Metagenomic Next-generation Sequencing Research Articles

Clinical application and evaluation of metagenomic next-generation sequencing in pathogen detection for suspected central nervous system infections

Central nervous system Infections (CNSIs) is a disease characterized by complex pathogens, rapid disease progression, high mortality rate and high disability rate. Here, we evaluated the clinical value of metagenomic next generation sequencing (mNGS) in the diagnosis of central nervous system infections and explored the factors affecting the results of mNGS. We conducted a retrospective study to compare mNGS with conventional methods including culture, smear and etc. 111 suspected CNS infectious patients were enrolled in this study, and clinical data were recorded. Chi-square test were used to evaluate independent binomial variables, taking p < 0.05 as statistically significant threshold. Of the 111 enrolled cases, 57.7% (64/111) were diagnosed with central nervous system infections. From these cases, mNGS identified 39.6% (44/111) true-positive cases, 7.2% (8/111) false-positive case, 35.1% (39/111) true-negative cases, and 18.0% (20/111) false-negative cases. The sensitivity and specificity of mNGS were 68.7% (44/64) and 82.9% (39/47), respectively. Compared with culture, mNGS provided a higher pathogen detection rate in CNSIs patients (68.7% (44/64) vs. 26.5% (17/64), p < 0.0001). Compared to conventional methods, positive percent agreement and negative percent agreement was 84.60% (44/52) and 66.1% (39/59) separately. At a species-specific read number (SSRN) ≥ 2, mNGS performance in the diagnosis of definite viral encephalitis and/or meningitis was optimal (area under the curve [AUC] 0.758, 95% confidence interval [CI] 0.663–0.854). In bacterial CNSIs patients with significant CSF abnormalities (CSF WBC > 300*106/L), the positive rate of CSF mNGS is higher. To sum up, conventional microbiologic testing is insufficient to detect all neuroinvasive pathogens, and mNGS exhibited satisfactory diagnostic performance in CNSIs and with an overall detection rate higher than culture (p < 0.0001).

Severe community-acquired pneumonia caused by Chlamydia abortus in China: a case report

BackgroundChlamydia abortus causes abortions in ruminants; it can also cause miscarriages and stillbirths in pregnant women. However, it rarely causes pneumonia in humans. Here, we report a case of severe community-acquired pneumonia caused by C. abortus.Case presentationOn admission to our hospital, a 74-year-old woman reported that she had had a fever, cough, phlegm in her throat, and shortness of breath for 10 days. In the local hospital, she was initially diagnosed with community-acquired pneumonia and treated with piperacillin–tazobactam for 4 days. However, her condition worsened, and she was therefore transferred to our hospital. On arrival at our emergency department, she was diagnosed with severe community-acquired pneumonia and treated with a high-flow nasal cannula and meropenem; she was then transferred to the Department of Respiratory Medicine. There, her condition continued to worsen despite continued treatment with the high-flow nasal cannula and omadacycline. After 24 h and emergency tracheal intubation, the patient was sent to the intensive care unit (ICU) for further treatment. The doctors in the ICU again adjusted the treatment, this time to meropenem along with mechanical ventilation; they also instituted methylprednisolone, ulinastatin, nadroparin calcium, and human immunoglobulin. In addition, bronchoalveolar lavage fluid was sent for metagenomic next-generation sequencing (mNGS). Subsequent mNGS suggested the presence of C. abortus, sequence number 5072; we therefore discontinued the meropenem and implemented a combination of doxycycline and moxifloxacin. After 8 days of treatment in the ICU, the patient’s condition improved; she was then extubated and, 3 days later, transferred back to the respiratory medicine department. The respiratory physician continued to administer doxycycline and moxifloxacin for 4 days, after which the patient was discharged with medication. A month later, a repeat computed tomography (CT) scan of the chest suggested that the lesions in both lungs had been largely absorbed.ConclusionC. abortus can occasionally cause pneumonia in humans and, rarely, severe, life-threatening pneumonia. mNGS is uniquely suited for the early detection of this unusual infection. The combination of doxycycline and quinolones has been shown to be effective in severe pneumonia caused by C. abortus.

Detection Ewingella americana from a patient with Andersson lesion in ankylosing spondylitis by metagenomic next-generation sequencing test: a case report

BackgroundAndersen’s lesion (AL) is a rare complication of ankylosing spondylitis (AS), characterized by nonneoplastic bone destruction, typically manifested as bone destruction and sclerosis in the vertebral body and/or intervertebral disc area. At present, there is no consensus on the pathology and etiology of AL. Repeated trauma, inflammation in essence and part of the natural history of Ankylosing spondylitis itself are the most widely recognized theories of the etiology of AL. However, positive bacteria cultured in bone biopsy of Andersen’s lesion (AL) in Ankylosing spondylitis patients are extremely rare. Herein, we report a rare case of detecting Ewingella americana from a patient with Andersson lesion in ankylosing spondylitis by Metagenomic Next-Generation Sequencing (mNGS) Test.Case presentationThis case involved a 39-year-old male with a history of AS for 11 years, who developed AL (T11/12) in the thoracic vertebrae. After sufficient preoperative preparation, we successfully performed one-stage posterior approach corrective surgery and collected bone biopsies samples for examination. Cultured bacteria were not found, and pathological histology indicated infiltration of inflammatory cells. However, it is worth noting that we discovered a gram-negative bacterium, the Ewingella americana, through mNGS testing. Further histopathological examination suggests chronic inflammatory cell infiltration. After one-stage posterior approach corrective surgery, the patient’s condition significantly improved. At the 6-month follow-up, the pain significantly decreased, and the patient returned to normal life.ConclusionWe detected Ewinia americana in the bone biopsies of Andersson lesion (AL) in ankylosing spondylitis patient by mNGS.

Pulmonary microbial spectrum in late-stage SARS-CoV-2 infection: a case series.

Coronavirus disease 2019 (COVID-19), a kind of respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily spreads through the respiratory tract from human to human. Its extensive and rapid spread has led to a global pandemic, causing great harm to human health and economic development all over the world. Current known evidence indicates that SARS-CoV-2 has evolved accumulating multiple mutations, with altered infectivity and viral replication capacity. A better understanding of the complications of COVID-19 and its relationship with underlying diseases is crucial for the prevention and treatment of SARS-CoV-2. This case series reviewed case data of our 4 recent patients with severe or critical COVID-19, including treatment plan, status of pulmonary infection and their microbiology workup with metagenomic next-generation sequencing with bronchoalveolar lavage fluid. This report shed light on the significance of rapid and accurate clinical diagnosis and treatment on COVID-19.

Imaging modalities in neurolisteriosis: a literature review

Listeriosis caused by Listeria monocytogenes due to its ability to withstand harsh conditions and form biofilms on post-processed food poses a serious public health issue. It typically manifests itself with fever and gastrointestinal symptoms, but it can escalate with life-threatening conditions, especially in immunocompromised patients, the elderly, oncologically sick, and even pregnant women. The diagnosis is based on blood and cerebrospinal fluid culture growth, but it presents significant challenges due to deceptive findings and low positivity rates, the golden standard includes molecular diagnostic tests such as real-time PCR and metagenomic next-generation sequencing, which offer higher sensitivity and rapid detection. Radiological imaging, particularly magnetic resonance imaging, can play a crucial role in diagnosis of central nervous system (CNS) invasion by L. monocytogenes, enabling the detection of characteristic CNS lesions. The aim of the paper was to sum up the imaging features of L. monocytogenes CNS invasions in conventional imaging techniques, which can potentially speed up the diagnostic workflow for patients presenting with neurological symptoms associated with L. monocytogenes infection, particularly when conventional tests yield inconclusive results.

Case Report: Taking action or standing by: managing a preterm neonate at the risk of neonatal varicella by metagenomic next-generation sequencing

Case Report: Taking action or standing by: managing a preterm neonate at the risk of neonatal varicella by metagenomic next-generation sequencing

Multiple brain abscesses caused by Nocardia farcinica infection after hand injury: A case report and literature review.

Nocardia infection is commonly regarded as an opportunistic pulmonary pathogen affecting debilitated or immunocompromised individuals. Brain abscesses caused by Nocardia farcinica are rare and pose a diagnostic challenge. Traditional diagnostic techniques for identifying Nocardia species, such as blood culture, microscopy, and pathology, have shown inadequate performance. In the reported case, we applied metagenomic next-generation sequencing (mNGS) to diagnose a case of brain abscess due to N. farcinica. A 66-year-old female developed a brain abscess after sustaining a hand injury. The patient exhibited a gradual change in personality and experienced tremors in her right upper limb for a duration of 1 month. The pathogen responsible for the multiple brain abscesses was identified in the cerebrospinal fluid as N. farcinica through mNGS. Antibiotic treatment included trimethoprim-sulfamethoxazole, linezolid, amikacin, meropenem, and moxifloxacin. The patient's symptoms and signs improved significantly after administration of antibiotics to which the pathogen is known to be sensitive. After 5 months of follow-up, magnetic resonance imaging of the head showed that the abscess was basically cured. The patient lived a normal life with no adverse drug reactions. Nocardia brain infection is characterized by an insidious onset and lacks distinctive clinical and imaging features. mNGS was advantageous for the timely identification and management of Nocardia-associated brain abscess in the present case and obviated the need for invasive brain surgery. Expeditious and precise diagnosis coupled with prompt antibiotic therapy can significantly reduce the mortality rate associated with this condition.

Prediction of antimicrobial resistance in Klebsiella pneumoniae using genomic and metagenomic next-generation sequencing data.

Klebsiella pneumoniae is a significant pathogen with increasing resistance and high mortality rates. Conventional antibiotic susceptibility testing methods are time-consuming. Next-generation sequencing has shown promise for predicting antimicrobial resistance (AMR). This study aims to develop prediction models using whole-genome sequencing data and assess their feasibility with metagenomic next-generation sequencing data from clinical samples. On the basis of 4170 K. pneumoniae genomes, the main genetic characteristics associated with AMR were identified using a LASSO regression model. Consequently, the prediction model was established, validated and optimized using clinical isolate read simulation sequences. To evaluate the efficacy of the model, clinical specimens were collected. Four predictive models for amikacin, ciprofloxacin, levofloxacin and piperacillin/tazobactam, initially had positive predictive values (PPVs) of 90%, 85%, 84% and 94%, respectively, when they were originally constructed. When applied to clinical specimens, their PPVs increased to 96%, 96%, 95% and 100%, respectively. Meanwhile, there were negative predictive values (NPVs) of 100% for ciprofloxacin and levofloxacin, and 'not applicable' (NA) for amikacin and piperacillin/tazobactam. Our method achieved antibacterial phenotype classification accuracy rates of 96.08% for amikacin, 96.15% for ciprofloxacin, 95.31% for levofloxacin and 100% for piperacillin/tazobactam. The sequence-based prediction antibiotic susceptibility testing (AST) reported results in an average time of 19.5 h, compared with the 67.9 h needed for culture-based AST, resulting in a significant reduction of 48.4 h. These preliminary results demonstrated that the performance of prediction model for a clinically significant antimicrobial-species pair was comparable to that of phenotypic methods, thereby encouraging the expansion of sequence-based susceptibility prediction and its clinical validation and application.

Metagenomic next-generation sequencing for the diagnosis of invasive pulmonary aspergillosis in type 2 diabetes mellitus patients

Invasive pulmonary aspergillosis (IPA) in patients with diabetes mellitus has high incidence, especially in Type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) for IPA in patients with T2DM. A total of 66 patients with T2DM were included, including 21 IPA and 45 non-IPA patients, from January 2022 to December 2022. The demographic characteristics, comorbidities, laboratory test results, antibiotic treatment response, and 30-day mortality rate of patients were analyzed. The diagnostic accuracy of mNGS and conventional methods was compared, including sensitivity, specificity, positive predictive value and negative predictive value. The sensitivity and specificity of mNGS were 66.7% and 100.0%, respectively, which were significantly higher than those of fluorescence staining (42.1% and 100%), serum 1,3-β-D-glucan detection (38.1% and 90.9%), serum galactomannan detection (14.3% and 94.9%) and BALF galactomannan detection (47.3% and 70.7%). Although the sensitivity of BALF culture (75.0%) was higher than that of mNGS (66.7%), the turnover time of mNGS was significantly shorter than that of traditional culture (1.6 days vs. 5.0 days). The sensitivity of mNGS combined with BALF culture reached 100.0%. In addition, mNGS has a stronger ability to detect co-pathogens with IPA. 47.6% of T2DM patients with IPA were adjusted the initial antimicrobial therapy according to the mNGS results. This is the first study to focus on the diagnostic performance of mNGS in IPA infection in T2DM patients. MNGS can be used as a supplement to conventional methods for the diagnosis of IPA in patients with T2DM.

Case report: Rare pulmonary fungal infection caused by Penicillium digitatum: the first clinical report in China

Penicillium digitatum is a common plant pathogen that causes citrus rot, which is extremely rare in humans. We report a case of a 66-year-old man with a history of consuming large amounts of citrus fruits, smoking for 30 years, and a history of emphysema. He had experienced intermittent coughing with sputum for more than 10 years and was admitted to the hospital due to worsening of symptoms over the past month. Despite antibiotic treatment, his condition did not improve. Subsequently, bronchoalveolar lavage fluid (BALF) was detected by metagenomic next-generation sequencing (mNGS), which showed the presence of P. digitatum. The fungal culture of BALF also indicated the presence of the Penicillium genus. The diagnosis was lung infection caused by P. digitatum, and the patient was treated with itraconazole. The lung infection was controlled. This is the third reported case of invasive pulmonary fungal infection caused by P. digitatum worldwide at the genus level, and the first reported case in China. Although human infections caused by P. digitatum are rare, as an emerging opportunistic pathogen, the detection of this fungus in immunocompromised patients should still be clinically important.

Microbiological characteristics of the lower airway in adults with bronchiectasis: a prospective cohort study

BackgroundMicrobial infection and colonization are frequently associated with disease progression and poor clinical outcomes in bronchiectasis. Identification of pathogen spectrum is crucial for precision treatment at exacerbation of bronchiectasis.MethodsWe conducted a prospective cohort study in patients with bronchiectasis exacerbation onset and stable state. Bronchoalveolar lavage fluid (BALF) was collected for conventional microbiological tests (CMTs) and metagenomic Next-Generation Sequencing (mNGS). Bronchiectasis patients were monitored for documenting the time to the next exacerbation during longitudinal follow-up.ResultsWe recruited 168 eligible participants in the exacerbation cohorts, and 38 bronchiectasis patients at stable state at longitudinal follow-up. 141 bronchiectasis patients at exacerbation onset had definite or probable pathogens via combining CMTs with mNGS reports. We identified that Pseudomonas aeruginosa, non-tuberculous mycobacteria, Haemophilus influenzae, Nocardia spp, and Staphylococcus aureus were the top 5 pathogens with a higher detection rate in our cohorts via combination of CMTs and mNGS analysis. We also observed strong correlations of Pseudomonas aeruginosa, Haemophilus influenzae, non-tuberculous mycobacteria with disease severity, including the disease duration, Bronchiectasis Severity Index, and lung function. Moreover, the adjusted pathogenic index of potential pathogenic microorganism negatively correlated (r = -0.7280, p < 0.001) with the time to the next exacerbation in bronchiectasis.ConclusionWe have revealed the pathogenic microbial spectrum in lower airways and the negative correlation of PPM colonization with the time to the next exacerbation in bronchiectasis. These results suggested that pathogens contribute to the progression of bronchiectasis.

Rhino-orbital-cerebral mucormycosis caused by Rhizopus arrhizus diagnosis via metagenomics next-generation sequencing: a case report

Rhino-orbital-cerebral mucormycosis (ROCM) is a rare, invasive, and fatal fungal disease that is often easily misdiagnosed in the early stages due to the lack of specific clinical manifestations and adequate auxiliary examinations. Early diagnosis and timely therapy are essential for successful treatment. In this report, we presented a 46-year-old man with diabetes who experienced gradual vision loss, right ptosis, swelling, and headaches that progressively worsened to death within 4 days after admission. It was finally confirmed as a fungal Rhizopus arrhizus infection by metagenomics next-generation sequencing (mNGS). Our report has proved that mNGS testing should be strongly recommended in highly suspected patients.

Outcomes in solid organ transplant recipients receiving organs from a donor with Fusarium solani species complex meningitis.

Five organs (heart, right lung, liver, right, and left kidneys) from a deceased patient were transplanted into five recipients in four US states; the deceased patient was identified as part of a healthcare-associated fungal meningitis outbreak among patients who underwent epidural anesthesia in Matamoros, Mexico. After transplant surgeries occurred, Fusarium solani species complex, a fungal pathogen with a high case-mortality rate, was identified in cerebrospinal fluid from the organ donor by metagenomic next-generation sequencing (mNGS) and fungal-specific polymerase chain reaction and in plasma by mNGS. Four of five transplant recipients received recommended voriconazole prophylaxis; four were monitored weekly by serum (1-3)-β-d-glucan testing. All five were monitored for signs of infection for at least 3 months following transplantation. The liver recipient had graft failure, which was attributed to an etiology unrelated to fungal infection. No fungal DNA was identified in sections of the explanted liver, suggesting that F. solani species complex did not contribute to graft failure. The remaining recipients experienced no signs or symptoms suggestive of fusariosis. Antifungal prophylaxis may be useful in preventing donor-derived infections in recipients of organs from donors that are found to have Fusarium meningitis.

Fulminant fatal pneumonia and bacteremia due to Aeromonas dhakensis in an immunocompetent man: a case report and literature review

BackgroundAeromonas dhakensis is associated with soft tissue infection, bacteremia and gastroenteritis. Involvement of respiratory system in adults is extremely rare. We report a case of fulminant pneumonia and bacteremia due to A. dhakensis in a patient without underlying diseases.Case presentationA 26-year-old man became ill suddenly with pneumonia after swimming in a river. Despite intensive support measures in the intensive care unit, he died 13 hours after admission and 4 days after his first symptoms. Autopsy showed abundant Gram-negative bacteria, massive inflammatory cell infiltration, edema, necrosis and hemorrhage in lung tissue. A. dhakensis was isolated from blood culture taken at admission and bronchoalveolar lavage fluid (BALF) after intubation. Moreover, A. dhakensis was also detected in lung tissue by metagenomic next-generation sequencing (mNGS) assay. The infection may have come from river water.ConclusionIn patients who develop a fulminant pneumonia after contacting an aquatic environment, A. dhakensis should be alerted and mNGS may aid in the detection of aquatic pathogens by being more sensitive and specific versus traditional bacterial culture.

Application of metagenomic next-generation sequencing in the etiological diagnosis of refractory pneumonia in children

ObjectiveMetagenomic next-generation sequencing (mNGS) was used to analyze the etiological distribution of refractory pneumonia in children. We compared its efficacy in pathogen diagnosis against traditional methods to provide a basis for clinical adjustment and treatment.MethodsA total of 60 children with refractory pneumonia treated at the Department of Respiratory Medicine, Children’s Hospital Affiliated with the Capital Institute of Paediatrics, from September 2019 to December 2021 were enrolled in this study. Clinical data (including sex, age, laboratory tests, complications, and discharge diagnosis) and lower respiratory tract specimens were collected, including bronchoalveolar lavage fluid (BALF), deep sputum, pleural effusion, lung abscess puncture fluid, traditional respiratory pathogens (culture, acid-fast staining, polymerase chain reaction, serological testing, etc.), and mNGS detection methods were used to determine the distribution of pathogens in children with refractory pneumonia and to compare the positive rate and diagnostic efficiency of mNGS and traditional pathogen detection for different types of pathogens.ResultsAmong the 60 children with refractory pneumonia, 43 specimens were positive by mNGS, and 67 strains of pathogens were detected, including 20.90% (14 strains) of which were Mycoplasma pneumoniae, 11.94% (8 strains) were Streptococcus pneumoniae, 7.46% (5 strains) were cytomegalovirus, and 5.97% (4 strains) were Candida albicans. Thirty-nine strains of Mycoplasma pneumoniae (41.03%, 16 strains), Streptococcus pneumoniae (10.26%, 4 strains), Candida albicans (7.69%, 3 strains), and Aspergillus (5.13%, 2 strains) were detected using traditional methods. The positive rate of mNGS detection was 90.48%, and the positive rate of the traditional method was 61.90% (p = 0.050), especially for G+ bacteria. The positive rate of mNGS was greater than that of traditional methods (p &amp;lt; 0.05), but they had no significant difference in detecting G- bacteria, viruses, fungi, or Mycoplasma/Chlamydia. Among the 60 patients, 21 had mixed infections, 25 had single infections, and the other 14 had unknown pathogens. Mycoplasma pneumoniae was most common in both mixed infections and single infections. The sensitivity, specificity, positive predictive value, and negative predictive value of mNGS were 95.45, 37.50, 80.77, and 75.00%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the traditional methods were 72.72, 62.50, 84.21, and 45.45%, respectively. The clinical compliance of mNGS was 80.00%, and that of the traditional method was 70.00%. The sensitivity and negative predictive value of mNGS were high, and the difference in the sensitivity for detecting G+ bacteria was statistically significant (p &amp;lt; 0.05). However, the differences in G- bacteria, fungi, and Mycoplasma/Chlamydia were not statistically significant (p &amp;gt; 0.05). Due to the small sample size, statistical analysis could not be conducted on viral infections.ConclusionmNGS has higher overall efficacy than traditional methods for the etiological diagnosis of refractory pneumonia in children. The application of mNGS can significantly improve the detection rate of pathogens in children with refractory pneumonia. The sensitivity and negative predictive value of mNGS for detecting G+ bacteria are greater than those of other methods, and it can exclude the original suspected pathogenic bacteria. Unnecessary antibiotic use was reduced, but there was no statistically significant difference in G- bacteria, fungi, or Mycoplasma/Chlamydia.

Clinical Impact of Plasma Metagenomic Next-Generation Sequencing on Infection Diagnosis and Antimicrobial Therapy in Immunocompromised Patients.

Clinical impact of plasma metagenomic next-generation sequencing (mNGS) on infection diagnosis and antimicrobial therapy in immunocompromised patients with suspected infection remains unclear. Between March and December 2022, 424 cases with fever, infection history, mechanical ventilation, or imaging abnormalities underwent plasma mNGS testing at a single center. Eleven patients have received solid organ transplantation, and the remaining patients were categorised into febrile neutropenia (FN), non-neutropenia (NN), and non-haematologic disease (NTHD) groups based on immunosuppression severity. The diagnostic rate of infection and the utilisation of antimicrobial agents based on mNGS were assessed. The use of mNGS significantly improved the diagnostic rates for fungi in the FN (56.1%, P = 0.003) and NN (58.8%, P = 0.008) groups versus the NHD group (33.3%). Positive impacts associated with therapy were significantly greater than negative impacts across all three groups (all P < 0.001), and the utilisation of escalation therapy was significantly more frequent in the FN group than in the NN groups (P = 0.006). Over 70% of cases with negative mNGS results across the three groups underwent de-escalation therapy, with >1/3 being discontinued, preventing antimicrobial overuse. Plasma mNGS has a clinically confirmed positive impact in immunocompromised patients with neutropenia, improving the diagnosis of fungal infections and antimicrobial therapy.

Metagenomic Next-Generation Sequencing-Based Fine-Needle Aspiration in Patients With Suspected Infected Pancreatic Necrosis.

Fine-needle aspiration (FNA) is no longer recommended for diagnosing infected pancreatic necrosis (IPN) due to a high false-negative rate. Metagenomic next-generation sequencing (mNGS) is a valuable tool for identifying potential pathogens. We hypothesized that adding mNGS to the standard FNA procedure may increase diagnostic accuracy. This is a prospective, single-arm feasibility study enrolling patients with acute necrotizing pancreatitis complicated by suspected IPN. Computed tomography-guided FNA was performed immediately after enrollment, and the drainage samples were subjected to culture and mNGS assays simultaneously. Confirmatory IPN within the following week of the index FNA procedure was the reference standard. The diagnostic performance of FNA-mNGS and the impact of mNGS results on treatment were evaluated. Historical controls were used for comparison of clinical outcomes. There was no significant difference between mNGS and culture in the positive rate (75% vs 70%, P = 0.723). The accuracy of FNA-mNGS was 80.0%, with a sensitivity of 82.35%, specificity of 66.67%, positive predictive value of 93.3%, and negative predictive value of 40.0%. The results of the mNGS led to treatment change in 16 of 20 patients (80%), including implementing percutaneous catheter drainage (n = 7), expanding antibiotic coverage (n = 2), percutaneous catheter drainage and expanding coverage (n = 4), narrowing antibiotic coverage (n = 1), and discontinuation of antibiotics (n = 2). The FNA-mNGS approach was not associated with improved clinical outcomes compared with the historical control group. The addition of mNGS to standard FNA has comparable diagnostic accuracy with culture-based FNA and may not be associated with improved clinical outcomes.

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

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

Metagenomic next-generation sequencing promotes diagnosis and treatment of Pneumocystis jirovecii pneumonia in non-HIV infected children: a retrospective study

BackgroundMetagenomic next-generation sequencing (mNGS) excels in diagnosis of infection pathogens. We aimed to evaluate the performance of mNGS for the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in non-HIV infected children.MethodsTotally 36 PJP children and 61 non-PJP children admitted to the pediatric intensive care unit from March 2018 to December 2021 were retrospectively enrolled. Clinical features of PJP children were summarized. 1,3-β-D glucan (BDG) test and bronchoalveolar lavage fluid (BALF) mNGS were used for evaluation of PJP diagnostic performance. Antimicrobial management modifications for PJP children after the mNGS results were also reviewed.ResultsPneumocystis jirovecii was detected in all PJP children by mNGS (36/36), and the sensitivity of mNGS was 100% (95% confidence interval [CI]: 90.26–100%). The sensitivity of BDG was 57.58% (95% CI: 39.22–74.52%). Of the 26 (72.2%) PJP patients with mixed infection, twenty-four (66.7%) were detected by BALF-mNGS. Thirteen patients (36.1%) had their antimicrobial management adjusted according to the mNGS results. Thirty-six PJP children included 17 (47.2%) primary immunodeficiency and 19 (52.8%) secondary immunodeficiency, of whom 19 (52.8%) survived and 17 (47.2%) died. Compared to survival subgroup, non-survival subgroup had a higher rate of primary immunodeficiency (64.7% vs. 31.6%, P = 0.047), younger age (7 months vs. 39 months, P = 0.011), lower body weight (8.0 kg vs. 12.0 kg, P = 0.022), and lower T lymphocyte counts.ConclusionsThe mortality rate of PJP in immunosuppressed children without HIV infection is high and early diagnosis is challenging. BALF-mNGS could help identify PJP and guide clinical management.

Clinical Metagenomic Next-Generation Sequencing for Diagnosis of Central Nervous System Infections: Advances and Challenges.

Central nervous system (CNS) infections carry a substantial burden of morbidity and mortality worldwide, and accurate and timely diagnosis is required to optimize management. Metagenomic next-generation sequencing (mNGS) has proven to be a valuable tool in detecting pathogens in patients with suspected CNS infection. By sequencing microbial nucleic acids present in a patient's cerebrospinal fluid, brain tissue, or samples collected outside of the CNS, such as plasma, mNGS can detect a wide range of pathogens, including rare, unexpected, and/or fastidious organisms. Furthermore, its target-agnostic approach allows for the identification of both known and novel pathogens. This is particularly useful in cases where conventional diagnostic methods fail to provide an answer. In addition, mNGS can detect multiple microorganisms simultaneously, which is crucial in cases of mixed infections without a clear predominant pathogen. Overall, clinical mNGS testing can help expedite the diagnostic process for CNS infections, guide appropriate management decisions, and ultimately improve clinical outcomes. However, there are key challenges surrounding its use that need to be considered to fully leverage its clinical impact. For example, only a few specialized laboratories offer clinical mNGS due to the complexity of both the laboratory methods and analysis pipelines. Clinicians interpreting mNGS results must be aware of both false negatives-as mNGS is a direct detection modality and requires a sufficient amount of microbial nucleic acid to be present in the sample tested-and false positives-as mNGS detects environmental microbes and their nucleic acids, despite best practices to minimize contamination. Additionally, current costs and turnaround times limit broader implementation of clinical mNGS. Finally, there is uncertainty regarding the best practices for clinical utilization of mNGS, and further work is needed to define the optimal patient population(s), syndrome(s), and time of testing to implement clinical mNGS.