Detection of Cytomegalovirus in Bronchoalveolar Lavage Fluid from HIV-Positive Individuals with Community Acquired Pneumonia

Pneumocystis jirovecii pneumonia co-infection with cytomegalovirus pneumonia in a patient with acquired immunodeficiency syndrome: A case report and literature review

Cytomegalovirus (CMV) pneumonia is an uncommon presentation of CMV among patients with HIV/AIDS, particularly in co-infection with Pneumocystis jirovecii pneumonia (PCP). A case was reported with a literature review, and a comprehensive literature search was performed using the PubMed/MEDLINE and Scopus databases. We report a 52-year-old male with AIDS presenting with progressively worsening dyspnea over 1 week. One month earlier, he had completed a 21-day course of PCP treatment, showed improvement and was discharged. Two weeks before presentation, he started antiretroviral therapy (ART), but his dyspnea worsened significantly 1 week later. Chest radiography showed bilateral ground glass opacities. Bronchoscopy and lung biopsy revealed nuclear enlargement with prominent intranuclear inclusions and marginated chromatin of alveolar cells on H&E staining, along with positive immunohistochemistry for CMV. Grocott's methenamine silver staining identified 3-5 μm irregular yeast-like organisms resembling crushed ping-pong balls, consistent with P. jirovecii. He was treated with intravenous ganciclovir for a total of 21 days, and his clinical and radiologic findings completely resolved. CMV pneumonia co-infection with PCP is extremely rare and should be considered among patients with severely immunocompromise with interstitial pneumonitis unresponsive to PCP treatment or recurring after treatment.

Inhibition of the PI3K/AKT Signaling Pathway or Overexpression of Beclin1 Blocks Reinfection of Streptococcus pneumoniae After Infection of Influenza A Virus in Severe Community-Acquired Pneumonia

Streptococcus pneumoniae (S. pneumoniae) and viruses are considered as primary risks of community-acquired pneumonia (CAP), and the effects of co-infection bacterial and virus in the prognosis of patients with severe CAP (SCAP) are poorly described. Therefore, this study is conducted to investigate the regulation of Beclin1-PI3K/AKT axis in reinfection of S. pneumoniae after influenza A virus in mice model of bronchoalveolar lavage fluid (BALF). Samples of sputum and BALF were collected from patients with SCAP for etiological detection. The expression of each gene was determined by RT-qPCR and western blot analysis. Influenza A/PR/8/34 and S. pneumoniae were used to establish the mice model of reinfection pneumonia. The virus quantity, expression levels of inflammatory factors, bacterial load, and myeloperoxidase (MPO) activity were tested. HE staining was applied to observe histopathology of lung tissue. The expression of Beclin1 was downregulated and the PI3K/AKT pathway was activated in viral pneumonia. In vivo experiment, the reinfection of S. pneumoniae following influenza A virus infection increased the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice. In contrast, inhibition of the PI3K/AKT pathway or overexpression of Beclin1 reduced the number of S. pneumoniae population, the activity of MPO, and the expression of TNF-α, IL-6, and IFN-γ in BALF of mice reinfected with S. pneumoniae after influenza A virus infection. Collectively, our study demonstrates that inhibition of the PI3K/AKT signaling pathway or overexpressed Beclin1 alleviates reinfection of S. pneumoniae after influenza A virus infection in SCAP.