Single Host Research Articles

Involvement of the SIX10 Gene in the Pathogenicity of Fusarium oxysporum Formae Speciales in Strawberries

Strawberries are planted globally as an important crop. Fusarium oxysporum f. sp. fragariae (Fof), a haploid mitosporic, pathogenic fungus with obvious host specificity, is responsible for an economically devastating soil-borne disease seriously threatening strawberry. Fusarium oxysporum is distributed in soils worldwide and causes vascular wilt and root rot disease in over 100 plant species. However, the formae speciales of F. oxysporum commonly have a very narrow host range, often restricted to a single host plant species. We isolated and identified pathogenic F. oxysporum from diseased strawberry samples collected from different provinces in China. Further analysis showed that among the 55 F. oxysporum isolates, only 70.91% belonged to Fof, and the remaining 29.09% were named Fo. The mycelial growth of Fof was faster than that of Fo at 20, 30, and 35 °C. The sporulation ability of Fof was weaker than that of Fo, and Fof presented a significantly higher germination rate under high temperatures. Fof and Fo from strawberry were not pathogenic to tomato or cucumber plants, and Fof showed significantly higher pathogenicity on strawberry than Fo. To explore the pathogenic mechanism of Fof, we knocked out SIX10 in Fof. The mycelial growth rate of ΔFofSIX10 was significantly slower than that of the wild type, but there were no significant differences in spore production. The pathogenicity of ΔFofSIX10 to strawberry was significantly weakened, showing decreased severity of symptoms, indicated by root and crown rot, and wilt. Our research provides a basis for understanding the interaction between F. oxysporum and the host strawberry and the occurrence and management of Fusarium disease on strawberry.

A new method for detecting mixed Mycobacterium tuberculosis infection and reconstructing constituent strains provides insights into transmission

BackgroundMixed infection with multiple strains of the same pathogen in a single host can present clinical and analytical challenges. Whole genome sequence (WGS) data can identify signals of multiple strains in samples, though the precision of previous methods can be improved. Here, we present MixInfect2, a new tool to accurately detect mixed samples from Mycobacterium tuberculosis short-read WGS data. We then evaluate three approaches for reconstructing the underlying mixed constituent strain sequences. This allows these samples to be included in downstream analysis to gain insights into the epidemiology and transmission of mixed infections.MethodsWe employed a Gaussian mixture model to cluster allele frequencies at mixed sites (hSNPs) in each sample to identify signals of multiple strains. Building upon our previous tool, MixInfect, we increased the accuracy of classifying in vitro mixed samples through multiple improvements to the bioinformatic pipeline. Major and minor proportion constituent strains were reconstructed using three approaches and assessed by comparing the estimated sequence to the known constituent strain sequence. Lastly, mixed infections in a real-world Mycobacterium tuberculosis population from Moldova were detected with MixInfect2 and clusters of recent transmission that included major and minor constituent strains were built.ResultsAll 36/36 in vitro mixed and 12/12 non-mixed samples were correctly classified with MixInfect2, and major strain proportions were estimated with high accuracy (within 3% of the true strain proportion), outperforming previous tools. Reconstructed major strain sequences closely matched the true constituent sequence by taking the allele at the highest frequency at hSNPs, while the best-performing approach to reconstruct the minor proportion strain sequence was identifying the closest non-mixed isolate in the same population, though no approach was effective when the minor strain proportion was at 5%. Finally, fewer mixed infections were identified in Moldova than previous estimates (6.6% vs 17.4%) and we found multiple instances where the constituent strains of mixed samples were present in transmission clusters.ConclusionsMixInfect2 accurately detects samples with evidence of mixed infection from short-read WGS data and provides an excellent estimate of the mixture proportions. While there are limitations in reconstructing the constituent strain sequences of mixed samples, we present recommendations for the best approach to include these isolates in further analyses.

A phylogenetic epidemiology approach to predicting the establishment of multi-host plant pests

Forecasting emergent pest spread is paramount to mitigating their impacts. For host-specialized pests, epidemiological models of spread through a single host population are well developed. However, most pests attack multiple host species; the challenge is predicting which communities are most vulnerable to infestation. Here, we develop a phylogenetically-informed approach to predict establishment of emergent multi-host pests across heterogeneous landscapes. We model a beetle-pathogen symbiotic complex on trees, introduced from Southeast Asia to California. The phyloEpi model for likelihood of establishment was predicted from the phylogenetic composition of woody species in the invaded community and the influence of temperature on beetle reproduction. Plant communities dominated by close relatives of known epidemiologically critical hosts were four times more likely to become infested than communities with more distantly related species. Where microclimate favored beetle reproduction, pest establishment was greater than expected based only on species composition. We applied this phyloEpi model to predict infestation risk in California using weather data and complete tree inventories from 9262 1-km2 grids in 170 cities. Regions in the state predicted with low likelihood of infestation were confirmed by independent monitoring. Analysts can adapt these phylogenetic ecology tools to predict spread of any multi-host pest in novel habitats.

Extensive transcriptional differentiation and specialization of a single-host parasite aligns with niche turnover generated by its host's metamorphosis.

Foundational theory on life cycle evolution suggests that given genetic independence, the phenotypes presented by different life stages will diverge more when they occupy more distinct niches. When divergence between stages is significant and punctual, we typically consider the life cycle complex. In parasites, the delineation between simple and complex life cycles is usually made between those that utilize single and multiple host species. However, many parasites can experience significant niche shifts in a single host. To explore the potential for a host's metamorphosis to shape divergence between stages across its parasite's life cycle, we quantified the transcriptional differentiation and specialization that the protozoan parasite Ophryocystis elektroscirrha exhibits across the metamorphosis of its host, the monarch butterfly. We found evidence that O. elektroscirrha differentiates in concordance with the ecological turnover imposed by monarch transitions to different stages, and that patterns of transcriptional decoupling across O. elektroscirrha exceeded even those of its host. However, due to its greater gene content, the monarch butterfly exhibited greater total transcriptional turnover than its parasite. These findings suggest that a deeper understanding of life cycle evolution for both free-living and parasitic lifestyles may be facilitated by more nuanced and continuous descriptions of life cycle complexity.

Complex species structure of Lecithaster salmonis (Digenea: Lecithasteridae), a fish parasite in the Arctic and Pacific Northwest.

Studying complexes of cryptic or pseudocryptic species opens new horizons for the understanding of speciation processes, an important yet vague issue for the digeneans. We investigated a hemiuroidean trematode Lecithaster salmonis across a wide geographic range including the northern European seas (White, Barents, and Pechora), East Siberian Sea, and the Pacific Northwest (Sea of Okhotsk and Sea of Japan). The goals were to explore the genetic diversity within L. salmonis through mitochondrial (cox1 and nad5 genes) and ribosomal (ITS1, ITS2, 28S rDNA) marker sequences, to study morphometry of maritae, and to revise the life cycle data. Mitochondrial markers showed that L. salmonis is likely divided into six lineages (referred to as operational taxonomic units, OTUs), which often occur in sympatry, sometimes in a single host specimen. Variation in rDNA was not consistent with that in the mitochondrial markers. Morphometric analysis of maritae was performed for four out of six OTUs; it showed that some OTUs had significant differences from the others, but some did not. The effect of host species on the morphometric characteristics cannot be excluded. Intramolluscan stages were identified for two OTUs; they differed clearly by the structure of cercariae and also by the species of the first intermediate host. The case of L. salmonis is instructive in how different criteria for species delimitation can contradict each other. We regard this as a sign of recent or ongoing speciation and suggest using the name Lecithaster cf. salmonis. The most promising criteria to differentiate genetic lineages within L. cf. salmonis are first intermediate hosts and morphological characteristics of the cercariae: shape of the delivery tube and caudal cyst, and length of the filamentous appendage.

Caenorhabditis nematodes influence microbiome and metabolome characteristics of their natural apple substrates over time.

The microbiomes of host organisms and their direct source environments are closely linked and key for shaping microbial community dynamics. The relationship between these linked dynamics is largely unexplored because source substrates are usually unavailable. To address this current knowledge gap, we employed bacteriovorous Caenorhabditis nematodes as a unique model system, for which source substrates like rotting apples can be easily collected. We compared single host microbiomes with their corresponding apple source substrates, as well as nematode-free substrates, over a 2-year sampling period in the botanical garden in Kiel, Germany. We found that single worms have unique microbiomes, which overlap most strongly with nematodes from the same source apple. A comparison to previous, related work revealed that variation in microbiome composition of natural Caenorhabditis isolates is significantly influenced by the substrate type, from which worms were obtained (e.g., fruits or compost). Our current sampling further showed that microbiome assembly is mostly driven by dispersal limitation. Importantly, two independent analysis approaches consistently suggest that worm microbiomes significantly influence characteristics of the apple microbiomes, possibly indicating niche construction by nematodes. Moreover, combining apple microbiome and metabolome data, we identified individual microbes and specific compounds indicative of fruit ripening that are significantly associated with nematode presence. In conclusion, our study elucidates the complex relationship between host microbiomes and their directly connected substrate microbiomes. Our analyses underscore the significant influence of nematode microbiomes on shaping the apple microbiome and, consequently, the fruit's metabolic capacity, thereby enhancing our general understanding of host-microbiome interactions in their natural habitat.IMPORTANCEAlmost all complex organisms are host to a microbial community, the microbiome. This microbiome can influence diverse host functions, such as food processing, protection against parasites, or development. The relationship between host and microbiome critically depends on the assembly of the microbial community, which may be shaped by microbes in the directly linked environment, the source microbiome. This assembly process is often not well understood because of the unavailability of source substrates. Here, we used Caenorhabditis nematodes as a model system that facilitates a direct comparison of host and source microbiomes. Based on a 2-year sampling period, we identified (i) a clear link between assembly dynamics of host and source microbiomes, (ii) a significant influence of nematode microbiomes on apple microbiomes, and (iii) specific microbes and compounds that are associated with the presence of nematodes in the sampled substrates. Overall, our study enhances our understanding of microbiome assembly dynamics and resulting functions.

Exploring the Metal Composition of Eri Silkworm Cocoons Reared on Diverse Host Plant Combinations

Background: The objective of this study was to analyze the chemical composition of Eri silk cocoons that were reared on various combinations of host plants. The primary host plant castor and secondary host plants such as kesseru, tapioca, gulancha and papaya were utilized in various combinations for different instars. Methods: The present analysis was conducted in lab at Department of Entomology, Institute of Agricultural Sciences, Siksha ‘O’ Anusandhan, Bhubaneswar, Odisha, India during spring season of the year 2022-23. SEM/EDX was used to investigate the cocoons metal elements. Each sample was examined separately to evaluate metal content. Conductive carbon tape attached specimens to stubs. The metal elemental analysis of the scaffold was performed by EDX attached to the scanning electron microscope. Result: For silk cocoon inner surfaces, the metal elements were ordered as follows: C greater than O greater than Mo greater than K greater than Cl greater than Ca greater than Si greater than Na greater than Mg greater than Al. Some Eri cocoons were produced on different host plants and had somewhat different exteriors, but all had evenly distributed components. C and O were abundant on all silk cocoons’ inner and outer surfaces. Cocoons produced on many host plants have higher chemical metal element levels on their exterior and interior surfaces than those raised on a single host plant. The study suggests that chemical factors have a role in silk cocooning, encouraging the creation of β-sheet structure.

Diverse phage communities are maintained stably on a clonal bacterial host.

Bacteriophages are the most abundant and phylogenetically diverse biological entities on Earth, yet the ecological mechanisms that sustain this extraordinary diversity remain unclear. In this study, we discovered that phage diversity consistently outstripped the diversity of their bacterial hosts under simple experimental conditions. We assembled and passaged dozens of diverse phage communities on a single, nonevolving strain of Escherichia coli until the phage communities reached equilibrium. In all cases, we found that two or more phage species coexisted stably, despite competition for a single, clonal host population. Phage coexistence was supported through host phenotypic heterogeneity, whereby bacterial cells adopting different growth phenotypes served as niches for different phage species. Our experiments reveal that a rich community ecology of bacteriophages can emerge on a single bacterial host.

High Defect Tolerance Breaking the Design Limitation of Full-Spectrum Multimodal Luminescence Materials.

With the development of optical anti-counterfeiting and the increasing demand for high-level information encryption, multimodal luminescence (MML) materials attract much attention. However, the discovery of these multifunctional materials is very accidental, and the versatile host suitable for developing such materials remains unclear. Here, a grossite-type fast ionic conductor CaGa4O7, characterized by layered and tunnel structure with excellent defect tolerance, is found to meet the needs of various luminescent processes. Almost all luminescent modes, including down/up-conversion luminescence (DCL/UCL), long persistent luminescence (LPL), mechanoluminescence (ML), and X-ray excited optical luminescence (XEOL), are realized in this single host. Full-spectrum (from violet to near-infrared) photoluminescence and ML as well as multicolor XEOL are achieved by simply changing the doped luminescent center. A series of anti-counterfeiting devices, including the quasi-dynamic display of famous paintings, digital information encryption, and multi-color handwritten signatures, are designed to show the encryption of information in temporal and spatial dimensions. This study clarifies the importance of defect tolerance of the host for the development of MML materials, and provides a unique insight into the cross-field applications of special functional materials, which is a new strategy to accelerate the development of novel MML materials.

Prevalence of Gastrointestinal Helminths in Domestic Chicken of Two Different Districts in Manipur, India

The aim of the research is to determine the prevalence and identification of gastrointestinal helminth parasite of the chicken based on the gut necropsy as well as to the impact of the parasite load on the health status of chicken found in different locality of Thoubal and Kakching districts of Manipur. The gut sample were collected from different chicken centre and household backyard management area located in the above two different districts. The 87 gut samples were taken from chicken centre in 14 different villages namely Heirok, Wangjing, Kairenbikhok, Khongjom, Salungpham, Tekcham, Khangabok, Yairipok Charangpat, Athokpham, Pallel, Kakching, Wabagai, Hiyanglam. The examinations taken in this study are gut examination using gut necropsy. Result showed that 52.9% samples were positive for helminthiasis infection consisting of Ascaridia sp. (45%), Raillintina sp. (41.67%), Heterakis sp. (11.67%) and Stronggylidae sp. (1.67%) out of the 14 different Location. Mixed infection with two or more parasites was common. Ascaridia sp. was found with highest prevalence of 45% and Strongylidae sp. was lowest prevalence with 1.67% out of the 14 location. The free-range management system of raising domestic chickens specially in the rural areas exposes the birds to diseases when scavenging for food. This research was embarked upon to conduct a survey on the gastrointestinal helminths that parasitize the intestinal tract of domestic chicken using the floatation method from Dec 2022 up to October 2024 in the parasitology laboratory, Department of Zoology, Dhanamanjuri University. The gastrointestinal tracts of 87 domestic chickens slaughtered in Thoubal and Kakching Districts of Manipur, India were examined for helminth parasites. A total of 87 birds were collected whereas 46 infected representing 52.9% of the study population. Four helminth parasites were encountered including Raillietina sp., Ascaridia sp., Heterakis sp. but in case of Strongylidae sp. only one from Heirok, Elangbam leikai from a local breed chicken called Kaonayen (local name). Raillietina sp. was the most abundant Cestode parasite while Ascaridia sp. was the most abundant nematode parasite recovered from the domestic chickens. In a single host of local breed chicken from Heirok khunou 9 helminth parasites were collected two nematodes and seven cestodes. Another interesting things is that from different regions of gastrointestinal tracts of a local breed 152 nematodes and 30 cestodes were found from a single host and the chicken was dead due to heavy infection of the helminth worms which was collected from Heirok laimayum leikai on 23 March 2024 which is a new findings of heavy infection. Site preferences by the parasites in the gastrointestinal tract of the birds were small intestine, large intestine and caeca. There was no statistically significant difference (p<0.05) in the infection rate between sexes.

Blood-Feeding Patterns and Resting Behavior of Aedes aegypti from Three Health Districts of Ouagadougou City, Burkina Faso.

Recent dengue outbreaks have occurred in Ouagadougou and Bobo-Dioulasso, the two major cities of Burkina Faso. Dengue is a viral disease transmitted primarily by Aedes aegypti, a highly anthropophilic mosquito that thrives in human-transformed environments and breeds predominantly in artificial containers. In 2018, we investigated the resting and blood-feeding habits of Ae. aegypti in urban settings of Ouagadougou. In a 3-month cross-sectional study starting in August 2018, indoors and outdoors resting adult mosquitoes were collected using Prokopack aspirators in three health districts (HD). All mosquitoes were morphologically identified, and DNA was extracted from blood-fed Ae. aegypti females. A multiplex polymerase chain reaction with specific primers was used to identify the origin of the blood meal. A total of 4,256 adult Ae. aegypti mosquitoes, including 1,908 females, were collected. A preference for exophily was recorded in Bogodogo and Nongremassom, although an unexpectedly higher proportion of blood-fed females were found indoors than outdoors. Respectively, 96.09%, 91.03%, and 95.54% of the blood meals successfully analyzed in Baskuy, Bogodogo, and Nongremassom were from a single human host, with the remainder from domestic mammals as single or multiple hosts. Modeling total Ae. aegypti and blood-fed female counts showed that among other predictors, human density, outdoor environment, and house type affect their total densities. Our study revealed an exophilic tendency as well as a pronounced anthropophilic preference of Ae. aegypti adults, critical findings to consider when planning accurate entomological surveillance and effective interventions against Ae. aegypti in urban settings.

The impact of simultaneous infections on phage-host ecology.

Phages use bacterial host resources to replicate, intrinsically linking phage and host survival. To understand phage dynamics, it is essential to understand phage-host ecology. A key step in this ecology is infection of bacterial hosts. Previous work has explored single and multiple, sequential infections. Here we focus on the theory of simultaneous infections, where multiple phages simultaneously attach to and infect one bacterial host cell. Simultaneous infections are a relevant infection dynamic to consider, especially at high phage densities when many phages attach to a single host cell in a short time window. For high bacterial growth rates, simultaneous infection can result in bi-stability: depending on initial conditions phages go extinct or co-exist with hosts, either at stable densities or through periodic oscillations of a stable limit cycle. This bears important consequences for phage applications such as phage therapy: phages can persist even though they cannot invade. Consequently, through spikes in phage densities it is possible to infect a bacterial population even when the phage basic reproductive number is less than one. In the regime of stable limit cycles, if timed right, only small densities of phage may be necessary.

Semi-Monolithic Multijunction Devices for Unassisted Photoelectrochemical Water Splitting

Although foundational to multi-junction (MJ) photoelectrochemical (PEC) device synthesis, monolithic integration presents major limitations in process compatibility. Consequently, conductive adhesive-based interconnection scheme emerged as a suitable method to overcome limitations and to integrate incompatible material classes into MJ devices without compromising the integrity of the constituent layers. As the conductive adhesive generally employ a polymer matrix, the conductivity of this composite material depends on the conductive filler material. Among which, a core-shell type silver coated PMMA (Ag-PMMA) conductive microsphere filler has gained significant interest in the PV and PEC community due to its ability to exhibit reliable out-of-plane electrical conductivity (0.1 Ω-cm2) and good optical transparency (T > 90%), as we demonstrate for an epoxy-based transparent conductive composite (TCC) consisting of low particle loading (0.1 - 5 vol%).By implementation of the Ag-PMMA based TCC paired with a device exfoliation method, further referred to as semi-monolithic integration, independently processed substrate-grown single junction (SJ) devices were successively bonded and transferred via exfoliation onto a single host substrate to create a MJ device. As a proof-of-concept demonstration, we constructed the world’s first whole-chalcopyrite triple junction MJ device comprising 1.13 eV and 1.44 eV Cu(In,Ga)Se2 and 1.85 eV CuGa3Se5 sub-cells, with the TCC acting as the recombination layer between each sub-cell. The device exhibited an open circuit voltage of 1.85 V and is capable of splitting water with an STH efficiency of 3% in a PV-electrolysis configuration. Furthermore, a TCC-based bifacial MJ device comprising 1.7eV perovskite and 1.1eV Cu(In,Ga)Se2 sub-cells exhibited STH efficiency exceeding 10% in a PV-electrolysis configuration.Although the use of Ag-PMMA based TCC has shown to be an effective approach to prepare MJ devices, mechanical and electrical design and optimization is required to reliably appropriate the TCC as an optoelectronic device interconnect and to scale the semi-monolithic integration method. In the context of mechanical optimization, it has been shown that the degree of deformation of conductive microsphere filler is a key factor in establishing electrical connections. Up until now, the load-deformation characteristic of a single Ag-PMMA microsphere has not been measured. As such, we present in this communication a mechanical model based on measured load-deformation characteristics of a single Ag-PMMA microsphere to facilitate a spring model to better predict the deformation of multi-particle systems with respect to applied load. Furthermore, a finite element electrical model is implemented to determine the effects of electrical contacts across the sub-cell emitter layer and the resulting charge transport resistive losses. Hence, we demonstrate the critical factors influencing the quality of TCC as an anisotropic electrical interconnection layer, and provide a computational mechanical and electrical model to understand and mitigate parasitic resistive losses.

Orthogonal Upconversion Luminescence from Core/Shell-Structured Upconversion Nanophosphors

Upconversion nanophosphors (UCNPs) are lanthanide ion-doped nanocrystals that exhibit anti-Stokes shift luminescence. Typically, UCNPs such as NaYF4:Yb,Er and NaYF4:Yb,Tm emit green and blue light under 980 nm near-infrared (NIR) light excitation. The emission color of lanthanide ion-doped UCNPs depends on the dopant ions in the host nanocrystals. Thus, one can adjust the dopant ions to control the upconversion (UC) luminescence color. For example, UC luminescence color can be tuned by co-doping activator ions into a single host nanocrystal and adjusting the ratio of two different activator ions. In addition, UC luminescence color can be tuned through energy migration UC process in core/shell-structured nanoparticles and by controlling the pulse of an NIR laser. Recently, orthogonal UC luminescence has been reported. In this study, UC luminescence color tuning is shown from the orthogonal UC luminescent UCNPs. To achieve orthogonal UC luminescence, core/multishell-structured UCNPs are synthesized. Depending on the excitation wavelength of NIR light, the UC luminescence color changes, and the core/multishell-structured UCNPs exhibit various UC luminescence colors by adjusting the excitation conditions. Finally, the feasibility of applying core/multishell-structured UCNPs in transparent displays is investigated.

Impact of water physicochemical properties on the survival of Oncomelania hupensis snails, the intermediate host of Schistosoma japonicum

BackgroundSchistosoma japonicum, the causative agent of schistosomiasis, heavily relies on its single intermediate host, the Oncomelania hupensis snail, for its life cycle. Controlling these snails effectively plays a pivotal role in curbing the transmission and prevalence of this disease. While prior research has extensively investigated the impact of environmental factors such as temperature and vegetation on snail survival, growth, and reproduction, the contribution of water physicochemical properties has been notably underexplored. This study presents laboratory experiments designed to comprehensively explore the influence of water physicochemical properties on snail survival, offering valuable insights into environmental factors for more precise predictions of snail distribution.MethodsWe meticulously conducted laboratory snail survival experiments using water from different sources (river water/tap water), and employed a statistical approach amalgamating principal component analysis with Cox regression to preliminarily investigate the effects of different water physicochemical properties on the survival of snails.ResultsOur analysis indicates that after a 6-month laboratory snail survival experiment, the survival rate in the tap water group was significantly higher than that in the river water group for infected snails (χ2 = 7.74, p = 0.005), while the difference in survival rates for non-infected snails was not statistically significant (χ2 = 0.61, p = 0.434). The Principal Component-Cox regression analysis revealed that in the infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, while phosphate and total nitrogen were risk factors. In the non-infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, and total nitrogen, ammonia nitrogen, phosphate, and nitrate were risk factors.ConclusionsThis study underscores the substantial impact of water quality’s physicochemical properties on snail survival. The effects of water quality on snails are complex, and maintaining an appropriate level of organic matter content and controlling the pH value at a weak alkalescency level prove beneficial for snail survival. These findings hold significant promise for advancing our understanding of snail-borne diseases and optimizing control strategies.

Stochastic models allow improved inference of microbiome interactions from time series data.

How can we figure out how the different microbes interact within microbiomes? To combine theoretical models and experimental data, we often fit a deterministic model for the mean dynamics of a system to averaged data. However, in the averaging procedure a lot of information from the data is lost-and a deterministic model may be a poor representation of a stochastic reality. Here, we develop an inference method for microbiomes based on the idea that both the experiment and the model are stochastic. Starting from a stochastic model, we derive dynamical equations not only for the average, but also for higher statistical moments of the microbial abundances. We use these equations to infer distributions of the interaction parameters that best describe the biological experimental data-improving identifiability and precision. The inferred distributions allow us to make predictions but also to distinguish between fairly certain parameters and those for which the available experimental data does not give sufficient information. Compared to related approaches, we derive expressions that also work for the relative abundance of microbes, enabling us to use conventional metagenome data, and account for cases where not a single host, but only replicate hosts, can be tracked over time.

Monogenean parasitic flatworms

Vanhove and colleagues introduce monogenean parasitic flatworms, a species-rich group of ectoparasitic flatworms that are mostly found on the skin, gills, or fins of fish and have a life cycle involving a single host.

Atypical rhizobia trigger nodulation and pathogenesis on the same legume hosts

The emergence of commensalism and mutualism often derives from ancestral parasitism. However, in the case of rhizobium-legume interactions, bacterial strains displaying both pathogenic and nodulation features on a single host have not been described yet. Here, we isolated such a bacterium from Medicago nodules. On the same plant genotypes, the T4 strain can induce ineffective nodules in a highly competitive way and behave as a harsh parasite triggering plant death. The T4 strain presents this dual ability on multiple legume species of the Inverted Repeat-Lacking Clade, the output of the interaction relying on the developmental stage of the plant. Genomic and phenotypic clustering analysis show that T4 belongs to the nonsymbiotic Ensifer adhaerens group and clusters together with T173, another strain harboring this dual ability. In this work, we identify a bacterial clade that includes rhizobial strains displaying both pathogenic and nodulating abilities on a single legume host.

Enhancing antibacterial efficacy through macrocyclic host complexation of fluoroquinolone antibiotics for overcoming resistance

The use of supramolecular assemblies in pharmaceuticals has garnered significant interest. Recent studies have shown that the activities of antibacterial agents can be enhanced through complexation with cyclic oligomers and metal ions. Notably, these complexes sometimes possess greater therapeutic properties than the parent drugs. To develop microbiologically potent supramolecular drugs, the complexation of macrocyclic hosts with fluoroquinolone (FQ) antibiotics was investigated. FQs are a successful family of antibiotics that target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, leading to bacterial cell death through the inhibition of DNA synthesis. However, antibiotic resistance resulting from the repeated use of FQs over time has limited their effectiveness against resistant pathogens. To overcome this issue, the encapsulation of FQs in polyphenolic macrocycles was investigated. This study highlights resorcinarene, a polyphenolic host with antibacterial properties, and its ability to chemically interact with FQs. The inclusion complexation process was analyzed using NMR and FTIR techniques. The binding constants determined by 1H-NMR titration revealed that levofloxacin forms more stable complexes with resorcinarene than with β-cyclodextrin, which aligned with MD simulations. Assessment of the geometric characteristics of the inclusion complexes using 2D NMR analysis confirmed that different moieties of various FQs can fit into a single host cavity and improve activity against gram-negative bacteria. Overall, these findings suggest that encapsulation in polyphenolic macrocycles is a promising strategy for utilizing FQs against antibiotic-resistant bacteria.

Heteroatoms Modulate the Copper Single Atom Catalytic Host Materials for Promoting the Redox Reaction in Aqueous Zinc‐Selenium Batteries

AbstractAqueous zinc‐selenium (Zn‐Se) batteries have garnered much attention due to their inherent safety and high specific capacity. Unfortunately, the problem of sluggish redox reaction represents a significant obstacle to the development of aqueous Zn‐Se batteries. Here, a nitrogen‐phosphorus asymmetrically coordinated copper single atom catalytic host material (CuN3P1@C) is synthesized for an aqueous Zn‐Se battery. The CuN3P1@C host material exhibits a rich porous structure, high‐loading of Cu single atoms, and unique asymmetric coordination environment, which significantly reduces the reaction energy barrier for the redox reaction between Se and Zn, enhancing the electrochemical performance of the aqueous Zn‐Se battery. Consequently, the Se/CuN3P1@C cathode achieves a high specific capacity of 756 mAh g−1 at 0.2 A g−1 and cycling stability of 4 000 cycles at 5.0 A g−1 (capacity decay of 0.0044% per cycle). Meanwhile, the conversion mechanism of an aqueous Zn‐Se battery is systematically explored via systematical characteristics and density functional theory calculations. This work opens up a novel approach to boosting the redox reaction of aqueous Zn‐Se batteries by modulating single atom‐based host materials via heteroatoms.