyzed in the Microbiology Laboratory of the University Hospital Virgen de las Nieves (Granada, Spain) between 2016 and 2020. Various machine learning algorithms were applied to predict positive urine cultures and the type of isolated microorganism. Random Forest demonstrated the best performance, achieving an accuracy (percentage of correct positive and negative classifications) of 82.2% and an area under the ROC curve of 87.1%. Moreover, the Tree algorithm successfully predicted the presence of Gram-negative bacilli in urine cultures with an accuracy of 79.0%. Among the most relevant predictive variables were the presence of leukocytes and nitrites in the urine dipstick test, along with elevated white cells count, monocyte count, lymphocyte percentage in blood and creatinine levels. The integration of AI algorithms and non-microbiological parameters within the diagnostic and management pathways of UTI holds considerable promise. However, further validation with clinical data is required for integration into hospital practice.
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A de novo reference genome of the golden jackal, Canis aureus bioRxivpreprint
A de novo reference genome of the golden jackal, Canis aureus
The golden jackal (Canis aureus) is rapidly expanding its range in Europe, driven by climate and habitat changes, human influence, and changes in competition with wolves. Its ecological flexibility enables it to thrive in various habitats, including urban areas, raising concerns about its potential role in spreading zoonotic diseases. Jackals may act as reservoirs for pathogens such as Lyme disease and babesiosis, affecting wildlife, humans, and pets. Their close genetic relationship with domestic dogs also increases the risk of hybridization and host-jumping, complicating disease dynamics. To better understand their dispersal ability and host-pathogen dynamics, we present the first chromosome-level genome assembly of the golden jackal, generated using PacBio HiFi sequencing and reference-based scaffolding. The final assembly has a total length of 2.53 Gb in 325 scaffolds, with 98.41% of the sequence anchored to the expected 38+XY chromosomes. The assembly shows high contiguity, with scaffold and contig N50 values of 68.03 Mb and 56.64 Mb, respectively. Annotation revealed 26,084 protein-coding genes, and repetitive elements account for 40.58% of the total assembly. This high-quality reference genome provides an essential resource for studying the genetic basis of the golden jackal's adaptation, ecological interactions, and potential as a zoonotic reservoir. It also supports efforts to monitor population expansion and its effects on ecosystems. By advancing our understanding of golden jackal genetics, this work enables future research on evolution, host-pathogen dynamics, and the broader consequences of wildlife dispersal in a rapidly changing environment.
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Pathogens, Vol. 14, Pages 1025: Climate and the Parasite Paradox: Tick–Host Networks Depend on Gradients of Environmental Overlap Pathogens
Pathogens, Vol. 14, Pages 1025: Climate and the Parasite Paradox: Tick–Host Networks Depend on Gradients of Environmental Overlap
This study investigates how climate gradients shape tick–host associations, testing the hypothesis that variations in climate leverage some associations, which can be ecosystem-specific. To test this hypothesis, we modelled tick–host associations across the Western Palearctic using climatic variables and a large dataset of georeferenced tick (seven species, n = 23,462) and vertebrate host records (n = 6.5 million across 162 species aggregated into 50 genera). Niche overlap with hosts is highly variable but consistently significant (p < 0.05) in every tested ecosystem of the target territory. Montane grasslands exhibit the lowest values of tick–host niche overlap, meaning that they support the smallest but still resilient set of available hosts. Host phylogenetic diversity (PD) depends on the ecosystem rather than tick species; PD is lowest in montane grasslands (supporting previous results) and in the case of D. reticulatus in savannas and scrubland. Nestedness of tick–host networks, known to be related to the resilience of parasite–host networks, is highest in climatically extreme ecosystems, reflecting adaptability of tick–host networks, as measured by niche overlap on modelled distribution. Multidimensional scaling confirms that host community composition and niche overlap vary significantly across ecosystems, supporting the hypothesis of host rewiring under diverse climatic conditions. These findings may have important implications for the concept of community composition and the circulation of tick-borne pathogens.
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