In recent years, due to the extensive usage of immunosuppressant and the rise of patients with cancers and organ transplantation, the incidence rate of invasive fungal infection, especially invasive pulmonary fungal infection, has increased. Besides the clinical manifestations, medical history and imaging, the diagnosis of pulmonary mycosis mainly depends on pathogen detection methods in clinical microbiology laboratory. However, due to the difficulty in fungi culturing and the low sensitivity of smear microscopy, better molecular biology methods are needed. To date, the emergence of metagenomic next-generation sequencing (mNGS) has improved the identification rate of pulmonary fungal infections. mNGS is significantly superior to traditional detection methods in rapid, accurate, and comprehensive determination of fungi from various clinical specimens, especially atypical fungi. However, some problems in mNGS method have to be addressed including sample collection, report interpretation, and its combination with traditional microbiology methods. With the in-depth discussion and solution of the above problems, mNGS will be indispensable to the etiological diagnosis of pulmonary invasive fungal infection.
ObjectiveTo explore the clinical value of metagenomic next-generation sequencing (mNGS) in diagnosis and treatment of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). MethodsBetween April 2020 and March 2023, 10 patients with PJI after TKA were admitted. There were 3 males and 7 females with an average age of 69.9 years (range, 44-83 years). Infection occurred after 8-35 months of TKA (mean, 19.5 months). The duration of infection ranged from 16 to 128 days (mean, 37 days). The preoperative erythrocyte sedimentation rate (ESR) was 15-85 mm/1 h (mean, 50.2 mm/1 h). The C reactive protein (CRP) was 4.4-410.0 mg/L (mean, 192.8 mg/L). The white blood cell counting was (3.4-23.8)×109/L (mean, 12.3×109/L). The absolute value of neutrophils was (1.1-22.5)×109/L (mean, 9.2×109/L). After admission, the joint fluid was extracted for bacterial culture method and mNGS test, and sensitive antibiotics were chosen according to the results of the test, and the infection was controlled in combination with surgery. Results Seven cases (70%) were detected as positive by bacterial culture method, and 7 types of pathogenic bacteria were detected; the most common pathogenic bacterium was Streptococcus lactis arrestans. Ten cases (100%) were detected as positive by mNGS test, and 11 types of pathogenic bacteria were detected; the most common pathogenic bacterium was Propionibacterium acnes. The difference in the positive rate between the two methods was significant (P=0.211). Three of the 7 patients who were positive for both the bacterial culture method and the mNGS test had the same results for the type of pathogenic bacteria, with a compliance rate of 42.86% (3/7). The testing time (from sample delivery to results) was (4.95±2.14) days for bacterial culture method and (1.60±0.52) days for mNGS test, and the difference was significant (t=4.810, P<0.001). The corresponding sensitive antibiotic treatment was chosen according to the results of bacterial culture method and mNGS test. At 3 days after the one-stage operation, the CRP was 6.8-48.2 mg/L (mean, 23.6 mg/L); the ESR was 17-53 mm/1 h (mean, 35.5 mm/1 h); the white blood cell counting was (4.5-8.1)×109/L (mean, 6.1×109/L); the absolute value of neutrophils was (2.3-5.7)×109/L (mean, 4.1×109/L). All patients were followed up 12-39 months (mean, 23.5 months). One case had recurrence of infection at 6 months after operation, and the remaining 9 cases showed no signs of infection, with an infection control rate of 90%. Conclusion Compared with bacterial culture method, mNGS test can more rapidly and accurately detect pathogenic bacteria for PJI after TKA, which is important for guiding antibiotics combined with surgical treatment of PJI.
In recent years, with the wide application of metagenomics next-generation sequencing, more and more rare pathogens have been detected in our clinical work, including non-tuberculous Mycobacterium, Corynebacterium, Fusarium, Cryptococcus pneumoniae, human herpes virus, torque teno virus, parvovirus, Tropheryma whipplei, Bartonella, Chlamydia psittaci, etc. It is difficult to determine whether these rare pathogens are clinically significant and need treatment. This article puts forward some suggestions and discussions on the diagnosis and treatment of pulmonary infections with some rare pathogens.
Objective To analyze the clinical data of patients with Tropheryma whipplei pneumonia, and summarize the clinical characteristics, diagnosis, and treatment methods of Tropheryma whipplei pneumonia. Methods The data of Tropheryma whipplei pneumonia patients from three hospitals in Hunan Province between January 1, 2021 and October 1, 2022 were retrospectively collected. The clinical symptoms, laboratory examination, metagenomics next-generation sequencing (mNGS), CT imaging features, diagnosis and treatments of the included patients were analyzed. Results A total of 4 patients were included. Among them, there were 2 males and 2 females. The main manifestations were cough, expectoration, fever, and shortness of breath. There were 2 cases of diffuse ground glass opacity in both lungs, 1 case of pulmonary nodule, 1 case of pulmonary cavity, 1 case of pleural disease, 2 cases of pulmonary exudative lesions, and 1 case of mediastinal lymphadenectasis. The mNGS results showed that Tropheryma whipplei was detected in all 4 patients, and the median number of serial number (lower quartile, upper quartile) was 1 528 (1 480, 1 576). After anti infection treatment, 3 cases were treated effectively, and 1 case had poor treatment effect. Conclusions mNGS is an effective method to diagnose Tropheryma whipplei pneumonia. The measurement of serum lactate dehydrogenase level is helpful to evaluate the disease and determine the prognosis. Piperacillin tazobactam, meropenem and doxycycline are effective for this disease, while moxifloxacin and trimethoprim / sulfamethoxazole are not recommended because they may be naturally resistant. Without active etiological treatment, the disease may persist in migration and lead to extrapulmonary involvement.
The morbidity and mortality of pulmonary infection are high among infectious diseases worldwide. Rapid and accurate etiological diagnosis is the key to timely and effective treatment. Metagenomic next-generation sequencing (mNGS) technology has brokenthrough the limitations of traditional pathogenic microorganism detection methods and improved the detection rate of pathogens. In this paper, the application and advantages of mNGS technology in the diagnosis of bacteria, fungi, viruses and mixed infections in the lungs are analyzed, and the challenges and breakthroughs in RNA detection, wall breaking of firmicutes and host DNA clearance are described, in order to achieve targeted and accurate etiological diagnosis through mNGS, so as to effectively treat pulmonary infections.
Objective To analysis and explore the value of metagenomics next-generation sequencing (mNGS) and clinical characteristics of Chlamydia psittaci (C. psittaci) pneumonia. Methods Totally 5 patients who were diagnosed with C. psittaci pneumonia and were treated in the Department of Respiratory and Critical Care Medicine and the Department of Infectious Diseases of Huazhong University of Science and Technology Union Shenzhen Hospital from Febuary 2021 to March 2021 were enrolled in the study. The clinical data of the patients were analyzed, and the clinical characteristics of the disease and treatment experience were summarized. Results The main symptoms of the 5 patients were high fever and cough, 4 of them had a history of raising parrots. The white blood cell and the neutrophils were mostly normal or slightly increased, the C reactive protein and erythrocyte sedimentation rate were significantly increased. The chest CT showed exudation and consolidation of one or several lung lobes. The serious patients might develop respiratory failure, if they were not treated by effective antibiotics. The diagnosis was based on clinical manifestations, contact history and alveolar lavage fluid that were detected by mNGS technology of C. psittaci nucleic acid sequence. The accuracy of detecting pathogens in alveolar lavage fluid by mNGS was high. In addition, mNGS could also identify other bacteria or viruses. After the timely adjustment of treatment, the condition of the patients was improved relied on tetracycline drugs or quinolone drugs, which shortened the diagnosis time and course of C. psittaci pneumnonia and reduced the use of unnecessary antibacterial drugs. Conclusions mNGS is of great significance in diagnosing C. psittaci pneumonia. The timely use of appropriate antibacterial drugs can achieve favorable therapeutic effect.
ObjectiveTo improve the understanding of psittacosis, the clinical data of 8 cases are reviewed. The application of pathogen metagenomics next-generation sequencing (mNGS) in the diagnosis of nocardiosis is also investigated.MethodsThe clinical data of eight patients with psittacosis diagnosed by mNGS in Nanjing Drum Tower Hospital from January 2018 to May 2020 were reviewed. The clinical characteristics, laboratory examination characteristics and imaging changes were analyzed, and the treatment outcome was followed-up.ResultsAmong the eight cases, there were six males and two females, aged 43～83 years old, with an average age of 64±12 years old. Six of them had a clear history of poultry exposure. The major clinical manifestations were fever, cough, dyspnea, etc. Chest high-resolution computed tomography (HRCT) may have solid shadow, ground glass like shadow. Chlamydia psittaci was detected by mNGS in eight patients’ bronchoalveolar lavage fluid. Minocycline or moxifloxacin were administrated, six patients were discharged after their condition improved, and two patients died.ConclusionsThe incidence of psittacosis is low, and its clinical manifestations lack specificity. In the course of the disease, there may be different degrees of fever, cough, sputum, dyspnea and other symptoms. The lungs can be heard with wet rales, chest HRCT can be seen ground glass shadow, consolidation shadow, accompanied by air bronchogram. Chlamydia psittaci can be detected in alveolar lavage fluid by mNGS. The patients need to be treated for a long time, lasting at least 10 to 14 days. Tetracycline drugs should be the first choice, and can be combined with other antibiotics with activity against gram-positive and gram-negative bacteria in critical patients.
Objective To summarize and explore the clinical features, diagnosis and treatment of severe pulmonary tuberculosis (TB). Methods One death case of pulmonary TB in The First Affiliated Hospital of Soochow University was analyzed, related publications of case reports and articles relevant on the analysis and study of pulmonary tuberculosis deaths from Pubmed between January 2012 and March 2022 were also reviewed. Results A 25-year-old female patient was admitted for "intermittent cough with sputum for more than 1 year, aggravated with chest tightness and shortness of breath for 5 days". She had no underlying disease. Pulmonary TB was diagnosed by TB bacterium smear and next-generation sequencing of bronchoalveolar lavage fluid. The patient was in shock compensation period and developed acute respiratory distress syndrome immediately after admission. Through active anti-tuberculosis, invasive mechanical ventilation, intra-aortic balloon counterpulsation and continuous renal replacement therapy, the disease continued to deteriorate and she died on the third day after admission. A total of 269 pulmonary TB deaths were retrieved. An analysis of 244 patients' past medical history showed that human immunodeficiency virus co-infection was the most common among young people and chronic diseases were the most common among the elderly. All 269 patients died of septic shock, respiratory failure and multiple organ dysfunction syndrome (MODS), among which hyponatremia was also a significant complication. The shortest time from admission to death was 7 days, while the longest average time was only 35 days. Conclusions Pulmonary TB could develop into septic shock and MODS with poor prognosis and high mortality. Health education on TB should be strengthened.
Objective By using metagenomic next-generation sequencing (mNGS), we aimed to analyze the microbes characteristics of lower respiratory tract of patients with pulmonary infection, so as to improve the further understanding of clinical etiological characteristics of patients with pulmonary infection. Methods A total of 840 patients with suspected pulmonary infection were enrolled from August 2020 to October 2021 in West China Hospital of Sichuan University. mNGS was used to detect the microbiome of bronchoalveolar lavage fluid of all patients, and the microbial characteristics of lower respiratory tract of all patients were retrospectively analyzed. Results A total of 840 patients were enrolled, of which 743 were positive for microbiome, with bacterial infection accounting for 35.13% (261/743). Acinetobacter baumannii accounted for 18.98% (141/743), followed by Streptococcus pneumoniae (14.13%, 105/743), Klebsiella pneumoniae (13.46%, 100/743), Enterococcus faecium (12.11%, 90/743) and Mycobacterium tuberculosis complex (11.98%, 89/743). Acinetobacter baumannii had the highest average reads (2607.48). In addition, some specific pathogens were detected, such as 9 cases of Chlamydia psittaci. The main fungal infections were Candida albicans (12.38%, 92/743), Pneumocystis jirovecii (9.02%, 67/743) and Aspergillus fumigatus (7.40%, 55/743), among which the average reads of Pneumocystis jirovecii was higher (141.86) than Candida albicans and Aspergillus fumigatus. In addition, some special pathogens were also detected, such as a case of Talaromyces marneffei. The main viral infections included human β herpevirus 5 (17.90%, 133/743), human γ herpevirus 4 (17.36%, 129/743), human β herpevirus 7 (16.15%, 120/743) and human α herpevirus 1 (13.59%, 101/743), among which the average reads of human herpesvirus type 1 (367.27) was the highest. Parasitic infection was least, with only 2 cases of Echinococcus multilocularis, 2 cases of Angiostrongylus cantonensis, 2 cases of Dermatophagoides pteronyssinus and 1 case of Dermatophagoides farinae, which were mainly infected with bacteria and viruses. In addition, a total of 407 patients were diagnosed with mixed infection, of which virus and bacteria mixed infection was the most (22.61%, 168/743). The distribution of microorganisms in different seasons also has certain characteristics. For example, bacteria (Acinetobacter baumannii) were most frequently detected in autumn and winter, while viruses (human gamma-herpesvirus type 4) were most frequently detected in spring and summer. Conclusions In the lower respiratory tract of patients with pulmonary infection, the main gram-negative bacteria are Acinetobacter baumannii and Klebsiella pneumoniae, while the main gram-positive bacteria are Streptococcus pneumoniae, Enterococcus faecium and Mycobacterium tuberculosis complex; the main fungi are Candida albicans, Pneumocystis jirovecii and Aspergillus fumigatus; the main viruses are human β herpevirus 5, human γ herpevirus 4 and human β herpevirus 7. However, parasites are rarely detected and have no obvious characteristics. Bacterial infection and bacterial virus mixed infection are the main co-infections; the microbial characteristics of autumn and winter are different from those of spring and summer. In addition, attention should be paid to special pathogenic microorganisms, such as Chlamydia psittaci and Talaromyces marneffei. These characteristics could be used as reference and basis for the pathogenic diagnosis of pulmonary infection.
ObjectiveTo explore the application and clinical value of metagenomic next-generation sequencing (mNGS) combined with Omadacycline in the treatment of Refractory Mycoplasma pneumoniae pneumonia (RMPP).MethodsThe clinical data, relevant laboratory results, diagnosis and treatment process, and imaging outcomes of four patients diagnosed with Mycoplasma pneumoniae pneumonia through mNGS were analyzed. ResultsThe clinical symptoms at onset in all four patients were consistent with Mycoplasma pneumoniae pneumonia. After conventional treatment with macrolides, tetracyclines, or quinolone antibiotics, the symptoms showed no significant improvement, and there was a trend of radiological worsening. Following the confirmation of Mycoplasma pneumoniae infection through mNGS of bronchoalveolar lavage fluid, and due to various reasons preventing the use of the aforementioned drugs, omadacycline was ultimately chosen for treatment. Radiological improvements were observed in all cases, leading to a good prognosis and discharge. ConclusionsFor pneumonia cases where the infectious pathogen cannot be identified and conventional treatment has failed, mNGS can be utilized for early and accurate diagnosis. In cases of RMPP, Omadacycline can be employed as an alternative treatment to prevent delays in care and reduce the risk of complications.