Genetic Content Research Articles

High Antimicrobial Susceptibility of Cloacal Enterococci and Escherichia coli from Free-Living Dalmatian and Great White Pelicans with Detection of Cefotaximase CTX-M-15 Producing Escherichia coli ST69.

Background/Objectives: In 2022, an outbreak of H5N1 highly pathogenic avian influenza (HPAI) killed 60% of the largest breeding colony of Dalmatian pelicans (DPs) in the world at Mikri Prespa Lake (Greece), prompting a multidisciplinary study on HPAI and other pathogens. This study determines the antimicrobial resistance rates of cloacal enterococci and Escherichia coli in DPs. Methods: Fifty-two blood and cloacal swab samples were collected from 31 nestlings (20 DP/11 great white pelicans) hatched after the H5N1 outbreak at the Prespa colony and 21 subadult/adult DPs captured at a spring migration stopover. The swabs were inoculated in non-selective and chromogenic-selective media. Identification was performed using MALDI-TOF, and antimicrobial susceptibility was tested. The genetic content was characterized using PCR and sequencing, and the clonality of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates was characterized using Multilocus Sequence Typing. Results: Twenty-eight non-repetitive E. coli and 45 enterococci isolates were recovered in non-selective media; most of them were susceptible to all antibiotics tested (85.7% E. coli/91.1% enterococci). Three of the fifty-two samples (6%, all adults) contained ESBL-E. coli isolates (detected in chromogenic ESBL plates), all carrying the blaCTX-M-15 gene and belonging to the lineage ST69. Conclusions: Despite the susceptibility of most fecal E. coli and enterococci isolates to all antibiotics tested, the finding that E. coli of lineage ST69 carry blaCTX-M-15 is of concern. This high-risk clone needs further investigation to elucidate its primary sources and address the growing threat of antimicrobial resistance from an integrated "One Health" perspective. Furthermore, it is imperative to study the potential impacts of ESBL-E. coli on the endangered DP further.

Complete genome sequence of Limosilactobacillus reuteri LU150, a potential vitamin B12 producer from the NORDBIOTIC collection.

We performed whole-genome sequencing of Limosilactobacillus reuteri LU150, a human fecal isolate from the NORDBIOTIC collection. The genome consists of 2,039,406 bp with a GC content of 38.9%. The genetic content of LU150 suggests its probiotic potential.

Analysis of Nursing Education Curricula in Spain: Integration of Genetic and Genomic Concepts.

The integration of genetics and genomics into nursing practice is essential for addressing genetic pathologies and providing personalized patient care. This study aims to analyze the nursing education curricula across Spanish universities to understand how genetic and genomic concepts are incorporated. Using the "Qué estudiar y dónde en la Universidad" (QEDU) database, an official source provided by the Spanish Ministry of Universities, a systematic review of 4720 teaching guides from 118 university centers was conducted. Our findings reveal that 12 centers do not include any genetic or genomic content, while 43% of the remaining centers focus solely on basic genetics. In contrast, 57% cover advanced topics, such as genetic counseling and pharmacogenetics. Teaching methodologies predominantly involve lectures and seminars, with limited practical training. On average, three to six ECTS credits out of the total 240 required for the Nursing Degree are dedicated to genetics and genomics. This study highlights the need for curriculum updates and standardization to ensure comprehensive training in these crucial areas. Improved integration of genetic and genomic education will better prepare nursing professionals to meet the evolving demands of modern healthcare. This study was not registered.

B Chromosomes in Wheat: Evolution, Functions and Breeding Potential

Supernumerary B chromosomes (Bs) have been documented in over 2000 species across the plant, animal, and fungal kingdoms, representing one of the most intriguing components of the genome that have consistently garnered significant attention in the past. These Bs form a distinct category of chromosomes that are not deemed essential. While coexisting with the standard set of chromosomes in an organism, the copy numbers of Bs can vary among individuals within a population or even among cells within a single organism. Multiple processes, including chromosomal rearrangement, uneven segregation, chromatid non-disjunction, and deletion in specific regions, lead to the formation of the Bs from the A chromosome. These dispensable Bs possess their own genetic content and do not undergo recombination with A chromosomes. Although various roles of Bs in breeding have been explored in the literature, their specific role in wheat improvement remains unclear. The understanding of their origins, composition, and evolutionary history in wheat is still incomplete. Therefore, this review discusses the current knowledge of the genetic makeup of Bs, their functions, their relationship with A chromosomes, and the morphogenetic consequences in the context of wheat.

Berberine-loaded iron oxide nanoparticles alleviate cuprizone-induced astrocytic reactivity in a rat model of multiple sclerosis

Berberine (BBN) is a naturally occurring alkaloid as a secondary metabolite in many plants and exhibits several benefits including neuroprotective activities. However, data on the neuromodulating potential of nanoformulated BBN are still lacking. In the present study, BBN loaded within iron oxide nanoparticles (BBN-IONP) were prepared and characterized by transmission electron microscopy FTIR, X-ray photoelectron spectroscopy particle-size distribution, zeta potential, and HPLC. The remyelinating neuroprotective potential of BBN-IONP relative to free BBN was evaluated against cuprizone (CPZ)-induced neurotoxicity (rats administered 0.2% CPZ powder (w/w) for five weeks). CPZ rats were treated with either free BBN or IONP-BBN (50 mg/kg/day, orally) for 14 days. Cognitive function was estimated using Y-maze. Biochemically, total antioxidant capacity lipid peroxides and reduced glutathione in the brain tissue, as well as, serum interferon-gamma levels were estimated. Moreover, the genetic expression contents of myelin basic protein Matrix metallopeptidase-9 Tumor necrosis factor-α (TNF-α), and S100β were measured. The histopathological patterns and immunohistochemical assessment of Glial Fibrillary Acidic Protein in both cerebral cortex and hippocampus CA1 regions were investigated. CPZ-rats treated with either free BBN or IONP-BBN demonstrated memory restoring, anti-oxidative, anti-inflammatory, anti-astrocytic, and remyelinating activities. Comparing free BBN with IONP-BBN revealed that the latter altered the neuromodulating activities of BBN, showing superior neuroprotective activities of IONP-BBN relative to BBN. In conclusion, both forms of BBN possess neuroprotective potential. However, the use of IONPs for brain delivery and the safety of these nano-based forms need further investigation.

Genomic and Phenotypic Variations Among Thai-53 and Mycobacterium leprae Clinical Isolates: Implications for Leprosy Pathogenesis and Research.

Throughout Mycobacterium leprae's (M. leprae) evolutionary trajectory, nearly half of its genome was converted into pseudogenes. Despite this drastic reduction in genetic content, the genome sequence identity among M. leprae isolates worldwide is remarkably high compared to other pathogens. In this study, we investigated the genotype and morphotype of three M. leprae strains: the reference strain Thai-53 (genotype 1A), and two clinical isolates from Brazilian leprosy relapse patients, which were Br014-03 (genotypes 3I) and Br014-01(4N). We compared their genome sequences and their interaction with human Schwann cells from the ST88-14 lineage and with human primary macrophages. On the genetic level, we observed over a hundred missense mutations in the three strains, translated into significant phenotypic changes such as: prolonged doubling time, altered cytokine induction, reduced interaction rates, and decreased intracellular viability in Schwann cells. Our findings underscore the concept that despite their 99.992% identity, even small genomic disparities in M. leprae genomes can elicit substantial alterations in bacilli interaction with host cells and subsequent immune responses. Consequently, our data could lead to better comprehension of correlation between pathogen mutations and the diverse clinical manifestations observed in leprosy patients.

Matching excellence: Oxford Nanopore Technologies' rise to parity with Pacific Biosciences in genome reconstruction of non-model bacterium with high G+C content.

The reconstruction of complete bacterial genomes is essential for microbial research, offering insights into genetic content, ontology and regulation. While Pacific Biosciences (PacBio) provides high-quality genomes, its cost remains a limitation. Oxford Nanopore Technologies (ONT) offers long reads at a lower cost, yet its error rate raises scepticism. Recent ONT advancements, such as new Flow cells (R10.4.1), chemistry (V14) and duplex mode, improve data quality. Our study compares ONT with PacBio and Illumina, including hybrid data. We used Propionibacterium freudenreichii, a bacterium with a genome known for being difficult to reconstruct. By combining data from ONT's Native Barcoding and a custom-developed BARSEQ method, we achieved high-quality, near-perfect genome assemblies. Our findings demonstrate, for the first time, that the combination of nanopore-only long-native with shorter PCR DNA reads (~3 kb) results in high-quality genome reconstruction, comparable to hybrid data assembly from two sequencing platforms. This endorses ONT as a cost-effective, stand-alone strategy for bacterial genome reconstruction. Additionally, we compared methylated motif detection between PacBio and ONT R10.4.1 data, showing that results comparable to PacBio are achievable using ONT, especially when utilizing the advanced Nanomotif tool.

Gray wolf breeders are more vulnerable to harvest during the breeding season

AbstractIn cooperatively breeding carnivores, breeders are vital to perpetuating the group; the death or removal of an individual breeder can greatly affect group composition, genetic content, and short‐term population growth. Understanding the number of breeders harvested and timing of harvest can increase our knowledge of how mortality affects groups of cooperative breeders. Gray wolves (Canis lupus) in Idaho, USA, are exposed to annual harvest and are an ideal species for studying the effects of harvest on breeder turnover. We combined genotypes from tissue samples of harvested wolves with parentage analyses and cementum annuli ages and estimated when and how many breeding wolves were harvested. We genotyped and aged 229 adults and 203 pups using tissue and tooth samples from wolves harvested between 2014 and 2016. We identified a minimum count of 33 breeders in the harvest and found that they were disproportionately harvested more during the breeding season. We estimated that a minimum of ~14.5% of adult wolves harvested annually, or approximately 1 in 7, were breeders. We posit their behavior during breeding season may increase their vulnerability to harvest. By linking animal life history with vulnerability to human‐caused mortality we show that managers could structure harvest seasons so there is less overlap with wolves’ breeding season if there is concern about the demographic consequences of harvesting breeders.

Efficacy and Predictive Factors Analysis of Androgen Deprivation Plus Novel Hormone Therapy as Neoadjuvant Treatment for High-Risk Prostate Cancer.

This investigation explored the clinical features, pathological outcomes, and biochemical recurrence (BCR) duration among high-risk prostate cancer (HRPC) patients who have undergone neoadjuvant therapy (NAT) in combination with radical prostatectomy (RP) and pelvic lymph node dissection (PLND). Additionally, we identified prognostic indicators that discern pathological complete response (pCR) or minimal residual disease (MRD) and BCR. In total, we examined 76 HRPC patients, who received NAT with either androgen deprivation therapy (ADT) plus apalutamide or ADT plus abiraterone, with subsequent RP and PLND. We conducted a genetic evaluation of patients receiving neoadjuvant apalutamide. Additionally, patient pathological outcomes, circulating prostate-specific antigen (PSA) response rates, and BCR duration were analyzed. Lastly, we employed uni- and multivariate analyses to screen for prognostic factors that govern pCR or MRD and BCR duration. Patient median age and median PSA at presentation were 69 years (IQR: 66-73), and 47.6 ng/mL (IQR: 24.1-105.75), respectively. We observed marked changes in pCR or MRD rates between the two cohorts. In particular, the ADT plus apalutamide cohort (51.5%) exhibited enhanced rates relative to the ADT plus abiraterone cohort (25.6%) (p = 0.03). The median BCR duration was substantially prolonged among neoadjuvant apalutamide cohort relative to the neoadjuvant abiraterone cohort (261 days vs. 76 days, p = 0.04). Using multivariate analysis, we revealed that the postintervention pre-RP PSA content (≤ 0.1 ng/mL vs. > 0.1 ng/mL) remained a substantial stand-alone indicator of pCR or MRD (odds ratio: 10.712, 95% CI: 2.725-42.105, p < 0.001). Furthermore, supplemental analyses revealed that the ADT plus apalutamide cohort exhibited an augmented serum response rate, which, in turn, reduced the post-intervention pre-RP PSA content. Based on our genetic profiling of the neoadjuvant apalutamide cohort demonstrated high-frequency deleterious changes in the AR axis (30.3%), followed by TP53 mutations (15.15%). Patients with defective AR axis experienced a remarkably shorter median BCR duration relative to patients with other or no genetic alterations (52.5 days vs. 286 and 336 days, respectively, p < 0.0001). Furthermore, using multivariate analysis, we demonstrated that achieving pCR or MRD (hazard ratio [HR]: 0.170, 95% CI: 0.061-0.477, p < 0.001) and presence of defective AR signaling (HR: 11.193, 95% CI: 3.499-35.806, p < 0.001) were strong stand-alone indicators of BCR. Herein, we demonstrated the superior performance of ADT plus apalutamide in achieving pCR or MRD and in extending BCR duration among HRPC patients. Post-intervention pre-RP PSA content as well as genetic shifts, especially in the AR axis, are critical indicators of patient pathological and clinical outcomes. These findings highlight the significance of genetic testing and PSA content monitoring in treating HRPC patients.

MATEdb2, a Collection of High-Quality Metazoan Proteomes across the Animal Tree of Life to Speed Up Phylogenomic Studies.

Recent advances in high-throughput sequencing have exponentially increased the number of genomic data available for animals (Metazoa) in the last decades, with high-quality chromosome-level genomes being published almost daily. Nevertheless, generating a new genome is not an easy task due to the high cost of genome sequencing, the high complexity of assembly, and the lack of standardized protocols for genome annotation. The lack of consensus in the annotation and publication of genome files hinders research by making researchers lose time in reformatting the files for their purposes but can also reduce the quality of the genetic repertoire for an evolutionary study. Thus, the use of transcriptomes obtained using the same pipeline as a proxy for the genetic content of species remains a valuable resource that is easier to obtain, cheaper, and more comparable than genomes. In a previous study, we presented the Metazoan Assemblies from Transcriptomic Ensembles database (MATEdb), a repository of high-quality transcriptomic and genomic data for the two most diverse animal phyla, Arthropoda and Mollusca. Here, we present the newest version of MATEdb (MATEdb2) that overcomes some of the previous limitations of our database: (i) we include data from all animal phyla where public data are available, and (ii) we provide gene annotations extracted from the original GFF genome files using the same pipeline. In total, we provide proteomes inferred from high-quality transcriptomic or genomic data for almost 1,000 animal species, including the longest isoforms, all isoforms, and functional annotation based on sequence homology and protein language models, as well as the embedding representations of the sequences. We believe this new version of MATEdb will accelerate research on animal phylogenomics while saving thousands of hours of computational work in a plea for open, greener, and collaborative science.

The Gut Microbiome Advances Precision Medicine and Diagnostics for Inflammatory Bowel Diseases

The gut microbiome emerges as an integral component of precision medicine because of its signature variability among individuals and its plasticity, which enables personalized therapeutic interventions, especially when integrated with other multiomics data. This promise is further fueled by advances in next-generation sequencing and metabolomics, which allow in-depth high-precision profiling of microbiome communities, their genetic contents, and secreted chemistry. This knowledge has advanced our understanding of our microbial partners, their interaction with cellular targets, and their implication in human conditions such as inflammatory bowel disease (IBD). This explosion of microbiome data inspired the development of next-generation therapeutics for treating IBD that depend on manipulating the gut microbiome by diet modulation or using live products as therapeutics. The current landscape of artificial microbiome therapeutics is not limited to probiotics and fecal transplants but has expanded to include community consortia, engineered probiotics, and defined metabolites, bypassing several limitations that hindered rapid progress in this field such as safety and regulatory issues. More integrated research will reveal new therapeutic targets such as enzymes or receptors mediating interactions between microbiota-secreted molecules that drive or modulate diseases. With the shift toward precision medicine and the enhanced integration of host genetics and polymorphism in treatment regimes, the following key questions emerge: How can we effectively implement microbiomics to further personalize the treatment of diseases like IBD, leveraging proven and validated microbiome links? Can we modulate the microbiome to manage IBD by altering the host immune response? In this review, we discuss recent advances in understanding the mechanism underpinning the role of gut microbes in driving or preventing IBD. We highlight developed targeted approaches to reverse dysbiosis through precision editing of the microbiome. We analyze limitations and opportunities while defining the specific clinical niche for this innovative therapeutic modality for the treatment, prevention, and diagnosis of IBD and its potential implication in precision medicine.

Taxonomic and functional partitioning of Chloroflexota populations under ferruginous conditions at and below the sediment-water interface.

The adaptation of the phylum Chloroflexota to various geochemical conditions is thought to have originated in primitive microbial ecosystems, involving hydrogenotrophic energy conservation under ferruginous anoxia. Oligotrophic deep waters displaying anoxic ferruginous conditions, such as those of Lake Towuti, and their sediments may thus constitute a preferential ecological niche for investigating metabolic versatility in modern Chloroflexota. Combining pore water geochemistry, cell counts, sulfate reduction rates, and 16S rRNA genes with in-depth analysis of metagenome-assembled genomes, we show that Chloroflexota benefit from cross-feeding on metabolites derived from canonical respiration chains and fermentation. Detailing their genetic contents, we provide molecular evidence that Anaerolineae have metabolic potential to use unconventional electron acceptors, different cytochromes, and multiple redox metalloproteins to cope with oxygen fluctuations, and thereby effectively colonizing the ferruginous sediment-water interface. In sediments, Dehalococcoidia evolved to be acetogens, scavenging fatty acids, haloacids, and aromatic acids, apparently bypassing specific steps in carbon assimilation pathways to perform energy-conserving secondary fermentations combined with CO2 fixation via the Wood-Ljungdahl pathway. Our study highlights the partitioning of Chloroflexota populations according to alternative electron acceptors and donors available at the sediment-water interface and below. Chloroflexota would have developed analogous primeval features due to oxygen fluctuations in ancient ferruginous ecosystems.

Structure and evolution of metapolycentromeres.

Metapolycentromeres consist of multiple sequential domains of centromeric chromatin associated with a centromere-specific variant of histone H3 (CENP-A), functioning collectively as a single centromere. To date, they have been revealed in nine flowering plant, five insect and six vertebrate species. In this paper, we focus on their structure and possible mechanisms of emergence and evolution. The metapolycentromeres may vary in the number of centromeric domains and in their genetic content and epigenetic modifications. However, these variations do not seem to affect their function. The emergence of metapolycentromeres has been attributed to multiple Robertsonian translocations and segmental duplications. Conditions of genomic instability, such as interspecific hybridization and malignant neoplasms, are suggested as triggers for the de novo emergence of metapolycentromeres. Addressing the "centromere paradox" - the rapid evolution of centromeric DNA and proteins despite their conserved cellular function - we explore the centromere drive hypothesis as a plausible explanation for the dynamic evolution of centromeres in general, and in particular the emergence of metapolycentromeres and holocentromeres. Apparently, metapolycentromeres are more common across different species than it was believed until recently. Indeed, a systematic review of the available cytogenetic publications allowed us to identify 27 candidate species with metapolycentromeres. Тhe list of the already established and newly revealed candidate species thus spans 27 species of flowering plants and eight species of gymnosperm plants, five species of insects, and seven species of vertebrates. This indicates an erratic phylogenetic distribution of the species with metapolycentromeres and may suggest an independent emergence of the metapolycentromeres in the course of evolution. However, the current catalog of species with identified and likely metapolycentromeres remains too short to draw reliable conclusions about their evolution, particularly in the absence of knowledge about related species without metapolycentromeres for comparative analysis. More studies are necessary to shed light on the mechanisms of metapolycentromere formation and evolution.

NeuroBooster Array: A Genome-Wide Genotyping Platform to Study Neurological Disorders Across Diverse Populations.

Commercial genome-wide genotyping arrays have historically neglected coverage of genetic variation across populations. We aimed to create a multi-ancestry genome-wide array that would include a wide range of neuro-specific genetic content to facilitate genetic research in neurological disorders across multiple ancestral groups, fostering diversity and inclusivity in research studies. We developed the Illumina NeuroBooster Array (NBA), a custom high-throughput and cost-effective platform on a backbone of 1,914,934 variants from the Infinium Global Diversity Array and added custom content comprising 95,273 variants associated with more than 70 neurological conditions or traits, and we further tested its performance on more than 2000 patient samples. This novel platform includes approximately 10,000 tagging variants to facilitate imputation and analyses of neurodegenerative disease-related genome-wide association study loci across diverse populations. In this article, we describe NBA's potential as an efficient means for researchers to assess known and novel disease genetic associations in a multi-ancestry framework. The NBA can identify rare genetic variants and accurately impute more than 15 million common variants across populations. Apart from enabling sample prioritization for further whole-genome sequencing studies, we envisage that NBA will play a pivotal role in recruitment for interventional studies in the precision medicine space. From a broader perspective, the NBA serves as a promising means to foster collaborative research endeavors in the field of neurological disorders worldwide. Ultimately, this carefully designed tool is poised to make a substantial contribution to uncovering the genetic etiology underlying these debilitating conditions. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

A Novel Bioprotective Strain of Lactiplantibacillus plantarumF2-Physiological, Genetical, and Antimicrobial Characterization.

Lactiplantibacillus plantarum is a member of lactic acid bacteria that improves the quality of fermented foods while also having a positive impact on human health. In this study, L. plantarum F2 was studied for characteristics such as biochemical and genetic identification, metabolite production, antimicrobial activity, and plasmid content. This strain exerts antimicrobial activity against some Gram-positive and Gram-negative pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella, and Escherichia coli) with inhibition zone diameters ranging between 17.0 and 29.0 mm; it can ferment glucose, arabinose, galactose, lactose, and demonstrated the ability to grow at high temperature (50°C). Another physiological specification of the strain was the morphology of the isolate in selective medium, the de Man, Rogosa, Sharpe medium (MRS medium containing triphenyl tetrazolium chloride), which exhibits a chromogenic colony (characterized as purple colonies) on the modified-MRS (mMRS) medium. Metabolites such as lactic acid and diacetyl production of the strain F2 were also investigated using chromatography and found to be 10.07 and 0.05 µg/mL, respectively. The peptides of the isolate's cell-free supernatant were determined to be ∼80 kDa, and finally, the plasmid isolated from the strain F2 was identified as L. plantarum strain KLDS1.0386 plasmid p4, which may be responsible for some characteristic properties, such as antimicrobial peptide production of the strain.

On the Nature of the Last Common Ancestor: A Story from its Translation Machinery.

The Last Common Ancestor (LCA) is understood as a hypothetical population of organisms from which all extant living creatures are thought to have descended. Its biology and environment have been and continue to be the subject of discussions within the scientific community. Since the first bacterial genomes were obtained, multiple attempts to reconstruct the genetic content of the LCA have been made. In this review, we compare 10 of the most extensive reconstructions of the gene content possessed by the LCA as they relate to aspects of the translation machinery. Although each reconstruction has its own methodological biases and many disagree in the metabolic nature of the LCA all, to some extent, indicate that several components of the translation machinery are among the most conserved genetic elements. The datasets from each reconstruction clearly show that the LCA already had a largely complete translational system with a genetic code already in place and therefore was not a progenote. Among these features several ribosomal proteins, transcription factors like IF2, EF-G, and EF-Tu and both class I and class II aminoacyl tRNA synthetases were found in essentially all reconstructions. Due to the limitations of the various methodologies, some features such as the occurrence of rRNA posttranscriptional modified bases are not fully addressed. However, conserved as it is, non-universal ribosomal features found in various reconstructions indicate that LCA's translation machinery was still evolving, thereby acquiring the domain specific features in the process. Although progenotes from the pre-LCA likely no longer exist recent results obtained by unraveling the early history of the ribosome and other genetic processes can provide insight to the nature of the pre-LCA world.

Pericardium decellularization in a one-day, two-step protocol.

Scaffolds used in tissue engineering can be obtained from synthetic or natural materials, always focusing the effort on mimicking the extracellular matrix of human native tissue. In this study, a decellularization process is used to obtain an acellular, biocompatible non-cytotoxic human pericardium graft as a bio-substitute. An enzymatic and hypertonic method was used to decellularize the pericardium. Histological analyses were performed to determine the absence of cells and ensure the integrity of the extracellular matrix (ECM). In order to measure the effect of the decellularization process on the tissue's biological and mechanical properties, residual genetic content and ECM biomolecules (collagen, elastin, and glycosaminoglycan) were quantified and the tissue's tensile strength was tested. Preservation of the biomolecules, a residual genetic content below 50ng/mg dry tissue, and maintenance of the histological structure provided evidence for the efficacy of the decellularization process, while preserving the ECM. Moreover, the acellular tissue retains its mechanical properties, as shown by the biomechanical tests. Our group has shown that the acellular pericardial matrix obtained through the super-fast decellularization protocol developed recently retains the desired biomechanical and structural properties, suggesting that it is suitable for a broad range of clinical indications.

Generation of empty cell envelopes of Streptococcus pyogenes using biosurfactants

BackgroundBacterial ghost cells (BGCs) are cell envelopes that devoid of cytoplasmic and genetic contents in purpose of variable applications, including their great potential as vaccine candidates and their effectiveness as delivery systems for drugs and proteins. To our knowledge, this is the first study to produce Gram-positive BGCs by treating Streptococcus pyogenes (S. pyogenes) ATCC 19615 with Tween80 (TW80) or TritonX-100 (TX100), followed by preliminary testing of their antigenicity and safety in NIH/Ola-Hsd mice. The produced BGCs were confirmed by the presence of intact cells under a light microscope, the absence of growth signs upon re-cultivation. The transmembrane tunnels were visualized using a scanning electron microscope, and subsequently, considerable quantities of released DNA and protein were detected in the culture supernatant of the BGCs. The antigenicity of the produced BGCs was tested through three intra-nasal immunization doses followed by infection. Afterward, the opsonic activity and the IgG levels were measured, followed by a comprehensive histopathological examination for selected tissues and organs.ResultsThe sera of immunized mice exhibited a significant rise in both opsonic activity (TW80 produced BGC = 68% and TX100 produced BGC = 75%) and IgG levels (TW80 produced BGC = a threefold increase and TX100 produced BGC = a fourfold increase) when compared to the positive control group "non-immunized challenged with ATCC 19615." Histopathological analysis revealed that the BGCs produced by TW80 are relatively safer and have a less severe impact than those produced by TX100.ConclusionThe study's findings suggest that Sp-BGC/TW80 is initially effective and safe in vivo. However, further pre-clinical studies are necessary to confirm its effectiveness and ensure complete safety, specifically in terms of the absence of autoimmunity and antibody cross-reactivity with myosin proteins in human cardiac tissues.

Genetic and environmental factors shaping goat milk oligosaccharide composition

Oligosaccharides (OS) in milk have been suggested to influence the health and development of the newborn by promoting growth of beneficial gut bacteria, stimulating brain development, and enhancing immune functions. Goat milk is a natural source of specific OS, which could be a potential beneficial ingredient for infant formula. In this study, goat milk oligosaccharide (gMOS) content from approximately 1,000 dairy goats across 18 commercial farms was studied. A genomic relationship matrix was used to unravel genetic and environmental factors shaping gMOS content. The most abundant gMOS identified was 3'-NGL, with a concentration of 32.05 mg/kg, while 3-FL exhibited the lowest concentration at 1.85 mg/kg. Acidic OS had a notably higher content (81.67 mg/kg) than neutral OS (24.88 mg/kg). High variability in gMOS content was observed among individual goats, which could for a large extent be attributed to genetic differences. Heritability estimates ranged from 31% for 3'-GL to 85% for 3-FL. High positive genetic correlations (>0.57) were estimated between 3'-SL and 6'-SL, and between 6'-GL and 3'-GL. The contribution of differences between farms to variation in milk OS content varied from 3% for 3'-NGL to 45% for 6'-SL. While gMOS like 3'-GL, 6'-GL, and 6'-NGL, were significantly influenced by systematic environmental factors such as the lactation stage, the impact of these factors was relatively minor compared with the importance of genetic and farm effects. This research, which stands out due to its relatively large sample size, underscores the pivotal role of genetics, and to a smaller extent farm practices like feed ration, in determining gMOS composition.

Association of pathogenic determinants of Fusobacterium necrophorum with bacteremia, and Lemierre’s syndrome

Fusobacterium necrophorum is a Gram-negative anaerobic bacterium responsible for localized infections of the oropharynx that can evolve into bacteremia and/or septic thrombophlebitis of the jugular vein or peritonsillar vein, called Lemierre’s syndrome. To identify microbial genetic determinants associated with the severity of this life-threatening disease, 70 F. necrophorum strains were collected and grouped into two categories according to the clinical presentation: (i) localized infection, (ii) bacteremia with/without Lemierre’s syndrome. Comparative genomic analyses revealed two clades with distinct genetic content, one clade being significantly enriched with isolates from subjects with bacteremia. To identify genetic determinants contributing to F. necrophorum pathogenicity, genomic islands and virulence factor orthogroups (OVFs) were predicted. The presence/absence profiles of OVFs did not group isolates according to their clinical category, but rather according to their phylogeny. However, a variant of lktA, a key virulence factor, with a frameshift deletion that results in two open reading frames, was associated with bacteremia. Moreover, a genome-wide association study identified three orthogroups associated with bacteremic strains: (i) cas8a1, (ii) a sodium/solute symporter, and (iii) a POP1 domain-containing protein. Further studies must be performed to assess the functional impact of lktA mutation and of these orthogroups on the physiopathological mechanisms of F. necrophorum infections.