Metagenomics next-generation sequencing tests take the stage in the diagnosis of lower respiratory tract infections

Diagnostic value of metagenomic next-generation sequencing for bronchoalveolar lavage diagnostics in patients with lower respiratory tract infections

BACKGROUND

Current diagnostic methods of lower respiratory tract infections (LRTIs) often lack specificity, underscoring the necessity for advanced technologies such as metagenomic next-generation sequencing (mNGS).

METHODS

This retrospective study compared bronchoalveolar lavage fluid (BALF) analysis using mNGS and conventional microbiological tests (CMT) to evaluate their effectiveness in pathogen identification and alignment with clinical diagnoses.

RESULTS

In this study involving 369 patients suspected of LTRIs, mNGS identified pathogens in 342 cases (92.7%), showing superior diagnostic performance compared to CMT (58.8%). The positive agreement and negative agreement rates of mNGS were 92.7% and 96.3%, respectively, both significantly higher than those of CMT (both p<0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of mNGS were significantly higher than those of CMT, with values of 99.7% vs. 57.1%, 68.4% vs. 26.3%, 96.5% vs. 87.1%, and 96.3% vs. 6.3%, respectively (all p<0.001). Pathogen detection rates among the patients showed that 89.7% had evidence of LRTIs, with bacterial infections (20.1%), mycoplasma (13.6%), mycobacterium (4.3%), fungal (4.1%), viral (3.3%), and mixed infections (44.4%) being the most common. Furthermore, the study also differentiated the distribution of pathogens between adults and pediatric patients, and assessed the impact of pathogen types on severe outcomes using multivariate logistic regression, revealing that viral and fungal infections were more likely associated with severe symptoms, whereas mycoplasma infections typically presented with milder symptoms.

CONCLUSIONS

BALF mNGS proves effective for rapid, comprehensive pathogen detection in LRTIs, warranting its early use for enhanced diagnosis and management, especially across different age groups.

Predictive Application Value of Metagenomic Next-Generation Sequencing in the Resistance of Carbapenem-Resistant Enterobacteriaceae

Objective: Although metagenomic next-generation sequencing (mNGS) technology has achieved notable outcomes in pathogen detection, there remains a gap in the research regarding its application in predicting the antibiotic resistance of pathogenic bacteria. This study aims to analyze the clinical application value of mNGS in predicting the resistance of carbapenem-resistant Enterobacteriaceae (CRE), as well as the relevant influencing factors, thereby providing valuable insights for clinical antimicrobial therapy. Methods: Nonduplicate isolates of Enterobacterales bacteria collected from Liaocheng People's Hospital from April 2023 to June 2024 were selected, and CRE bacteria were screened. mNGS was used to detect resistance genes, and the results were compared with those of polymerase chain reaction (PCR) to evaluate the specificity and sensitivity of gene detection. Furthermore, the performance of mNGS in identifying pathogenic microorganisms and predicting antibiotic resistance was assessed by comparing the sequencing results with those of antimicrobial susceptibility testing (AST). Results: A total of 46 isolates were confirmed as CRE through traditional AST and were further identified using the Vitek MS and Vitek 2 systems. The results indicated 27 isolates of Klebsiella pneumoniae, 14 isolates of Escherichia coli, 2 isolates of Enterobacter hormaechei, 2 isolates of Enterobacter cloacae, and 1 isolate of Citrobacter freundii. These isolates were subjected to both mNGS and PCR for detection. The calculation of the area under the receiver operating characteristic (ROC) curve demonstrated the reliability of mNGS in detecting resistance genes. Conclusion: mNGS demonstrated high sensitivity in predicting the presence of carbapenemase resistance genes in CRE, showing potential in early indication of isolate resistance information, thereby facilitating timely guidance for clinical treatment strategies.

Pulmonary infection caused by Tropheryma whipplei: a case report and review of the literature

BACKGROUND

Tropheryma whipplei pneumonia is an infrequent medical condition. The clinical symptoms associated with this disease are nonspecific, often resulting in misdiagnosis or missed diagnosis. Therefore, sharing and summarizing the experiences in the diagnosis and treatment of this disease can deepen global understanding and awareness of it.

CASE PRESENTATION

The patient is a 78-year-old married Han Chinese female who was admitted to the hospital after experiencing fever, dry cough, and fatigue for 4 days. A lung computed tomography scan revealed inflammatory exudation in the lower left lung, accompanied by pleural effusion. The bronchoalveolar lavage fluid was subjected to further analysis using metagenomic next-generation sequencing, which identified 41 genetic sequences associated with Tropheryma whipplei. Consequently, she was diagnosed with Tropheryma whipplei pneumonia. After initiating treatment with doxycycline and biapenem, the patient's symptoms showed significant improvement. Upon discharge, the patient continued treatment with a combination of doxycycline and hydroxychloroquine, which was discontinued after 4 days. At 12-month follow-up, the patient reported overall good health, with no symptoms of fever, cough, or any other discomfort.

CONCLUSION

Tropheryma whipplei pneumonia is a rare condition with nonspecific symptoms. The application of metagenomic next-generation sequencing technology in pulmonary infections helps to rapidly identify rare pathogens, providing a solid foundation for precise and effective antibacterial treatment for patients.

Clinical and metagenomic predicted antimicrobial resistance in pediatric critically ill patients with infectious diseases in a single center of Zhejiang

BACKGROUND

Antimicrobial resistance (AMR) poses a significant threat to pediatric health; therefore, precise identification of pathogens as well as AMR is imperative. This study aimed at comprehending antibiotic resistance patterns among critically ill children with infectious diseases admitted to pediatric intensive care unit (PICU) and to clarify the impact of drug-resistant bacteria on the prognosis of children.

METHODS

This study retrospectively collected clinical data, identified pathogens and AMR from 113 children's who performed metagenomic next-generation sequencing for pathogen and antibiotic resistance genes identification, and compared the clinical characteristic difference and prognostic effects between children with and without AMR detected.

RESULTS

Based on the presence or absence of AMR test results, the 113 patients were divided into Antimicrobial resistance test positive group (AMRT+, n = 44) and Antimicrobial resistance test negative group (AMRT-, n = 69). Immunocompromised patients (50% vs. 28.99%, P = 0.0242) and patients with underlying diseases (70.45% vs. 40.58%, P = 0.0019) were more likely to develop resistance to antibiotics. Children in the AMRT + group showed significantly increased C-reaction protein, score of pediatric sequential organ failure assessment and pediatric risk of mortality of children and longer hospital stay and ICU stay in the AMRT + group compared to the AMRT+- group (P < 0.05). Detection rate of Gram-negative bacteria was significantly higher in the AMRT + group rather than Gram-positive bacteria (n = 45 vs. 31), in contrast to the AMRT- group (n = 10 vs. 36). Cephalosporins, β-lactams/β-Lactamase inhibitors, carbapenems and sulfonamides emerged as the most common types of drug resistance in children. Resistance rates to these antibiotics exhibited considerable variation across common pathogens, including Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii.

CONCLUSIONS

The development of drug resistance in bacteria will significantly affect the prognosis of patients. The significant differences in drug resistance of common pathogenic bacteria indicate that identification of drug resistance is important for the rational use of antibiotics and patient prognosis.

C. Calado C. Early Mortality Prediction in Intensive Care Unit Patients Based on Serum Metabolomic Fingerprint

Predicting mortality in intensive care units (ICUs) is essential for timely interventions and efficient resource use, especially during pandemics like COVID-19, where high mortality persisted even after the state of emergency ended. Current mortality prediction methods remain limited, especially for critically ill ICU patients, due to their dynamic metabolic changes and heterogeneous pathophysiological processes. This study evaluated how the serum metabolomic fingerprint, acquired through Fourier-Transform Infrared (FTIR) spectroscopy, could support mortality prediction models in COVID-19 ICU patients. A preliminary univariate analysis of serum FTIR spectra revealed significant spectral differences between 21 discharged and 23 deceased patients; however, the most significant spectral bands did not yield high-performing predictive models. By applying a Fast-Correlation-Based Filter (FCBF) for feature selection of the spectra, a set of spectral bands spanning a broader range of molecular functional groups was identified, which enabled Naïve Bayes models with AUCs of 0.79, 0.97, and 0.98 for the first 48 h of ICU admission, seven days prior, and the day of the outcome, respectively, which are, in turn, defined as either death or discharge from the ICU. These findings suggest FTIR spectroscopy as a rapid, economical, and minimally invasive diagnostic tool, but further validation is needed in larger, more diverse cohorts.

Intensive reprocessing of reusable bronchoscopes can reduce the false positive rate of Xpert MTB/RIF caused by nucleic acid residue

Background/Purpose

Tuberculosis remains a leading cause of infectious death worldwide, The potential for nucleic acid residue on bronchoscopes to cause false positive results in molecular diagnostic methods and subsequently lead to tuberculosis misdiagnosis has long perplexed clinical.

Methods

We utilized Xpert MTB/RIF to analyze the liquid collected after bronchoscope washing, employed by patients either with or without active pulmonary tuberculosis, and subjected to standard reprocessing (SR) or intensive reprocessing (IR) procedures. The IR procedure included specialized training and the provision of patient information to cleaning staff before the SR procedure, and repeated washing and suction of the bronchoscope with sterilized water post SR procedure.

Results

55 participants enrolled in the study were divided into three groups: SR group (n = 28), IR group(n = 14), and the control group(n = 13). Among the 55 enrolled patients, neither Mycobacterium tuberculosis nor contamination was detected by MIGT 960 liquid culture in the washing liquid. The positive rate of MTB/RIF in the SR group (12/28) was significantly higher than that in the IR group (1/14), with a statistically significant difference observed between them (42.86 % vs. 7.14 %, P=0.018).

Conclusions

Nucleic acid residue on reusable bronchoscopes cleaned via the SR procedure was found to potentially cause false positives in MTB/RIF tests. Reprocessing bronchoscopes via the IR procedure was effective in significantly reducing nucleic acid residue, although complete elimination was not achieved.

Extensive erythematous plaques of fungal origin in an overseas student: Cutaneous manifestation of coccidioidomycosis

We present a case of Coccidioides posadasii infection which was contracted during study abroad. This coccidioidomycosis showed atypical manifestations and was diagnosed by a combination of tissue biopsy, metagenomic next-generation sequencing, internal transcribed spacer sequencing and culture. Initial treatment with fluconazole was not effective. Antifungal therapy was switched to voriconazole based on drug sensitivity results with good result. This case demonstrates the clinical significance of combining multiple diagnostic methods.

Lower respiratory tract microbiome is associated with checkpoint inhibitor pneumonitis in lung cancer patients

Background

The gut microbiome is associated with the occurrence and severity of immune-related adverse events (irAEs) in cancer patients undergoing immunotherapy. However, the relationship between the lower respiratory tract (LRT) microbiome and checkpoint inhibitor pneumonitis (CIP) in lung cancer patients who underwent immunotherapy is unclear. The aim of the present study was to investigate the associations between the LRT microbiome and CIP in lung cancer patients receiving immunotherapy.

Methods

This retrospective study included lung cancer patients who received immunotherapy and had metagenomic next-generation sequencing (mNGS) results of LRT specimens [bronchoalveolar lavage fluid (BALF)]. Based on their final diagnosis, the patients were allocated to either the CIP group or the non-CIP group. We conducted an exploratory analysis of the LRT microbiome in the CIP and non-CIP patients, delineating the microbial composition, and comparing the differences between the two groups.

Results

In total, 52 lung patients were included in the study, of whom 33 were allocated to the CIP group and 19 to the non-CIP group. The alpha- and beta-diversity analyses revealed no significant differences between the two groups. In the CIP group, the dominant phyla were Firmicutes (41.7%), Acinetobacter (18.2%), and Proteobacteria (16.3%). In the non-CIP group, the dominant phyla were Firmicutes (38.2%), Acinetobacter (18.4%), and Proteobacteria (17.8%). Notably, the relative abundance of the Proteobacteria phylum (P<0.001) and Firmicutes phylum (P=0.01) was significantly higher in the CIP group than the non-CIP group.

Conclusions

The elevated relative abundance of the Proteobacteria and Firmicutes phyla in the LRT samples is associated with CIP in lung cancer patients.

Combining interferon-γ release assays and metagenomic next-generation sequencing for diagnosis of pulmonary tuberculosis: a retrospective study

BACKGROUND

Rapid diagnosis of pulmonary tuberculosis (PTB) is urgently needed. We aimed to improve diagnosis rates by combining tuberculosis-interferon (IFN)-γ release assays (TB-IGRA) with metagenomic next-generation sequencing (mNGS) for PTB diagnosis.

METHODS

A retrospective study of 29 PTB and 32 non-TB patients from our hospital was conducted between October 2022 and June 2023. Samples were processed for TB-IGRA and mNGS tests according to the manufacturer's protocol.

RESULTS

The levels of IFN-γ release in PTB patients were significantly higher than those in non-TB patients (604.15 ± 112.18 pg/mL, and 1.04 ± 0.38 pg/mL, respectively; p < 0.0001). Regarding presenting symptoms or signs, cough and thoracalgia were less common in PTB patients than in non-TB patients (p = 0.001 and p = 0.024, respectively). Total protein and albumin levels in the sera of PTB patients were significantly elevated compared to non-TB patients (p = 0.039 and p = 0.004, respectively). The area under the ROC curve (AUC) for TB-IGRA in PTB diagnosis was 0.939. With an optimal IFN-γ cut-off value of 14.3 pg/mL (Youden's index 0.831), sensitivity was 86.2% and specificity was 96.9%. ROC curve analysis for mNGS and TB-IGRA combined with mNGS showed AUCs of 0.879 and 1, respectively. The AUC of TB-IGRA combined with mNGS was higher than that of TB-IGRA and mNGS alone.

CONCLUSIONS

TB-IGRA combined with mNGS may be an effective method for diagnosing tuberculosis, and can be used in the clinical diagnosis of PTB.

Deciphering the pathogen heterogeneity for precise diagnosis and personalized therapeutics of infections after kidney transplantation: insights from metagenomic next-generation sequencing

Introduction

The aim of this study was to compare the detection performance of mNGS against that of conventional tests (CT) in patients suffering from infection after kidney transplantation.

Methods

A total of 138 samples from 85 kidney transplant patients with acute or chronic infections were simultaneously analyzed using mNGS and CT from July 2021 to August 2023.

Results

Compared with CT, mNGS demonstrated a higher sensitivity (95.96% vs. 27.27%) but lower specificity (48.72% vs. 84.62%) in pathogen detection. Moreover, mNGS exhibited significant advantages in detecting mixed and rare infections. The pathogens commonly identified in kidney transplant patients were severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), followed by Pneumocystis jirovecii and Cytomegalovirus (CMV). mNGS guided the precise clinical diagnosis in 89.13% of cases and assisted in altering therapeutics from empirical antibiotic approaches to personalized plans in 56.10% of cases, including treatment escalation (40.65%), initiation (11.38%), drug adjustment (3.25%), and de-escalation (0.81%).

Discussion

Our study demonstrated the superior detection performance of mNGS and its significant clinical value. This reflected the great potential of mNGS as a complementary clinical detection technology for kidney transplant patients.

Risk factor assessment and microbiome analysis in peritoneal dialysis-related peritonitis reveal etiological characteristics

Background

Peritoneal dialysis-related peritonitis (PDRP) is one of the most common complications of peritoneal dialysis (PD). Understanding the risk factors and etiological characteristics is indispensable for infection prevention and improving the outcome and life quality.

Methods

A total of 70 PD patients were separated into the PDRP group (n=25) and the control group (n=45). Variables, including gender, age, body mass index, primary diseases, and history of basic diseases, in the two groups were analyzed to assess the risk factors of PDRP. Metagenomic next-generation sequencing (mNGS) and microbial culture were compared in detecting pathogenic microorganisms. Gut microbiota analysis was performed in 35 PDRP patients based on mNGS data.

Results

Dialysis time and times of dialysate change were the risk factors of PDRP, and times of dialysate change was the independent risk factor of PDRP (p = 0.046). mNGS produced higher sensitivity (65.79%) than microbial culture (36.84%) in identifying pathogenic microorganisms. Staphylococcus aureus and Klebsiella pneumoniae (four cases) were the most frequent pathogens causing PDRP, followed by Staphylococcus capitis (three cases). β diversity of the gut microbiota was significantly different between patients with fewer times of dialysate change (≤4) and more (>5), as well as between patients with gram-positive (G+) bacterial and gram-negative (G-) bacterial infection.

Conclusion

The dialysis time and times of dialysate changes not only are risk factors for peritonitis in PD patients but also stimulate significant changes in the gut microbiome structure in PDRP patients. These findings may provide a novel viewpoint for the management of patients with PDRP.

Acetate-producing bacterium Paenibacillus odorifer hampers lung cancer growth in lower respiratory tract: an in vitro study

Lung cancer accounts for the large majority of cancer incidence and mortality worldwide for decades. The dysbiotic microbiome and its metabolite secretions in the gut have been regarded as the dominant biological factors in oncogenesis, development, and progression, adding probiotic components of which have come to be potential therapeutic regimes. However, there still exists little knowledge about whether probiotic microorganisms in lower airways inhibit lung cancer by lung microenvironment remodulation. In this study, we performed bioinformatics analysis from previous sequencing data and specific microbiome databases to identify the potent protective microbes in lower airways, followed by bacterial cultivation and morphological verifications in vitro. We found that Paenibacillus odorifer was correlated closely with the anti-tumorous by-product acetic acid in lower respiratory tract. Additionally, the enrichment of this microorganism in the health, rather than in lung neoplasms from public data sets, further confirmed its protective activity in preserving pulmonary homeostasis. Colony cultivation of this strain and targeted metabolite analysis indicated that Paenibacillus odorifer proliferation was weakened at 37°C but lasted longer than it did at the optimal temperature. And performing as a candidate origin of acetic acid, this strain was liable to inhibit the growth of lung cancer cells in time- and dose-dependent approaches which was validated by colony formation assays. These results suggested that Paenibacillus odorifer functions as a candidate probiotic in lower airways to restrict lung cancer cell growth by releasing protective molecules, indicating a potential preventive microbial strategy.IMPORTANCEVarious types of microorganisms in lower respiratory tracts protect local homeostasis against oncogenesis. Although extensive efforts engaged in gut microbiome-mediated pulmonary carcinogenesis, emerging evidence suggested the crucial role of microbial metabolites from respiratory tracts in modulating carcinogenesis-related host inflammation and DNA damage in lung cancer, which was still not fully understood in lower respiratory tract microbes and its metabolite-mediated microecological environment homeostasis in preventing or alleviating lung cancer. In this study, we analyzed the lower respiratory tract microbiome and SCFAs expression among different lung segments from the same participants, further identifying that Paenibacillus odorifer was correlated closely with anti-tumorous by-product, acetate acid in lower respiratory tract by multi-omics analysis. And previous experiments showed this strain could inhibit the growth of lung cancer cells in vitro. These findings indicated that Paenibacillus odorifer in lower respiratory tracts might perform as a candidate probiotic against lung carcinogenesis by releasing protective factor acetate, which further presented a promising diagnostic and interventional approach in clinical settings of lung cancer.

New insights into the roles of fungi and bacteria in the development of medicinal plant

BACKGROUND

The interaction between microorganisms and medicinal plants is a popular topic. Previous studies consistently reported that microorganisms were mainly considered pathogens or contaminants. However, with the development of microbial detection technology, it has been demonstrated that fungi and bacteria affect beneficially the medicinal plant production chain.

AIM OF REVIEW

Microorganisms greatly affect medicinal plants, with microbial biosynthesis a high regarded topic in medicinal plant-microbial interactions. However, it lacks a systematic review discussing this relationship. Current microbial detection technologies also have certain advantages and disadvantages, it is essential to compare the characteristics of various technologies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review first illustrates the role of fungi and bacteria in various medicinal plant production procedures, discusses the development of microbial detection and identification technologies in recent years, and concludes with microbial biosynthesis of natural products. The relationship between fungi, bacteria, and medicinal plants is discussed comprehensively. We also propose a future research model and direction for further studies.

A rare case of prostatic malakoplakia with multidrug-resistant Escherichia coli: a case report

Prostatic malakoplakia is an uncommon chronic inflammatory disorder, tumor-like but non-cancerous, the diagnosis of which pivots crucially on the identification of characteristic Michaelis-Gutmann bodies within the pathological tissue. We hereby present an inaugural case report of prostatic malakoplakia concurrent with sepsis caused by multidrug-resistant Escherichia coli, verified through blood culture and metagenomic next-generation sequencing (mNGS). The pathogenesis might be associated with infections by Escherichia coli, immune system irregularities, or lysosomal dysfunction. Although the patient had no chronic underlying diseases, he presented early with sepsis and multi-organ dysfunction. This case emphasizes the imperative to further investigate the association between malakoplakia and Escherichia coli, the necessity for prompt diagnosis, and the supportive role of mNGS, and the treatment strategy focuses on rapid control of infection and systemic inflammatory response.

Rapid and precise identification of cervicothoracic necrotizing fasciitis caused by Prevotella and Streptococcus constellatus by using Nanopore sequencing technology: a case report

Introduction

Cervicothoracic necrotizing fasciitis (CNF) is one form of necrotizing soft-tissue infections, which could lead to patient demise during short course. Therefore, early recognition and immediate treatment contribute to promising prognosis of patients.

Case presentation

A 58-year-old diabetic patient presented with a sore throat and progressive irritation of the neck and chest for 4 days. The initial diagnosis was considered to be soft-tissue infection and the clinician gave empirical anti-infectious medication for expectant treatment. During the course of disease, surgical incision was performed to relieve suffocation and shortness of breath. The drainage fluids were detected with microbiological culture and molecular sequencing. Nanopore sequencing technology (NST) helped to identify the coinfection of Streptococcus constellatus and Prevotella spp., which was not recognized during the original period of 15 days. The precise identification of pathogen supported to guide the pharmacologic treatment with meropenem and linezolid. Ultimately, combined with the surgical observation and post-surgical pathological examination, the patient was diagnosed as CNF, which could be much more acute and serious than normal soft-tissue infections. The patient has been successfully treated with prompt antimicrobial medication and appropriate surgical debridement.

Conclusion

This case presented a CNF patient with type 2 diabetes, successfully recovered after prompt microbial detection, precise anti-infectious treatment, and appropriate surgical intervention. It highlights the importance of recognizing pathogen by applying rapid microbiological detection, including NST, in acute and serious infectious disease.

Pulmonary coccidioidomycosis in China: Case reports and literature review

Coccidioidomycosis is a fungal infection commonly found in the tropical regions of southwestern United States, such as Arizona, the Central Valley of California, parts of New Mexico, and western Texas. The endemic regions also extend into northern Mexico and include focal endemic areas in sections of Central America and Argentina. Coccidioides species have also been reported in central and southern Utah, Nevada, and the central part of Washington State., the pathogenic bacteria commonly colonize the lungs. China, which is outside the traditionally established endemic area, is witnessing a rise in reported cases of pulmonary coccidioidomycosis. Meanwhile, the comorbidities of the disease began to become complicated. We reported two Chinese patients with pulmonary coccidioidomycosis complicated by organizing pneumonia and reviewed 42 cases of Chinese patients in the literature from 1958 to 2024. Out of the 44 patients from 13 different provinces (Including Hong Kong Special Administrative Region and Taiwan), the average age was (43.08 ± 3.03) years. Among them, 34 (76.7 %) were male, while 10 (23.3 %) were female, cough/sputum (81.8 %) are the most common symptoms, the cases are concentrated in coastal areas. 27(61.4 %) were Imported and 17(38.6 %) were domestic primary cases, showing a higher proportion of imported cases compared to domestic primary cases. Misdiagnosis and mistreatment have a significant impact on patients, the combination of new technologies and traditional pathology diagnosis have substantially promoted precise diagnosis for clinician in non-endemic areas. Interestingly, the histopathological findings of the two patients we report showed evident organizing pneumonia and an increased eosinophil count, the application of corticosteroid drugs notably improved the patients' conditions. Overall, at least 84.1 % of patients had a favorable prognosis. Considering the changing epidemiology of pulmonary coccidioidomycosis, Chinese healthcare providers should be cautious about their patients' travel history, particularly among male individuals.

Application of the second-generation sequencing technology of metagenomics in the detection of pathogens in respiratory patients

OBJECTIVE

To explore the application value of the second-generation metagenomic next-generation sequencing (mNGS) in the detection of pathogens in patients with pulmonary infection.

METHODS

We conducted a retrospective analysis of 65 pulmonary infection cases treated at our institution and the Fifth People's Hospital of Shanghai between January 2021 and May 2023. All subjects were subjected to mNGS, targeted next-generation sequencing (tNGS), and conventional microbiological culture. A comparative analysis was performed to evaluate the diversity and quantity of pathogens identified by these methodologies and to appraise their respective diagnostic capabilities in pulmonary infection diagnostics.

RESULTS

The mNGS successfully identified etiological agents in 60 of the 65 cases, compared to tNGS, which yielded positive results in 42 cases, and conventional laboratory cultures, which detected pathogens in 24 cases. At the bacterial genus level, mNGS discerned 9 genera, 11 species, and 92 isolates of pathogenic bacteria, whereas tNGS identified 8 genera, 8 species, and 71 isolates. Conventional methods were less sensitive, detecting only 6 genera, 7 species, and 33 isolates. In terms of fungal detection, mNGS identified 4 fungal species, tNGS detected 4 isolates of the Candida genus, and conventional methods identified 2 isolates of the same genus. Viral detection at the species level revealed 10 species and 46 isolates by mNGS, whereas tNGS detected only 3 species and 7 isolates. The area under the receiver operating characteristic curve (AUC) with 95% confidence intervals for diagnosing pulmonary infections was 0.818 (0.671 to 0.966) for mNGS, 0.668 (0.475 to 0.860) for tNGS, and 0.721 (0.545 to 0.897) for conventional culture.The mNGS demonstrates superior diagnostic efficacy and pathogen detection breadth in critically ill patients with respiratory infections, offering a significant advantage by reducing the time to diagnosis. The enhanced sensitivity and comprehensive pathogen profiling of mNGS underscore its potential as a leading diagnostic tool in clinical microbiology.

Next-Generation Sequencing and Bioinformatics Consortium Approach to Genomic Surveillance

Genomic surveillance programs benefit greatly from a network of committed, well-supported laboratories that conduct ongoing surveillance activities for pathogens of public health importance. The experiences of the Global Emerging Infections Surveillance program provide insights for building and maintaining genomic surveillance capabilities for public health and pandemic preparedness and response. To meet the needs of US Department of Defense and the Military Health System to use genomics to monitor pathogens of military and public health importance, Global Emerging Infections Surveillance convened a consortium of experts in genome sequencing, bioinformatics, and genomic epidemiology. The experts developed a 3-tiered framework for building and maintaining next-generation sequencing and bioinformatics capabilities for genomic surveillance within the Department of Defense. The consortium strategy was developed before the COVID-19 pandemic, leading to a network prepared to respond with existing resources and expand as new funding became available.

MetaAll: integrative bioinformatics workflow for analysing clinical metagenomic data

Over the past decade, there have been many improvements in the field of metagenomics, including sequencing technologies, advances in bioinformatics and the development of reference databases, but a one-size-fits-all sequencing and bioinformatics pipeline does not yet seem achievable. In this study, we address the bioinformatics part of the analysis by combining three methods into a three-step workflow that increases the sensitivity and specificity of clinical metagenomics and improves pathogen detection. The individual tools are combined into a user-friendly workflow suitable for analysing short paired-end (PE) and long reads from metagenomics datasets-MetaAll. To demonstrate the applicability of the developed workflow, four complicated clinical cases with different disease presentations and multiple samples collected from different biological sites as well as the CAMI Clinical pathogen detection challenge dataset were used. MetaAll was able to identify putative pathogens in all but one case. In this case, however, traditional microbiological diagnostics were also unsuccessful. In addition, co-infection with Haemophilus influenzae and Human rhinovirus C54 was detected in case 1 and co-infection with SARS-Cov-2 and Influenza A virus (FluA) subtype H3N2 was detected in case 3. In case 2, in which conventional diagnostics could not find a pathogen, mNGS pointed to Klebsiella pneumoniae as the suspected pathogen. Finally, this study demonstrated the importance of combining read classification, contig validation and targeted reference mapping for more reliable detection of infectious agents in clinical metagenome samples.

Exploring the clinical and diagnostic value of metagenomic next-generation sequencing for urinary tract infection: a systematic review and meta-analysis

BACKGROUND

A new pathogen detection tool, metagenomic next-generation sequencing (mNGS), has been widely used for infection diagnosis, but the clinical and diagnostic value of mNGS in urinary tract infection (UTI) remains inconclusive. This systematic review with meta-analysis aimed to investigate the efficacy of mNGS in treating UTIs.

METHODS

A comprehensive literature search was performed in PubMed, Web of Science, Embase, and the Cochrane Library, and eligible studies were selected based on the predetermined criteria. The quality of the included studies was assessed via the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool, and the certainty of evidence (CoE) was measured by the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) score. Then, the positive detection rate (PDR), pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve of the summary receiver operating characteristic curve (AUROC) was estimated in Review Manager, Stata, and MetaDisc. Subgroup analysis, meta-regression, and sensitivity analysis were performed to reveal the potential factors that influence internal heterogeneity.

RESULTS

A total of 17 studies were selected for further analysis. The PDR of mNGS was markedly greater than that of culture (odds ratio (OR) = 2.87, 95% confidence interval [CI]: 1.72-4.81, p < 0.001, I2 = 90%). The GRADE score presented a very low CoE. Then, the pooled sensitivity was 0.89 (95% CI: 0.86-0.91, I2 = 39.65%, p = 0.06), and the pooled specificity was 0.75 (95% CI: 0.51-0.90, I2 = 88.64%, p < 0.001). The AUROC of the studies analyzed was 0.89 (95% CI: 0.86-0.92). The GRADE score indicated a low CoE.

CONCLUSION

The current evidence shows that mNGS has favorable diagnostic performance for UTIs. More high-quality prospective randomized controlled trials (RCTs) are expected to verify these findings and provide more information about mNGS in UTI treatment and prognosis.

Clinical evaluation of a highly multiplexed CRISPR-based diagnostic assay for diagnosing lower respiratory tract infection: a prospective cohort study

OBJECTIVE

Accurate and rapid identification of causative pathogens is essential to guide the clinical management of lower respiratory tract infections (LRTIs). Here we conducted a single-centre prospective study in 284 patients suspected of lower respiratory tract infections to evaluate the utility of a nucleic acid test based on highly multiplexed polymerase chain reaction (PCR) and CRISPR-Cas12a.

METHODS

We determined the analytical and diagnostic performance of the CRISPR assay using a combination of reference standards, including conventional microbiological tests (CMTs), metagenomic Next-Generation Sequencing (mNGS), and clinical adjudication by a panel of experts on infectious diseases and microbiology.

RESULTS

The CRISPR assay showed a higher detection rate (63.0%) than conventional microbiological tests (38.4%) and was lower than metagenomic Next-Generation Sequencing (72.9%). In detecting polymicrobial infections, the positivity rate of the CRISPR assay (19.4%) was higher than conventional microbiological tests (3.5%) and lower than metagenomic Next-Generation Sequencing (28.9%). The overall diagnostic sensitivity of the CRISPR assay (67.8%) was higher than conventional microbiological tests (41.8%), and lower than metagenomic Next-Generation Sequencing (93.2%).

CONCLUSIONS

Considering the low cost, ease of operation, short turnaround time, and broad range of pathogens detected in a single test, the CRISPR assay has the potential to be implemented as a screening tool for the aetiological diagnosis of lower respiratory tract infections patients, especially in cases where atypical bacteria or coinfections are suspected.

Case report: Systemic multi-organ involvement in an adult-onset immunodeficiency patient infected with Talaromyces marneffei

Adult-onset immunodeficiency (AOID) mediated by anti-interferon-γ autoantibodies (AIGA) is a rare condition, particularly prevalent in Southeast Asia and southern China. We present a case study of a 62-year-old female with AOID who developed a severe pulmonary infection caused by Talaromyces marneffei (TM), leading to acute respiratory failure, generalized rash, multiple lymphadenopathies, bone destruction, and a mediastinal mass. Treatment included mechanical ventilation, antifungal medication, and corticosteroids, resulting in complete recovery and discharge. This case underscores the challenges of managing complex infections in AOID patients and highlights the importance of early diagnosis through metagenomic next-generation sequencing (mNGS) and appropriate intervention to improve clinical outcomes.

Pulmonary actinomycosis misdiagnosed as lung cancer: a case report

Pulmonary actinomycosis is a rare pulmonary infectious disease that is often challenging to diagnose early and has a high misdiagnosis rate. In some cases, it can be particularly difficult to distinguish pulmonary actinomycosis from lung cancer. We herein report a rare case of pulmonary actinomycosis in which the preoperative examinations strongly suggested lung cancer, leading to the patient undergoing right upper lung resection and bronchoplasty. The patient had a good postoperative recovery; however, the postoperative pathology report indicated pulmonary actinomycosis. In this report, we summarize the key aspects of the diagnosis and treatment of pulmonary actinomycosis to aid clinicians in reducing the likelihood of misdiagnosis.

Clinical utility of metagenomic next-generation sequencing on bronchoalveolar lavage fluid in diagnosis of lower respiratory tract infections

BACKGROUND

In this study, we aimed to evaluate the clinical utility of Metagenomic Next-Generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) in diagnosis of Lower Respiratory Tract Infections (LRTIs).

METHODS

In this study, we retrospectively analyzed 186 hospitalized patients who were suspected with LRTIs and performed mNGS (DNA) test of BALF simultaneously at The Fifth Affiliated Hospital of Sun Yat-Sen University from March 2023 to August 2023. Suspected LRTI was based on LRTI related clinical manifestations or imaging examination. Among them, 155 patients had undergone conventional culture and mNGS (DNA) testing simultaneously. Finally, 138 cases (89.03%,138/155) were diagnosed as LRTI and 17 cases (10.97%,17/155) were diagnosed as non-LRTI. Both detecting rate and diagnostic efficacy of mNGS and conventional culture were compared.

RESULTS

The positive detection rates of pathogens between mNGS and conventional culture were significant different (81.29% VS 39.35%, P < 0.05). Compared with paired conventional culture result, the sensitivity of mNGS in diagnosis of LRTIs was more superior (88.41% VS 43.48%; P < 0.05), the specificity was opposite (76.47% VS 94.12%; P > 0.05). Furthermore, 77.54% and 35.51% of LRTI cases were being etiologically diagnosed by mNGS and culture respectively. Importantly, mNGS directly led to a change of treatment regimen in 58 (37.42%) cases, including antibiotic adjustment (29.68%) and ruling out active infection (7.74%). Moreover, treatment regimen remained unchanged in 97 (62.58%) cases, considering the current antibiotic therapy already covered the detected pathogens (36.13%) or empirical treatment was effective (11.61%).

CONCLUSIONS

mNGS can identify a wide range of pathogens in LRTIs, with improved sensitivity and being more superior at diagnosing LRTIs etiologically. mNGS has the potential to enhance clinical outcomes by optimizing the treatment regimens.

Comparative analysis of metagenomic and targeted next-generation sequencing for pathogens diagnosis in bronchoalveolar lavage fluid specimens

Background

Although the emerging NGS-based assays, metagenomic next-generation sequencing (mNGS) and targeted next-generation sequencing (tNGS), have been extensively utilized for the identification of pathogens in pulmonary infections, there have been limited studies systematically evaluating differences in the efficacy of mNGS and multiplex PCR-based tNGS in bronchoalveolar lavage fluid (BALF) specimens.

Methods

In this study, 85 suspected infectious BALF specimens were collected. Parallel mNGS and tNGS workflows to each sample were performed; then, we comparatively compared their consistency in detecting pathogens. The differential results for clinically key pathogens were confirmed using PCR.

Results

The microbial detection rates of BALF specimens by the mNGS and tNGS workflows were 95.18% (79/83) and 92.77% (77/83), respectively, with no significant difference. mNGS identified 55 different microorganisms, whereas tNGS detected 49 pathogens. The comparative analysis of mNGS and tNGS revealed that 86.75% (72/83) of the specimens were complete or partial concordance. Particularly, mNGS and tNGS differed significantly in detection rates for some of the human herpesviruses only, including Human gammaherpesvirus 4 (P<0.001), Human betaherpesvirus 7 (P<0.001), Human betaherpesvirus 5 (P<0.05) and Human betaherpesvirus 6 (P<0.01), in which tNGS always had higher detection rates. Orthogonal testing of clinically critical pathogens showed a total coincidence rate of 50% for mNGS and PCR, as well as for tNGS and PCR.

Conclusions

Overall, the performance of mNGS and multiplex PCR-based tNGS assays was similar for bacteria and fungi, and tNGS may be superior to mNGS for the detection of DNA viruses. No significant differences were seen between the two NGS assays compared to PCR.

Lung microbiota: implications and interactions in chronic pulmonary diseases

The lungs, as vital organs in the human body, continuously engage in gas exchange with the external environment. The lung microbiota, a critical component in maintaining internal homeostasis, significantly influences the onset and progression of diseases. Beneficial interactions between the host and its microbial community are essential for preserving the host's health, whereas disease development is often linked to dysbiosis or alterations in the microbial community. Evidence has demonstrated that changes in lung microbiota contribute to the development of major chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), asthma, and lung cancer. However, in-depth mechanistic studies are constrained by the small scale of the lung microbiota and its susceptibility to environmental pollutants and other factors, leaving many questions unanswered. This review examines recent research on the lung microbiota and lung diseases, as well as methodological advancements in studying lung microbiota, summarizing the ways in which lung microbiota impacts lung diseases and introducing research methods for investigating lung microbiota.

Detection of rare microorganisms in bone and joint infections by metagenomic next-generation sequencing

Aims

This aim of this study was to analyze the detection rate of rare pathogens in bone and joint infections (BJIs) using metagenomic next-generation sequencing (mNGS), and the impact of mNGS on clinical diagnosis and treatment.

Methods

A retrospective analysis was conducted on 235 patients with BJIs who were treated at our hospital between January 2015 and December 2021. Patients were divided into the no-mNGS group (microbial culture only) and the mNGS group (mNGS testing and microbial culture) based on whether mNGS testing was used or not.

Results

A total of 147 patients were included in the no-mNGS group and 88 in the mNGS group. The mNGS group had a higher detection rate of rare pathogens than the no-mNGS group (21.6% vs 10.2%, p = 0.016). However, the mNGS group had lower rates of antibiotic-related complications, shorter hospital stays, and higher infection control rates compared with the no-mNGS group (p = 0.017, p = 0.003, and p = 0.028, respectively), while there was no significant difference in the duration of antibiotic use (p = 0.957). In culture-negative cases, the mNGS group had lower rates of antibiotic-related complications, shorter hospital stays, and a higher infection control rate than the no-mNGS group (p = 0.036, p = 0.033, p = 0.022, respectively), while there was no significant difference in the duration of antibiotic use (p = 0.748).

Conclusion

mNGS improves detection of rare pathogens in BJIs. mNGS testing reduces antibiotic-related complications, shortens hospital stay and antibiotic use duration, and improves treatment success rate, benefits which are particularly evident in culture-negative cases.

Active herpesviruses are associated with intensive care unit (ICU) admission in patients pulmonary infection and alter the respiratory microbiome

Background

The Herpesviridae family contains several human-related viruses, which are able to establish colonizing and latency in the human body, posing a significant threat to the prognosis of patients. Pulmonary infections represent one of the predominant infectious diseases globally, characterized by diverse and multifaceted clinical manifestations that have consistently attracted clinician's concern. However, the relationship of herpesviruses on the prognosis of pulmonary infections and the respiratory microbiota remains poorly understood.

Methods

Here, we retrospectively analyzed respiratory samples from 100 patients with pulmonary infection detected by metagenomic next-generation sequencing (mNGS).

Results

Employing mNGS, five herpesvirus species were detected: Human alphaherpesvirus 1 (HSV-1), Human gammaherpesvirus 4 (EBV), Human betaherpesvirus 5 (CMV), Human betaherpesvirus 7 (HHV-7), and Human betaherpesvirus 6B (HHV-6B). Regression analysis showed that the age and positivity of herpesviruses in patients were independently correlated with ICU admission rates. In addition, positivity of herpesvirus was related with increased ICU days and total hospital stay. The herpesvirus-positive group demonstrated markedly higher incidences of co-infections and fungi-positive, predominantly involving Pneumocystis jirovecii and Aspergillus fumigatus. Analysis of respiratory microbiota revealed a substantially altered community composition within the herpesvirus-positive group, and herpesviruses were significantly positively correlated with the diverse respiratory opportunistic pathogens.

Conclusion

Overall results substantiate that the active herpesviruses in patients with pulmonary infections were significantly associated with high ICU admission rate. Moreover, the herpesviruses promotes the dysbiosis of the respiratory microbiota and an increased proportion of co-infections. These insights could contribute to unraveling the underlying mechanisms connecting active herpesviruses to the progression of severe illnesses.

Metatranscriptomics: A Tool for Clinical Metagenomics

In the field of bioinformatics, amplicon sequencing of 16S rRNA genes has long been used to investigate community membership and taxonomic abundance in microbiome studies. As we can observe, shotgun metagenomics has become the dominant method in this field. This is largely owing to advancements in sequencing technology, which now allow for random sequencing of the entire genetic content of a microbiome. Furthermore, this method allows profiling both genes and the microbiome's membership. Although these methods have provided extensive insights into various microbiomes, they solely assess the existence of organisms or genes, without determining their active role within the microbiome. Microbiome scholarship now includes metatranscriptomics to decipher how a community of microorganisms responds to changing environmental conditions over a period of time. Metagenomic studies identify the microbes that make up a community but metatranscriptomics explores the diversity of active genes within that community, understanding their expression profile and observing how these genes respond to changes in environmental conditions. This expert review article offers a critical examination of the computational metatranscriptomics tools for studying the transcriptomes of microbial communities. First, we unpack the reasons behind the need for community transcriptomics. Second, we explore the prospects and challenges of metatranscriptomic workflows, starting with isolation and sequencing of the RNA community, then moving on to bioinformatics approaches for quantifying RNA features, and statistical techniques for detecting differential expression in a community. Finally, we discuss strengths and shortcomings in relation to other microbiome analysis approaches, pipelines, use cases and limitations, and contextualize metatranscriptomics as a tool for clinical metagenomics.

Clinical utility of metagenomic next-generation sequencing in the diagnosis of invasive pulmonary aspergillosis in acute exacerbation of chronic obstructive pulmonary disease patients in the intensive care unit

Objective

To explore the clinical utility of metagenomic next-generation sequencing (mNGS) in diagnosing invasive pulmonary aspergillosis (IPA) among patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in the intensive care unit (ICU).

Methods

A retrospective analysis was conducted on patients with AECOPD admitted to the ICU of Xinxiang Central Hospital in Henan Province, China, between March 2020 and September 2023, suspected of having IPA. Bronchoalveolar lavage fluid (BALF) samples were collected for fungal culture, the galactomannan (GM) test, and mNGS. Based on host factors, clinical features, and microbiological test results, patients were categorized into 62 cases of IPA and 64 cases of non-IPA. Statistical analysis was performed to compare the diagnostic efficacy of fungal culture, the serum and BALF GM test, and mNGS detection for IPA in patients with AECOPD.

Results

1. The sensitivity and specificity of mNGS in diagnosing IPA were 70.9% and 71.8% respectively, with the sensitivity of mNGS surpassing that of fungal culture (29.0%, P<0.01), serum GM test (35.4%, P<0.01), and BALF GM test (41.9%, P<0.05), albeit with slightly lower specificity compared to fungal culture (90.6%, P >0.05), serum GM test (87.5%, P >0.05), and BALF GM test (85.9%, P >0.05).Combining fungal culture with the GM test and mNGS resulted in a sensitivity of 80.6% and a specificity of 92.2%, underscoring a superior diagnostic rate compared to any single detection method. 2.mNGS accurately distinguished strains of the Aspergillus genus. 3.The area under the ROC curves of mNGS was 0.73, indicating good diagnostic performance. 4.The detection duration for mNGS is shorter than that of traditional fungal culture and GM testing.

Conclusion

mNGS presents a pragmatic and highly sensitive approach, serving as a valuable complementary tool to conventional microbiological tests (CMT). Our research demonstrated that, compared to fungal culture and GM testing, mNGS exhibits superior diagnostic capability for IPA among patients with AECOPD. Integration of mNGS with established conventional methods holds promise for improving the diagnosis rate of IPA.

Clinical challenge of diagnosing non-ventilator hospital-acquired pneumonia and identifying causative pathogens: a narrative review

Non-ventilated hospital-acquired pneumonia (NV-HAP) is associated with a significant healthcare burden, arising from high incidence and associated morbidity and mortality. However, accurate identification of cases remains challenging. At present, there is no gold-standard test for the diagnosis of NV-HAP, requiring instead the blending of non-specific signs and investigations. Causative organisms are only identified in a minority of cases. This has significant implications for surveillance, patient outcomes and antimicrobial stewardship. Much of the existing research in HAP has been conducted among ventilated patients. The paucity of dedicated NV-HAP research means that conclusions regarding diagnostic methods, pathology and interventions must largely be extrapolated from work in other settings. Progress is also limited by the lack of a widely agreed definition for NV-HAP. The diagnosis of NV-HAP has large scope for improvement. Consensus regarding a case definition will allow meaningful research to improve understanding of its aetiology and the heterogeneity of outcomes experienced by patients. There is potential to optimize the role of imaging and to incorporate novel techniques to identify likely causative pathogens. This would facilitate both antimicrobial stewardship and surveillance of an important healthcare-associated infection. This narrative review considers the utility of existing methods to diagnose NV-HAP, with a focus on the significance and challenge of identifying pathogens. It discusses the limitations in current techniques, and explores the potential of emergent molecular techniques to improve microbiological diagnosis and outcomes for patients.

Coinfection of Cedecea lapagei and Aspergillus sydowii detected in bronchoalveolar lavage fluid of a patient with pulmonary infection using metagenomic next-generation sequencing: A case report

Background

Cedecea lapagei (C. lapagei), as a potential human pathogen, has been reported in limited cases of human infections in medical literature. However, the increasing frequency of isolating Cedecea lapagei from clinical specimens underscores its growing clinical significance that should not be underestimated. Aspergillus sydowii (A. sydowii), commonly isolated from various environments, serves as a pathogen of human cryptic aspergillosis. Clinical pathological changes caused by A. sydowii are not obvious, posing a significant challenge in clinical diagnosis. Consequently, metagenomic next-generation sequencing (mNGS) are required for precise differentiation and identification of pathogens.

Case description

Here we present a case demonstrating successful treatment outcome in a patient with pulmonary infection caused by coinfection of C. lapagei and A. sydowii, as identified through metagenomic next-generation sequencing. The patient, a 50-year-old male, presented with worsening cough, sputum production, and hemoptysis. Metagenomic next-generation sequencing (mNGS) analysis of the bronchoalveolar lavage fluid (BALF) revealed the presence of both C. lapagei and A. sydowii. Subsequently, C. lapagei was also detected by culture in the same BALF sample, however while clinical fungal cultures and (1-3)-β-D glucan testing yielded negative results. Based on these findings along with imaging features and clinical symptoms of the patient, the final diagnosis was determined to be a co-infection of C. lapagei and A. sydowii.

Conclusion

The clinical manifestations of human infections caused by C. lapagei are not specific; patients with cryptic aspergillosis may have been previously overlooked due to improper specimen selection or negative routine tests. Therefore, precise identification of pathogens is crucial. This case report highlights the value of mNGS in detecting C. lapagei and A. sydowii in BALF, enabling timely diagnosis with coinfections.

The etiological diagnostic value of metagenomic next-generation sequencing in suspected community-acquired pneumonia

BACKGROUND

The emergence of metagenomic next-generation sequencing (mNGS) may provide a promising tool for early and comprehensive identification of the causative pathogen in community-acquired pneumonia (CAP). In this study, we aim to further evaluate the etiological diagnostic value of mNGS in suspected CAP.

METHODS

A total of 555 bronchoalveolar lavage fluid (BALF) samples were collected for pathogen detection by mNGS from 541 patients with suspected CAP. The clinical value was assessed based on infection diagnosis and treatment guidance. The diagnostic performance for pathogen identification by mNGS and sputum culture and for tuberculosis (TB) by mNGS and X-pert MTB/RIF were compared. To evaluate the potential for treatment guidance, we analyzed the treatment regimen of patients with suspected CAP, including imaging changes of lung after empirical antibacterial therapy, intensified regimen, antifungal treatment, and a 1-year follow up for patients with unconfirmed diagnosis and non-improvement imaging after anti-infective treatment and patients with high suspicion of TB or NTM infection who were transferred to the Wuhan Pulmonary Hospital for further diagnosis and even anti-mycobacterium therapy.

RESULTS

Of the 516 BALF samples that were analyzed by both mNGS and sputum culture, the positivity rate of mNGS was significantly higher than that of sputum culture (79.1% vs. 11.4%, P = 0.001). A total of 48 samples from patients with confirmed TB were analyzed by both mNGS and X-pert MTB/RIF, and the sensitivity of mNGS for the diagnosis of active TB was significantly lower than that of X-pert MTB/RIF (64.6% vs. 85.4%, P = 0.031). Of the 106 pathogen-negative cases, 48 were ultimately considered non-infectious diseases, with a negative predictive value of 45.3%. Of the 381 pathogen-positive cases, 311 were eventually diagnosed as CAP, with a positive predictive value of 81.6%. A total of 487 patients were included in the evaluation of the therapeutic effect, and 67.1% improved with initial empirical antibiotic treatment. Of the 163 patients in which bacteria were detected, 77.9% improved with antibacterial therapy; of the 85 patients in which fungi were detected, 12.9% achieved remission after antifungal therapy.

CONCLUSIONS

Overall, mNGS had unique advantages in the detection of suspected CAP pathogens. However, mNGS was not superior to X-pert MTB/RIF for the diagnosis of TB. In addition, mNGS was not necessary as a routine test for all patients admitted with suspected CAP. Furthermore, when fungi are detected by mNGS, antifungal therapy should be cautious.

Nasal Lavage Fluid Proteomics Reveals Potential Biomarkers of Asthma Associated with Disease Control

Purpose

Little research has explored the proteomic characteristics of nasal lavage fluid from asthmatic patients. This study aims to investigate whether differentially expressed proteins (DEPs) in nasal lavage fluid can serve as a biomarker to differentiate asthma patients from healthy controls (HCs) and to discern between individuals with well controlled and poorly controlled asthma.

Patients and Methods

We enrolled patients with allergic rhinitis (AR), asthma, or both conditions, and HCs in this study. We recorded patients' demographic and medical history data and administered asthma quality of life questionnaire (AQLQ) and asthma control questionnaire (ACQ). Nasal fluid samples were collected, followed by protein measurements, and proteomic analysis utilizing the data-independent acquisition (DIA) method.

Results

Twenty-four with asthma, 27 with combined asthma+ AR, 25 with AR, and 12 HCs were enrolled. Four proteins, superoxide dismutase 2 (SOD2), serpin B7 (SERPINB7), kallikrein-13 (KLK13), and bleomycin hydrolase (BLMH) were significantly upregulated in nasal lavage fluid samples of asthma without AR, compared to HCs (Fold change ≥2.0, false-discovery rate [FDR] <0.05). Conversely, 56 proteins including secretoglobin family 2A member 1 (SCGB2A1) were significantly downregulated (fold change ≥2.0, FDR <0.05). Furthermore, 96.49% of DEPs including peptidase inhibitor 3 (PI3) and C-X-C motif chemokine 17 (CXCL17) were upregulated in poorly controlled asthma patients without AR relative those with well- or partly controlled asthma (fold change ≥1.5, FDR <0.05). Search tool for the retrieval of interacting genes/proteins (STRING) analysis showed that PI3, with 18 connections, may be pivotal in asthma control.

Conclusion

The study revealed significant alteration in the nasal lavage proteome in asthma without AR patients. Moreover, our results indicated a potential association between the expression of proteome in the upper airway and the level of asthma control. Specifically, PI3 appears to be a key role in the regulation of asthma without AR.

Clinical application value of metagenome next-generation sequencing in pulmonary diffuse exudative lesions: a retrospective study

Objective

This study aims to investigate the clinical application value of Metagenome Next-Generation Sequencing (mNGS) for pulmonary diffuse exudative lesions.

Methods

From January 1, 2014, to November 31, 2021, 136 cases with chest radiologic presentations of pulmonary diffuse exudative lesions admitted to Fujian Provincial Hospital were included in the study; of those, 77 patients underwent mNGS pathogen detection. Based on the pathogen detection outcomes and clinical diagnoses, patients were categorized into an infection group (IG) and a non-infection group (NIG). A comparison was made between the diagnostic efficacy of the mNGS technique and traditional culture methods. Meanwhile, 59 patients clinically identified as having infectious pulmonary diffuse exudative lesions but who did not receive mNGS testing were designated as the non-NGS infection group (non-IG). A retrospective cohort study was conducted on patients in both the IG and non-IG, with a 30-day all-cause mortality endpoint used for follow-up.

Outcomes

When compared to conventional culture methods, mNGS demonstrated an approximate 35% increase in sensitivity (80.0% vs 45.5%, P<0.001), without significant disparity in specificity (77.3% vs 95.5%, P=0.185). Under antibiotic exposure, the positivity rate detected by mNGS was notably higher than that by traditional culture methods, indicating that mNGS is less affected by exposure to antibiotics (P<0.05). Within 30 days, the all-cause mortality rate for patients in the IG versus the non-IG was 14.55% and 37.29%, respectively (P<0.05). Following a COX regression analysis to adjust for confounding factors, the analysis revealed that a CURB-65 score ≥3 points (HR=3.348, P=0.001) and existing cardiovascular disease (HR=2.473, P=0.026) were independent risk factors for these patients. Conversely, mNGS testing (HR=0.368, P=0.017) proved to be an independent protective factor.

Conclusion

mNGS technology makes it easier to pinpoint the cause of pulmonary diffuse infectious exudative lesions without much interference from antibiotics, helping doctors spot and diagnose these issues early on, thereby playing a key role in helping them decide the best treatment approach for patients. Such conclusions may have a bias, as the performance of traditional methods might be underestimated due to the absence of complete results from other conventional diagnostic techniques like serological testing and PCR.

Viruses associated with measles-like illnesses in Uganda

OBJECTIVES

In this study, we investigated the causes of measles-like illnesses (MLI) in the Uganda national surveillance program in order to inform diagnostic assay selection and vaccination strategies.

METHODS

We used metagenomic next-generation sequencing (M-NGS) on the Illumina platform to identify viruses associated with MLI (defined as fever and rash in the presence of either cough, coryza or conjunctivitis) in patient samples that had tested IgM negative for measles between 2010 and 2019.

RESULTS

Viral genomes were identified in 87/271 (32%) of samples, of which 44/271 (16%) contained 12 known viral pathogens. Expected viruses included rubella, human parvovirus B19, Epstein Barr virus, human herpesvirus 6B, human cytomegalovirus, varicella zoster virus and measles virus (detected within the seronegative window-period of infection) and the blood-borne hepatitis B virus. We also detected Saffold virus, human parvovirus type 4, the human adenovirus C2 and vaccine-associated poliovirus type 1.

CONCLUSIONS

The study highlights the presence of undiagnosed viruses causing MLI in Uganda, including vaccine-preventable illnesses. NGS can be used to monitor common viral infections at a population level, especially in regions where such infections are prevalent, including low and middle income countries to guide vaccination policy and optimize diagnostic assays.

Application of metagenomic next-generation sequencing technology in the etiological diagnosis of peritoneal dialysis-associated peritonitis

Pathogens detected by metagenomic next-generation sequencing (mNGS) and the laboratory blood culture flask method were compared to understand the advantages and clinical significance of mNGS assays in the etiological diagnosis of peritoneal dialysis-associated peritonitis (PDAP). The study involved a total of 37 patients from the hospital's peritoneal dialysis centre, six of whom were patients with non-peritoneal dialysis-associated peritonitis. Peritoneal dialysis samples were collected from the 37 patients, who were divided into two groups. One group's samples were cultured using conventional blood culture flasks, and the other samples underwent pathogen testing using mNGS. The results showed that the positive rate of mNGS was 96.77%, while that of the blood culture flask method was 70.97% (p < 0.05). A total of 29 pathogens were detected by mNGS, namely 24 bacteria, one fungus, and four viruses. A total of 10 pathogens were detected using the bacterial blood culture method, namely nine bacteria and one fungus. The final judgment of the PDAP's causative pathogenic microorganism was made by combining the clinical condition, response to therapy, and the whole-genome sequencing findings. For mNGS, the sensitivity was 96.77%, the specificity was 83.33%, the positive predictive value was 96.77%, and the negative predictive value was 83.33%. For the blood culture flask method, the sensitivity was 70.97%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 0%. In conclusion, mNGS had a shorter detection time for diagnosing peritoneal dialysis-related peritonitis pathogens, with a higher positive rate than traditional bacterial cultures, providing significant advantages in diagnosing rare pathogens.

Simplifying Data Analysis in Biomedical Research: An Automated, User-Friendly Tool

Robust data normalization and analysis are pivotal in biomedical research to ensure that observed differences in populations are directly attributable to the target variable, rather than disparities between control and study groups. ArsHive addresses this challenge using advanced algorithms to normalize populations (e.g., control and study groups) and perform statistical evaluations between demographic, clinical, and other variables within biomedical datasets, resulting in more balanced and unbiased analyses. The tool's functionality extends to comprehensive data reporting, which elucidates the effects of data processing, while maintaining dataset integrity. Additionally, ArsHive is complemented by A.D.A. (Autonomous Digital Assistant), which employs OpenAI's GPT-4 model to assist researchers with inquiries, enhancing the decision-making process. In this proof-of-concept study, we tested ArsHive on three different datasets derived from proprietary data, demonstrating its effectiveness in managing complex clinical and therapeutic information and highlighting its versatility for diverse research fields.

Bacteremia caused by Nocardia farcinica: a case report and literature review

BACKGROUND

Nocardia farcinica is one of the most common Nocardia species causing human infections. It is an opportunistic pathogen that often infects people with compromised immune systems. It could invade human body through respiratory tract or skin wounds, cause local infection, and affect other organs via hematogenous dissemination. However, N. farcinica-caused bacteremia is uncommon. In this study, we report a case of bacteremia caused by N. farcinica in China.

CASE PRESENTATION

An 80-year-old woman was admitted to Peking Union Medical College Hospital with recurrent fever, right abdominal pain for one and a half month, and right adrenal gland occupation. N. farcinica was identified as the causative pathogen using blood culture and plasma metagenomics next-generation sequencing (mNGS). The clinical considerations included bacteremia and adrenal gland abscess caused by Nocardia infection. As the patient was allergic to sulfanilamide, imipenem/cilastatin and linezolid were empirically administered. Unfortunately, the patient eventually died less than a month after the initiation of anti-infection treatment.

CONCLUSION

N. farcinica bacteremia is rare and its clinical manifestations are not specific. Its diagnosis depends on etiological examination, which can be confirmed using techniques such as Sanger sequencing and mNGS. In this report, we have reviewed cases of Nocardia bloodstream infection reported in the past decade, hoping to improve clinicians' understanding of Nocardia bloodstream infection and help in its early diagnosis and timely treatment.

Assessment and clinical utility of metagenomic next-generation sequencing for suspected lower respiratory tract infections

OBJECTIVES

This study aims to compare the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) to traditional diagnostic methods in patients with lower respiratory tract infections (LRTIs), elucidate the etiological spectrum of these infections, and explore the impact of mNGS on guiding antimicrobial therapy.

METHODS

We retrospectively analyzed data from 128 patients admitted to the Respiratory Department of Anqing 116 Hospital between July 2022 and July 2023. All patients had undergone both mNGS and conventional microbiological techniques (CMT) for LRTI diagnosis. We assessed the diagnostic performance of these methods and examined the influence of mNGS on antimicrobial decision-making.

RESULTS

Overall, mNGS demonstrated superior sensitivity (96.8%) and accuracy (96.8%) compared to CMT. For Mycobacterium tuberculosis detection, the accuracy and sensitivity of mNGS was 88.8% and 77.6%, which was lower than the 94.7% sensitivity of the T-spot test and the 79.6% sensitivity of CMT. In fungal pathogen detection, mNGS showed excellent sensitivity (90.5%), specificity (86.7%), and accuracy (88.0%). Bacteria were the predominant pathogens detected (75.34%), with Mycobacterium tuberculosis (41.74%), Streptococcus pneumoniae (21.74%), and Haemophilus influenzae (16.52%) being most prevalent. Bacterial infections were most common (62.10%), followed by fungal and mixed infections (17.74%). Of the 118 patients whose treatment regimens were adjusted based on mNGS results, 102 (86.5%) improved, 7 (5.9%) did not respond favorably, and follow-up was lost for 9 patients (7.6%).

CONCLUSIONS

mNGS offers rapid and precise pathogen detection for patients with suspected LRTIs and shows considerable promise in diagnosing Mycobacterium tuberculosis and fungal infections. By broadening the pathogen spectrum and identifying polymicrobial infections, mNGS can significantly inform and refine antibiotic therapy.

Enhancing Clinical Utility: Utilization of International Standards and Guidelines for Metagenomic Sequencing in Infectious Disease Diagnosis

Metagenomic sequencing has emerged as a transformative tool in infectious disease diagnosis, offering a comprehensive and unbiased approach to pathogen detection. Leveraging international standards and guidelines is essential for ensuring the quality and reliability of metagenomic sequencing in clinical practice. This review explores the implications of international standards and guidelines for the application of metagenomic sequencing in infectious disease diagnosis. By adhering to established standards, such as those outlined by regulatory bodies and expert consensus, healthcare providers can enhance the accuracy and clinical utility of metagenomic sequencing. The integration of international standards and guidelines into metagenomic sequencing workflows can streamline diagnostic processes, improve pathogen identification, and optimize patient care. Strategies in implementing these standards for infectious disease diagnosis using metagenomic sequencing are discussed, highlighting the importance of standardized approaches in advancing precision infectious disease diagnosis initiatives.

Disseminated Histoplasmosis Infection Diagnosed by Metagenomic Next-Generation Sequencing: A Case Report

Histoplasmosis is an endemic disease caused by Histoplasma capsulatum. This systemic disease can affect various organs beyond the lungs, such as the liver, spleen, adrenal gland, and lymph nodes. The clinical symptoms can range from asymptomatic to severe, life-threatening conditions, depending on the state of the patient's immune system. This report describes a 40-year-old male who presented with reports of weight loss, low back pain, and progressively worsening movement disorder of the bilateral lower extremities for months. Computed tomography (CT) examination showed multiple lytic lesions of vertebral bodies, bilateral ribs, and pelvic bone, histopathological examination and tumor-related serum markers exclude tumors. mNGS was employed to identify H. capsulatum var. capsulatum as the etiological agent of the lesions in the bone biopsy. Through phylogenetic tree analysis, Histoplasma capsulatum var. Capsulatum (Hcc) was the main responsible pathogen, rarely reported in bone lesions. The patient underwent spinal surgery and was successfully treated with liposomal amphotericin B and itraconazole. Based on the diagnosis and treatment of this case, we discuss the epidemiologic status, clinical presentations, diagnostic criteria, and treatment guidelines of histoplasmosis to provide additional information about this disease. mNGS is utilized in this case, and it appears to be a reliable method for early and accurate diagnosis of this disease.

Airway necrosis and granulation tissue formation caused by Rhizopus oryzae leading to severe upper airway obstruction: a case report

Pulmonary Mucormycosis is a fatal infectious disease with high mortality rate. The occurrence of Mucormycosis is commonly related to the fungal virulence and the host's immunological defenses against pathogens. Mucormycosis infection and granulation tissue formation occurred in the upper airway was rarely reported. This patient was a 60-year-old male with diabetes mellitus, who was admitted to hospital due to progressive cough, sputum and dyspnea. High-resolution computed tomography (HRCT) and bronchoscopy revealed extensive tracheal mucosal necrosis, granulation tissue proliferation, and severe airway stenosis. The mucosal necrotic tissue was induced by the infection of Rhizopus Oryzae, confirmed by metagenomic next-generation sequencing (mNGS) in tissue biopsy. This patient was treated with the placement of a covered stent and local instillation of amphotericin B via bronchoscope. The tracheal mucosal necrosis was markedly alleviated, the symptoms of cough, shortness of breath, as well as exercise tolerance were significantly improved. The placement of airway stent and transbronchial microtube drip of amphotericin B could conduce to rapidly relieve the severe airway obstruction due to Mucormycosis infection.

Association between Clinical Characteristics and Microbiota in Bronchiectasis Patients Based on Metagenomic Next-Generation Sequencing Technology

This study aimed to investigate the disparities between metagenomic next-generation sequencing (mNGS) and conventional culture results in patients with bronchiectasis. Additionally, we sought to investigate the correlation between the clinical characteristics of patients and their microbiome profiles. The overarching goal was to enhance the effective management and treatment of bronchiectasis patients, providing a theoretical foundation for healthcare professionals. A retrospective survey was conducted on 67 bronchiectasis patients admitted to The First Hospital of Jiaxing from October 2019 to March 2023. Clinical baseline information, inflammatory indicators, and pathogen detection reports, including mNGS, conventional blood culture, bronchoalveolar lavage fluid (BALF) culture, and sputum culture results, were collected. By comparing the results of mNGS and conventional culture, the differences in pathogen detection rate and pathogen types were explored, and the diagnostic performance of mNGS compared to conventional culture was evaluated. Based on the various pathogens detected by mNGS, the association between clinical characteristics of bronchiectasis patients and mNGS microbiota results was analyzed. The number and types of pathogens detected by mNGS were significantly larger than those detected by conventional culture. The diagnostic efficacy of mNGS was significantly superior to conventional culture for all types of pathogens, particularly in viral detection (p < 0.01). Regarding pathogen detection rate, the bacteria with the highest detection rate were Pseudomonas aeruginosa (17/58) and Haemophilus influenzae (11/58); the fungus with the highest detection rate was Aspergillus fumigatus (10/21), and the virus with the highest detection rate was human herpes virus 4 (4/11). Differences were observed between the positive and negative groups for P. aeruginosa in terms of common scoring systems for bronchiectasis and whether the main symptom of bronchiectasis manifested as thick sputum (p < 0.05). Significant distinctions were also noted between the positive and negative groups for A. fumigatus regarding Reiff score, neutrophil percentage, bronchiectasis etiology, and alterations in treatment plans following mNGS results reporting (p < 0.05). Notably, 70% of patients with positive A. fumigatus infection opted to change their treatment plans. The correlation study between clinical characteristics of bronchiectasis patients and mNGS microbiological results revealed that bacteria, such as P. aeruginosa, and fungi, such as A. fumigatus, were associated with specific clinical features of patients. This underscored the significance of mNGS in guiding personalized treatment approaches. mNGS could identify multiple pathogens in different types of bronchiectasis samples and was a rapid and effective diagnostic tool for pathogen identification. Its use was recommended for diagnosing the causes of infections in bronchiectasis patients.

Application value of metagenomics next-generation sequencing in the diagnosis of respiratory virus infection after congenital heart surgery

Background

Timely and accurate pathogen diagnosis can be challenging in children who contract a respiratory virus following congenital heart surgery (CHS). This often results in suboptimal drug use and treatment delays. Metagenomics next-generation sequencing (mNGS) is a swift, efficient, and unbiased method for obtaining microbial nucleic acid sequences. This technology holds promise as a comprehensive diagnostic tool, especially for pathogens undetectable by traditional methods. However, the efficacy of mNGS in the context of congenital heart disease infections remains uncertain. This study aimed to explore the diagnostic value of mNGS for respiratory virus infections post-CHS.

Methods

We conducted a retrospective analysis of patients who developed respiratory tract infections post-CHS and were admitted to our cardiac center between July 2021 and December 2022. The patients were categorized into the following two groups based on the diagnostic method used: (I) the mNGS group (comprising 62 patients); and (II) the conventional microbiological test (CMT) group (comprising 70 patients). Bronchoalveolar lavage fluid (BALF) samples from these patients were tested to identify pathogens.

Results

The mNGS group had significantly higher detection rates for both viral infections and mixed viral infections than the CMT group (56.45% vs. 17.14%, P<0.001, and 80.00% vs. 16.67%, P<0.001, respectively). In the mNGS group, 19.35% of the patients received antiviral therapy, and 61.29% received an anti-infective regimen adjustment. Conversely, in the CMT group, only 4.29% received antiviral therapy, and 28.57% received an anti-infective regimen adjustment. A higher percentage of patients showed improved respiratory symptoms in the mNGS group than the CMT group (74.19% vs. 44.29%, P=0.001). Additionally, the mNGS group had a shorter duration of mechanical ventilation and a reduced length of stay in the cardiac intensive care unit than the CMT group (P=0.012).

Conclusions

Using mNGS for BALF enhances the detection of respiratory viral infections and coexisting viral infections post-CHS. This facilitates more precise treatment strategies and could potentially lead to improved patient outcomes.

Genomic attributes of airway commensal bacteria and mucosa

Microbial communities at the airway mucosal barrier are conserved and highly ordered, in likelihood reflecting co-evolution with human host factors. Freed of selection to digest nutrients, the airway microbiome underpins cognate management of mucosal immunity and pathogen resistance. We show here the initial results of systematic culture and whole-genome sequencing of the thoracic airway bacteria, identifying 52 novel species amongst 126 organisms that constitute 75% of commensals typically present in heathy individuals. Clinically relevant genes encode antimicrobial synthesis, adhesion and biofilm formation, immune modulation, iron utilisation, nitrous oxide (NO) metabolism and sphingolipid signalling. Using whole-genome content we identify dysbiotic features that may influence asthma and chronic obstructive pulmonary disease. We match isolate gene content to transcripts and metabolites expressed late in airway epithelial differentiation, identifying pathways to sustain host interactions with microbiota. Our results provide a systematic basis for decrypting interactions between commensals, pathogens, and mucosa in lung diseases of global significance.

16S rRNA Next-Generation Sequencing May Not Be Useful for Examining Suspected Cases of Spontaneous Bacterial Peritonitis

Background and Objectives: Ascites, often associated with liver cirrhosis, poses diagnostic challenges, particularly in detecting bacterial infections. Traditional methods have limitations, prompting the exploration of advanced techniques such as 16S rDNA next-generation sequencing (NGS) for improved diagnostics in such low-biomass fluids. The aim of this study was to investigate whether the NGS method enhances detection sensitivity compared to a conventional ascites culture. Additionally, we aimed to explore the presence of a microbiome in the abdominal cavity and determine whether it has a sterile condition. Materials and Methods: Ten patients with clinically suspected spontaneous bacterial peritonitis (SBP) were included in this study. A traditional ascites culture was performed, and all ascites samples were subjected to 16S ribosomal RNA gene amplification and sequencing. 16S rRNA gene sequencing results were interpreted by comparing them to positive and negative controls for each sample. Results: Differential centrifugation was applied to all ascites samples, resulting in very small or no bacterial pellets being harvested. The examination of the 16S amplicon sequencing libraries indicated that the target amplicon products were either minimally visible or exhibited lower intensity than their corresponding negative controls. Contaminants present in the reagents were also identified in the ascites samples. Sequence analysis of the 16S rRNA gene of all samples showed microbial compositions that were akin to those found in the negative controls, without any bacteria isolated that were unique to the samples. Conclusions: The peritoneal cavity and ascites exhibit low bacterial biomass even in the presence of SBP, resulting in a very low positivity rate in 16S rRNA gene sequencing. Hence, the 16S RNA sequencing method does little to enhance the rate of positive samples compared to traditional culture methods, including in SBP cases.

Diagnostic strategy of metagenomic next-generation sequencing for gram negative bacteria in respiratory infections

OBJECTIVE

This study aims to identify the most effective diagnostic method for distinguishing pathogenic and non-pathogenic Gram-negative bacteria (GNB) in suspected pneumonia cases using metagenomic next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) samples.

METHODS

The effectiveness of mNGS was assessed on BALF samples collected from 583 patients, and the results were compared with those from microbiological culture and final clinical diagnosis. Three interpretational approaches were evaluated for diagnostic accuracy.

RESULTS

mNGS outperformed culture significantly. Among the interpretational approaches, Clinical Interpretation (CI) demonstrated the best diagnostic performance with a sensitivity of 87.3%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 98.3%. CI's specificity was significantly higher than Simple Interpretation (SI) at 37.9%. Additionally, CI excluded some microorganisms identified as putative pathogens by SI, including Haemophilus parainfluenzae, Haemophilus parahaemolyticus, and Klebsiella aerogenes.

CONCLUSION

Proper interpretation of mNGS data is crucial for accurately diagnosing respiratory infections caused by GNB. CI is recommended for this purpose.

Metagenomic next-generation sequencing in detecting pathogens in pediatric oncology patients with suspected bloodstream infections

BACKGROUND

Studies on mNGS application in pediatric oncology patients, who are at high risk of infection, are quite limited.

METHODS

From March 2020 to June 2022, a total of 224 blood samples from 195 pediatric oncology patients who were suspected as bloodstream infections were enrolled in this study. Their clinical and laboratory data were retrospectively reviewed, and the diagnostic performance of mNGS was assessed.

RESULTS

Compared to the reference tests, mNGS showed significantly higher sensitivity (89.8% vs 32.5%, P < 0.001) and clinical agreement (76.3% vs 51.3%, P < 0.001) in detecting potential pathogens and distinguishing BSI from non-BSI. Especially, mNGS had an outstanding performance for virus detection, contributing to 100% clinical diagnosed virus. Samples from patients with neutropenia showed higher incidence of bacterial infections (P = 0.035). The most identified bacteria were Escherichia coli, and the overall infections by gram-negative bacteria were significantly more prevalent than those by gram-positive ones (90% vs 10%, P < 0.001). Overall, mNGS had an impact on the antimicrobial regimens' usage in 54.3% of the samples in this study.

CONCLUSIONS

mNGS has the advantage of rapid and effective pathogen diagnosis in pediatric oncology patients with suspected BSI, especially for virus.

IMPACT

Compared with reference tests, mNGS showed significantly higher sensitivity and clinical agreement in detecting potential pathogens and distinguishing bloodstream infections (BSI) from non-BSI. mNGS is particularly prominent in clinical diagnosed virus detection. The incidence of bacterial infection was higher in patients with neutropenia, and the overall infection rate of Gram-negative bacteria was significantly higher than that of Gram-positive bacteria. mNGS affects the antimicrobial regimens' usage in more than half of patients.