Department of Respiratory and Critical Care Medicine, West China Hospital, West China Clinical Medical School, Sichuan University, Chengdu, China.
Department of Critical Care Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Front Immunol. 2023 Sep 21;14:1271919. doi: 10.3389/fimmu.2023.1271919. eCollection 2023.
Post-operative etiological studies are critical for infection prevention in lung transplant recipients within the first year. In this study, mNGS combined with microbial culture was applied to reveal the etiological characteristics within one week (ultra-early) and one month (early) in lung transplant recipients, and the epidemiology of infection occurred within one month.
In 38 lung transplant recipients, deep airway secretions were collected through bronchofiberscope within two hours after the operation and were subjected to microbial identification by mNGS and microbial culture. The etiologic characteristics of lung transplant recipients were explored. Within one month, the infection status of recipients was monitored. The microbial species detected by mNGS were compared with the etiological agents causing infection within one month.
The detection rate of mNGS in the 38 airway secretions specimens was significantly higher than that of the microbial culture (P<0.0001). MNGS identified 143 kinds of pathogenic microorganisms; bacterial pathogens account for more than half (72.73%), with gram-positive and -negative bacteria occupying large proportions. Fungi such as are also frequently detected. 5 (50%) microbial species identified by microbial culture had multiple drug resistance (MDR). Within one month, 26 (68.42%) recipients got infected (with a median time of 9 days), among which 10 (38.46%) cases were infected within one week. In the infected recipients, causative agents were detected in advance by mNGS in 9 (34.62%) cases, and most of them (6, 66.67%) were infected within one week (ultra-early). In the infection that occurred after one week, the consistency between mNGS results and the etiological agents was decreased.
Based on the mNGS-reported pathogens in airway secretions samples collected within two hours, the initial empirical anti-infection regimes covering the bacteria and fungi are reasonable. The existence of bacteria with MDR forecasts the high risk of infection within 48 hours after transplant, reminding us of the necessity to adjust the antimicrobial strategy. The predictive role of mNGS performed within two hours in etiological agents is time-limited, suggesting continuous pathogenic identification is needed after lung transplant.
术后病因学研究对于肺移植受者术后 1 年内的感染预防至关重要。本研究应用 mNGS 联合微生物培养，在肺移植受者术后 2 小时内，于超早期（1 周内）和早期（1 月内）揭示病因特征，并分析 1 月内的感染流行病学。
38 例肺移植受者术后 2 小时内行支气管镜检查，留取深部气道分泌物，应用 mNGS 和微生物培养进行微生物鉴定。探索肺移植受者的病因特征。1 个月内监测受者的感染情况。比较 mNGS 检测到的微生物种属与 1 月内感染的病原体。
38 例气道分泌物标本 mNGS 的检测率明显高于微生物培养（P<0.0001）。mNGS 鉴定出 143 种致病微生物；细菌病原体占一半以上（72.73%），革兰阳性和革兰阴性菌占比大。真菌也经常被检测到。微生物培养鉴定的 5 种（50%）微生物种属具有多重耐药性（MDR）。1 个月内 26 例（68.42%）受者发生感染（中位时间 9 天），其中 10 例（38.46%）在 1 周内发生感染。在感染的受者中，9 例（34.62%）通过 mNGS 提前检测到病原体，其中 6 例（66.67%）在 1 周内（超早期）发生感染。在 1 周后发生的感染中，mNGS 结果与病原体的一致性降低。
基于术后 2 小时内气道分泌物样本中 mNGS 报告的病原体，覆盖细菌和真菌的初始经验性抗感染方案是合理的。MDR 细菌的存在预测移植后 48 小时内感染的风险较高，提醒我们有必要调整抗菌策略。mNGS 在 2 小时内对病原体的预测作用是有限的，提示肺移植后需要持续进行病原学鉴定。
