This article reports the clinical characteristics and treatment processes of three cases of mucormycosis occurring after hematopoietic stem cell transplantation in children, along with a review of relevant literature. All three patients presented with chest pain as the initial symptom, and metagenomic next-generation sequencing (mNGS) confirmed the mucycete infection early in all cases. Two patients recovered after treatment, while one succumbed to disseminated infection. mNGS has facilitated early diagnosis and treatment, reducing mortality rates. Additionally, surgical intervention is an important strategy for improving the prognosis of this condition.
Humans ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Mucormycosis/etiology* ; Male ; High-Throughput Nucleotide Sequencing/methods* ; Child ; Female ; Metagenomics ; Child, Preschool

OBJECTIVE: To explore the clinical application value of metagenomic next-generation sequencing (mNGS) in pathogen detection of bloodstream infection secondary to hematologic diseases in children. METHODS: 42 children with bloodstream infections secondary to hematologic diseases admitted to the Children's Hematology and Tumor Center of the Affiliated Hospital of Guangdong Medical University from November 2021 to May 2023 were included in the study, and their clinical data, results of peripheral blood mNGS and traditional blood culture, pathogen distribution characteristics, and diagnostic efficacy of mNGS were retrospectively analyzed. RESULTS: Among the 42 children included, there were 2 cases (4.8%) of aplastic anemia (AA), 27 cases (64.3%) of acute lymphoblastic leukemia (ALL), 7 cases (16.7%) of acute myeloid leukemia (AML), 1 case (2.4%) of chronic myeloid leukemia (CML), 2 cases (4.8%) of hemophagocytic lymphohistiocytosis (HLH), 2 cases (4.8%) of non-Hodgkin lymphoma (NHL), and 1 case (2.4%) of Wiskott-Aldrich syndrome (WAS). In mNGS testing, pathogens were detected in 31 peripheral blood samples, with a positive rate of 73.8% (31/42), significantly higher than the pathogen positive rate of 16.7% (7/42) detected by traditional blood culture, and the difference was statistically significant (P < 0.05). Among the pathogen-positive cases detected by mNGS, 23 cases (74.2%) were positive for bacteria, 12 cases (38.7%) were positive for viruses, and 9 cases (29.0%) were positive for fungi. 32.2% (10/31) of the pathogen-positive samples detected by mNGS were mixed pathogens, which could not be effectively detected by traditional blood culture. CONCLUSION Peripheral blood mNGS has advantages in the detection of pathogens of bloodstream infection secondary to hematologic diseases, with a higher detection rate of pathogen positivity than traditional blood cultures. It can detect viruses, rare pathogens and mixed pathogens, and has good clinical application value.
Child ; Child, Preschool ; Female ; Humans ; Male ; Hematologic Diseases/immunology* ; High-Throughput Nucleotide Sequencing ; Metagenomics ; Retrospective Studies ; Sepsis/microbiology*

Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging, yet there is limited understanding of gut microbiome variation in advanced age. Here, we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years, with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations. In addition to two adult-like enterotypes dominated by Bacteroides (ET-Bacteroides) and Prevotella (ET-Prevotella), we identified a novel enterotype dominated by Escherichia (ET-Escherichia), whose prevalence increased in advanced age. Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus (T2DM) or diet. We characterized the distinct taxonomic and functional profiles of ET-Escherichia, and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype, as well as the lowest species diversity. In addition, we carried out a series of correlation analyses and co-abundance network analyses, which showed that several factors were likely linked to the overabundance of Escherichia members, including advanced age, vegetable intake, and fruit intake. Overall, our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population. Considering the different age distribution of each enterotype, these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.
Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Bacteroides ; China ; Diabetes Mellitus, Type 2/microbiology* ; Escherichia coli/classification* ; Gastrointestinal Microbiome/genetics* ; Metagenomics ; East Asian People

Phages, as obligate bacterial and archaeal parasites, constitute a virus group of paramount ecological significance due to their exceptional abundance and genetic diversity. These biological entities serve as critical regulators in Earth's ecosystems, driving biogeochemical cycles, energy fluxes, and ecosystem services across terrestrial and marine environments. Within soil microbiomes, phages function as microbial "dark matter," maintaining the soil-plant system balance through precise modulation of the microbial community structure and functional dynamics. Despite the growing research interests in soil phages in recent years, the proportion of such studies in environmental virology remains disproportionately low, which is primarily attributed to researchers' limited familiarity with the research methodologies for phage microecology, incomplete technical frameworks, and inherent challenges posed by soil environmental complexity. To address these challenges, this review synthesizes cutting-edge methodologies for soil phage investigation from four aspects: (1) tangential flow filtration (TFF)-based phage enrichment strategies; (2) integrated quantification approaches combining double-layer agar plating, epifluorescence microscopy, and flow cytometry; (3) multi-omics analytical pipelines leveraging metagenomics and viromics datasets; and (4) computational frameworks merging machine learning algorithms with eco-evolutionary theory for deciphering phage-host interaction networks. Through comparative analysis of methodological principles, technical merits, and application scopes, we establish a comprehensive workflow for soil phage research. Future research in this field should prioritize: (1) construction of soil phage resource libraries, (2) exploration of RNA phages based on transcriptomes, (3) functional characterization of unknown genes, and (4) deep integration and interaction validation of multi-omics data. This systematic methodological synthesis provides critical technical references for addressing fundamental challenges in characterizing soil phages regarding the community structure, functional potential, and interaction mechanisms with hosts.
Bacteriophages/physiology* ; Soil Microbiology ; Ecosystem ; Microbiota ; Metagenomics/methods*

Small urban wetlands are widely distributed and susceptible to human activities, serving as important sources and sinks of carbon. Microorganisms play a crucial role in carbon cycle, while limited studies have been conducted on the microbial diversity in small urban wetlands and the functions of microbiome in carbon fixation and metabolism. To probe into the microbiome-driven carbon cycling in small urban wetlands and dissect the composition and functional groups of microbiome, we analyzed the relationships between the microbiome structure, element metabolism pathways, and habitat physicochemical properties in sediment samples across three small wetlands in Huzhou City, and compared them with natural wetlands in the Zoige wetland. High-throughput sequencing of 16S rRNA gene amplicons and metagenomics was employed to determine the species and functional groups. Sixty medium to high-quality metagenome-assembled genomes (MAGs) were constructed, including 55 bacterial and 5 archaeal taxa, and their potential in driving elemental cycles were analyzed, with a focus on carbon fixation. Several bacterial species were found to encode a nearly complete carbon fixation pathway, including the Calvin cycle, the reductive tricarboxylic acid cycle, the Wood-Ljungdahl pathway, and the reductive glycine pathway. There were several potential novel carbon-fixing bacterial members, such as those belonging to Syntrophorhabdus (Desulfobacterota) and UBA4417 (Bacteroidetes), which had high relative abundance in the wetland microbiome. Unveiling the genetic potential of these functional groups to facilitate element cycling is of great scientific importance for enhancing the carbon sequestration capacity of small urban wetlands.
Wetlands ; Microbiota/genetics* ; Carbon Cycle/genetics* ; Bacteria/classification* ; RNA, Ribosomal, 16S/genetics* ; China ; Cities ; Geologic Sediments/microbiology* ; Archaea/classification* ; Metagenomics ; Metagenome

Japanese spotted fever(JSF)is an infectious disease caused by Rickettsia japonica,with nonspecific clinical symptoms and a high risk of misdiagnosis.We reported a case of JSF,in which Rickettsia japonica was detected in blood cells by metagenomic next-generation sequencing.The patient recovered after treatment with doxycycline.This report provides a reference for the clinical diagnosis and treatment of JSF.
Humans ; High-Throughput Nucleotide Sequencing ; Metagenomics ; Rickettsia/isolation & purification* ; Spotted Fever Group Rickettsiosis/microbiology*

Recent advancements in molecular techniques such as real-time PCR, isothermal amplification, next-generation sequencing, metagenomics, microarray, and CRISPR-infectious disease diagnostics have significantly evolved and improved over the past years. This overview will explore the innovations that have shaped the molecular diagnostics workflow, as well as the progress made in these innovative techniques. Additionally, it will address existing gaps, unmet needs, and the potential future directions for further enhancing diagnostic capabilities in the field.

In recent years, many studies have found that vaginal microbiota is closely related to female reproductive tract diseases. However, traditional microbial culture technology has the defects of long culture cycle and most microorganisms cannot be cultured. The development of metagenomics technique has broken the limitations of culture technology, and has been gradually applied to the study of vaginal microorganisms with the characteristics of high throughput, short time, identification of microbial population structure and gene function. It also provides technical support for elucidating the relationship between vaginal microbiota and female reproductive tract diseases. This article mainly introduces the metagenomics techniques and their applications in prevention, screening and diagnosis of common female reproductive tract diseases, and discusses their promising development and limitations to be overcome.
Female ; Humans ; Microbiota/genetics* ; Vagina ; Metagenomics/methods*

OBJECTIVE: To improve the understanding of the virome and bacterial microbiome in the wildlife rescue station of Poyang Lake, China. METHODS: Ten smear samples were collected in March 2019. Metagenomic sequencing was performed to delineate bacterial and viral diversity. Taxonomic analysis was performed using the Kraken2 and Bracken methods. A maximum-likelihood tree was constructed based on the RNA-dependent RNA polymerase (RdRp) region of picornavirus. RESULTS: We identified 363 bacterial and 6 viral families. A significant difference in microbial and viral abundance was found between samples S01-S09 and S10. In S01-S09, members of Flavobacteriia and Gammaproteobacteria were the most prevalent, while in S10, the most prevalent bacteria class was Actinomycetia. Among S01-S09, members of Myoviridae and Herelleviridae were the most prevalent, while the dominant virus family of S10 was Picornaviridae. The full genome of the pigeon mesivirus-like virus (NC-BM-233) was recovered from S10 and contained an open reading frame of 8,124 nt. It showed the best hit to the pigeon mesivirus 2 polyprotein, with 84.10% amino acid identity. Phylogenetic analysis showed that RdRp clustered into Megrivirus B. CONCLUSION This study provides an initial assessment of the bacteria and viruses in the cage-smeared samples, broadens our knowledge of viral and bacterial diversity, and is a way to discover potential pathogens in wild birds.
Animals ; Animals, Wild/genetics* ; Lakes ; Phylogeny ; Picornaviridae/genetics* ; Viruses/genetics* ; China ; Metagenomics ; Genome, Viral

The application of metagenomic second-generation sequencing (mNGS) is shifting from research to clinical laboratories due to rapid technological advances and significant cost reductions. Although many studies and case reports have confirmed that the success of mNGS in improving the prevention, diagnosis, treatment and tracking of infectious diseases, there are still some obstacles that must be overcome. The results of mNGS show all the possible pathogens in the sample, however, in the face of thousands of microbes that can infect humans, it remains challenging to accurately identify the key pathogens. So far, there is no unified interpretation standard for mNGS in clinical practice. This article reviews the interpretation of mNGS results for pathogen infection in different systems, the clinical interpretation and application regulations of mNGS results, and the challenges of mNGS interpretation in pathogen diagnosis.
Humans ; Communicable Diseases ; Metagenomics ; Sensitivity and Specificity