Rapid advancements in long-read sequencing have facilitated species-level microbial profiling through full-length 16S rRNA sequencing (~ 1500 bp), and more notably, by the newer 16S-ITS-23S ribosomal RNA operon (RRN) sequencing (~ 4500 bp). RRN sequencing is emerging as a superior method for species resolution, exceeding the capabilities of short-read and full-length 16S rRNA sequencing. However, being in its early stages of development, RRN sequencing has several underexplored or understudied elements, highlighting the need for a critical and thorough examination of its methodologies. Key areas that require detailed analysis include understanding how primer pairs, sequencing platforms, and classifiers and databases affect the accuracy of species resolution achieved through RRN sequencing. Our study addresses these gaps by evaluating the effect of primer pairs using four RRN primer combinations, and that of sequencing platforms by employing PacBio and Oxford Nanopore Technologies (ONT) systems. Furthermore, two classification methods (Minimap2 and OTU clustering), in combination with four RRN reference databases (MIrROR, rrnDB, and two versions of GROND) were compared to identify consistent and accurate classification methods with RRN sequencing. Here we demonstrate that RRN primer pair choice and sequencing platform do not substantially bias taxonomic profiles for most of the tested mock communities, while classification methods significantly impact the accuracy of species-level assignments. Of the classification methods tested, Minimap2 classifier in combination with the GROND database most consistently provided accurate species-level classification across the communities tested, irrespective of sequencing platform.
Bacteriophage research has experienced a renaissance in recent years, owing to their therapeutic potential and versatility in biotechnology, particularly in combating antibiotic resistant-bacteria along the farm-to-fork continuum. However, certain pathogens remain underexplored as targets for phage therapy, including the zoonotic pathogen Streptococcus suis which causes infections in pigs and humans. Despite global efforts, the genome of only one infective S. suis phage has been described. Here, we report the isolation of two phages that infect S. suis: Bonnie and Clyde. The phages infect 58% of 100 S. suis strains tested, including representatives of seven different serotypes and thirteen known sequence types from diverse geographical origins. Clyde suppressed bacterial growth in vitro within two multi-strain mixes designed to simulate a polyclonal S. suis infection. Both phages demonstrated stability across various temperatures and pH levels, highlighting their potential to withstand storage conditions and maintain viability in delivery formulations. Genome comparisons revealed that neither phage shares significant nucleotide identity with any cultivated phages in the NCBI database and thereby represent novel species belonging to two distinct novel genera. This study is the first to investigate the adhesion devices of S. suis infecting phages. Structure prediction and analysis of adhesion devices with AlphaFold2 revealed two distinct lineages of S. suis phages: Streptococcus thermophilus-like (Bonnie) and S. suis-like (Clyde). The structural similarities between the adhesion devices of Bonnie and S. thermophilus phages, despite the lack of nucleotide similarity and differing ecological niches, suggest a common ancestor or convergent evolution, highlighting evolutionary links between pathogenic and non-pathogenic streptococcal species. These findings provide valuable insights into the genetic and phenotypic characteristics of phages that can infect S. suis, providing new data for the therapeutic application of phages in a One Health context.
Food system microbiomes include complex microbial networks that range from soil and marine environments to primary agriculture, farming, food processing, and distribution, and which influence human and environmental health. Advances in “omics” technologies, such as metagenomics, metatranscriptomics, metaproteomics, metabolomics, and culturomics, and their integration have deepened our understanding of microbiome dynamics and interactions. This growing knowledge is being leveraged to develop microbiome-based solutions enabling more sustainable food systems. This review explores microbiome interconnections along the food system and how this and other knowledge relating to microbiomes can be harnessed to, among other things, enhance crop resilience and productivity, improve animal health and performance, refine management practices in fishing and aquaculture, or prolong shelf life and reduce food spoilage during distribution. The often-overlooked role of bacteriophages on shaping microbiomes is discussed, as is the impact of diet on the human gut microbiota and, in turn, health. Despite advances, knowledge remains incomplete in particular areas and targeted experimental approaches are necessary to fill these gaps—going beyond merely predicting microbiome functionality. Ultimately, the ideal development of microbiome-based innovations in food systems will require collaboration between stakeholders and regulators to ensure safety, efficacy, and widespread adoption, unlocking its full potential to improve the health of animals, humans and the environment globally.
Mechanisms underlying the disruption of self-tolerance in acquired autoimmunity remain unclear. Immunoglobulin A (IgA) nephropathy is an acquired autoimmune disease where deglycosylated IgA1 (IgA subclass 1) auto-antigens are recognized by IgG auto-antibodies, forming immune complexes that are deposited in the kidneys, leading to glomerulonephritis. In the intestinal microbiota of patients with IgA nephropathy, there was increased relative abundance of mucin-degrading bacteria, including Akkermansia muciniphila . IgA1 was deglycosylated by A. muciniphila both in vitro and in the intestinal lumen of mice. This generated neo-epitopes that were recognized by autoreactive IgG from the sera of patients with IgA nephropathy. Mice expressing human IgA1 and the human Fc α receptor I (α1 KI -CD89 tg ) that underwent intestinal colonization by A. muciniphila developed an aggravated IgA nephropathy phenotype. After deglycosylation of IgA1 by A. muciniphila in the mouse gut lumen, IgA1 crossed the intestinal epithelium into the circulation by retrotranscytosis and became deposited in the glomeruli of mouse kidneys. Human α-defensins—a risk locus for IgA nephropathy—inhibited growth of A. muciniphila in vitro. A negative correlation observed between stool concentration of α-defensin 6 and quantity of A. muciniphila in the guts of control participants was lost in patients with IgA nephropathy. This study demonstrates that gut microbiota dysbiosis contributes to generation of auto-antigens in patients with IgA nephropathy and in a mouse model of this disease.
Lactiplantibacillus plantarum is a commensal bacterial species often found within the human gut. To expand our knowledge about this human-associated taxon with potential probiotic properties, here we present the draft genome sequence of Lactiplantibacillus plantarum strain APC2688, isolated from a human fecal sample.
Abstract Background The field of 16S rRNA-targeted metagenetics has been enhanced through the improved accuracy of long-read sequencing. More specifically, recent advances have facilitated the transition from short-read sequencing of 16S rRNA gene regions to full-length sequencing of the entire 16S gene (~1500 bp) and, in turn, sequencing of the 16S, Internal Transcribed Spacer (ITS), and 23S regions covering a DNA region known as the ribosomal RNA operon (RRN) (~4500 bp). These technological advances offer the potential to achieve at least species-level resolution when analysing microbiomes, increasing interest in RRN sequencing. However, before widespread adoption of this approach can occur successfully, a thorough assessment of its strengths and limitations is necessary. Results This study assesses the effects of RRN primer pairs and sequencing platforms on RRN sequencing, while also aiming to benchmark taxonomic classification methods. In this context, we study the effect four RRN primer combinations; four mock communities, three sequencing platforms (PacBio, Oxford Nanopore Technologies, and Illumina), two classification approaches (Minimap2 alignment and OTU clustering), and four RRN reference databases (MIrROR, rrnDB, and two iterations of FANGORN) alongside two 16S databases (Greengenes2 and SILVA). Our study reveals that choice of primer pair and sequencing platform do not substantially bias the taxonomic profiles provided by RRN sequencing for a majority of the mock communities. However, community composition was identified as a confounding factor. The classification method significantly impacts the accuracy of species-level taxonomic assignment. Applying Minimap2 in combination with the FANGORN database was found to provide the most accurate profile for most microbial communities, irrespective of sequencing platform. Conclusions Long-read sequencing of the RRN operon provides species-level resolution surpassing that of Illumina-based 16S rRNA gene sequencing. Our findings advocate for the use of RRN sequencing in species-level microbial profiling. We extensively benchmark the factors involved to provide a valuable resource, aiding the advancement and adoption of RRN sequencing, while highlighting some ongoing challenges.
Sequence comparison of 16S rRNA PCR amplicons is an established approach to taxonomically identify bacterial isolates and profile complex microbial communities. One potential application of recent advances in long-read sequencing technologies is to sequence entire rRNA operons and capture significantly more phylogenetic information compared to sequencing of the 16S rRNA (or regions thereof) alone, with the potential to increase the proportion of amplicons that can be reliably classified to lower taxonomic ranks. Here we describe GROND (Genome-derived Ribosomal Operon Database), a publicly available database of quality-checked 16S-ITS-23S rRNA operons, accompanied by multiple taxonomic classifications. GROND will aid researchers in analysis of their data and act as a standardised database to allow comparison of results between studies.
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Chlorate has become a concern in the food and beverage sector, related to chlorine sanitizers in industrial food production and water treatment. It is of particular concern to regulatory bodies due to the negative health effects of chlorate exposure. This study investigated the fate of chlorate in raw milk and isolated bacterial strains of interest responsible for chlorate breakdown. Unpasteurized milk was demonstrated to have a chlorate-reducing capacity, breaking down enriched chlorate to undetectable levels in 11 days. Further enrichment and isolation using conditions specific to chlorate-reducing bacteria successfully isolated three distinct strains of Hafnia paralvei. Chlorate-reducing bacteria were observed to grow in a chlorate-enriched medium with lactate as an electron donor. All isolated strains were demonstrated to reduce chlorate in liquid medium; however, the exact mechanism of chlorate degradation was not definitively identified in this study.
Peri-hilar cholangiocarcinoma (pCCA) is chemorefractory and limited genomic analyses have been undertaken in Western idiopathic disease. We undertook comprehensive genomic analyses of a U.K. idiopathic pCCA cohort to characterize its mutational profile and identify new targets. Whole exome and targeted DNA sequencing was performed on forty-two resected pCCA tumors and normal bile ducts, with Gene Set Enrichment Analysis (GSEA) using one-tailed testing to generate false discovery rates (FDR). 60% of patients harbored one cancer-associated mutation, with two mutations in 20%. High frequency somatic mutations in genes not typically associated with cholangiocarcinoma included mTOR, ABL1 and NOTCH1. We identified non-synonymous mutation (p.Glu38del) in MAP3K9 in ten tumors, associated with increased peri-vascular invasion (Fisher's exact, p < 0.018). Mutation-enriched pathways were primarily immunological, including innate Dectin-2 (FDR 0.001) and adaptive T-cell receptor pathways including PD-1 (FDR 0.007), CD4 phosphorylation (FDR 0.009) and ZAP70 translocation (FDR 0.009), with overlapping HLA genes. We observed cancer-associated mutations in over half of our patients. Many of these mutations are not typically associated with cholangiocarcinoma yet may increase eligibility for contemporary targeted trials. We also identified a targetable MAP3K9 mutation, in addition to oncogenic and immunological pathways hitherto not described in any cholangiocarcinoma subtype.
AbstractObjectivesJuvenile-onset systemic lupus erythematosus (jSLE) affects 15–20% of lupus patients. Clinical heterogeneity between racial groups, age groups and individual patients suggests variable pathophysiology. This study aimed to identify highly penetrant damaging mutations in genes associated with SLE/SLE-like disease in a large national cohort (UK JSLE Cohort Study) and compare demographic, clinical and laboratory features in patient sub-cohorts with ‘genetic’ SLE vs remaining SLE patients.MethodsBased on a sequencing panel designed in 2018, target enrichment and next-generation sequencing were performed in 348 patients to identify damaging gene variants. Findings were integrated with demographic, clinical and treatment related datasets.ResultsDamaging gene variants were identified in ∼3.5% of jSLE patients. When compared with the remaining cohort, ‘genetic’ SLE affected younger children and more Black African/Caribbean patients. ‘Genetic’ SLE patients exhibited less organ involvement and damage, and neuropsychiatric involvement developed over time. Less aggressive first line treatment was chosen in ‘genetic’ SLE patients, but more second and third line agents were used. ‘Genetic’ SLE associated with anti-dsDNA antibody positivity at diagnosis and reduced ANA, anti-LA and anti-Sm antibody positivity at last visit.ConclusionApproximately 3.5% of jSLE patients present damaging gene variants associated with younger age at onset, and distinct clinical features. As less commonly observed after treatment induction, in ‘genetic’ SLE, autoantibody positivity may be the result of tissue damage and explain reduced immune complex-mediated renal and haematological involvement. Routine sequencing could allow for patient stratification, risk assessment and target-directed treatment, thereby increasing efficacy and reducing toxicity.
Introduction It has been hypothesised that the regular consumption of safe, live microbes confers health-promoting attributes, including the prevention of disease. To address this hypothesis, we propose a scoping review approach that will systematically assess the large corpus of relevant literature that is now available on this research topic. This article outlines a protocol for a scoping review of published studies on interventions with live microbes in non-patient populations across eight health categories. The scoping review aims to catalogue types of interventions, measured outcomes, dosages, effectiveness, as well as current research gaps.Methods and analysis The scoping review will follow the six-staged protocol as proposed by Arksey and O’Malley and will include the following stages: defining the research questions (stage 1); defining the eligibility criteria and finalising search strategy (stage 2); selection of studies based on the eligibility criteria (stage 3); development of a data extraction framework and charting of data (stage 4); aggregation of results and summarisation of findings (stage 5); and the optional consultation with stakeholders (stage 6), which will not be performed.Ethics and dissemination Since the scoping review synthesises information from existing literature, no separate ethical approval is required. The findings of the scoping review will be communicated for publication to an open-access, peer-reviewed scientific journal, presented at relevant conferences, and disseminated at future workshops with all relevant data and documents being available online through the Open Science Framework (https://osf.io/kvhe7).
In recent years, there has been a global resurgence of public interest in fermented foods. In parallel, there have been several new studies that associate the consumption of fermented foods with a variety of beneficial impacts. These combined developments have led to a renewed focus in research and innovation vis-à-vis fermented foods, particularly traditional fermented foods, with an aim to harness this information to develop novel fermented foodstuffs and ingredients and make them available in the market. Consequently, an ever greater and more diverse array of fermented foods, including functional fermented foods with health benefits, are becoming available for public consumption in global markets, with the number expected to grow substantially in the coming decade. This rapidly expanding portfolio of commercially available fermented foods has in turn required an evolution in the corresponding global regulatory frameworks. Due to the innovative and emerging nature of these foods, combined with historical differences in regulator approaches, significant disharmony exists across these frameworks, with individual nations and organizations often adopting unique approaches relating to the establishment of standards and specifications. In this review, we provide an overview of the current regulatory frameworks for a diversity of fermented foods across multiple jurisdictions, with special emphasis on differences in legislative structures and approaches, regulatory harmonization, and current legislative limitations. Overall, the review provides important perspective and context in relation to current global fermented food regulatory practices with possible directions and recommendations for future legislative efforts.
Bacterial infections of livestock threaten the sustainability of agriculture and public health through production losses and contamination of food products. While prophylactic and therapeutic application of antibiotics has been successful in managing such infections, the evolution and spread of antibiotic-resistant strains along the food chain and in the environment necessitates the development of alternative or adjunct preventive and/or therapeutic strategies. Additionally, the growing consumer preference for "greener" antibiotic-free food products has reinforced the need for novel and safer approaches to controlling bacterial infections. The use of bacteriophages (phages), which can target and kill bacteria, are increasingly considered as a suitable measure to reduce bacterial infections and contamination in the food industry. This review primarily elaborates on the recent veterinary applications of phages and discusses their merits and limitations. Furthermore, using Streptococcus suis as a model, we describe the prevalence of prophages and the anti-viral defence arsenal in the genome of the pathogen as a means to define the genetic building blocks that are available for the (synthetic) development of phage-based treatments. The data and approach described herein may provide a framework for the development of therapeutics against an array of bacterial pathogens.
The microbial communities present within fermented foods are diverse and dynamic, producing a variety of metabolites responsible for the fermentation processes, imparting characteristic organoleptic qualities and health-promoting traits, and maintaining microbiological safety of fermented foods. In this context, it is crucial to study these microbial communities to characterise fermented foods and the production processes involved. High Throughput Sequencing (HTS)-based methods such as metagenomics enable microbial community studies through amplicon and shotgun sequencing approaches. As the field constantly develops, sequencing technologies are becoming more accessible, affordable and accurate with a further shift from short read to long read sequencing being observed. Metagenomics is enjoying wide-spread application in fermented food studies and in recent years is also being employed in concert with synthetic biology techniques to help tackle problems with the large amounts of waste generated in the food sector. This review presents an introduction to current sequencing technologies and the benefits of their application in fermented foods.
The etiology of Crohn's disease (CD) is multifactorial. Bacterial and fungal microbiota are involved in the onset and/or progression of the disease. A bacterial dysbiosis in CD patients is accepted; however, less is known about the mycobiome and the relationships between the two communities. We investigated the interkingdom relationships, their metabolic consequences, and the changes in the fungal community during relapse and remission in CD.Two cohorts were evaluated: a British cohort (n = 63) comprising CD and ulcerative colitis patients, and controls. The fungal and bacterial communities of biopsy and fecal samples were analyzed, with the fecal volatiles; datasets were also integrated; and a Dutch cohort (n = 41) comprising CD patients and healthy controls was analyzed for stability of the gut mycobiome.A dysbiosis of the bacterial community was observed in biopsies and stool. Results suggest Bacteroides is likely key in CD and may modulate Candida colonization. A dysbiosis of the fungal community was observed only in the Dutch cohort; Malassezia and Candida were increased in patients taking immunosuppressants. Longitudinal analysis showed an increase in Cyberlindnera in relapse. Saccharomyces was dominant in all fecal samples, but not in biopsies, some of which did not yield fungal reads; amino acid degradation was the main metabolic change associated with CD and both bacteria and fungi might be implicated.We have shown that Bacteroides and yeasts may play a role in CD; understanding their role and relationship in the disease would shed new light on the development and treatment of CD.
Alterations in the human microbiome have been observed in a variety of conditions such as asthma, gingivitis, dermatitis and cancer, and much remains to be learned about the links between the microbiome and human health. The fusion of artificial intelligence with rich microbiome datasets can offer an improved understanding of the microbiome’s role in human health. To gain actionable insights it is essential to consider both the predictive power and the transparency of the models by providing explanations for the predictions. We combine the collection of leg skin microbiome samples from two healthy cohorts of women with the application of an explainable artificial intelligence (EAI) approach that provides accurate predictions of phenotypes with explanations. The explanations are expressed in terms of variations in the relative abundance of key microbes that drive the predictions. We predict skin hydration, subject's age, pre/post-menopausal status and smoking status from the leg skin microbiome. The changes in microbial composition linked to skin hydration can accelerate the development of personalized treatments for healthy skin, while those associated with age may offer insights into the skin aging process. The leg microbiome signatures associated with smoking and menopausal status are consistent with previous findings from oral/respiratory tract microbiomes and vaginal/gut microbiomes respectively. This suggests that easily accessible microbiome samples could be used to investigate health-related phenotypes, offering potential for non-invasive diagnosis and condition monitoring. Our EAI approach sets the stage for new work focused on understanding the complex relationships between microbial communities and phenotypes. Our approach can be applied to predict any condition from microbiome samples and has the potential to accelerate the development of microbiome-based personalized therapeutics and non-invasive diagnostics.
Abstract: Background: Whole-genome sequencing (WGS) of SARS-CoV-2 laboratory-confirmed cases can provide insights into viral transmission and genetic diversity at a population level. However, less is known about the impact of non-pharmaceutical interventions (NPIs), including lockdowns, on circulating SARS-CoV-2 lineages and variants of concern, the relative contribution of travel to re-emergence of pandemic waves within communities or how different lineages and variants contribute to disease severity. Methods: We have conducted an analysis within a prospective, multicentre observational study of individuals attending four hospitals in the South-East of Ireland with COVID-19. Samples underwent WGS from which lineages and variants were assigned, lineage frequency was plotted over time and phylogenetic analysis was employed to determine the origin of variants detected post-lockdown. Univariate and multivariate analyses assessed relationships between viral lineage/variant and COVID-19 disease severity. Results: We analysed 225 genome sequences across two SARS-CoV-2 waves, 134 (59.6%) from wave 1 (March to June) and 91 (40.4%) from wave 2 (July to December), representing 15.2% of COVID-19 admissions to these hospitals during the sampling periods. Four variants (B.1.1.162, B1.1.70, B.1.1.267 and B.1.1) comprised 68% of variants detected during wave 1. Of these variants, only a single B.1.1.70 sequence was detected in wave 2, while the B.1.177 lineage emerged and contributed to 82.3% of lineages detected. Phylogenetic analysis suggested multiple introductions of wave 2 variants from outside Ireland. We found no consistent association between SARS-CoV-2 lineages and disease severity. Conclusions: These data suggest elimination of common SARS-CoV-2 lineages from hospitalised cases associated with effective NPIs and that importation of new viral variants through travel was a significant contributor to the re-emergence of the pandemic in the second wave in Ireland. Our findings highlight the importance of genomic surveillance in identifying circulating viral genetic diversity and variants of concern and, also, modelling the disease burden of SARS-CoV-2.
Mitochondrial DNA (mtDNA) is highly polymorphic and encodes 13 proteins which are critical to the production of ATP via oxidative phosphorylation. As mtDNA is maternally inherited and undergoes negligible recombination, acquired mutations have subdivided the human population into several discrete haplogroups. Mitochondrial haplogroup has been found to significantly alter mitochondrial function and impact susceptibility to adverse drug reactions. Despite these findings, there are currently limited models to assess the effect of mtDNA variation upon susceptibility to adverse drug reactions. Platelets offer a potential personalised model of this variation, as their anucleate nature offers a source of mtDNA without interference from the nuclear genome. This study, therefore, aimed to determine the effect of mtDNA variation upon mitochondrial function and drug-induced mitochondrial dysfunction in a platelet model. The mtDNA haplogroup of 383 healthy volunteers was determined using next-generation mtDNA sequencing (Illumina MiSeq). Subsequently, 30 of these volunteers from mitochondrial haplogroups H, J, T and U were recalled to donate fresh, whole blood from which platelets were isolated. Platelet mitochondrial function was tested at basal state and upon treatment with compounds associated with both mitochondrial dysfunction and adverse drug reactions, flutamide, 2-hydroxyflutamide and tolcapone (10–250 μM) using extracellular flux analysis. This study has demonstrated that freshly-isolated platelets are a practical, primary cell model, which is amenable to the study of drug-induced mitochondrial dysfunction. Specifically, platelets from donors of haplogroup J have been found to have increased susceptibility to the inhibition of complex I-driven respiration by 2-hydroxyflutamide. At a time when individual susceptibility to adverse drug reactions is not fully understood, this study provides evidence that inter-individual variation in mitochondrial genotype could be a factor in determining sensitivity to mitochondrial toxicants associated with costly adverse drug reactions.