Hybrid Strains Research Articles

Chromosomal Type II Toxin–Antitoxin Systems May Enhance Bacterial Fitness of a Hybrid Pathogenic Escherichia coli Strain Under Stress Conditions

The functions of bacterial plasmid-encoded toxin–antitoxin (TA) systems are unambiguous in the sense of controlling cells that fail to inherit a plasmid copy. However, its role in chromosomal copies is contradictory, including stress-response-promoting fitness and antibiotic treatment survival. A hybrid pathogenic Escherichia coli strain may have the ability to colonize distinct host niches, facing contrasting stress environments. Herein, we determined the influence of multiple environmental stress factors on the bacterial growth dynamic and expression profile of previously described TA systems present in the chromosome of a hybrid atypical enteropathogenic and extraintestinal E. coli strain. Genomic analysis revealed 26 TA loci and the presence of five type II TA systems in the chromosome. Among the tested stress conditions, osmotic and acid stress significantly altered the growth dynamics of the hybrid strain, enhancing the necessary time to reach the stationary phase. Using qPCR analyses, 80% of the studied TA systems were differentially expressed in at least one of the tested conditions, either in the log or in the stationary phase. These data indicate that type II TA systems may contribute to the physiology of pathogenic hybrid strains, enabling their adaptation to different milieus.

Assessment of Thermoelectric Properties of Bi2Se3: Insights from Hybrid Functional Studies, Strain Engineering, and Machine Learning Methodology

AbstractThermoelectric properties in topological insulator Bi2Se3 are explored with multifaceted strategies, i.e., hybrid functional with strain and artificial intelligence methodology. The assessment with the experimental band gap values recognizes the limitations of conventional functional and the effectiveness of screened hybrid functionals. A thorough investigation into the impact of biaxial and uniaxial strain on thermoelectric parameters uncovers distinctive behaviors in n‐type and p‐type Bi2Se3, providing insights into optimal strain conditions for improved performance. Furthermore, the studies on the role of topologically non‐trivial surface states (TNSS) in thermoelectric properties reveal that TNSS significantly dominate electronic transport. Dual scattering time approximation elucidates the segregation of thermoelectric transport contributions from bulk and surface states, highlighting the importance of controlling the relaxation time ratio for enhanced thermoelectric performance. Additionally, the prediction of thermoelectric properties using Random Forest and Neural Networks models showcase impressive agreement with density functional theory predictions across varying temperatures, offering a powerful tool for understanding complex temperature‐dependent trends in thermoelectric properties. In summary, this interdisciplinary study presents a unique approach to advancing the understanding and optimization of thermoelectric properties in Bi2Se3. It provides a comprehensive framework for tailoring material behavior for diverse thermoelectric applications.

The formation of nicotine heterosis is mainly achieved by enhancing the nicotine transport capacity in hybrids

Nicotine exhibits obvious heterosis, which can be used to create Nicotiana tabacum L. (tobacco) varieties with varying nicotine content. However, the reasons for the formation of nicotine heterosis and its relationship to nicotine transport and accumulation remain unknown. This study conducted a comprehensive analysis of six tobacco hybrids with varying heterosis levels and their parent materials from various aspects, such as phenotype, physiology, and transcriptomics. The results showed that the direct path coefficient of transport heterosis to nicotine heterosis was highest in hybrids, at 0.98, and a highly significant positive correlation between the two. The plant height, thick stalk circumference, large flow of tissue fluid in the stalk, and high nicotine concentration of tobacco were the underlying factors that led to the strong nicotine transport capacity of hybrids. The formation of nicotine transport heterosis in hybrids was mainly influenced by non-additive gene effects (accounting for 89.93%), with over-dominant effects playing a dominant role (accounting for 58.79%). Among non-additive expression DEGs, nicotine transporter related multi antimicrobial extrusion protein, drug/metabolite transporter, ABC family transporter, and glutathione S-transferase were significantly upregulated in hybrid strains. The RT-qPCR results indicated that these genes related nicotine transport also exhibited heterosis at the expression level. Our results revealed that the formation of nicotine heterosis is mainly achieved by enhancing the nicotine transport capacity in hybrids. The results are not only beneficial for promoting the theoretical study of nicotine heterosis in tobacco and the breeding and utilization of hybrids, but are also of great significance for guiding nicotine production and promoting its multipurpose utilization.

Comparison of Preimplantation Mouse Embryos with Different Genetic Backgrounds as Models for Evaluating Human Embryo Culture Media Composition.

Can the best culture medium be determined by mouse embryo testing? Zygotes/embryos of four different mouse strains: inbred Balb/c (n = 79) and C57Bl/6 (n = 95), F1 hybrid DBA/2*C57Bl/6 (n = 133), and outbred ICR (n = 69) were incubated in vitro in four culture media: 1-Step Culture Medium (VitaVitro), CSC medium (Irvine Scientific), Sage 1-Step medium (Origio), G-TL medium (Vitrolife). The embryos were cultured under standard conditions at atmospheric oxygen: 37℃; 6% CO2, 100% humidity. Standard MEA-test parameters (number of expanded blastocysts on E4.5), as well as additional characteristics (embryo development on E2.5-E4.5, number of hatching and hatched blastocysts on E4.5, embryo arrest and degeneration) were assessed for each of the strain-medium combinations. The results were compared across strains as well as across media. Embryo development depended on both the media and the mouse strain. Embryos from inbred and outbred mice were more sensitive to suboptimal culture conditions compared to the hybrid strain; this was reflected in reduced blastocyst and hatching rates, as well as an increased percentage of arrested and degraded embryos. The choice of optimal media depended strongly on the strain: CSC was better for Balb/c, Sage 1-step for C57Bl/6, while both were preferred for hybrids, and G-TL for outbreds. VitaVitro was quite good for hybrids and performed worse for other strains. Overall, the embryos of each strain behaved differently in different media, and it was not possible to make a real preference for any of them over human embryos based on the results of any single mouse strain. Only a pooled sample of different mouse strains can be used for comprehensive media MEA testing. MEA testing with any strain of mice is doomed to error due to their specific culture requirements. Hybrid mice are too reproductively efficient and cannot be used to distinguish media based on their subtle differences. Outbred and inbred mice are too sensitive and may be delayed or degraded in culture media that is well suited to the requirements of human embryos. Combined analysis of multiple mouse strains should be used to test media more fully and may serve as a model for the heterogeneity of human embryos in IVF clinics.

Presence of carbapenem resistance in hybrid Escherichia coli pathovars from ready-to-eat fresh-cut fruits in Accra, Ghana.

This study reports the presence of carbapenem-resistant Escherichia coli hybrid pathovars and its prevalence in 200 fresh-cut fruits from Accra. Standard culture methods were used to quantify microbial indicators and E. coli on fresh-cut fruits retailed in formal and informal outlets in Accra. The Kirby-Bauer disc diffusion method was used to determine the antibiotic resistance profile of E. coli, while multiplex PCR was employed to identify the virulence and carbapenem-resistance genes. Escherichia coli prevalence in cut fruits was 17%, with pawpaw, watermelon, and mixed fruit having higher prevalence than pineapple. Of the 34 E. coli isolates from fresh-cut fruits, 44% showed broad resistance to beta-lactam antibiotics, while 5.9% showed carbapenem resistance. The study identified virulence genes associated with all E. coli isolates, including stx1, stx2, escV, and ipaH, of which 97% were hybrid pathovars bearing genes for Shiga toxin-producing E. coli/enteropathogenic E. coli/enteroinvasive E. coli. The carbapenemase gene, blaIMP, was associated with both carbapenem-resistant E. coli phenotypes identified. Despite a low-carbapenem-resistance prevalence observed among E. coli isolates, hypervirulent hybrid strains of E. coli is present in fresh-cut fruits in the sampling area, posing a potential public health risk to fresh-cut fruit consumers.

Chemical quality evaluation and characteristics of interspecific hybrid (G. uralensis × G. glabra) C-18 strain as a new Licorice cultivar.

The development of new cultivars is essential for establishing a method of producing licorice in Japan. A suitable new cultivar for domestic licorice production, known as the interspecific hybrid strain C-18, was developed by crossbreeding Glycyrrhiza uralensis Fisch. (as the seed parent, possessing a high glycyrrhizin (GL) content, strain OMP-28) and Glycyrrhiza glabra L. (as the pollen parent, known for vigorous growth, strain OMP-10). Both G. uralensis and G. glabra are specified in the Pharmacopoeia of Japan (18th edition) as the source plants for Glycyrrhizae Radix. After 2years of cultivation, strain C-18 exhibited robust growth, with a fresh weight of 148.8g and a stem diameter of 0.89mm. The GL content in the dry weight was measured at 3.61%. Seedlings cultivated from rhizomes in the field for 2years showed a tap root fresh weight per plant of 120 ± 21g, with an average GL content relative to the dry weight of 2.68% ± 0.38%. Although glabridin, a characteristic compound of G. glabra, was not detected, glycycoumarin, a characteristic compound of G. uralensis, was detected via HPLC analysis. Strain C-18 contained glycycoumarin as a characteristic compound of G. uralensis but lacked glabridin, a compound characteristic of G. glabra. Additionally, 2,3-dehydrokievitone (1) and parvisoflavone A (2) were identified as distinctive components of the interspecific hybrid (G. uralensis × G. glabra) C-18.

Is there any relationship between the effectiveness of some Heterorhabditis bacteriophora isolates on the host and their average penetration rate?

Entomopathogenic nematodes, such as Heterorhabditis bacteriophora, have been widely recognized for their potential in biological control strategies to manage agricultural pests effectively. This study aimed to evaluate the penetration rate and efficacy of different H. bacteriophora isolates, including two isolates (HB4 and HBNL) and a hybrid strain (HBH), against Tenebrio molitor L. (Col: Tenebrionidae) adults. The research also aimed to determine whether there was a correlation between the mortality caused by these isolates and their penetration. These isolates were applied to T. molitor adults at different concentrations 0.78 IJs (infective juveniles)/cm2 (50 IJs/Petri dishes), 1.57 IJs/cm2 (100 IJs/Petri dishes), 2.36 IJs/cm2 (150 IJs/Petri dishes), 3.14 IJs/cm2 (200 IJs/Petri dishes), 3.93 IJs/cm2 (250 IJs/Petri dishes), 7.86 IJs/cm2 (500 IJs/Petri dishes), 11.8 IJs/cm2 (750 IJs/Petri dishes), 15.72 IJs/cm2 (1000 IJs/Petri dishes), 19.66 IJs/cm2 (1250 IJs/Petri dishes). Another objective of the study was to observe the penetration rate means of these nematodes at consistent concentrations and record the resulting mortality rates. The findings revealed that the highest mortality rate of 100% was achieved at concentrations of 250, 500, 750, 1000, and 1250 IJs/Petri dishes. The HBH hybrid strain also exhibited the highest penetration rate mean of 20.33 IJs at a concentration of 1250 IJs/Petri dishes. These results highlight the efficacy of H. bacteriophora isolates and the hybrid strain in controlling T. molitor adults, with significant mortality rates observed at higher nematode concentrations. The study's emphasis on penetration rate means and the relationship between nematode concentration and pest mortality underscores the importance of optimizing entomopathogenic nematode applications for effective pest management.

Physiological reactions of some entomopathogenic nematodes to long-term storage

Entomopathogenic nematodes (EPNs) are commonly used for pest control. Determining the optimal storage duration for EPNs is crucial for their effective utilization. The aim of this study is to determine the efficacy and reproductive capacities of some EPNs stored for different durations. Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) HBH Hybrid Strain, HBNL, and HB4 isolates, as well as Steinernema feltiae Weiser, 1955 (Rhabditida: Steinernematidae) SADIÇ and ST5 isolates, were used in the study. The Infective Juveniles (IJs) stored at 4ºC for 6, 12, 18, and 24 months were assessed for their efficacy and reproductive capacities on last instar larvae of Galleria mellonella L., 1758 (Lepidoptera: Pyralidae) at the end of the periods. This study was conducted at Bursa Uludağ University, Plant Protection Department, Nematology Laboratory. The highest mortality rate observed on G. mellonella larvae was 86.67% on the H. bacteriophora HBH Hybrid Strain stored for 6 months. Similarly, the highest reproductive capacity was determined to be 153 000 IJs/G. mellonella larva, also on the H. bacteriophora HBH Hybrid Strain stored for 6 months. This study showed significant results in determining the effects of storage durations on the efficacy and reproductive capacity of the EPNs.

Classification of Cannabis Strains Based on their Chemical Fingerprint-A Broad Analysis of Chemovars in the German Market.

Introduction: Cannabis cultivars were usually categorized based on their genetic profile as sativa, indica, or hybrid types. However, these three criteria do not allow sufficient differentiation between the numerous varieties of cannabis strains. Furthermore, this classification is based on morphological and bio-geographical properties of the plants and does not represent the chemical composition of different cultivars. The concentration of cannabinoids and terpenes are crucial for the pharmacological effect, not only because of the known entourage effect, and therefore needs to be considered by categorization. Materials and Methods: A total of 140 medicinal cannabis flowers available on the German market were analyzed regarding their individual terpene profile using GC-MS analysis. Statistical evaluation was performed to investigate correlations and data relations as well as for clustering. Results: Multivariate analysis showed correlations between individual terpenes. However, there was no statistical correlation between terpene profiles and their respective genetic profile. Terpene profiles of sativa, indica, and hybrid strains are quite heterogenous and clearly showed that there is no relation between terpenes and the estimated pharmacological effect. As a result, we suggest a new classification system based on individual terpene profiles to faster a comprehensive understanding of the expected medical effect. Discussion: Considering main terpenes, we established a concept of six clusters with various terpene profiles being attributed to different medicinal applications. We excluded tetrahydrocannabinol (THC) and cannabidiol (CBD) content from clustering as most of the strains were THC dominant and therefore distort the results. Our pattern of strains with similar terpene profiles might refine the existing classes of chemotypes with different THC:CBD content. Conclusion: The categorization of cannabis strains based on their terpene profiles allows a clearer, finer and, above all, more meaningful classification than the existing sativa/indica classification. Due to the entourage effect and the interactions between cannabinoids and terpenes, this group of substances is also given the necessary consideration when selecting the right medicine for the individual. Within the next steps, further studies are needed with the aim of mapping clinical validated effects to our chemovars. If it is possible to correlate therapy of symptoms to specific chemical profiles personalized cannabinoid therapy will be possible.

Shiga Toxin-Producing Escherichia coli Strains from Romania: A Whole Genome-Based Description.

The zoonotic Shiga toxin-producing Escherichia coli (STEC) group is unanimously regarded as exceptionally hazardous for humans. This study aimed to provide a genomic perspective on the STEC recovered sporadically from humans and have a foundation of internationally comparable data. Fifty clinical STEC isolates, representing the culture-confirmed infections reported by the STEC Reference Laboratory between 2016 and 2023, were subjected to whole-genome sequencing (WGS) analysis and sequences were interpreted using both commercial and public free bioinformatics tools. The WGS analysis revealed a genetically diverse population of STEC dominated by non-O157 serogroups commonly reported in human STEC infections in the European Union. The O26:H11 strains of ST21 lineage played a major role in the clinical disease resulting in hospitalisation and cases of paediatric HUS in Romania surpassing the O157:H7 strains. The latter were all clade 7 and mostly ST1804. Notably, among the Romanian isolates was a stx2a-harbouring cryptic clade I strain associated with a HUS case, stx2f- and stx2e-positive strains, and hybrid strains displaying a mixture of intestinal and extraintestinal virulence genes were found. As a clearer picture emerges of the STEC strains responsible for infections in Romania, further surveillance efforts are needed to uncover their prevalence, sources, and reservoirs.

Uropathogenic E. coli and Hybrid Pathotypes in Mexican Women with Urinary Tract Infections: A Comprehensive Molecular and Phenotypic Overview.

Uropathogenic Escherichia coli (UPEC) is the main cause of urinary tract infections (UTIs) and carries virulence and resistance factors often found in mobilizable genetic elements, such as plasmids or pathogenicity islands (PAIs). UPEC is part of the extraintestinal pathogenic E. coli (ExPEC), but hybrid strains possessing both diarrheagenic E. coli (DEC) and ExPEC traits, termed "hypervirulent", present a significant health threat. This study assessed the prevalence of UPEC PAIs, ExPEC sequence types (ST), DEC genes, carbapenemase and extended-spectrum β-lactamase (ESBL) phenotypes, resistance genotypes, and plasmids in 40 clinical isolates of UPEC. Results showed that 72.5% of isolates had PAIs, mainly PAI IV536 (53%). ESBL phenotypes were found in 65% of β-lactam-resistant isolates, with 100% of carbapenem-resistant isolates producing carbapenemase. The predominant ESBL gene was blaCTX-M-2 (60%), and the most common resistance gene in fluoroquinolone and aminoglycoside-resistant isolates was aac(6')Ib (93%). Plasmids were present in 57% of isolates, and 70% belonged to the ST131 clonal group. Molecular markers for DEC pathotypes were detected in 20 isolates, with 60% classified as hybrid pathotypes. These findings indicate significant pathogenic potential and the presence of hybrid pathotypes in E. coli UTI clinical isolates in the Mexican population.

Genomic and epidemiological evidence for the emergence of a L. infantum/L. donovani hybrid with unusual epidemiology in northern Italy.

Leishmania (L.) infantum is one of the main causative agents of animal and human leishmaniasis across many endemic areas in South America, Europe, North Africa, and Asia. Despite its clinical significance, little is known about the genetic diversity of L. infantum circulating in a given endemic area. Here, we investigate this important open question by applying a comparative genomics approach to seven L. infantum isolates from different hosts and Italian regions, including the northern part of the country (Emilia-Romagna, RER), Sicily, and Sardinia, as an initial attempt to explore the breadth of parasite genetic heterogeneity in Italy. Additionally, microsatellite analysis was carried out to compare the isolates from RER with other 70 L. infantum strains from the same region as well as 65 strains belonging to the L. donovani complex from other countries. We revealed important karyotypic instability and identified strain-specific changes in gene dosage, which affected important virulence factors such as amastins and surface antigen-like proteins. Single nucleotide polymorphism-based clustering analysis of these genomes together with over 80 publicly available L. infantum and L. donovani genomes placed the Italian isolates into three geographically distinct clusters within the Mediterranean basin and uncovered three isolates clustering with putative L. infantum/L. donovani hybrids isolated in Cyprus. As judged by microsatellite profiling, these hybrid isolates are representative of a sub-population of parasites circulating in northern Italy that preferentially infect humans but not dogs. Our results place Italy at the crossroads of L. infantum infection in the Mediterranean and call attention to the public health risk represented by the introduction of non-European Leishmania species.IMPORTANCEThis study closes important knowledge gaps with respect to Leishmania (L.) infantum genetic heterogeneity in a given endemic country, as exemplified here for Italy, and reveals genetic hybridization as a main cause for re-emerging human leishmaniasis in northern Italy. The observed high diversity of Leishmania parasites on the Italian peninsula suggests different geographical origins, with genomic adaptation to various ecologies affecting both pathogenicity and transmission potential. This is documented by the discovery of a putative L. infantum/L. donovani hybrid strain, which has been shown to preferentially infect humans but not dogs. Our results provide important information to health authorities, which need to consider the public health risk represented by the introduction of new Leishmania species into EU countries due to population displacement or travel from countries where exotic/allochthonous parasite species are endemic.

Genetic and virulence characteristics of hybrid Shiga toxin-producing and atypical enteropathogenic Escherichia coli strains isolated in South Korea.

The predominant hybrid pathogenic E. coli, enterohemorrhagic E. coli (EHEC), combines characteristics of Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC), contributing to global outbreaks with severe symptoms including fatal consequences. Since EHEC infection was designated as a notifiable disease in 2000 in South Korea, around 2000 cases have been reported, averaging approximately 90 cases annually. In this work, genome-based characteristic analysis and cell-based assay of hybrid STEC/aEPEC strains isolated from livestock feces, animal source foods, and water in South Korea was performed. To identify the virulence and antimicrobial resistance genes, determining the phylogenetic position of hybrid STEC/aEPEC strains isolated in South Korea, a combination of real-time PCR and whole-genome sequencing (WGS) was used. Additionally, to assess the virulence of the hybrid strains and compare them with genomic characterization, we performed a cell cytotoxicity and invasion assays. The hybrid STEC/aEPEC strains harbored stx and eae genes, encoding Shiga toxins and E. coli attachment/effacement related protein of STEC and EPEC, respectively. Furthermore, all hybrid strains harbored plasmid-carried enterohemolysin(ehxCABD), a key virulence factor in prevalent pathogenic E. coli infections, such as diarrheal disease and hemolytic-uremic syndrome (HUS). Genome-wide phylogenetic analysis revealed a close association between all hybrid strains and specific EPEC strains, suggesting the potential acquisition of Stx phages during STEC/aEPEC hybrid formation. Some hybrid strains showed cytotoxic activity against HeLa cells and invasive properties against epithelial cells. Notably, all STEC/aEPEC hybrids with sequence type (ST) 1,034 (n = 11) exhibited higher invasiveness than those with E2348/69. This highlights the importance of investigating potential correlations between STs and virulence characteristics of E. coli hybrid strains. Through genome-based characterization, we confirmed that the hybrid STEC/aEPEC strains are likely EPEC strains that have acquired STEC virulence genes via phage. Furthermore, our results emphasize the potential increased danger to humans posed by hybrid STEC/aEPEC strains isolated in South Korea, containing both stx and eaeA, compared to STEC or EPEC alone.

Genome sequence of pan drug-resistant enteroaggregative Escherichia coli belonging to ST38 clone from India, an emerging EAEC/UPEC hybrid pathotype

Here, we report the genomic characterization of a pan drug-resistant (PDR) enteroaggregative Escherichia coli (EAEC) isolated from an immunocompromised infant who had diarrhea. The isolate belonged to the sequence type (ST) 38, which is a known enteroaggregative Escherichia coli (EAEC)/uropathogenic Escherichia coli (UPEC) hybrid strain having multi-drug resistance (MDR). The strain carried genes encoding multiple resistances to carbapenems, third-generation cephalosporins, polymyxin, fluoroquinolones, aminoglycosides, fosfomycin, nitrofurantoin, sulphonamides, and multiple efflux pump genes. Interspecies horizontal transfer, inter-strain, and clonal spread of these resistances to commensals and pathogens will be worrisome. We are concerned about the spread of such PDR strains. The genomic characterization of such strains will be useful in understanding the genetic makeup of EAEC/UPEC hybrid strains and developing new vaccines/diagnostics and therapeutics.

Differences in metabolism among Saccharomyces species and their hybrids during wine fermentation.

This study aimed to investigate how parental genomes contribute to yeast hybrid metabolism using a metabolomic approach. Previous studies have explored central carbon and nitrogen metabolism in Saccharomyces species during wine fermentation, but this study analyses the metabolomes of Saccharomyces hybrids for the first time. We evaluated the oenological performance and intra- and extracellular metabolomes, and we compared the strains according to nutrient consumption and production of the main fermentative by-products. Surprisingly, no common pattern was observed for hybrid genome influence; each strain behaved differently during wine fermentation. However, this study suggests that the genome of the S. cerevisiae species may play a more relevant role in fermentative metabolism. Variations in biomass/nitrogen ratios were also noted, potentially linked to S. kudriavzevii and S. uvarum genome contributions. These results open up possibilities for further research using different "omics" approaches to comprehend better metabolic regulation in hybrid strains with genomes from different species.

Optimizing mycelial protein yield in Pleurotus djamor via ARTP mutagenesis and hybridization strategies

With the world’s population rapidly increasing, the demand for high-quality protein is on the rise. Edible fungi breeding technology stands as a crucial avenue to obtain strains with high yield, high-quality protein, and robust stress resistance. To address the protein supply gap, Atmospheric and Room Temperature Plasma (ARTP) mutagenesis, and spore hybridization techniques were employed to enhance Pleurotus djamor mycelium protein production. Beginning with the original strain Pleurotus djamor JD-1, ARTP was utilized to mutate spore suspension. The optimal treatment time for Pleurotus djamor spores, determined to achieve optimal mortality, was 240 s. Through primary and secondary screenings, 6 mutant strains out of 39 were selected, exhibiting improved protein yield and growth rates compared to the original strain. Among these mutagenic strains, 240S–4 showcased the highest performance, with a mycelial growth rate of 9.5±0.71 mm/d, a biomass of 21.45±0.54 g/L, a protein content of 28.75±0.92%, and a remarkable protein promotion rate of 128.03±7.29%. Additionally, employing spore hybridization and breeding, 7 single-nuclei strains were selected for pin-two hybridization, resulting in 21 hybrid strains. The biomass and protein content of 9 hybrid strains surpassed those of the original strains. One hybrid strain, H-5, exhibited remarkable mycelial protein production, boasting a mycelial growth rate of 26.5±0.7 mm/d, a biomass of 21.70±0.46 g/L, a protein content of 28.44±0.22%, and a protein promotion rate of 128.02±1.73%. Notably, both strains demonstrated about a 28% higher mycelial protein yield than the original strains, indicating comparable effectiveness between hybrid breeding and mutagenesis breeding. Finally, we analyzed the original and selected strains by molecular biological identification, which further proved the effectiveness of the breeding method. These findings present novel insights and serve as a reference for enhancing edible fungi breeding, offering promising avenues to meet the escalating protein demand.

Genetic diversity promotes resilience in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disorder with multifactorial etiology, including genetic factors that play a significant role in disease risk and resilience. However, the role of genetic diversity in preclinical AD studies has received limited attention. We crossed five Collaborative Cross strains with 5xFAD C57BL/6J female mice to generate F1 mice with and without the 5xFAD transgene. Amyloid plaque pathology, microglial and astrocytic responses, neurofilament light chain levels, and gene expression were assessed at various ages. Genetic diversity significantly impacts AD-related pathology. Hybrid strains showed resistance to amyloid plaque formation and neuronal damage. Transcriptome diversity was maintained across ages and sexes, with observable strain-specific variations in AD-related phenotypes. Comparative gene expression analysis indicated correlations between mouse strains and human AD. Increasing genetic diversity promotes resilience to AD-related pathogenesis, relative to an inbred C57BL/6J background, reinforcing the importance of genetic diversity in uncovering resilience in the development of AD. Genetic diversity's impact on AD in mice was explored. Diverse F1 mouse strains were used for AD study, via the Collaborative Cross. Strain-specific variations in AD pathology, glia, and transcription were found. Strains resilient to plaque formation and plasma neurofilament light chain (NfL) increases were identified. Correlations with human AD transcriptomics were observed.

The role of drought in the efficacy of some entomopathogenic nematodes

Entomopathogenic nematodes (EPNs) are endoparasitic organisms commonly used in the control of agricultural pests. There are several factors that determine the efficacy of EPNs on hosts, with one of the most significant being soil moisture. The aim of this study is to determine the effectiveness of some EPNs on hosts at different doses and under different soil moisture conditions. The study utilized 1 Hybrid Strain and 3 EPN isolates, Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae) HBH hybrid strain, Steinernema carpocapsae Weiser, 1955 TUR-S4 isolate, and Steinernema feltiae Weiser, 1955 (Rhabditida: Steinernematidae) TUR-S3 and S-Bilecik isolates. These species were applied to Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae) larvae at 5, 10, and 15 Infective Juveniles (IJs) doses, under 1, 4, 7, 10, and 13% soil moisture conditions. The study was conducted in 2024 at Bursa Uludağ University, Faculty of Agriculture, Department of Plant Protection, Nematology Laboratory. As a result, the highest mortality rates on T. molitor larvae were obtained at 13% soil moisture with 15 IJs, 100% for HBH, 93.33% for TUR-S4, 86.67% for TUR-S3, and 83.33% for S-Bilecik. This study carries important implications for understanding the relationship between EPN efficacy on hosts and soil moisture.

Emergence of multidrug resistant, ctx negative seventh pandemic Vibrio cholerae O1 El Tor sequence type (ST) 69 in coastal water of Kerala, India

Seventh pandemic Vibrio choleare O1 El Tor strain is responsible for the on-going pandemic outbreak of cholera globally. This strain evolved from non-pathogenic V. cholerae by acquiring seventh pandemic gene (VC 2346), pandemic Islands (VSP1 and VSP2), pathogenicity islands (VP1 and VP2) and CTX prophage region. The cholera toxin production is mainly attributed to the presence of ctx gene in these strains. However, several variants of this strain emerged as hybrid strains or atypical strains. The present study aimed to assess the aquatic environment of Cochin, India, over a period of 5 years for the emergence of multidrug resistant V. cholerae and its similarity with seventh pandemic strain. The continuous surveillance and monitoring resulted in the isolation of ctx negative, O1 positive V. cholerae isolate (VC6) from coastal water, Cochin, Kerala. The isolate possessed the biotype specific O1 El Tor tcpA gene and lacked other biotype specific ctx, zot, ace and rst genes. Whole genome analysis revealed the isolate belongs to pandemic sequence type (ST) 69 with the possession of pandemic VC2346 gene, pathogenic island VPI1, VPI2, and pandemic island VSP1 and VSP2. The isolate possessed several insertion sequences and the SXT/R391 family related Integrative Conjugative Elements (ICEs). In addition to this, the isolate genome carried virulence genes such as VgrG, mshA, ompT, toxR, ompU, rtxA, als, VasX, makA, and hlyA and antimicrobial resistance genes such as gyrA, dfrA1, strB, parE, sul2, parC, strA, VC1786ICE9-floR, and catB9. Moreover, the phylogenetic analysis suggests that the isolate genome is more closely related to seventh pandemic V.cholerae O1 N16961 strain. This study reports the first incidence of environmental ctx negative seventh pandemic V. choleare O1 El Tor isolate, globally and its presence in the aquatic system likely to induce toxicity in terms of public health point of view. The presence of this isolate in the aquatic environment warns the strict implementation of the epidemiological surveillance on the occurrence of emerging strains and the execution of flagship program for the judicious use of antibiotics in the aquatic ecosystem.

Development of Cross-Reactive Live Attenuated Influenza Vaccine Candidates against Both Lineages of Influenza B Virus.

Influenza viruses continue to cause a significant social and economic burden globally. Vaccination is recognized as the most effective measure to control influenza. Live attenuated influenza vaccines (LAIVs) are an effective means of preventing influenza, especially among children. A reverse genetics (RG) system is required to rapidly update the antigenic composition of vaccines, as well as to design LAIVs with a broader spectrum of protection. Such a system has been developed for the Russian LAIVs only for type A strains, but not for influenza B viruses (IBV). All genes of the B/USSR/60/69 master donor virus (B60) were cloned into RG plasmids, and the engineered B60, as well as a panel of IBV LAIV reassortants were rescued from plasmid DNAs encoding all viral genes. The engineered viruses were evaluated in vitro and in a mouse model. The B60 RG system was successfully developed, which made it possible to rescue LAIV reassortants with the desired antigenic composition, including hybrid strains with hemagglutinin and neuraminidase genes belonging to the viruses from different IBV lineages. The LAIV candidate carrying the HA of the B/Victoria-lineage virus and NA from the B/Yamagata-lineage virus demonstrated optimal characteristics in terms of safety, immunogenicity and cross-protection, prompting its further assessment as a broadly protective component of trivalent LAIV. The new RG system for B60 MDV allowed the rapid generation of type B LAIV reassortants with desired genome compositions. The generation of hybrid LAIV reassortants with HA and NA genes belonging to the opposite IBV lineages is a promising approach for the development of IBV vaccines with broad cross-protection.