Exploring the Clinical Utility of Metagenomic Next-Generation Sequencing in the Diagnosis of Pulmonary Infection

Retrospective clinical and microbiologic analysis of metagenomic next-generation sequencing in the microbiological diagnosis of cutaneous infectious granulomas

BACKGROUND

Cutaneous infectious granulomas (CIG) are localized and chronic skin infection caused by a variety of pathogens such as protozoans, bacteria, worms, viruses and fungi. The diagnosis of CIG is difficult because microbiological examination shows low sensitivity and the histomorphological findings of CIG caused by different pathogens are commonly difficult to be distinguished.

OBJECTIVE

The objective of this study is to explore the application of mNGS in tissue sample testing for CIG cases, and to compare mNGS with traditional microbiological methods by evaluating sensitivity and specificity.

METHODS

We conducted a retrospective study at the Department of Dermatology of Sun Yat-sen Memorial Hospital, Sun Yat-sen University from January 1st, 2020, to May 31st, 2024. Specimens from CIG patients with a clinical presentation of cutaneous infection that was supported by histological examination were retrospectively enrolled. Specimens were delivered to be tested for microbiological examinations and mNGS.

RESULTS

Our data show that mNGS detected Non-tuberculosis mycobacteria, Mycobacterium tuberculosis, fungi and bacteria in CIG. Compared to culture, mNGS showed a higher positive rate (80.77% vs. 57.7%) with high sensitivity rate (100%) and negative predictive value (100%). In addition, mNGS can detect more pathogens in one sample and can be used to detect variable samples including the samples of paraffin-embedded tissue with shorter detective time. Of the 21 patients who showed clinical improvement within a 30-day follow-up, eighteen had their treatments adjusted, including fifteen who continued treatment based on the results of mNGS.

CONCLUSIONS

mNGS could provide a potentially rapid and effective alternative detection method for diagnosis of cutaneous infectious granulomas and mNGS results may affect the clinical prognosis resulting from enabling the patients to initiate timely treatment.

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.

Value of bronchoalveolar lavage fluid metagenomic next-generation sequencing in acute exacerbation of fibrosing interstitial lung disease: an individualized treatment protocol based on microbiological evidence

BACKGROUND

Acute exacerbation of fibrosing interstitial lung diseases (AE-ILD) is a serious life-threatening event per year. Methylprednisolone and/or immunosuppressive agents (ISA) are a mainstay in any regimen, under the premise that pulmonary infection has been promptly identified and controlled. We investigated the value of bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) on the treatment adjustment of AE-ILD.

METHODS

We conducted a cross-sectional observational study. All data were collected prospectively and retrospectively analyzed. We included fifty-six patients with AE-ILD and nineteen stable ILD who underwent BALF mNGS at the beginning of admission.

RESULTS

Patients with a variety of ILD classification were included. Connective-tissue disease related ILD (CTD-ILD) occupy the most common underlying non-idiopathic pulmonary fibrosis (non-IPF). The infection-triggered AE accounted for 39.29%, with the majority of cases being mixed infections. The microorganisms load in the AE-ILD group was significantly higher. After adjusted by mNGS, the therapy coverage number of pathogens was significantly higher compared to the initial treatment (p < 0.001). After treatment, the GGO score and the consolidation score were significantly lower during follow up in survivors (1.57 ± 0.53 vs. 2.38 ± 0.83 with p < 0.001, 1.11 ± 0.24 vs. 1.49 ± 0.47 with p < 0.001, respectively). Some detected microorganisms, such as Tropheryma whipplei, Mycobacterium, Aspergillus, and mixed infections were difficult to be fully covered by empirical medication. BALF mNGS was also very helpful for excluding infections and early administration of methylprednisolone and/or ISA.

CONCLUSIONS

mNGS has been shown to be a useful tool to determine pathogens in patients with AE-ILD, the results should be fully analyzed. The comprehensive treatment protocol based on mNGS has been shown crucial in AE-ILD patients.

Clinical impact of metagenomic next-generation sequencing of bronchoalveolar lavage fluids for the diagnosis of pulmonary infections in respiratory intensive care unit

Background

The real-world clinical impact of mNGS on BALF in the respiratory intensive care unit (RICU) is not yet fully understood.

Methods

We investigated the clinical impact of mNGS on BALF samples obtained from 92 patients admitted to the RICU over a 2-year period. We utilized both mNGS and culture methods to evaluate the effectiveness of mNGS in diagnosing pulmonary infections. The clinical impact of mNGS were evaluated by the clinician committees.

Results

Among the 92 diagnosed patients, 78 cases (84.7 %) were determined to have infectious diseases caused by pathogenic microorganisms, and the bacterial infections constituted the most prevalent diagnostic category. For mixed infection, the most common type was the Pneumocystis jironecii and cytomegalovirus co-infection. The mNGS results had a positive impact on the clinical management of 43 cases (46.7 %). Moreover, 19 cases (44.2 %) of positive clinical impacts were solely based on new diagnoses made possible by mNGS results. These new diagnoses were particularly helpful for identifying rare pathogens, which could not be detected by conventional diagnostic methods.

Conclusions

The BALF mNGS has a positive real-world impact in RICU. Clinician committee play a critical role in ensuring the appropriate use of mNGS.

Microbial signatures predictive of short-term prognosis in severe pneumonia

Objective

This retrospective cohort study aimed to investigate the composition and diversity of lung microbiota in patients with severe pneumonia and explore its association with short-term prognosis.

Methods

A total of 301 patients diagnosed with severe pneumonia underwent bronchoalveolar lavage fluid metagenomic next-generation sequencing (mNGS) testing from February 2022 to January 2024. After applying exclusion criteria, 236 patients were included in the study. Baseline demographic and clinical characteristics were compared between survival and non-survival groups. Microbial composition and diversity were analyzed using alpha and beta diversity metrics. Additionally, LEfSe analysis and machine learning methods were employed to identify key pathogenic microorganism associated with short-term mortality. Microbial interaction modes were assessed through network co-occurrence analysis.

Results

The overall 28-day mortality rate was 37.7% in severe pneumonia. Non-survival patients had a higher prevalence of hypertension and exhibited higher APACHE II and SOFA scores, higher procalcitonin (PCT), and shorter hospitalization duration. Microbial α and β diversity analysis showed no significant differences between the two groups. However, distinct species diversity patterns were observed, with the non-survival group showing a higher abundance of Acinetobacter baumannii, Klebsiella pneumoniae, and Enterococcus faecium, while the survival group had a higher prevalence of Corynebacterium striatum and Enterobacter. LEfSe analysis identified 29 distinct terms, with 10 potential markers in the non-survival group, including Pseudomonas sp. and Enterococcus durans. Machine learning models selected 16 key pathogenic bacteria, such as Klebsiella pneumoniae, significantly contributing to predicting short-term mortality. Network co-occurrence analysis revealed greater complexity in the non-survival group compared to the survival group, with differences in central genera.

Conclusion

Our study highlights the potential significance of lung microbiota composition in predicting short-term prognosis in severe pneumonia patients. Differences in microbial diversity and composition, along with distinct microbial interaction modes, may contribute to variations in short-term outcomes. Further research is warranted to elucidate the clinical implications and underlying mechanisms of these findings.

Prevalence of Co-infection of Culture-Proven Bacterial Pathogens in Microbiologically Confirmed Pulmonary Tuberculosis Patients From a Tertiary Care Center

Tuberculosis (TB) is a chronic condition that weakens the immune system, causes structural changes in the lungs, and can lead to infections by other bacterial pathogens. Very few studies have been done to understand the magnitude of co-infection with other bacterial pathogens, so this study was conducted to understand the co-infection pattern and burden. A total of 174 microbiologically confirmed pulmonary TB patients' samples, identified by cartridge-based nucleic acid amplification test, were further tested for other bacterial pathogens by culture over a period of five months from May 2023 to September 2023. The isolates' identification and drug susceptibility were performed using the VITEK 2 system (bioMérieux, Marcy-l'Étoile, France). Of the 174 pulmonary samples tested, 19 samples grew a significant amount of other bacterial pathogens, making the prevalence 10.91% (19/174). Among the pulmonary samples tested, 54.59% were sputum, 38.5% were bronchoalveolar lavage, and 6.89% were endotracheal aspirate. Additionally, 70.11% of the patients tested were in the age group of 19-60 years. Of the patients who had co-infection, 94.73% (18/19) were male. The most common bacterial infection was caused by Pseudomonas aeruginosa, which was identified in 36.84% of the co-infection cases (7/19). This was followed by Acinetobacter baumannii in 31.57% (6/19), Klebsiella pneumoniae in 26.31% (5/19), and Stenotrophomonas maltophilia in 5.28% (1/19). Acinetobacter baumannii and Klebsiella pneumoniae showed high drug resistance, ranging from 60% to 100% against various groups of drugs tested. None of the patient samples with co-infection showed rifampicin resistance. Among all the samples with co-infection, the majority (42.10%, or 8/19) had a high load of Mycobacterium tuberculosis complex detected by CBNAAT Ultra (Cepheid, Sunnyvale, California). Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae are unusual pathogens causing infection in community patients and are known to cause illness in hospitalized patients. These organisms' resistance was also similar to the resistance shown by hospital-acquired infections. This indicates that bacterial co-infection in pulmonary TB patients will be similar to the pattern of hospital-acquired infections. The high prevalence of bacterial co-infections (10.91%) in patients with pulmonary TB poses a significant challenge as these bacterial pathogens are not susceptible to anti-tubercular drugs. Therefore, comprehensive screening for other bacterial infections in all pulmonary TB patients is crucial for effective treatment and outcomes.

Cell-free DNA: a promising biomarker in infectious diseases

Infectious diseases pose serious threats to public health worldwide. Conventional diagnostic methods for infectious diseases often exhibit low sensitivity, invasiveness, and long turnaround times. User-friendly point-of-care tests are urgently needed for early diagnosis, treatment monitoring, and prognostic prediction of infectious diseases. Cell-free DNA (cfDNA), a promising non-invasive biomarker widely used in oncology and pregnancy, has shown great potential in clinical applications for diagnosing infectious diseases. Here, we discuss the most recent cfDNA research on infectious diseases from both the pathogen and host perspectives. We also discuss the technical challenges in this field and propose solutions to overcome them. Additionally, we provide an outlook on the potential of cfDNA as a diagnostic, treatment, and prognostic marker for infectious diseases.

Metagenomic Next-generation Sequencing for Pathogen Identification in Bronchoalveolar Lavage Fluid From Neonates Receiving Extracorporeal Membrane Oxygenation

BACKGROUND

Neonates on extracorporeal membrane oxygenation (ECMO) are at high risk of infection. Rapid and accurate identification of pathogens is essential to improve the prognosis of children on ECMO. Metagenome next-generation sequencing (mNGS) has been used in recent years to detect pathogenic bacteria, but evidence for its use in neonates on ECMO is lacking.

METHODS

This retrospective study was conducted using an electronic medical record system. We analyzed the results of mNGS and conventional microbiological tests (CMTs) in bronchoalveolar lavage fluid of neonates receiving ECMO support with pulmonary infections in our hospital from July 2021 to January 2023.

RESULTS

We screened 18 ECMO-supported neonates with pneumonia for inclusion in the study. The median age of the included children was 2 (1-4) days, the median gestational age was 38.3 (33-40 +4 ) weeks, and the median weight was 3.3 (2.2-4.8) kg. The detection rate of mNGS was 77.8% (14/18), higher than the 44.4% (8/18) of CMT ( P = 0.04). A total of 20 pathogens were detected in mNGS, with the top 3 most common pathogens being Klebsiella pneumoniae , Acinetobacter baumannii and Escherichia coli . Mixed infections were found in 14 cases (77.8%), including 13 cases (72.2%) with mixed infections detected by mNGS and 7 cases (27.8%) with mixed infections detected by CMT. A total of 9 children underwent treatment changes based on mNGS results and all of them experienced relief of symptoms.

CONCLUSION

Compared with CMT, mNGS can detect pathogens earlier and more sensitively, and may play an important role in ECMO-supported neonatal pneumonia pathogen detection and optimization of antibiotic therapy.

Clinical performance of metagenomic next-generation sequencing for diagnosis of pulmonary Aspergillus infection and colonization

Background

Investigations assessing the value of metagenomic next-generation sequencing (mNGS) for distinguish Aspergillus infection from colonization are currently insufficient.

Methods

The performance of mNGS in distinguishing Aspergillus infection from colonization, along with the differences in patients' characteristics, antibiotic adjustment, and lung microbiota, were analyzed.

Results

The abundance of Aspergillus significantly differed between patients with Aspergillus infection (n=36) and colonization (n=32) (P < 0.0001). Receiver operating characteristic (ROC) curve result for bronchoalveolar lavage fluid (BALF) mNGS indicated an area under the curve of 0.894 (95%CI: 0.811-0.976), with an optimal threshold value of 23 for discriminating between Aspergillus infection and colonization. The infection group exhibited a higher proportion of antibiotic adjustments in comparison to the colonization group (50% vs. 12.5%, P = 0.001), with antibiotic escalation being more dominant. Age, length of hospital stay, hemoglobin, cough and chest distress were significantly positively correlated with Aspergillus infection. The abundance of A. fumigatus and Epstein-Barr virus (EBV) significantly increased in the infection group, whereas the colonization group exhibited higher abundance of A. niger.

Conclusion

BALF mNGS is a valuable tool for differentiating between colonization and infection of Aspergillus. Variations in patients' age, length of hospital stay, hemoglobin, cough and chest distress are observable between patients with Aspergillus infection and colonization.

Clinical application of metagenomic next-generation sequencing in non-immunocompromised patients with severe pneumonia supported by veno-venous extracorporeal membrane oxygenation

Objectives

This study aims to explore the pathogen-detected effect of mNGS technology and its clinical application in non-immunocompromised patients with severe pneumonia supported by vv-ECMO.

Methods

A retrospective analysis was conducted on a cohort of 50 non-immunocompromised patients who received vv-ECMO support for severe pneumonia between January 2016 and December 2022. These patients were divided into two groups based on their discharge outcomes: the deterioration group (Group D), which included 31 cases, and the improvement group (Group I), consisting of 19 cases. Baseline characteristics and clinical data were collected and analyzed.

Results

Among the 50 patients enrolled, Group D exhibited a higher prevalence of male patients (80.6% vs. 52.6%, p < 0.05), more smokers (54.8% vs. 21.1%, p < 0.05), and were older than those in Group I (55.16 ± 16.34 years vs. 42.32 ± 19.65 years, p < 0.05). Out of the 64 samples subjected to mNGS detection, 55 (85.9%) yielded positive results, with a positivity rate of 83.7% (36/43) in Group D and 90.5% (19/21) in Group I. By contrast, the positive rate through traditional culture stood at 64.9% (74/114). Among the 54 samples that underwent both culture and mNGS testing, 23 (42.6%) displayed consistent pathogen identification, 13 (24.1%) exhibited partial consistency, and 18 (33.3%) showed complete inconsistency. Among the last cases with complete inconsistency, 14 (77.8%) were culture-negative, while two (11.1%) were mNGS-negative, and the remaining two (11.1%) presented mismatches. Remarkably, mNGS surpassed traditional culture in pathogen identification (65 strains vs. 23 strains). Within these 65 strains, 56 were found in Group D, 26 in Group I, and 17 were overlapping strains. Interestingly, a diverse array of G+ bacteria, fungi, viruses, and special pathogens were exclusive to Group D. Furthermore, Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were more prevalent in Group D compared to Group I. Importantly, mNGS prompted antibiotic treatment adjustments in 26 patients (52.0%).

Conclusions

Compared with the conventional culture, mNGS demonstrated a higher positive rate, and emerges as a promising method for identifying mixed pathogens in non-immunodeficient patients with severe pneumonia supported by vv-ECMO. However, it is crucial to combine the interpretation of mNGS data with clinical information and traditional culture results for a comprehensive assessment.

Microbiomes Detected by Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing among HIV-Infected and Uninfected Patients with Pulmonary Infection

Comparison of lung microbiomes between HIV-infected and uninfected patients with pulmonary infection by metagenomic next-generation sequencing (mNGS) has not been described in China. The lung microbiomes detected in bronchoalveolar fluid (BALF) by mNGS among HIV-infected and uninfected patients with pulmonary infection were reviewed in the First Hospital of Changsha between January 2019 and June 2022. In total, 476 HIV-infected and 280 uninfected patients with pulmonary infection were enrolled. Compared with HIV-uninfected patients, the proportions of Mycobacterium (P = 0.011), fungi (P < 0.001), and viruses (P < 0.001) were significantly higher in HIV-infected patients. The higher positive rate of Mycobacterium tuberculosis (MTB; P = 0.018), higher positive rates of Pneumocystis jirovecii and Talaromyces marneffei (all P < 0.001), and higher positive rate of cytomegalovirus (P < 0.001) contributed to the increased proportions of Mycobacterium, fungi, and viruses among HIV-infected patients, respectively. The constituent ratios of Streptococcus pneumoniae (P = 0.007) and Tropheryma whipplei (P = 0.002) in the bacteria spectrum were significantly higher, while the constituent ratio of Klebsiella pneumoniae (P = 0.005) was significantly lower in HIV-infected patients than in HIV-uninfected patients. Compared with HIV-uninfected patients, the constituent ratios of P. jirovecii and T. marneffei (all P < 0.001) in the fungal spectrum were significantly higher, while the constituent ratios of Candida and Aspergillus (all P < 0.001) were significantly lower in HIV-infected patients. In comparison to HIV-infected patients without antiretroviral therapy (ART), the proportions of T. whipplei (P = 0.001), MTB (P = 0.024), P. jirovecii (P < 0.001), T. marneffei (P < 0.001), and cytomegalovirus (P = 0.008) were significantly lower in HIV-infected patients on ART. Significant differences in lung microbiomes exist between HIV-infected and uninfected patients with pulmonary infection, and ART influences the lung microbiomes among HIV-infected patients with pulmonary infection. IMPORTANCE A better understanding of lung microorganisms is conducive to early diagnosis and treatment and will improve the prognosis of HIV-infected patients with pulmonary infection. Currently, few studies have systematically described the spectrum of pulmonary infection among HIV-infected patients. This study is the first to provide comprehensive information on the lung microbiomes of HIV-infected patients with pulmonary infection (as assessed by more sensitive metagenomic next-generation sequencing of bronchoalveolar fluid) compared with those from HIV-uninfected patients, which could provide a reference for the etiology of pulmonary infection among HIV-infected patients.

Metagenomic Next-Generation Sequencing for Pathogens in Bronchoalveolar Lavage Fluid Improves the Survival of Patients with Pulmonary Complications After Allogeneic Hematopoietic Stem Cell Transplantation

INTRODUCTION

Unbiased metagenomic next-generation sequencing (mNGS) has been used for infection diagnosis. In this study, we explored the clinical diagnosis value of mNGS for pulmonary complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

From August 2019 to June 2021, a prospective study was performed to comparatively analyze the pathogenic results of mNGS and conventional tests for bronchoalveolar lavage fluid (BALF) from 134 cases involving 101 patients with pulmonary complications after allo-HSCT.

RESULTS

More pathogens were identified by mNGS than with conventional tests (226 vs 120). For bacteria, the diagnostic sensitivity (P = 0.144) and specificity (P = 0.687) were similar between the two methods. For fungus except Pneumocystis jirovecii (PJ), conventional tests had a significantly higher sensitivity (P = 0.013) with a similarly high specificity (P = 0.109). The sensitivities for bacteria and fungi could be increased with the combination of the two methods. As for PJ, both the sensitivity (100%) and specificity (99.12%) of mNGS were very high. For viruses, the sensitivity of mNGS was significantly higher (P = 0.021) and the negative predictive value (NPV) was 95.74% (84.27-99.26%). Pulmonary infection complications accounted for 90.30% and bacterium was the most common pathogen whether in single infection (63.43%) or mixed infection (81.08%). The 6-month overall survival (OS) of 88.89% in the early group (mNGS ≤ 7 days) was significantly higher than that of 65.52% (HR 0.287, 95% CI 0.101-0.819, P = 0.006) in the late group (mNGS > 7 days).

CONCLUSIONS

mNGS for BALF could facilitate accurate and fast diagnosis for pulmonary complications. Early mNGS could improve the prognosis of patients with pulmonary complications after allo-HSCT.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04051372.

Diagnostic performance and clinical impact of blood metagenomic next-generation sequencing in ICU patients suspected monomicrobial and polymicrobial bloodstream infections

Introduction

Early and effective application of antimicrobial medication has been evidenced to improve outcomes of patients with bloodstream infection (BSI). However, conventional microbiological tests (CMTs) have a number of limitations that hamper a rapid diagnosis.

Methods

We retrospectively collected 162 cases suspected BSI from intensive care unit with blood metagenomics next-generation sequencing (mNGS) results, to comparatively evaluate the diagnostic performance and the clinical impact on antibiotics usage of mNGS.

Results and discussion

Results showed that compared with blood culture, mNGS detected a greater number of pathogens, especially for Aspergillus spp, and yielded a significantly higher positive rate. With the final clinical diagnosis as the standard, the sensitivity of mNGS (excluding viruses) was 58.06%, significantly higher than that of blood culture (34.68%, P<0.001). Combing blood mNGS and culture results, the sensitivity improved to 72.58%. Forty-six patients had infected by mixed pathogens, among which Klebsiella pneumoniae and Acinetobacter baumannii contributed most. Compared to monomicrobial, cases with polymicrobial BSI exhibited dramatically higher level of SOFA, AST, hospitalized mortality and 90-day mortality (P<0.05). A total of 101 patients underwent antibiotics adjustment, among which 85 were adjusted according to microbiological results, including 45 cases based on the mNGS results (40 cases escalation and 5 cases de-escalation) and 32 cases on blood culture. Collectively, for patients suspected BSI in critical condition, mNGS results can provide valuable diagnostic information and contribute to the optimizing of antibiotic treatment. Combining conventional tests with mNGS may significantly improve the detection rate for pathogens and optimize antibiotic treatment in critically ill patients with BSI.

Metagenomic next-generation sequencing for pulmonary infections diagnosis in patients with diabetes

BACKGROUND

Diabetes mellitus is a major cause of high mortality and poor prognosis in patients with pulmonary infections. However, limited data on the application of metagenomic next-generation sequencing (mNGS) are available for diabetic patients. This study aimed to evaluate the diagnostic performance of mNGS in diabetic patients with pulmonary infections.

METHODS

We retrospectively reviewed 184 hospitalized patients with pulmonary infections at Guizhou Provincial People's Hospital between January 2020 to October 2021. All patients were subjected to both mNGS analysis of bronchoalveolar lavage fluid (BALF) and conventional testing. Positive rate by mNGS and the consistency between mNGS and conventional testing results were evaluated for diabetic and non-diabetic patients.

RESULTS

A total of 184 patients with pulmonary infections were enrolled, including 43 diabetic patients and 141 non-diabetic patients. For diabetic patients, the microbial positive rate by mNGS was significantly higher than that detected by conventional testing methods, primarily driven by bacterial detection (microbes: 95.3% vs. 67.4%, P = 0.001; bacteria: 72.1% vs. 37.2%, P = 0.001). mNGS and traditional tests had similar positive rates with regard to fungal and viral detection in diabetic patients. Klebsiella pneumoniae was the most common pathogen identified by mNGS in patients with diabetes. Moreover, mNGS identified pathogens in 92.9% (13/14) of diabetic patients who were reported negative by conventional testing. No significant difference was found in the consistency of the two tests between diabetic and non-diabetic groups.

CONCLUSIONS

mNGS is superior to conventional microbiological tests for bacterial detection in diabetic patients with pulmonary infections. mNGS is a valuable tool for etiological diagnosis of pulmonary infections in diabetic patients.

Metagenomic next-generation sequencing for detection of pathogens in children with hematological diseases complicated with infection

OBJECTIVE

Infection is one of the most common causes of death in children with hematological diseases. Here, we aim to investigate the value of metagenomic next-generation sequencing (mNGS) in the detection of causative pathogens in children with hematological diseases.

METHODS

In this retrospective study, specimens from children with hematological diseases, who were admitted to Sun Yat-Sen University between June 2019 and September 2021, were collected for culture and mNGS.

RESULTS

A total of 67 pediatric patients were enrolled, and 96 specimens were collected. The positive rate of mNGS was significantly higher than that of culture (57.2% vs 12.5%, P < 0.01). The concordance (90.9%, 10/11) between the positive results of the two methods was high. mNGS detected more cases with Pneumocystis jeroveci, Aspergillus flavus, viruses, and some rare pathogens than culture. Mixed infections were detected by mNGS in 16 cases. Clinical anti-infective treatment was adjusted according to the results of mNGS, the conditions of most patients improved.

CONCLUSION

Compared to culture, mNGS shows great advantages in diagnosing bacterial, fungal, viral, and mixed infections in children with hematologic diseases, positively impacting clinical care. mNGS can be used as a complement to culture for pathogen detection.

Advancing Microbe Detection for Lower Respiratory Tract Infection Diagnosis and Management with Metagenomic Next-Generation Sequencing

Background

Due to limitations of traditional microbiological methods and the presence of the oropharyngeal normal flora, there are still many pathogens that cause lower respiratory tract infections (LRTIs) cannot be detected. Metagenomic next-generation sequencing (mNGS) has the potential capacity to solve this problem.

Methods

This retrospective study successively reviewed 77 patients with LRTI and 29 patients without LRTI admitted to Tianjin Medical University General Hospital, China from August 2020 to June 2021. Pathogens in bronchoalveolar lavage fluid (BALF) specimens were detected adopting mNGS and traditional microbiological assays. The diagnostic performance of pathogens was compared between mNGS and BALF culture. The value of mNGS for aetiological and clinical impact investigation in LRTI was also evaluated.

Results

Among 77 patients with LRTI, 22.1%, 40.3%, and 65.0% of cases were detected as definite or probable pathogens by culture, all conventional microbiological tests, and mNGS, respectively. Using the final diagnosis as a gold standard, mNGS exhibited a sensitivity of 76.6% (95% confidence interval [CI], 65.6-85.5%), which was considerably superior to that of BALF culture (76.6% vs 18.2%; P < 0.01); specificity of 79.3% (95% CI, 60.3-92.0%), which was similar (79.3% vs 89.7%; P = 0.38); positive-predictive value of 90.8% (95% CI, 81.0-96.5%), and negative-predictive value of 56.1% (95% CI, 39.7-71.5%). According to our data, mNGS identified potential microorganisms in 66.7% (42/63) of culture-negative samples. Among 59 patients with pathogens identified by mNGS, conventional microbiological methods confirmed pathogenic infections in less than half (28/59) cases. Within the 77 patients, 34 (44.2%) patients received pathogen-directed therapy, 7 (9.1%) patients underwent antibiotic adjustment, and 3 (3.9%) patients stopped using antibiotics due to mNGS results.

Conclusion

mNGS exhibits high accuracy in diagnosing LRTI, and combine with traditional microbiological tests, causative pathogens can be detected in approximately 70.0% of cases, thus yields a positive effect on antibiotic application.

Diagnostic Value of Metagenomic Next-Generation Sequencing for Multi-Pathogenic Pneumonia in HIV-Infected Patients

Background

To evaluate the value and challenges of real-world clinical application of metagenomic next-generation sequencing (mNGS) for bronchoalveolar lavage fluid (BALF) in HIV-infected patients with suspected multi-pathogenic pneumonia.

Methods

Fifty-seven HIV-infected patients with suspected mixed pneumonia who were agreed to undergo the bronchoscopy were recruited and retrospectively reviewed the results of mNGS and conventional microbiological tests (CMTs) of BALF from July 2020 to June 2022.

Results

54 patients were diagnosed with pneumonia including 49 patients with definite pathogens and five patients with probable pathogens. mNGS exhibited a higher diagnostic accuracy for fungal detection than CMTs in HIV-infected patients with suspected pulmonary infection. The sensitivity of mNGS in diagnosis of pneumonia in HIV-infected patients was much higher than that of CMTs (79.6% vs 61.1%; P < 0.05). Patients with mixed infection had lower CD4 T-cell count and higher symptom duration before admitting to the hospital than those with single infection. The detection rate of mNGS for mixed infection was significantly higher than that of CMTs and more co-pathogens could be identified by mNGS. The most common pattern of mixed infection observed was fungi-virus (11/29, 37.9%), followed by fungi-virus-bacteria (6/29, 20.7%) coinfection in HIV-infected patients with multi-pathogenic pneumonia.

Conclusion

mNGS improved the pathogens detection rate and exhibited advantages in identifying multi-pathogenic pneumonia in HIV-infected patients. Early performance of bronchoscopy and mNGS are recommended in HIV-infected patients with low CD4 T cell counts and long duration of symptoms. The most common pattern of mixed infection observed was fungi-virus, followed by fungi-virus-bacteria coinfection in HIV infected patients with multi-pathogenic pneumonia.

The performance of metagenomic next-generation sequencing in diagnosing pulmonary infectious diseases using authentic clinical specimens: The Illumina platform versus the Beijing Genomics Institute platform

Introduction: Metagenomic next-generation sequencing (mNGS) has been increasingly used to detect infectious organisms and is rapidly moving from research to clinical laboratories. Presently, mNGS platforms mainly include those from Illumina and the Beijing Genomics Institute (BGI). Previous studies have reported that various sequencing platforms have similar sensitivity in detecting the reference panel that mimics clinical specimens. However, whether the Illumina and BGI platforms provide the same diagnostic performance using authentic clinical samples remains unclear. Methods: In this prospective study, we compared the performance of the Illumina and BGI platforms in detecting pulmonary pathogens. Forty-six patients with suspected pulmonary infection were enrolled in the final analysis. All patients received bronchoscopy, and the specimens collected were sent for mNGS on the two different sequencing platforms. Results: The diagnostic sensitivity of the Illumina and BGI platforms was notably higher than that of conventional examination (76.9% vs. 38.5%, p < 0.001; 82.1% vs. 38.5%, p < 0.001; respectively). The sensitivity and specificity for pulmonary infection diagnosis were not significantly different between the Illumina and BGI platforms. Furthermore, the pathogenic detection rate of the two platforms were not significantly different. Conclusion: The Illumina and BGI platforms exhibited similar diagnostic performance for pulmonary infectious diseases using clinical specimens, and both are superior to conventional examinations.

Interactive Web-Based Services for Metagenomic Data Analysis and Comparisons

Recently, sequencing technologies have become readily available, and scientists are more motivated to conduct metagenomic research to unveil the potential of a myriad of ecosystems and biomes. Metagenomics studies the composition and functions of microbial communities and paves the way to multiple applications in medicine, industry, and ecology. Nonetheless, the immense amount of sequencing data of metagenomics research and the few user-friendly analysis tools and pipelines carry a new challenge to the data analysis.Web-based bioinformatics tools are now being developed to facilitate the analysis of complex metagenomic data without prior knowledge of any programming languages or special installation. Specialized web tools help answer researchers' main questions on the taxonomic classification, functional capabilities, discrepancies between two ecosystems, and the probable functional correlations between the members of a specific microbial community. With an Internet connection and a few clicks, researchers can conveniently and efficiently analyze the metagenomic datasets, summarize results, and visualize key information on the composition and the functional potential of metagenomic samples under study. This chapter provides a simple guide to a few of the fundamental web-based services used for metagenomic data analyses, such as BV-BRC, RDP, MG-RAST, MicrobiomeAnalyst, METAGENassist, and MGnify.

The application of targeted nanopore sequencing for the identification of pathogens and resistance genes in lower respiratory tract infections

Objectives

Lower respiratory tract infections (LRTIs) are one of the causes of mortality among infectious diseases. Microbial cultures commonly used in clinical practice are time-consuming, have poor sensitivity to unculturable and polymicrobial patterns, and are inadequate to guide timely and accurate antibiotic therapy. We investigated the feasibility of targeted nanopore sequencing (TNPseq) for the identification of pathogen and antimicrobial resistance (AMR) genes across suspected patients with LRTIs. TNPseq is a novel approach, which was improved based on nanopore sequencing for the identification of bacterial and fungal infections of clinical relevance.

Methods

This prospective study recruited 146 patients suspected of having LRTIs and with a median age of 61 years. The potential pathogens in these patients were detected by both TNPseq and the traditional culture workups. We compared the performance between the two methods among 146 LRTIs-related specimens. AMR genes were also detected by TNPseq to prompt the proper utilization of antibiotics.

Results

At least one pathogen was detected in 133 (91.1%) samples by TNPseq, but only 37 (25.3%) samples contained positive isolates among 146 cultured specimens. TNPseq possessed higher sensitivity than the conventional culture method (91.1 vs. 25.3%, P < 0.001) in identifying pathogens. It detected more samples with bacterial infections (P < 0.001) and mixed infections (P < 0.001) compared with the clinical culture tests. The most frequent AMR gene identified by TNPseq was bla _TEM (n = 29), followed by bla _SHV (n = 4), bla _KPC (n = 2), bla _CTX-M (n = 2), and mecA (n = 2). Furthermore, TNPseq discovered five possible multi-drug resistance specimens.

Conclusion

TNPseq is efficient to identify pathogens early, thus assisting physicians to conduct timely and precise treatment for patients with suspected LRTIs.

Metagenomic next-generation sequencing contributes to the diagnosis of mixed pulmonary infection: a case report

BACKGROUND

Pulmonary cryptococcosis (PC) and mixed pulmonary infection are difficult to be diagnosed due to the non-specificity and their overlapping clinical manifestations. In terms of the clinical diagnosis of PC and mixed pulmonary infection, conventional tests have limitations such as a long detection period, a limited range of pathogens, and low sensitivity. Metagenomics next-generation sequencing (mNGS) is a nascent and powerful method that can detect pathogens without culture, to diagnose known and unexplained infections in reduced time.

CASE PRESENTATION

A 43-year-old female was admitted to the hospital after suffering from a cough for one month. At the time of admission, a contrast-enhanced chest CT revealed multiple nodules and plaques in her right lung, as well as the formation of cavities. The blood routine assays showed evidently increased white blood cell count (mainly neutrophils), CRP, and ESR, which suggested she was in the infection phase. The serum CrAg-LFA test showed a positive result. Initially, she was diagnosed with an unexplained pulmonary infection. Bronchoalveolar lavage fluid (BALF) samples were collected for microbial culture, immunological tests and the mNGS. Microbial culture and immunological tests were all negative, while mNGS detected Corynebacterium striatum, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Cryptococcus neoformans. The diagnosis was revised to PC and bacterial pneumonia. Lung infection lesions were healed after she received targeted anti-infection therapy with mezlocillin and fluconazole. In a follow-up after 2 months, the patient's symptoms vanished.

CONCLUSIONS

Here, we demonstrated that mNGS was capable of accurately distinguishing Cryptococcus from M. tuberculosis in pulmonary infection, and notably mNGS was capable of swiftly and precisely detecting pathogens in mixed bacterial and fungal pulmonary infection. Furthermore, the results of mNGS also have the potential to adjust anti-infective therapies.

Improving Suspected Pulmonary Infection Diagnosis by Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing: a Multicenter Retrospective Study

Metagenomic next-generation sequencing (mNGS) has been gradually applied to clinical practice due to its unbiased characteristics of pathogen detection. However, its diagnostic performance and clinical value in suspected pulmonary infection need to be evaluated. We systematically reviewed the clinical data of 246 patients with suspected pulmonary infection from 4 medical institutions between January 2019 and September 2021. The diagnostic performances of mNGS and conventional testing (CT) were systematically analyzed based on bronchoalveolar lavage fluid (BALF). The impacts of mNGS and CT on diagnosis modification and treatment adjustment were also assessed. The positive rates of mNGS and CT were 47.97% and 23.17%, respectively. The sensitivity of mNGS was significantly higher than that of CT (53.49% versus 23.26%, P < 0.01), especially for infections of Mycobacterium tuberculosis (67.86% versus 17.86%, P < 0.01), atypical pathogens (100.00% versus 7.14%, P < 0.01), viruses (92.31% versus 7.69%, P < 0.01), and fungi (78.57% versus 39.29%, P < 0.01). The specificity of mNGS was superior to that of CT, with no statistical difference (90.32% versus 77.42%, P = 0.167). The positive predictive value (PPV) and negative predictive value (NPV) of mNGS were 97.46% and 21.88%, respectively. Diagnosis modification and treatment adjustment were conducted in 32 (32/246, 13.01%) and 23 (23/246, 9.35%) cases, respectively, according to mNGS results only. mNGS significantly improved the diagnosis of suspected pulmonary infection, especially infections of M.tuberculosis, atypical pathogens, viruses, and fungi, and it demonstrated the pathogen distribution of pulmonary infections. It is expected to be a promising microbiological detection and diagnostic method in clinical practice.

IMPORTANCE Pulmonary infection is a heterogeneous and complex infectious disease with high morbidity and mortality worldwide. In clinical practice, a considerable proportion of the etiology of pulmonary infection is unclear, microbiological diagnosis being challenging. Metagenomic next-generation sequencing detects all nucleic acids in a sample in an unbiased manner, revealing the microbial community environment and organisms and improving the microbiological detection and diagnosis of infectious diseases in clinical settings. This study is the first multicenter, large-scale retrospective study based entirely on BALF for pathogen detection by mNGS, and it demonstrated the superior performance of mNGS for microbiological detection and diagnosis of suspected pulmonary infection, especially in infections of Mycobacterium tuberculosis, atypical pathogens, viruses, and fungi. It also demonstrated the pathogen distribution of pulmonary infections in the real world, guiding targeted treatment and improving clinical management and prognoses.

Metagenomic next-generation sequencing for the diagnosis of pulmonary aspergillosis in non-neutropenic patients: a retrospective study

This study aimed to obtain further in-depth information on the value of metagenomic next-generation sequencing (mNGS) for diagnosing pulmonary aspergillosis in non-neutropenic patients. We did a retrospective study, in which 33 non-neutropenic patients were included, of which 12 were patients with pulmonary aspergillosis and 21 were diagnosed with non-pulmonary aspergillosis. Fungi and all other co-pathogens in bronchoalveolar lavage fluid (BALF) (27 cases), blood (6 cases), and/or pleural fluid (1 case) samples were analyzed using mNGS. One of the patients submitted both BALF and blood samples. We analyzed the clinical characteristics, laboratory tests, and radiologic features of pulmonary aspergillosis patients and compared the diagnostic accuracy, including sensitivity, specificity, positive predictive value, and negative predictive value of mNGS with conventional etiological methods and serum (1,3)-β-D-glucan. We also explored the efficacy of mNGS in detecting mixed infections and co-pathogens. We further reviewed modifications of antimicrobial therapy for patients with pulmonary aspergillosis according to the mNGS results. Finally, we compared the detection of Aspergillus in BALF and blood samples from three patients using mNGS. In non-neutropenic patients, immunocompromised conditions of non-pulmonary aspergillosis were far less prevalent than in patients with pulmonary aspergillosis. More patients with pulmonary aspergillosis received long-term systemic corticosteroids (50% vs. 14.3%, p < 0.05). Additionally, mNGS managed to reach a sensitivity of 91.7% for diagnosing pulmonary aspergillosis, which was significantly higher than that of conventional etiological methods (33.3%) and serum (1,3)-β-D-glucan (33.3%). In addition, mNGS showed superior performance in discovering co-pathogens (84.6%) of pulmonary aspergillosis; bacteria, bacteria-fungi, and bacteria-PJP-virus were most commonly observed in non-neutropenic patients. Moreover, mNGS results can help guide effective treatments. According to the mNGS results, antimicrobial therapy was altered in 91.7% of patients with pulmonary aspergillosis. The diagnosis of Aspergillus detected in blood samples, which can be used as a supplement to BALF samples, seemed to show a higher specificity than that in BALF samples. mNGS is a useful and effective method for the diagnosis of pulmonary aspergillosis in non-neutropenic patients, detection of co-pathogens, and adjustment of antimicrobial treatment.

The role of metagenomic next-generation sequencing in the pathogen detection of invasive osteoarticular infection

OBJECTIVE

This study aimed to analyzed the pathogenic bacteria spectrum in invasive and primary osteoarticular infection (IOI and POI), and compared the pathogen detection rate of metagenomic next-generation sequencing (mNGS) and microbial culture in IOI and POI.

METHODS

The suspected POI and IOI cases from 2008 to 2021 were included. The diagnosis of POI or IOI were made by at least two orthopaedic surgeons, two infectious diseases specialist and one senior microbiologist. Demographic characteristics, microbial culture results and so on were recorded. The pathogenic bacteria spectrum in IOI and POI were analyzed and the ability of mNGS and microbial culture in pathogen detection in IOI and POI were compared.

RESULTS

There were 63 POI cases and 92 cases, the common pathogen in POI and IOI were both Staphylococcus aureus. There are more cases with negative microbial culture results and multiple infections in IOI, and many cases were caused by rare and fastidious bacteria. The introduction of the mNGS could significantly increase the pathogen detection rate to 92.39% in IOI, which was 8.69% higher than that of microbial culture (P=0.007), while the improvement in POI was limited to about 2%.

CONCLUSIONS

mNGS was an ideal tool for IOI pathogen detection.

Metagenomic next-generation sequencing for accurate diagnosis and management of lower respiratory tract infections

OBJECTIVES

This study aimed to evaluate the clinical value of metagenomic next-generation sequencing (mNGS) in patients with suspected lower respiratory tract infections (LRTIs).

METHODS

This retrospective study reviewed patients with suspected LRTIs in Wuhan Union Hospital. Data including demographic, laboratory, and radiological profiles; treatment; and outcomes were recorded and analyzed.

RESULTS

mNGS identified pathogenic microbes in 100/140 (71.4%) patients, although 135 (96.4%) had received empiric antibiotic treatment before the mNGS tests. Single bacterial infection (35/100, 35%) was the most common type of infection in patients with positive mNGS results, followed by single fungal infection (14/100, 14%), bacterial-viral co-infection (14/100, 14%), single viral infection (12/100, 12%), bacterial-fungal co-infection (9/100, 9%), fungal-viral co-infection (9/100, 9%), and bacterial-fungal-viral co-infection (7/100, 7%). Moreover, compared with culture test, mNGS showed higher sensitivity (63/85, 74.1% vs. 22/85, 25.9% P=0.001) and lower processing time (24 h vs 48 h). Antibiotic treatment was adjusted or confirmed based on the mNGS results in 123 (87.9%) patients, including 5 (3.6%), 33 (23.6%) and 85 (60.7%) patients in whom treatment was downgraded, upgraded and unchanged, respectively, and almost all patients, regardless of escalation, de-escalation, or no change in treatment, showed significant improvement in clinical symptoms and inflammatory indicators. Additionally, 17 (12.1%) patients were referred to Wuhan Pulmonary Hospital for further treatment because of confirmed or suspected tuberculosis.

CONCLUSIONS

mNGS could be a promising technique for microbiological diagnosis and antibiotic management, potentially improving outcomes of patients.

Enhanced DNA and RNA pathogen detection via metagenomic sequencing in patients with pneumonia

BACKGROUND

Metagenomic next-generation sequencing (mNGS) is an important supplement to conventional tests for pathogen detections of pneumonia. However, mNGS pipelines were limited by irregularities, high proportion of host nucleic acids, and lack of RNA virus detection. Thus, a regulated pipeline based on mNGS for DNA and RNA pathogen detection of pneumonia is essential.

METHODS

We performed a retrospective study of 151 patients with pneumonia. Three conventional tests, culture, loop-mediated isothermal amplification (LAMP) and viral quantitative real-time polymerase chain reaction (qPCR) were conducted according to clinical needs, and all samples were detected using our optimized pipeline based on the mNGS (DNA and RNA) method. The performances of mNGS and three other tests were compared. Human DNA depletion was achieved respectively by MolYsis kit and pre-treatment using saponin and Turbo DNase. Three RNA library preparation methods were used to compare the detection performance of RNA viruses.

RESULTS

An optimized mNGS workflow was built, which had only 1-working-day turnaround time. The proportion of host DNA in the pre-treated samples decreased from 99 to 90% and microbiome reads achieved an approximately 20-fold enrichment compared with those without host removal. Meanwhile, saponin and Turbo DNase pre-treatment exhibited an advantage for DNA virus detection compared with MolYsis. Besides, our in-house RNA library preparation procedure showed a more robust RNA virus detection ability. Combining three conventional methods, 76 (76/151, 50.3%) cases had no clear causative pathogen, but 24 probable pathogens were successfully detected in 31 (31/76 = 40.8%) unclear cases using mNGS. The agreement of the mNGS with the culture, LAMP, and viral qPCR was 60%, 82%, and 80%, respectively. Compared with all conventional tests, mNGS had a sensitivity of 70.4%, a specificity of 72.7%, and an overall agreement of 71.5%.

CONCLUSIONS

A complete and effective mNGS workflow was built to provide timely DNA and RNA pathogen detection for pneumonia, which could effectively remove the host sequence, had a higher microbial detection rate and a broader spectrum of pathogens (especially for viruses and some pathogens that are difficult to culture). Despite the advantages, there are many challenges in the clinical application of mNGS, and the mNGS report should be interpreted with caution.

Clinical Characteristics and Risk Factors for Pulmonary Infection in Emergency ICU Patients

Background

Pulmonary infection in the emergency ICUs increases patient morbidity, hospital stay, treatment costs, and the risk of related adverse events.

Methods

This study included 695 patients admitted to our emergency ICU between December 2019 and March 2021. Medical records of emergency ICU patients were reviewed to collect their clinical data, including antibiotic use, history of tracheostomy, history of mechanical ventilation, presence or absence of underlying disease, history of smoking, alcohol consumption, age, gender, and history of shock. Bacterial cultures were performed. The incidence, main clinical features, main pathogens, and risk factors of pulmonary infection in emergency ICU were analyzed.

Results

In this study, 69 of the 695 emergency ICU patients (9.93%) developed pulmonary infection. The main clinical features of patients with pulmonary infection included cough and expectoration (97.10%), shortness of breath and chest tightness (95.65%), leukocyte elevation (69.57%), confusion (31.88%), drowsiness (28.99%), persistent fever (27.54%), and nausea and vomiting (10.14%). The main pathogenic bacteria in those with pulmonary infection included Klebsiella pneumoniae (62.32%), Pseudomonas aeruginosa (49.28%), Streptococcus pneumoniae (21.74%), Staphylococcus aureus (39.13%), Candida albicans (7.25%), Pneumococcus pneumoniae (15.95%), Pseudomonas aeruginosa (24.64%), and lung diplococcus inflammatory (13.04%). Univariate analysis showed that there were no significant differences in the occurrence of pulmonary infection with regard to sex, smoking, and alcohol consumption, but there were significant differences with regard to age, basic disease, invasive surgery, and shock. Logistic regression analysis confirmed that age ≥ 80 years, invasive surgery, shock, and basic diseases ≥ 2 were important risk factors for pulmonary infection in emergency ICU patients.

Conclusion

Considering the clinical features and risk factors for pulmonary infection in the emergency ICU, preventive and control measures are required to minimize its occurrence and ensure good outcomes.