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

Background: Chlamydia 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 presentation: On 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. Conclusion: C. 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.

Diagnosis of pulmonary hemorrhagic leptospirosis complicated by invasive pulmonary aspergillosis complemented by metagenomic next-generation sequencing: a case report.

Background: Leptospirosis is a bacterial zoonosis with variable clinical manifestations. Pulmonary diffuse hemorrhagic leptospirosis often occurs rapidly and, when not promptly diagnosed and treated, it can be life-threatening. Aspergillus flavus is an opportunistic fungus that is commonly seen in immunosuppressed patients. Invasive pulmonary aspergillosis also progresses rapidly. This case study describes a patient with severe pneumonia caused by pulmonary hemorrhagic leptospirosis combined with invasive pulmonary aspergillosis. We have found almost no clinical reports to date on these two diseases occurring in the same patient. Case presentation: A 73-year-old male arrived at our hospital complaining of fever, general malaise, and hemoptysis that had lasted 4 days. The patient was initially diagnosed with severe pneumonia in the emergency department, but he did not respond well to empiric antibiotics. Subsequently, the patient's condition worsened and was transferred to the ICU ward after emergency tracheal intubation and invasive ventilator. In the ICU, antibacterial drugs were adjusted to treat bacteria and fungi extensively. Although the inflammatory indices decreased, the patient still had recurrent fever, and a series of etiological tests were negative. Finally, metagenomic next-generation sequencing (mNGS) of bronchial alveolar lavage fluid detected Leptospira interrogans and Aspergillus flavus. After targeted treatment with penicillin G and voriconazole, the patient's condition improved rapidly, and he was eventually transferred out of the ICU and recovered. Conclusion: Early recognition and diagnosis of leptospirosis is difficult, especially when a patient is co-infected with other pathogens. The use of mNGS to detect pathogens in bronchial alveolar lavage fluid is conducive to early diagnosis and treatment of the disease, and may significantly improve the prognosis in severe cases.

TNF-α and HMGB1: New Biomarkers of Acute Pulmonary Embolism.

OBJECTIVE: Inflammatory mediators have been implicated in the pathophysiology of acute pulmonary embolism (PE). However, the role of inflammatory mediator activation in the development of pulmonary embolism remains elusive. Here, we determined the reliability of the plasma levels of inflammatory markers tumor necrosis factor-alpha (TNF-α) and high mobility histone 1 (HMGB1) as diagnostic biomarkers of PE. METHODS: Eighty-seven patients with PE and ninety-two healthy adults were enrolled. Plasma levels of TNF-α and HMGB1 were measured before and after anticoagulation treatment using conventional commercialized ELISA. RESULTS: The mean concentrations of plasma TNF-α and HMGB1 in patients with PE before anticoagulation treatment were 3.36- and 2.54-fold higher than those in controls (p<0.0001), respectively. Similar results were obtained in patients with PE before anticoagulation treatment, in which plasma levels of TNF-α and HMGB1 were 3.99- and 1.99-fold higher (p<0.0001), respectively, than in PE patients after anticoagulation treatment. Among the two potential markers, TNF-α performed best in distinguishing patients with PE from controls. A significant positive correlation was found between the two markers' concentrations. CONCLUSIONS: These findings suggest that the plasma levels of TNF-α and HMGB1 may serve as potential biomarkers for PE.

Eosinophilic biomarkers for detection of acute exacerbation of chronic obstructive pulmonary disease with or without pulmonary embolism.

Eosinophilia has been implicated in the pathophysiology of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, the role of eosinophil activation in the development of AECOPD remains unclear. In the present study, the reliability of plasma levels of eosinophil activation markers, including eosinophil cationic protein (ECP), major basic protein (MBP), eosinophil-derived neurotoxin (EDN) and eosinophil peroxidase (EPX), were measured and used as diagnostic biomarkers of AECOPD with or without pulmonary embolism (PE). A total of 47 patients with AECOPD, 30 patients with AECOPD/PE and 35 healthy adults were enrolled in the present study. Plasma levels of ECP, EDN, EPX and MBP were measured using commercial ELISA kits. The mean concentrations of plasma ECP, EDN, EPX and MBP in the patients with AECOPD was significantly 2.87-, 3.06-, 1.60- and 1.92-fold higher, respectively, compared with the control group (P<0.05). Similar results were obtained in patients with AECOPD/PE, for whom plasma levels of ECP, EDN, EPX and MBP were significantly 2.06-, 2.21-, 1.42- and 2.42-fold higher, respectively, compared with the controls (P<0.05). No significant differences were observed in the levels of these proteins between patients with AECOPD or AECOPD/PE. Among the four potential markers, ECP was determined to be the optimal marker for distinguishing patients with AECOPD or AECOPD/PE from the controls. No significant correlation was observed between marker concentrations and gender, age or disease severity. The results of the present study may have clinical applications in the diagnosis of AECOPD using these novel biomarkers.