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Veterinary Sciences May 2024Metagenomics offers the potential to replace and simplify classical methods used in the clinical diagnosis of human and veterinary infectious diseases. Metagenomics... (Review)
Review
Metagenomics offers the potential to replace and simplify classical methods used in the clinical diagnosis of human and veterinary infectious diseases. Metagenomics boasts a high pathogen discovery rate and high specificity, advantages absent in most classical approaches. However, its widespread adoption in clinical settings is still pending, with a slow transition from research to routine use. While longer turnaround times and higher costs were once concerns, these issues are currently being addressed by automation, better chemistries, improved sequencing platforms, better databases, and automated bioinformatics analysis. However, many technical options and steps, each producing highly variable outcomes, have reduced the technology's operational value, discouraging its implementation in diagnostic labs. We present a case for utilizing non-targeted RNA sequencing (NT-RNA-seq) as an ideal metagenomics method for the detection of infectious disease-causing agents in humans and animals. Additionally, to create operational value, we propose to identify best practices for the "core" of steps that are invariably shared among many human and veterinary protocols. Reference materials, sequencing procedures, and bioinformatics standards should accelerate the validation processes necessary for the widespread adoption of this technology. Best practices could be determined through "implementation research" by a consortium of interested institutions working on common samples.
PubMed: 38921986
DOI: 10.3390/vetsci11060239 -
Journal of Fungi (Basel, Switzerland) May 2024Pulmonary mucormycosis (PM) is an invasive and potentially fatal fungal infection, with () being the most common pathogen. The routine therapy for this infection...
Oral Isavuconazole Combined with Nebulized Inhalation and Bronchoscopic Administration of Amphotericin B for the Treatment of Pulmonary Mucormycosis: A Case Report and Literature Review.
Pulmonary mucormycosis (PM) is an invasive and potentially fatal fungal infection, with () being the most common pathogen. The routine therapy for this infection includes surgery and antifungal agents. However, the therapeutic effects of single agents are unsatisfactory due to the rapid progression of mucormycosis, while not all patients can tolerate surgery. Innovative treatment methods like combination therapy await validations of their clinical efficacy. We report a case of PM that was diagnosed via metagenomics next-generation sequencing (mNGS) of black drainage fluid from the patient's lung. The patient eventually recovered and was discharged after a combination therapy of oral isavuconazole, inhaled amphotericin B, and local perfusion of amphotericin B through bronchoscopy, which may be a promising strategy for the treatment of PM, especially for cases where surgery is not possible. A retrospective study of 297 cases in a literature review highlights the different treatment methods used in clinical practice.
PubMed: 38921374
DOI: 10.3390/jof10060388 -
Frontiers in Medicine 2024pneumonia is very rare in normal people. At present, there is a lack of clinical data on the clinical characteristics and diagnosis and treatment experience of patients...
BACKGROUND
pneumonia is very rare in normal people. At present, there is a lack of clinical data on the clinical characteristics and diagnosis and treatment experience of patients with this type of infection. Our team had recently treated 7 cases of these patients. This study aims to comprehensively summarize and analyze the clinical characteristics and treatment methods of pneumonia, and to provide clinical evidence for the diagnosis and treatment of pneumonia.
METHODS
Clinical data were retrospectively collected from patients diagnosed with pneumonia through metagenomic next-generation sequencing (mNGS) at the Department of Pulmonary and Critical Care Medicine, Meizhou People's Hospital.
RESULTS
Seven patients with pneumonia reported a history of poultry exposure, experiencing fever alongside respiratory or digestive symptoms. Marked elevation of blood inflammation markers, accompanied by hypoproteinemia and liver damage, was observed. Chest CT scans revealed pneumonia and pleural effusion. was detected in blood or bronchoalveolar lavage fluid (BALF) through mNGS, often co-occurring with or other bacteria infections. Notably, Doxycycline demonstrated efficacy in treating
CONCLUSION
infection is a zoonotic disease, particularly among individuals with a history of poultry exposure, and mNGS emerges as a reliable diagnostic tool for its detection. infection manifests with systemic and lung inflammation, effectively addressed through Doxycycline therapy.
PubMed: 38919935
DOI: 10.3389/fmed.2024.1406737 -
Communicative & Integrative Biology 2024The Dead Sea is unique compared to other extreme halophilic habitats. Its salinity exceeds 34%, and it is getting saltier. The Dead Sea environment is characterized by a... (Review)
Review
The Dead Sea is unique compared to other extreme halophilic habitats. Its salinity exceeds 34%, and it is getting saltier. The Dead Sea environment is characterized by a dominance of divalent cations, with magnesium chloride (MgCl) levels approaching the predicted 2.3 M upper limit for life, an acidic pH of 6.0, and high levels of absorbed ultraviolet radiation. Consequently, only organisms adapted to such a polyextreme environment can survive in the surface, sinkholes, sediments, muds, and underwater springs of the Dead Sea. Metagenomic sequence analysis and amino acid profiling indicated that the Dead Sea is predominantly composed of halophiles that have various adaptation mechanisms and produce metabolites that can be utilized for biotechnological purposes. A variety of products have been obtained from halophilic microorganisms isolated from the Dead Sea, such as antimicrobials, bioplastics, biofuels, extremozymes, retinal proteins, colored pigments, exopolysaccharides, and compatible solutes. These resources find applications in agriculture, food, biofuel production, industry, and bioremediation for the detoxification of wastewater and soil. Utilizing halophiles as a bioprocessing platform offers advantages such as reduced energy consumption, decreased freshwater demand, minimized capital investment, and continuous production.
PubMed: 38919836
DOI: 10.1080/19420889.2024.2369782 -
Horticulture Research Jun 2024Root-associated microbiomes play a crucial role in plant responses to biotic and abiotic stresses. Plants can enrich beneficial microbes to increase their...
Root-associated microbiomes play a crucial role in plant responses to biotic and abiotic stresses. Plants can enrich beneficial microbes to increase their stress-relieving ability. Above-ground insect herbivory is among the most detrimental stresses for plants, especially to crop production. However, few studies have explored how root-associated microbiomes respond to herbivores and influence plant-defense functions under herbivory stress. We investigate the changes and functional role of root-associated microbial communities under herbivory stress using leafminer () and cowpea () as a focal system. We did this by using a combination of 16S ribosomal RNA gene profiling and metagenomic sequencing to test for differences in co-occurrence networks and functions between cowpea plants infested and noninfested with leafminers. The results demonstrated that leafminer infestation caused a shift in the rhizosphere microbiome, which was characterized by a significant variation in microbiome community structure and composition, the selection of hub microbes involved in nitrogen (N) metabolism, and functional enrichment related to N metabolism. Notably, nitrogen-fixing bacteria species were actively enriched and selected to be hubs in the rhizosphere. Inoculation with enhanced cowpea performance under leafminer stress and increased protease inhibitor levels to decrease leafminer fitness. Overall, our study characterized the changes of root-associated microbiota between leafminer-infested and noninfested cowpea plants and revealed the mechanisms underlying the rhizosphere microbiome shift that enhance plant performance and defense against herbivory. Our findings provide further support for the notion that plants enrich rhizosphere microbes to counteract aboveground insect herbivores.
PubMed: 38919561
DOI: 10.1093/hr/uhae121 -
Microbiome Jun 2024Microbial adaptation to salinity has been a classic inquiry in the field of microbiology. It has been demonstrated that microorganisms can endure salinity stress via...
BACKGROUND
Microbial adaptation to salinity has been a classic inquiry in the field of microbiology. It has been demonstrated that microorganisms can endure salinity stress via either the "salt-in" strategy, involving inorganic ion uptake, or the "salt-out" strategy, relying on compatible solutes. While these insights are mostly based on laboratory-cultured isolates, exploring the adaptive mechanisms of microorganisms within natural salinity gradient is crucial for gaining a deeper understanding of microbial adaptation in the estuarine ecosystem.
RESULTS
Here, we conducted metagenomic analyses on filtered surface water samples collected from a typical subtropical short residence-time estuary and categorized them by salinity into low-, intermediate-, and high-salinity metagenomes. Our findings highlighted salinity-driven variations in microbial community composition and function, as revealed through taxonomic and Clusters of Orthologous Group (COG) functional annotations. Through metagenomic binning, 127 bacterial and archaeal metagenome-assembled genomes (MAGs) were reconstructed. These MAGs were categorized as stenohaline-specific to low-, intermediate-, or high-salinity-based on the average relative abundance in one salinity category significantly exceeding those in the other two categories by an order of magnitude. Those that did not meet this criterion were classified as euryhaline, indicating a broader range of salinity tolerance. Applying the Boruta algorithm, a machine learning-based feature selection method, we discerned important genomic features from the stenohaline bacterial MAGs. Of the total 12,162 COGs obtained, 40 were identified as important features, with the "inorganic ion transport and metabolism" COG category emerging as the most prominent. Furthermore, eight COGs were implicated in microbial osmoregulation, of which four were related to the "salt-in" strategy, three to the "salt-out" strategy, and one to the regulation of water channel activity. COG0168, annotated as the Trk-type K transporter related to the "salt-in" strategy, was ranked as the most important feature. The relative abundance of COG0168 was observed to increase with rising salinity across metagenomes, the stenohaline strains, and the dominant Actinobacteriota and Proteobacteria phyla.
CONCLUSIONS
We demonstrated that salinity exerts influences on both the taxonomic and functional profiles of the microbial communities inhabiting the estuarine ecosystem. Our findings shed light on diverse salinity adaptation strategies employed by the estuarine microbial communities, highlighting the crucial role of the "salt-in" strategy mediated by Trk-type K transporters for microorganisms thriving under osmotic stress in the short residence-time estuary. Video Abstract.
Topics: Estuaries; Salinity; Metagenomics; Bacteria; Archaea; Metagenome; Adaptation, Physiological; Microbiota; Seawater; Water Microbiology
PubMed: 38918820
DOI: 10.1186/s40168-024-01817-w -
Applied Microbiology and Biotechnology Jun 2024Smokeless tobacco products (STPs) are attributed to oral cancer and oral pathologies in their users. STP-associated cancer induction is driven by carcinogenic compounds...
Smokeless tobacco products (STPs) are attributed to oral cancer and oral pathologies in their users. STP-associated cancer induction is driven by carcinogenic compounds including tobacco-specific nitrosamines (TSNAs). The TSNAs synthesis could enhanced due to the metabolic activity (nitrate metabolism) of the microbial populations residing in STPs, but identifying microbial functions linked to the TSNAs synthesis remains unexplored. Here, we rendered the first report of shotgun metagenomic sequencing to comprehensively determine the genes of all microorganisms residing in the Indian STPs belonging to two commercial (Moist-snuff and Qiwam) and three loose (Mainpuri Kapoori, Dohra, and Gudakhu) STPs, specifically consumed in India. Further, the level of nicotine, TSNAs, mycotoxins, and toxic metals were determined to relate their presence with microbial activity. The microbial population majorly belongs to bacteria with three dominant phyla including Actinobacteria, Proteobacteria, and Firmicutes. Furthermore, the STP-linked microbiome displayed several functional genes associated with nitrogen metabolism and antibiotic resistance. The chemical analysis revealed that the Mainpuri Kapoori product contained a high concentration of ochratoxins-A whereas TSNAs and Zink (Zn) quantities were high in the Moist-snuff, Mainpuri Kapoori, and Gudakhu products. Hence, our observations will help in attributing the functional potential of STP-associated microbiome and in the implementation of cessation strategies against STPs. KEY POINTS: •Smokeless tobacco contains microbes that can assist TSNA synthesis. •Antibiotic resistance genes present in smokeless tobacco-associated bacteria. •Pathogens in STPs can cause infections in smokeless tobacco users.
Topics: Tobacco, Smokeless; Metagenomics; Bacteria; Microbiota; Nitrosamines; India; Nicotine; Humans
PubMed: 38918238
DOI: 10.1007/s00253-024-13156-9 -
Microbiology (Reading, England) Jun 2024Metagenome community analyses, driven by the continued development in sequencing technology, is rapidly providing insights in many aspects of microbiology and becoming a...
Metagenome community analyses, driven by the continued development in sequencing technology, is rapidly providing insights in many aspects of microbiology and becoming a cornerstone tool. Illumina, Oxford Nanopore Technologies (ONT) and Pacific Biosciences (PacBio) are the leading technologies, each with their own advantages and drawbacks. Illumina provides accurate reads at a low cost, but their length is too short to close bacterial genomes. Long reads overcome this limitation, but these technologies produce reads with lower accuracy (ONT) or with lower throughput (PacBio high-fidelity reads). In a critical first analysis step, reads are assembled to reconstruct genomes or individual genes within the community. However, to date, the performance of existing assemblers has never been challenged with a complex mock metagenome. Here, we evaluate the performance of current assemblers that use short, long or both read types on a complex mock metagenome consisting of 227 bacterial strains with varying degrees of relatedness. We show that many of the current assemblers are not suited to handle such a complex metagenome. In addition, hybrid assemblies do not fulfil their potential. We conclude that ONT reads assembled with CANU and Illumina reads assembled with SPAdes offer the best value for reconstructing genomes and individual genes of complex metagenomes, respectively.
Topics: Metagenome; Benchmarking; High-Throughput Nucleotide Sequencing; Metagenomics; Bacteria; Sequence Analysis, DNA; Genome, Bacterial; Microbiota
PubMed: 38916949
DOI: 10.1099/mic.0.001469 -
Microbiology Spectrum Jun 2024Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who...
Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who were admitted to the Affiliated Hospital of Jining Medical University. This study primarily aimed to determine the diagnostic performance of mNGS and conventional microbiological tests (CMTs) using bronchoalveolar lavage fluid samples for detecting pathogens. Our findings indicated that mNGS performed significantly higher sensitivity (97.54% vs 28.68%, < 0.001), coincidence (90.34% vs 35.17%, < 0.001), and negative predictive value (80.00% vs 13.21%, < 0.001) but performed lower specificity than CMTs (52.17% vs 87.5%, < 0.001). as the most common bacterial pathogen had the largest proportion (22.90%, 30/131) in this study. In addition to bacteria, fungi, and virus, mNGS can detect a variety of atypical pathogens such as and . Mixed infections were common in patients with severe pneumonia, and bacterial-fungal-viral-atypical pathogens were the most complicated infection. After adjustments of antibiotics based on mNGS and CMTs, the clinical manifestation improved in 139 (95.86%, 139/145) patients. Our data demonstrated that mNGS had significant advantage in diagnosing respiratory tract infections, especially atypical pathogens and fungal infections. Pathogens were detected timely and comprehensively, contributing to the adjustments of antibiotic treatments timely and accurately, improving patient prognosis and decreasing mortality potentially.IMPORTANCEMetagenomic next-generation sequencing using bronchoalveolar lavage fluid can provide more comprehensive and accurate pathogens for respiratory tract infections, especially when considering the previous usage of empirical antibiotics before admission or complicated clinical presentation. This technology is expected to play an important role in the precise application of antimicrobial drugs in the future.
PubMed: 38916357
DOI: 10.1128/spectrum.00458-24 -
Microbiology Spectrum Jun 2024From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses...
From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses and bacteria tested negative. To uncover the possible cause of the disease, a metagenomic analysis was performed in the pooled small intestine samples from three 8-day-old diseased piglets. The results showed that Getah virus (GETV), an RNA virus, might be the potential pathogen that affects pig health. Subsequently, GETV nucleotide was detected in all of the 15 samples collected from three diseased piglets using quantitative reverse transcription PCR, suggesting GETV as the main pathogen of the disease. A GETV strain, designated as GDHYLC23, was successfully isolated using the swine testicle cell line. Sequence analysis showed that the epidemic strain had a unique 32-nucleotide repeat insertion in the 3' noncoding region. Phylogenetic analysis showed that GDHYLC23 belonged to the pandemic group III. The identification of GETV with new variations implies the continuous evolution of the virus, which poses potential threats to the swine industry.IMPORTANCEPig farms are faced with emerging and re-emerging viruses that may cause substantial economic loss. The identification of potentially pathogenic viruses helps to prevent and control the spread of diseases. In this study, by using metagenomic analysis, we found that a neglected virus, GETV with a unique insertion in the genome, was the main pathogen in one pig farm that suffered severe piglet death and sow reproductive disorders. Although the potential impact of such an insertion on viral pathogenicity is unknown, the surveillance of the continuing evolution of GETV in pig farms cannot be ignored.
PubMed: 38916356
DOI: 10.1128/spectrum.00483-24