宏基因二代测序技术对厌氧菌感染精准化诊断的临床价值

Clinical value of metagenomic next-generation sequencing in precise diagnosis of anaerobic bacteria infection

目的探讨宏基因二代测序技术对厌氧菌感染精准化诊断的临床价值。方法回顾性分析2017年2月-2019年2月复旦大学附属中山医院感染病科收治的16例临床诊断为厌氧菌感染患者的资料。描述其临床特点、比较宏基因二代测序与培养检测外周血、组织匀浆、脓液、灌洗液及无菌体液等标本厌氧菌的阳性率与时间,以阐明宏基因二代基因技术在厌氧菌诊断方面的优势。结果符合入组条件的厌氧菌感染患者共16例。厌氧菌感染部位包括:肺部(8例)、皮肤软组织(2例)、腹腔(1例)、混合部位感染(5例)。同时送厌氧菌培养及宏基因二代测序的微生物标本共29份,标本类型包括:外周血(3份)、组织匀浆(5份)、脓液(11份)、灌洗液(8份)和无菌部位体液(2份)。培养阳性率为20.67%(6/29),宏基因二代测序的阳性率为82.76%(24/29),后者高于前者(P<0.01)。按感染部位分层,肺部感染的标本中宏基因二代测序病原体检出的阳性率为71.43%(10/14)高于培养阳性率7.14%(1/14)(P<0.01);按标本类型分层,发现两种方法检测组织匀浆、脓液和灌洗液时宏基因二代测序的阳性率分别为80.00%(4/5)、100.00%(11/11)和62.50%(5/8),均高于培养阳性率(P<0.05)。二代测序的平均检测时间为(39.66±15.09)h短与培养(81.21±37.94)h(P<0.01)。结论宏基因二代测序技术对厌氧菌感染的病原体评估较培养更敏感、更快捷,在厌氧菌感染的精准化诊断方面具有优势。

OBJECTIVE To access the clinical value of metagenomic next-generation sequencing(mNGS) in precise diagnosis of anaerobic bacteria infection. METHODS The data of 16 patients who were clinically diagnosed with anaerobic bacteria infection and treated in Zhongshan Hospital of Fudan University from Feb 2017 to Feb 2019 were retrospectively analyzed, the clinical characteristics of the patients were described, and the positive rates and time of detection of anaerobic bacteria in samples such as peripheral blood, tissue homogenate, pus, bronchoalveolar lavage fluid and pleural fluid were compared between the mNGS and bacterial culture so as to clarify the advantages of mNGS in diagnosis of anaerobic bacteria. RESULTS Totally 16 patients with anaerobic infections were eligible for enrollment, 8 of whom had pulmonary infection, 2 had skin and soft tissue infection, 1 had abdominal infection, and 5 had mixed sites of infection. A total of 29 microbial specimens were submitted for culture of anaerobic bacteria culture and mNGS, including 3 peripheral blood specimens, 5 tissue homogenate specimens, 11 pus specimens, 8 bronchoalveolar lavage fluid specimens and 2 pleural fluid. The positive rate of the culture was 20.67%(6/29),significantly lower than 82.76%( 24/29) of mNGS(P<0.01). After stratification for the infection sites, the positive rate of detection of pathogens in the specimens of the patients with pulmonary infection was 71.43%(10/14) by mNGS, significantly higher than 7.14%(1/14)by the culture(P<0.01). After the stratification for the samples, the positive rates of mNGS were respectively 80.00%(4/5), 100.00%(11/11) and 62.50%(5/8) in detection of tissue homogenate, pus and bronchoalveolar lavage fluid, significantly higher than those of the culture(P<0.05). The average turn around time of mNGS was(39.66±15.09)hours, significantly shorter than(81.21±37.94)hours of the culture(P<0.01). CONCLUSION mNGS is more sensitive and less time consuming than the conventional culture in evaluating the pathogens causing the anaerobic bacteria infections, thus achieving a better performance for precise diagnosis of the anaerobic bacteria infection.