Investigating the Pulmonary Host Response of Acinetobacter baumannii Infection-Associated Pneumonia by Metagenomic Next-Generation Sequencing

• Published in: Biomedicines Vol. 13; no. 1; p. 142
• Main Authors: Chou, Mu-Jung, Cheng, Chih-Hung, Wang, Hui-Ching, Tsai, Ming-Ju, Sheu, Chau-Chyun, Chang, Wei-An
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.01.2025; MDPI
• Subjects: Acinetobacter baumannii; Actin; Antimicrobial resistance; Bacteria; Bacterial infections; Bacterial pneumonia; Bioinformatics; Bronchus; Causes of; Cytoskeleton; Drug resistance; Enzymes; Ferroptosis; Gene expression; Genes; Genetic aspects; Health aspects; Host-bacteria relationships; immune; Immune response; Infections; Information processing; Lavage; Lungs; Metagenomics; Metallo-β-lactamase; mNGS; NDM; Next-generation sequencing; Pathogens; Patients; Physiological aspects; Pneumonia; pulmonary host response; Signal transduction; Taiwan; United States > US; China; Shenzhen China; Acinetobacter baumannii; ferroptosis; immune; NDM; pulmonary host response; mNGS
• DOI: 10.3390/biomedicines13010142
• ISSN: 2227-9059

Background: For investigating the host response in Acinetobacter baumannii associated pneumonia, we analyzed the host genetic sequences obtained from metagenomic next-generation sequencing (mNGS). Methods: The samples for mNGS were bronchoalveolar lavage fluid (BALF) collected from the lungs of patients infected with A. baumannii and from patients without bacterial infections. BALF samples from patients with pneumonia were collected from the lungs of patients infected with A. baumannii with New Delhi metallo-β-lactamase (NDM, before treatment), A. baumannii with NDM (post-treatment), A. baumannii without resistant genes, and those without bacterial infection. Partek was used for investigating enriched functions and pathways related to the pulmonary host response to pneumonia caused by A. baumannii with NDM infection and A. baumannii without antimicrobial-resistant genes. The STRING was employed for identifying protein interaction pathways related to the pulmonary host response to pneumonia caused by A. baumannii without antimicrobial-resistant genes. Results: In pulmonary host response to pneumonia caused by A. baumannii with NDM, five immune system-related pathways and five pathways related to signal transduction were identified. No significant differences were observed in the immune system and signal transduction pathways in the pulmonary host response to pneumonia caused by A. baumannii without antimicrobial-resistant genes. However, significant differences were noted in the phagosome, ferroptosis, and regulation of the actin cytoskeleton in cellular processes. Conclusions: mNGS provides information not only on pathogen gene expression but also on host gene expression. In this study, we found that pneumonia with A. baumannii carrying the NDM resistance gene triggers stronger immune responses in the lung, while pneumonia with A. baumannii lacking antimicrobial resistance genes is more linked to iron-related pathways.