Metagenomic diagnosis of severe psittacosis using multiple sequencing platforms

Compare Clinical Characteristics of Psittacosis Pneumonia in 35 Patients and of Non Psittacosis Bacterial Pneumonia in 46 Patients

Background

We aimed to describe the difference between Chlamydia psittaci pneumonia group and non C. psittaci bacterial pneumonia group in community acquired pneumonia in this single-center clinical study.

Methods

We collected the data of 35 patients with C. psittaci pneumonia cases and 46 patients with non C. psittaci bacterial pneumonia cases diagnosed with metagenomic next-generation sequencing assays from February 2019 to December 2021 in Huaihua First People's Hospital in China.

Results

In the C. psittaci pneumonia group, 35 patients (100%) had a chance of exposure to poultry or birds, and their body temperature was greater than or equal to 39.0°C. The other common symptoms were a slow pulse (68.6%), cough (65.7%), expectoration (54.3%), chills (51.4%) and a shortness of breath (37.1%). Laboratory tests showed that >90% of the cases had markedly elevated infection indicators, and 97.1% of the cases had markedly declined calcium. The most common imaging finding was patchy shadows (94.3%), pleural effusion (68.6%), bilateral in 54.3% (n = 19) and unilateral in 45.7% (n = 16) participants, and 51.4% (n = 18) of cases met the criteria for severe pneumonia. In the non C. psittaci bacterial pneumonia group, 18 patients (39.1%) had a chance of exposure to poultry or birds, and 11 patients (23.9%) body temperature was greater than or equal to 39.0°C. Laboratory tests showed that >67% of cases had a mildly elevated infection indicators, and mildly declined serum albumin.

Conclusion

The following characteristics are more likely to help distinguish C. psittaci pneumonia from non C. psittaci bacterial pneumonia. Including had a chance of exposure to poultry or birds, high fever, exhibit chills, expectoration, relatively slow pulse, and progress into severe pneumonia. Percentage of neutrophils, C-reactive protein, procalcitonin, lactate dehydrogenase, and myoglobin levels are higher. Blood calcium and corrected calcium are lower. Chest CT showed pleural effusion, pericardial effusion, and mediastinal lymphadenopathy.

Case Report of Severe Chlamydia psittaci Pneumonia Treated with Omadacycline

The clinical severity of Chlamydia psittaci infection ranges from asymptomatic to severe pneumonia. Diagnosis poses challenges due to its similarity to other respiratory infections. Treatment includes tetracyclines, macrolides, and fluoroquinolones, with limited evidence on the efficacy of omadacycline. We report a case of an 86-year-old male with severe psittacosis treated with omadacycline, resulting in significant improvement. This highlights the necessity for further research on omadacycline's role in psittacosis treatment.

Pneumonia Caused by Chlamydia psittaci and SARS-CoV-2 Coinfection Diagnosed Using Metagenomic Next-Generation Sequencing: A Case Report

We report a case of pneumonia caused by coinfection with Chlamydia psittaci and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron XBB.1 variant, confirmed using metagenomic next-generation sequencing (mNGS) and quantitative polymerase chain reaction (qPCR). C. psittaci and SARS-CoV-2 were detected in bronchoalveolar lavage fluid using mNGS. Additionally, mNGS detected C. psittaci in blood and nasopharyngeal specimens and was more sensitive than qPCR. The patient recovered after treatment with moxifloxacin. This report highlights the use of coinfections of C. psittaci and SARS-CoV-2, as mNGS has already been recognized to be a diagnostic tool for identifying coinfections.

Diagnostic performance of metagenomic next-generation sequencing and conventional microbial culture for spinal infection: a retrospective comparative study

PURPOSE

The study evaluated the diagnostic performance of metagenomic next-generation sequencing (mNGS) as a diagnostic test for biopsy samples from patients with suspected spinal infection (SI) and compared the diagnostic performance of mNGS with that of microbial culture.

METHODS

All patients diagnosed with clinical suspicion of SI were enrolled, and data were collected through a retrospective chart review of patient records. Biopsy specimens obtained from each patient were tested via mNGS and microbial culture. Samples were enriched for microbial DNA using the universal DNA extraction kit, whole-genome amplified, and sequenced using MGISEQ-200 instrument. After Low-quality reads removed, the remaining sequences for microbial content were analyzed and aligned using SNAP and kraken2 tools.

RESULTS

A total of 39 patients (19 men and 20 women) were deemed suitable for enrollment. The detection rate for pathogens of mNGS was 71.8% (28/39), which was significantly higher than that of microbial culture (23.1%, p = 0.016). Mycobacterium tuberculosis complex was the most frequently isolated. Using pathologic test as the standard reference for SI, thirty-one cases were classified as infected, and eight cases were considered aseptic. The sensitivity and specificity values for detecting pathogens with mNGS were 87.1% and 87.5%, while these rates were 25.8% and 87.5% with conventional culture. mNGS was able to detect 88.9% (8/9) of pathogens identified by conventional culture, with a genus-level sensitivity of 100% (8/8) and a species-level sensitivity of 87.5% (7/8).

CONCLUSION

The present work suggests that mNGS might be superior to microbial culture for detecting SI pathogens.

Psittacosis: An Underappreciated and Often Undiagnosed Disease

The bacterial agent Chlamydia psittaci, and the resulting disease of psittacosis, is a little-known and underappreciated infectious disease by healthcare practitioners and in public health in general. C. psittaci infections can cause significant psittacosis outbreaks, with person-to-person transmission documented in the last decade. In this publication, we review the pathogen and its disease, as well as examine the potential for genetic manipulation in this organism to create a more deadly pathogen. Recent disease surveys indicate that currently, the highest incidences of human disease exist in Australia, Germany and the UK. We recommend the universal public health reporting of C. psittaci and psittacosis disease and increasing the promotion of public health awareness.

Chlamydia Psittaci Pneumonia-Induced Myocarditis: A Case Report

The incidence of Chlamydia psittaci infection has been reported to increase in recent years. The presentation of psittacosis infection varied widely, from none to severe symptoms. Mainly, psittacosis infection presents with pulmonary manifestations. Here, we report the case of a 60-year-old female patient with Chlamydia psittaci pneumonia complicated by myocarditis. After administering antibiotics, the patient recovered from severe atypical pneumonia and myocarditis. In general, Chlamydia psittaci rarely induces myocarditis. Moreover, the optimal therapeutic strategies remain unclear for such cases, especially with a high troponin T level. Metagenomic Next-Generation Sequencing (mNGS) can provide a quick and effective diagnosis of Chlamydia psittaci pneumonia; early intervention (antibiotic therapy and nutritional supplements for myocarditis) favors a good outcome, although complications may worsen the condition. Therefore, more studies are required to help improve understanding of the disease.

Application of nanopore adaptive sequencing in pathogen detection of a patient with Chlamydia psittaci infection

Introduction

Nanopore sequencing has been widely used in clinical metagenomic sequencing for pathogen detection with high portability and real-time sequencing. Oxford Nanopore Technologies has recently launched an adaptive sequencing function, which can enrich on-target reads through real-time alignment and eject uninteresting reads by reversing the voltage across the nanopore. Here we evaluated the utility of adaptive sequencing in clinical pathogen detection.

Methods

Nanopore adaptive sequencing and standard sequencing was performed on a same flow cell with a bronchoalveolar lavage fluid sample from a patient with Chlamydia psittacosis infection, and was compared with the previous mNGS results.

Results

Nanopore adaptive sequencing identified 648 on-target stop receiving reads with the longest median read length(688bp), which account for 72.4% of all Chlamydia psittaci reads and 0.03% of total reads in enriched group. The read proportion matched to C. psittaci in the stop receiving group was 99.85%, which was much higher than that of the unblock (<0.01%) and fail to adapt (0.02%) groups. Nanopore adaptive sequencing generated similar data yield of C. psittaci compared with standard nanopore sequencing. The proportion of C. psittaci reads in adaptive sequencing is close to that of standard nanopore sequencing and mNGS, but generated lower genome coverage than mNGS.

Discussion

Nanopore adaptive sequencing can effectively identify target C. psittaci reads in real-time, but how to increase the targeted data of pathogens still needs to be further evaluated.

Case Report: A Chlamydia psittaci pulmonary infection presenting with migratory infiltrates

Community-acquired pneumonia is a public health problem in all countries in the world, with a broad range of causative agents and Chlamydia psittaci infection tends to be overlooked. Pulmonary migratory infiltrates are commonly seen in eosinophilic pneumonia, cryptogenic organizing pneumonia, etc. However, the association of Chlamydia psittaci and pulmonary migratory infiltrates has been seldom described in literatures before. We reviewed a 64-year-old man referred to our hospital for treatment against Chlamydia psittaci pneumonia which was diagnosed by metagenomics next generation sequencing (mNGS). During the treatment period, chest imaging showed migratory infiltrates, which has been rarely described before.

Diagnosis by metagenomic next-generation sequencing of invasive pulmonary aspergillosis in an infant with chronic granulomatous disease

Invasive pulmonary aspergillosis (IPA) is a serious fungal infection, with a high degree of mortality in immunocompromised individuals. Diagnosis of IPA is challenging in that clinical manifestations are not specific, with sensitivity of traditional detection procedures low. We report a case of IPA in a chronic granulomatous disease (CGD) infant who was initially suspected to have a lung tumor. Aspergillus fumigatus was identified as the pathogen in bronchoalveolar lavage fluid (BALF) by next-generation sequencing (mNGS). The patient recovered rapidly following a change of appropriate antifungal treatment and was discharged. This case highlights the additional value of BALF-mNGS for the diagnosis of pediatric invasive pulmonary fungal infection in immune-deficient children.

Clinical value of metagenomic next-generation sequencing by Illumina and Nanopore for the detection of pathogens in bronchoalveolar lavage fluid in suspected community-acquired pneumonia patients

At present, metagenomic next-generation sequencing (mNGS) based on Illumina platform has been widely reported for pathogen detection. There are few studies on the diagnosis of major pathogens and treatment regulation using mNGS based on Illumina versus Nanopore. We aim to evaluate the clinical value of metagenomic next-generation sequencing (mNGS) by Illumina and Nanopore for the detection of pathogens in bronchoalveolar lavage fluid (BALF) in suspected community-acquired pneumonia (CAP) patients. BALF samples collected from 66 suspected CAP patients within 48 hours of hospitalization were divided into two parts, one for conventional culture and the other for mNGS by two platforms (Illumina and Nanopore). The clinical value based on infection diagnosis, diagnostic performance for main pathogens and treatment guidance were assessed. More types of species were detected by Nanopore than Illumina, especially in viruses, fungus and mycobacterium. Illumina and Nanopore showed similar detectability in bacterium except for mycobacterium tuberculosis complex/nontuberculosis mycobacteria. Pathogenic infection was established or excluded in 53 of 66 patients. There was little difference in the coincidence rate between Illumina and Nanopore with the clinical diagnosis, but both were superior to the culture (57.81%, 59.38%, 25%, respectively). Compared with Illumina, the diagnostic area under the curve of Nanopore was higher in fungi, but lower in bacteria and Chlamydia psittaci. There was no statistically significant difference between Illumina and Nanopore in guiding drug treatment (56.1% vs. 50%, p=0.43), but both were superior to the culture (56.1% vs. 28.8%, p=0.01; 50% vs. 28.8%, p=0.01). Single inflammatory indicators could not be used to determine whether the patients with culture-negative BALF were established or excluded from infection. The species detected at 1 h and 4 h by Nanopore were consistent to some extent, and its turn-around time (TAT) was significantly shorter than Illumina (p<0.01). Illumina and Nanopore both have its own advantages in pathogenic diagnosis and play similar roles in infection diagnosis and guiding clinical treatment. Nanopore has a relatively short TAT, which may be promising in rapid etiological diagnosis of acute and critically ill patients.

Clinical, radiological and pathological characteristics of moderate to fulminant psittacosis pneumonia

Background

Psittacosis pneumonia is a community-acquired pneumonia caused by Chlamydia psittaci. It is usually under-diagnosed due to its atypical clinical presentation and lack of routine laboratory tests.

Methods

To better understand the clinical features, 52 patients diagnosed with psittacosis pneumonia by metagenomic next-generation sequencing (mNGS) were enrolled in this study. The clinical, radiological and pathological characteristics were retrospectively analyzed.

Results

The onset of psittacosis pneumonia in this study occurred all year round, with a peak from December to January. Most of the patients were 51–80 years old. About 65.38% of patients had a history of exposure to poultry or parrots. Abnormalities of multiple clinical signals were detected in these patients. Elevated levels of neutrophil ratio, C-reactive protein, erythrocyte sedimentation rate, and procalcitonin were detected in most patients. Radiological evidence revealed air-space consolidation or ground-glass opacities in lungs of all patients, which is the typical feature of psittacosis pneumonia. In addition, hyperemia, swelling of bronchial mucosa, and bronchial patency were detected by bronchoscopy in all patients, and bronchial sub-mucosal edema, inflammatory cells infiltration and alveolar epithelial hyperplasia were identified in the bronchial mucosa and alveolar tissue. Beta-lactam antibiotics were administered for empirical treatment before mNGS in 17 patients but showed no improvement. The treatment was switched to doxycycline or moxifloxacin immediately since psittacosis pneumonia were suspected and confirmed by mNGS detection (within 48 hours). After receiving adjustment of treatment, 94.23% (49/52) of patients were cured successfully.

Conclusions

In conclusion, mNGS may be a promising approach for clinical diagnosis of psittacosis. For patients with a history of exposure to birds, hyperpyrexia, nonproductive cough, multiple elevated inflammatory markers, and air-space consolidation in lung, psittacosis pneumonia should be considered, especially when beta-lactam antibiotics showed limited efficacy.

Metagenomic next-generation sequencing for the diagnosis of Chlamydia psittaci pneumonia

The aim of this study was to investigate the clinical characteristics of Chlamydia psittaci pneumonia and evaluate the diagnostic value of Metagenomic Next-Generation Sequencing (mNGS). A total of 44 patients diagnosed with Chlamydia psittaci pneumonia using mNGS were retrospectively analysed. The demographic and clinical features, laboratory data, imaging findings and clinical outcomes were collected. Results showed that 65.91% of the patients had a history of exposure to poultry or birds. All patients presented with fever. Apart from systemic and respiratory symptoms, some patients also presented with digestive and neurological symptoms. Respiratory failure was common among patients. The key laboratory tests were normal white blood cell counts, slightly elevated PCT, changes in levels of cardiac enzymes, liver enzymes and hyponatremia. Chest imaging revealed that most of the lesions contained patchy exudation or lobar consolidation of one lobe, especially in the lower lobe. Consolidation of both lungs was seen in critically ill patients. Although quinolones were effective in most patients, tetracyclines should be the first choice of treatment. The overall prognosis was good; however, patients who developed severe pneumonia had poor prognosis. The incidence of chlamydia psittaci pneumonia may be underestimated due to the nonspecific clinical manifestations and lack of confirmatory testing methods. The use of mNGS has increased the number of patients diagnosed with chlamydia psittaci pneumonia. mNGS is an effective diagnostic method for chlamydia psittaci pneumonia.

Metagenomic next-generation sequencing identified psittacosis among poultry processing workers in Shandong Province, China

Human infection with Chlamydia psittaci is rare but difficult to recognize. We report an outbreak of psittacosis among poultry processing workers in China. We applied metagenomic next-generation sequencing and identified Chlamydia psittaci reads from samples of all seven patients, four of which were subsequently confirmed by PCR. Epidemiological results suggested that the poultry processed in the factory was the possible source of human infection.