Table 2_Precise pathogen detection and clinical characterization of bronchiectasis.xlsx

IntroductionThis study aims to evaluate the utility of molecular diagnostic techniques in identifying pathogens in bronchiectasis and to investigate the differences in clinical characteristics and pathogen distribution among patients with different microbial infections.
MethodsThis retrospective study collected and analyzed clinical data and lower respiratory tract pathogen detection results from 410 patients with bronchiectasis admitted to the Anning First People’s Hospital Affiliated to Kunming University of Science and Technology, between August 2020 and August 2024. By comparing molecular diagnostic methods with conventional culture, we assessed differences in pathogen detection rates and spectrum, evaluated the diagnostic performance of molecular techniques relative to traditional methodologies, and analyzed the clinical characteristics of bronchiectasis patients with different microbiological etiologies.
ResultsCompared with conventional microbiological testing (CMT), molecular diagnostics demonstrated significantly higher sensitivity, positive predictive value, and negative predictive value. The most frequently detected bacteria were Haemophilus influenzae (26.83%), Pseudomonas aeruginosa (14.88%), Streptococcus pneumoniae (13.17%), Klebsiella pneumoniae (9.02%), and Staphylococcus aureus (4.39%). Patients infected with P. aeruginosa had significantly lower body mass index (BMI) compared to those infected with H. influenzae, as well as more severe lung function impairment. Inflammatory markers, including white blood cell (WBC) count and C-reactive protein (CRP), were significantly higher in the P. aeruginosa group than in the H. influenzae group. In terms of pathogen detection, the conventional culture positivity rate was significantly higher in the P. aeruginosa group compared to the H. influenzae group, whereas the false-negative rate of culture was markedly higher in the H. influenzae group. Molecular diagnostics showed high true-positive rates in both groups, though slightly lower in the P. aeruginosa group than in the H. influenzae group. Furthermore, patients infected with P. aeruginosa had significantly higher rates of respiratory failure, cystic bronchiectasis, and oxygen therapy requirement compared to those infected with H. influenzae.
ConclusionThe application of molecular diagnostic technology has significantly improved the detection rate of pathogens in patients with bronchiectasis, especially for fastidious bacteria and rare pathogens. This method can provide a more comprehensive understanding of the distribution of microorganisms and disease characteristics, shorten the diagnosis cycle, accurately guide anti-infection treatment decisions and assist in prognosis assessment.

引言
本研究旨在评估分子诊断技术在支气管扩张症患者病原体鉴定中的应用价值，并探讨不同微生物感染患者的临床特征与病原体分布差异。
方法
本项回顾性研究收集并分析了2020年8月至2024年8月期间，昆明理工大学附属安宁市第一人民医院收治的410例支气管扩张症患者的临床资料与下呼吸道病原体检测结果。通过对比分子诊断方法与传统培养法，本研究评估了病原体检出率与检出谱的差异，评价了分子诊断技术相较于传统方法的诊断效能，并分析了不同微生物感染病因的支气管扩张症患者的临床特征。
结果
相较于传统微生物检测（conventional microbiological testing, CMT），分子诊断的灵敏度、阳性预测值与阴性预测值均显著更高。检出率最高的细菌依次为流感嗜血杆菌（26.83%）、铜绿假单胞菌（14.88%）、肺炎链球菌（13.17%）、肺炎克雷伯菌（9.02%）与金黄色葡萄球菌（4.39%）。铜绿假单胞菌感染患者的体质量指数（body mass index, BMI）显著低于流感嗜血杆菌感染患者，且肺功能损害更为严重。铜绿假单胞菌感染组的炎症标志物水平，包括白细胞（white blood cell, WBC）计数与C反应蛋白（C-reactive protein, CRP），均显著高于流感嗜血杆菌感染组。在病原体检出方面，铜绿假单胞菌感染组的传统培养阳性率显著高于流感嗜血杆菌感染组，而流感嗜血杆菌感染组的培养假阴性率显著更高。分子诊断在两组中均表现出较高的真阳性率，不过铜绿假单胞菌感染组的真阳性率略低于流感嗜血杆菌感染组。此外，相较于流感嗜血杆菌感染患者，铜绿假单胞菌感染患者的呼吸衰竭、囊性支气管扩张症发生率与氧疗需求均显著更高。
结论
分子诊断技术的应用显著提高了支气管扩张症患者的病原体检出率，尤其针对苛养菌与罕见病原体。该方法可更全面地反映微生物分布与疾病特征，缩短诊断周期，精准指导抗感染治疗决策，并辅助预后评估。