The microbiota of moon snail egg collars is shaped by host-specific factors.

Moon snails (Family: Naticidae) lay eggs using a mixture of mucus and sediment to form an egg mass commonly referred to as an egg collar. These egg collars do not appear to experience micro-biofouling or predation, and this observation led us to hypothesize that the egg collars possess a chemically rich microbiota that protect the egg collars from pathogens. Herein, we sought to gain an understanding of the bacterial composition of egg collars laid by a single species of moon snails, Neverita delessertiana, by amplifying and sequencing the 16S rRNA gene from the egg collar and sediment samples collected at four distinct geographical regions in southwest Florida. Relative abundance and non-metric multidimensional scaling plots revealed distinct differences in the bacterial composition between the egg collar and sediment samples. In addition, the egg collars had a lower α-diversity than the sediment, with specific genera being significantly enriched in the egg collars. Analysis of microorganisms consistent across two seasons suggests that Flavobacteriaceae make up a large portion of the core microbiota (36%-58% of 16S sequences). We also investigated the natural product potential of the egg collar microbiota by sequencing a core biosynthetic gene, the adenylation domains (ADs), within the gene clusters of non-ribosomal peptide synthetase (NRPS). AD sequences matched multiple modules within known NRPS gene clusters, suggesting that these compounds might be produced within the egg collar system. This study lays the foundation for future studies into the ecological role of the moon snail egg collar microbiota.IMPORTANCEAnimals commonly partner with microorganisms to accomplish essential tasks, including chemically defending the animal host from predation and/or infections. Understanding animal-microbe partnerships and the molecules used by the microbe to defend the animals from pathogens or predation has the potential to lead to new pharmaceutical agents. However, very few of these systems have been investigated. A particularly interesting system is nutrient-rich marine egg collars, which often lack visible protections, and are hypothesized to harbor beneficial microbes that protect the eggs. In this study, we gained an understanding of the bacterial strains that form the core microbiota of moon snail egg collars and gained a preliminary understanding of their natural product potential. This work lays the foundation for future work to understand the ecological role of the core microbiota and to study the molecules involved in chemically defending the moon snail eggs.

Free Vascularized Scapula tip Flap to L5-S1 Vertebral Defect After Chronic Infection Related to Interbody Fusion Cage: A Case Report.

Septic nonunion after vertebral fusion can lead to significant patient disability. The management of septic nonunions usually involves surgical debridement, bone fixation, and antibiotic therapy. Particularly challenging is lumbosacral vertebral nonunions, which necessitate a difficult surgical approach. We present a novel approach using a scapula tip free flap through an intra-abdominal approach to reconstruct a L5-S1 vertebral defect after a septic nonunion. Our patient, 31-year-old man, with no medical conditions, had a fusion of L5-S1 due to severe lower back pain secondary to isthmic spondylolysis and spondylolisthesis. Despite multiple attempts of surgical fusion, postoperatively the patient developed a septic nonunion. Following a modified DAIR, the nonunion was reconstructed with a scapula tip bone flap 4 × 3 × 2 cm. The subscapular vessels were anastomosed to the deep inferior epigastric vessels after an intra-abdominal inset. The patient was discharged at 15 days postoperatively without any complications. At 1-year follow-up the patient is pain-free, off opiate analgesia with radiological evidence of fusion between the scapula tip, L5 and the S1 vertebral body. This case report describes the use, for the first time, of a free scapula tip, to a lumbosacral spinal defect. The use of the free scapula tip flap may be considered for reconstruction of osseous spinal defects due to its long pedicle and the unique bone shape.

Tips to Virtually Plan Your Free Scapula Flap.

The use of virtual surgical planning (VSP) and computer-aided design and manufacturing to assist in osseous reconstruction has become the standard of care in head and neck reconstruction. The use of the free fibula flap with VSP remains the most common flap for osseous reconstruction, and as such, it is well described in the published literature. The scapular free flap (SFF) based on the angular branch has not yet garnered the same attention. The popularity of the SFF osseus head and neck reconstruction is increasing due to the flaps' inherently different properties and indications it can fulfill; the natural curvature of the bone, the reduced incidence of atheroscelerosis in the donor vessels and the earlier postoperative mobilization of the patient. In the preoperative planning process, the SFF presents several unique challenges and considerations that differ from the free fibula flap. It is important for surgeons already using, or considering using the SFF, that VSP is used correctly to achieve optimal outcomes. The authors aim to describe and clarify aspects of VSP use in SFF reconstruction in the head and neck area with a specific focus on: (1) The perforator-like vascular anatomy of the scapula; (2) How to maximize the shape of the scapula to minimize osteotomies; (3) Fine-tuning of scapula osteotomies on side table; (4) How to plan cutting guide placement and fit on the scapula. The authors hope that this article will help reconstructive microsurgeons plan and perform the SFF in conjunction with VSP.

Latent infection of an active giant endogenous virus in a unicellular green alga.

Latency is a common strategy in a wide range of viral lineages, but its prevalence in giant viruses remains unknown. Here we describe the activity and viral production from a 617 kbp integrated giant viral element in the model green alga Chlamydomonas reinhardtii. We resolve the integrated viral region using long-read sequencing and show that viral particles are produced and released in otherwise healthy cultures. A diverse array of viral-encoded selfish genetic elements are expressed during GEVE reactivation and produce proteins that are packaged in virions. In addition, we show that field isolates of Chlamydomonas sp. harbor latent giant viruses related to the C. reinhardtii GEVE that exhibit similar infection dynamics, demonstrating that giant virus latency is prevalent in natural host communities. Our work reports the largest temperate virus documented to date and the first active GEVE identified in a unicellular eukaryote, substantially expanding the known limits of viral latency.

Genomic analysis of hyperparasitic viruses associated with entomopoxviruses.

Polinton-like viruses (PLVs) are a diverse group of small integrative dsDNA viruses that infect diverse eukaryotic hosts. Many PLVs are hypothesized to parasitize viruses in the phylum Nucleocytoviricota for their own propagation and spread. Here, we analyze the genomes of novel PLVs associated with the occlusion bodies of entomopoxvirus (EPV) infections of two separate lepidopteran hosts. The presence of these elements within EPV occlusion bodies suggests that they are the first known hyperparasites of poxviruses. We find that these PLVs belong to two distinct lineages that are highly diverged from known PLVs. These PLVs possess mosaic genomes, and some essential genes share homology with mobile genes within EPVs. Based on this homology and observed PLV mosaicism, we propose a mechanism to explain the turnover of PLV replication and integration genes.

The Interruption of Transmission of Onchocerciasis in Abia, Anambra, Enugu, and Imo States, Nigeria: The Largest Global Onchocerciasis Stop-Treatment Decision to Date.

Onchocerciasis causes severe morbidity in sub-Saharan Africa. Abia, Anambra, Enugu, and Imo states of Nigeria were historically classified meso- or hyperendemic and eligible for ivermectin mass drug administration (MDA). After ≥25 years of annual and biannual MDA, serological and entomological assessments were conducted to determine if Onchocerca volvulus transmission was interrupted. Dried blood spots collected in October 2020 from ≥3167 children 5-9 years old in each state were screened for O. volvulus-specific Ov16 antibody by enzyme-linked immunosorbent assay. Additionally, 52,187 Simulium damnosum heads (≥8845 per state) collected over 12 months between 2021 and 2022 were tested by pooled polymerase chain reaction (PCR) for O-150 DNA. Among seven seropositive children, four were found for follow-up skin snip PCR to confirm active infection. Three were negative and the fourth was excluded as he was visiting from an endemic state. The final seroprevalence estimates of each state had 95% upper confidence limits (UCL) < 0.1%. All fly pools were negative by O-150 PCR, giving a 95% UCL infective fly prevalence < 0.05% in each state. Each state therefore met the World Health Organization epidemiological and entomological criteria for stopping MDA effective January 2023. With 18.9 million residents eligible for MDA, this marked the largest global onchocerciasis stop-treatment decision to date.

The Microbiota of Moon Snail Egg Collars is Shaped by Host-Specific Factors.

Moon Snails lay eggs using a mixture of mucus and sediment to form an egg mass commonly referred to as an egg collar. These collars do not appear to experience micro-biofouling or predation and this observation led us to hypothesize that the egg collars possess a chemically-rich microbiota that protect the egg collars from pathogens. Herein, we sought to gain an understanding of the bacterial composition of the egg collars by amplifying and sequencing the 16S rRNA gene from egg collar and sediment samples collected at four distinct geographical regions in SW Florida. Relative abundance and non-metric multidimensional scaling plots revealed distinct differences in the bacterial composition between the egg collar and sediment samples. In addition, the egg collars had a lower α-diversity than the sediment, with specific genera being significantly enriched in the egg collars. Analysis of microorganisms consistent across two seasons suggests that Flavobacteriaceae make up a large portion of the core microbiota (36 - 58% of 16S sequences). We also investigated the natural product potential of the egg collar microbiota by sequencing a core biosynthetic gene, the adenylation domains (AD), within the gene clusters of non-ribosomal peptide synthetase (NRPS). AD sequences matched multiple modules within known bioactive NRPs biosynthetic gene clusters, suggesting production is possible within the egg collar system and lays the foundation for future studies into the chemical and ecological role of this microbiota.

Motion Artifact Detection for T1-Weighted Brain MR Images Using Convolutional Neural Networks.

Quality assessment (QA) of magnetic resonance imaging (MRI) encompasses several factors such as noise, contrast, homogeneity, and imaging artifacts. Quality evaluation is often not standardized and relies on the expertise, and vigilance of the personnel, posing limitations especially with large datasets. Machine learning based on convolutional neural networks (CNNs) is a promising approach to address these challenges by performing automated inspection of MR images. In this study, a CNN for the detection of random head motion artifacts (RHM) in T1-weighted MRI as one aspect of image quality is proposed. A two-step approach aimed to first identify images exhibiting pronounced motion artifacts, and second to evaluate the feasibility of a more detailed three-class classification. The utilized dataset consisted of 420 T1-weighted whole-brain image volumes with isotropic resolution. Human experts assigned each volume to one of three classes of artifact prominence. Results demonstrate an accuracy of 95% for the identification of images with pronounced artifact load. The addition of an intermediate class retained an accuracy of 76%. The findings highlight the potential of CNN-based approaches to increase the efficiency of post-hoc QAs in large datasets by flagging images with potentially relevant artifact loads for closer inspection.

Do Residents Believe that Onchocerciasis Transmission Was Eliminated? Results of A Post-Treatment Surveillance Knowledge, Attitude, and Practices Survey in Three Foci of Uganda.

In Uganda, 15 of 17 foci have interrupted transmission of onchocerciasis (river blindness) and stopped mass drug administration (MDA) of ivermectin. This 2016 study describes the results of a knowledge, attitude, and practices survey regarding river blindness among participants (N = 1,577) 3-5 years after ivermectin MDA was halted in three foci: Imaramagambo halted in 2012, Kashoya-Kitomi in 2013, and Mt. Elgon in 2011. The study showed high levels of composite knowledge (focus-specific range: 66.8-81.2%) related to river blindness transmission, signs, symptoms, and treatment. However, 38.1% of respondents did not know that blackflies transmitted river blindness. Notably, 72.2% claimed they had not been informed why MDA was stopped, 56.3% did not believe river blindness had been eliminated, and 83.1% wanted ivermectin MDA to resume. During the 3-5 year post-treatment surveillance period, only 27.7% (438 of 1,577) reported being informed of what to do once treatments stopped, with the most knowledgeable hailing from the Mt. Elgon focus (47.9%). This study reinforces the need for programs to intensify health education and information dissemination when MDA is stopped. Programs must remind residents that although biting insects may persist, they no longer transmit river blindness. Incorporating messages about the elimination of river blindness into community health education campaigns can help improve the community's perceptions related to the disease's absence and the ending of a long-standing MDA intervention.

Single-cell RNA-seq of the rare virosphere reveals the native hosts of giant viruses in the marine environment.

Giant viruses (phylum Nucleocytoviricota) are globally distributed in aquatic ecosystems. They play fundamental roles as evolutionary drivers of eukaryotic plankton and regulators of global biogeochemical cycles. However, we lack knowledge about their native hosts, hindering our understanding of their life cycle and ecological importance. In the present study, we applied a single-cell RNA sequencing (scRNA-seq) approach to samples collected during an induced algal bloom, which enabled pairing active giant viruses with their native protist hosts. We detected hundreds of single cells from multiple host lineages infected by diverse giant viruses. These host cells included members of the algal groups Chrysophycae and Prymnesiophycae, as well as heterotrophic flagellates in the class Katablepharidaceae. Katablepharids were infected with a rare Imitervirales-07 giant virus lineage expressing a large repertoire of cell-fate regulation genes. Analysis of the temporal dynamics of these host-virus interactions revealed an important role for the Imitervirales-07 in controlling the population size of the host Katablepharid population. Our results demonstrate that scRNA-seq can be used to identify previously undescribed host-virus interactions and study their ecological importance and impact.

Synchronous retreat of Thwaites and Pine Island glaciers in response to external forcings in the presatellite era.

Today, relatively warm Circumpolar Deep Water is melting Thwaites Glacier at the base of its ice shelf and at the grounding zone, contributing to significant ice retreat. Accelerating ice loss has been observed since the 1970s; however, it is unclear when this phase of significant melting initiated. We analyzed the marine sedimentary record to reconstruct Thwaites Glacier's history from the early Holocene to present. Marine geophysical surveys were carried out along the floating ice-shelf margin to identify core locations from various geomorphic settings. We use sedimentological data and physical properties to define sedimentary facies at seven core sites. Glaciomarine sediment deposits reveal that the grounded ice in the Amundsen Sea Embayment had already retreated to within ~45 km of the modern grounding zone prior to ca. 9,400 y ago. Sediments deposited within the past 100+ y record abrupt changes in environmental conditions. On seafloor highs, these shifts document ice-shelf thinning initiating at least as early as the 1940s. Sediments recovered from deep basins reflect a transition from ice proximal to slightly more distal conditions, suggesting ongoing grounding-zone retreat since the 1950s. The timing of ice-shelf unpinning from the seafloor for Thwaites Glacier coincides with similar records from neighboring Pine Island Glacier. Our work provides robust new evidence that glacier retreat in the Amundsen Sea was initiated in the mid-twentieth century, likely associated with climate variability.

Prophylactic tranexamic acid for reducing intraoperative blood loss during cesarean section in women at high risk of postpartum hemorrhage: A double-blind placebo randomized controlled trial.

BACKGROUND: Postpartum hemorrhage remains a leading cause of maternal mortality especially in developing countries. The majority of previous trials on the effectiveness of tranexamic acid in reducing blood loss were performed in low-risk women for postpartum hemorrhage. A recent Cochrane Systematic Review recommended that further research was needed to determine the effects of prophylactic tranexamic acid for preventing intraoperative blood loss in women at high risk of postpartum hemorrhage. OBJECTIVE: This study aimed to evaluate the effectiveness and safety of tranexamic acid in reducing intraoperative blood loss when given prior to cesarean delivery in women at high risk of postpartum hemorrhage. STUDY DESIGN: The study is a double-blind randomized controlled trial. METHODS: The study consisted of 200 term pregnant women and high-risk preterm pregnancies scheduled for lower-segment cesarean delivery at Enugu State University of Science and Technology, Teaching Hospital, Parklane, Enugu, Nigeria. The participants were randomized into two arms (intravenous 1 g of tranexamic acid or placebo) in a ratio of 1:1. The participants received either 1 g of tranexamic acid or placebo (20 mL of normal saline) intravenously at least 10 min prior to commencement of the surgery. The primary outcome measures were the mean intraoperative blood loss and hematocrit change 48 h postoperatively. RESULTS: The baseline sociodemographic characteristics were similar in both groups. The tranexamic acid group when compared to the placebo group showed significantly lower mean blood loss (442.94 ± 200.97 versus 801.28 ± 258.68 mL; p = 0.001), higher mean postoperative hemoglobin (10.39 + 0.96 versus 9.67 ± 0.86 g/dL; p = 0.001), lower incidence of postpartum hemorrhage (1.0% versus 19.0%; p = 0.001), and lower need for use of additional uterotonic agents after routine management of the third stage of labor (39.0% versus 68.0%; p = 0.001), respectively. However, there was no significant difference in the mean preoperative hemoglobin (11.24 ± 0.88 versus 11.15 ± 0.90 g/dL; p = 0.457), need for other surgical intervention for postpartum hemorrhage (p > 0.05), and reported side effect, respectively, between the two groups. CONCLUSION: Prophylactic administration of tranexamic acid significantly decreases postpartum blood loss, improves postpartum hemoglobin, decreases the need for additional uterotonics, and prevents postpartum hemorrhage following cesarean section in pregnant women at high risk of postpartum hemorrhage. Its routine use during cesarean section in high-risk women may be encouraged.The trial was registered in the Pan-African Clinical Trial Registry with approval number PACTR202107872851363.

Gene duplication as a major force driving the genome expansion in some giant viruses.

IMPORTANCE: Giant viruses are noteworthy not only due to their enormous particles but also because of their gigantic genomes. In this context, a fundamental question has persisted: how did these genomes evolve? Here we present the discovery of cedratvirus pambiensis, featuring the largest genome ever described for a cedratvirus. Our data suggest that the larger size of the genome can be attributed to an unprecedented number of duplicated genes. Further investigation of this phenomenon in other viruses has illuminated gene duplication as a key evolutionary mechanism driving genome expansion in diverse giant viruses. Although gene duplication has been described as a recurrent event in cellular organisms, our data highlights its potential as a pivotal event in the evolution of gigantic viral genomes.

A timeline of bacterial and archaeal diversification in the ocean.

Microbial plankton play a central role in marine biogeochemical cycles, but the timing in which abundant lineages diversified into ocean environments remains unclear. Here, we reconstructed the timeline in which major clades of bacteria and archaea colonized the ocean using a high-resolution benchmarked phylogenetic tree that allows for simultaneous and direct comparison of the ages of multiple divergent lineages. Our findings show that the diversification of the most prevalent marine clades spans throughout a period of 2.2 Ga, with most clades colonizing the ocean during the last 800 million years. The oldest clades - SAR202, SAR324, Ca. Marinimicrobia, and Marine Group II - diversified around the time of the Great Oxidation Event, during which oxygen concentration increased but remained at microaerophilic levels throughout the Mid-Proterozoic, consistent with the prevalence of some clades within these groups in oxygen minimum zones today. We found the diversification of the prevalent heterotrophic marine clades SAR11, SAR116, SAR92, SAR86, and Roseobacter as well as the Marine Group I to occur near to the Neoproterozoic Oxygenation Event (0.8-0.4 Ga). The diversification of these clades is concomitant with an overall increase of oxygen and nutrients in the ocean at this time, as well as the diversification of eukaryotic algae, consistent with the previous hypothesis that the diversification of heterotrophic bacteria is linked to the emergence of large eukaryotic phytoplankton. The youngest clades correspond to the widespread phototrophic clades Prochlorococcus, Synechococcus, and Crocosphaera, whose diversification happened after the Phanerozoic Oxidation Event (0.45-0.4 Ga), in which oxygen concentrations had already reached their modern levels in the atmosphere and the ocean. Our work clarifies the timing at which abundant lineages of bacteria and archaea colonized the ocean, thereby providing key insights into the evolutionary history of lineages that comprise the majority of prokaryotic biomass in the modern ocean.

Microbiology: The curious case of the mysterious mirusvirus.

Long-read sequencing of a marine stramenopile genome yields a trove of insights into protist genomics and solves a 50-year-old viral mystery.

Contrasting drivers of abundant phage and prokaryotic communities revealed in diverse coastal ecosystems.

Phages (viruses of bacteria and archaea) are a ubiquitous top-down control on microbial communities by selectively infecting and killing cells. As obligate parasites, phages are inherently linked to processes that impact their hosts' distribution and physiology, but phages can also be impacted by external, environmental factors, such as UV radiation degrading their virions. To better understand these complex links of phages to their hosts and the environment, we leverage the unique ecological context of the Isthmus of Panama, which narrowly disconnects the productive Tropical Eastern Pacific (EP) and nutrient-poor Tropical Western Atlantic (WA) provinces. We could thus compare patterns of phage and prokaryotic communities at both global scales (between oceans) and local-scales (between habitats within an ocean). Although both phage and prokaryotic communities differed sharply between the oceans, phage community composition did not significantly differ between mangroves and reefs of the WA, while prokaryotic communities were distinct. These results suggest phages are more shaped by dispersal processes than local conditions regardless of spatial scale, while prokaryotes tend to be shaped by local conditions at smaller spatial scales. Collectively, we provide a framework for addressing the co-variability between phages and prokaryotes in marine systems and identifying factors that drive consistent versus disparate trends in community shifts, essential to informing models of biogeochemical cycles that include these interactions.

Kratosvirus quantuckense: the history and novelty of an algal bloom disrupting virus and a model for giant virus research.

Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through Acanthamoeba spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the Nucleocytoviricota, environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal Nucleocytoviricota should be considered a focal point in viral ecology. In this review, we report on Kratosvirus quantuckense (née Aureococcus anophagefferens Virus), an algae-infecting virus of the Imitervirales. Current systems for study in the Nucleocytoviricota differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of K. quantuckense. Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.

Automated classification of giant virus genomes using a random forest model built on trademark protein families.

Viruses of the phylum Nucleocytoviricota, often referred to as "giant viruses," are prevalent in various environments around the globe and play significant roles in shaping eukaryotic diversity and activities in global ecosystems. Given the extensive phylogenetic diversity within this viral group and the highly complex composition of their genomes, taxonomic classification of giant viruses, particularly incomplete metagenome-assembled genomes (MAGs) can present a considerable challenge. Here we developed TIGTOG (Taxonomic Information of Giant viruses using Trademark Orthologous Groups), a machine learning-based approach to predict the taxonomic classification of novel giant virus MAGs based on profiles of protein family content. We applied a random forest algorithm to a training set of 1,531 quality-checked, phylogenetically diverse Nucleocytoviricota genomes using pre-selected sets of giant virus orthologous groups (GVOGs). The classification models were predictive of viral taxonomic assignments with a cross-validation accuracy of 99.6% to the order level and 97.3% to the family level. We found that no individual GVOGs or genome features significantly influenced the algorithm's performance or the models' predictions, indicating that classification predictions were based on a comprehensive genomic signature, which reduced the necessity of a fixed set of marker genes for taxonomic assigning purposes. Our classification models were validated with an independent test set of 823 giant virus genomes with varied genomic completeness and taxonomy and demonstrated an accuracy of 98.6% and 95.9% to the order and family level, respectively. Our results indicate that protein family profiles can be used to accurately classify large DNA viruses at different taxonomic levels and provide a fast and accurate method for the classification of giant viruses. This approach could easily be adapted to other viral groups.

Simulated inventory and distribution of 137Cs released from multiple sources in the global ocean.

Radioactive cesium (137Cs) is distributed in the world's oceans as a result of global fallout from atmospheric nuclear weapons tests, releases from fuel reprocessing plants, and inputs from nuclear power plant accident. In order to detect future radionuclide contamination, it is necessary to establish a baseline global distribution of radionuclides such as 137Cs and to understand the ocean transport processes that lead to that distribution. In order to aid in the interpretation of the observed database, we have conducted a suite of simulations of the distribution of 137Cs using a global ocean general circulation model (OGCM). Simulated 137Cs radioactivity concentrations agree well with observations, and the results were used to estimate the changes in inventories for each ocean basin. 137Cs activity concentration from atmospheric nuclear weapons tests are expected to be detectable in the world ocean until at least 2030.