Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
Asia Pacific Influenza Institute, Korea University College of Medicine, Seoul, Republic of Korea.
Medicine (Baltimore). 2024 Aug 2;103(31):e38988. doi: 10.1097/MD.0000000000038988.
Carbapenem-resistant Acinetobacter baumannii (CRAB) pneumonia has been a serious problem in the intensive care unit (ICU). However, defined characteristics of respiratory microbiome in CRAB pneumonia are lacking nowadays. This study aimed to analyze respiratory microbiome of CRAB pneumonia compared to non-CRAB pneumonia and reveal the clinical significance of respiratory microbiome data in these patients. Patients diagnosed with severe pneumonia with mechanical ventilation were enrolled in the ICU of a tertiary care hospital. Respiratory specimens were collected on days 1, 4, 7, and 14 in each participant via tracheal aspiration. Clinical data and outcomes of each enrolled patient were collected via electronic medical records. Microbiome analysis was conducted with collected respiratory specimens undergone by next-generation sequencing of microbial 16S ribosomal DNA. Six CRAB pneumonia, 4 non-CRAB pneumonia and 5 healthy controls were enrolled. In CRAB pneumonia, CRAB was detected in 3 patients by sputum culture at day 1, while it was negative at day 1 and detected later in the others by follow-up sputum culture. Beta diversity plot analysis showed differences between each group. Shannon index was decreased markedly at day 4 in CRAB pneumonia compared to the others. Among CRAB pneumonia cases, 3 respiratory specimens were culture-negative, but positive by microbiome analysis. Lower respiratory microbiome in CRAB pneumonia had distinct characteristics and early loss of diversity compared to non-CRAB pneumonia, which might be related to poor clinical course. Moreover, CRAB acquisition and colonization would be predicted by preemptive microbiome analysis, which will contribute to effective infection control in the ICU.
耐碳青霉烯鲍曼不动杆菌（CRAB）肺炎是重症监护病房（ICU）的一个严重问题。然而，目前缺乏对 CRAB 肺炎呼吸微生物组特征的明确描述。本研究旨在分析 CRAB 肺炎与非 CRAB 肺炎患者的呼吸微生物组，并揭示这些患者呼吸微生物组数据的临床意义。
在一家三级医院的 ICU 中，纳入了被诊断为患有机械通气的严重肺炎的患者。通过气管抽吸，在每位患者的第 1、4、7 和 14 天收集呼吸标本。通过电子病历收集每位入组患者的临床数据和结局。通过对采集的呼吸标本进行微生物 16S 核糖体 DNA 的下一代测序来进行微生物组分析。共纳入 6 例 CRAB 肺炎、4 例非 CRAB 肺炎和 5 例健康对照者。在 CRAB 肺炎中，3 例患者在第 1 天的痰培养中检测到 CRAB，而在其他患者中，在第 1 天为阴性，通过后续的痰培养检测到。β多样性图分析显示了各组之间的差异。与其他组相比，CRAB 肺炎组在第 4 天的 Shannon 指数显著下降。在 CRAB 肺炎病例中，有 3 例呼吸标本培养阴性，但通过微生物组分析呈阳性。与非 CRAB 肺炎相比，CRAB 肺炎患者的下呼吸道微生物组特征明显不同，多样性早期丧失，这可能与不良的临床病程有关。此外，通过预先的微生物组分析可以预测 CRAB 的获得和定植，这将有助于 ICU 中的有效感染控制。
