Abstract：
The positive detection rate of blood metagenomic next-generation sequencing (mNGS) was still too low to meet clinical needs, while pus from the site of primary infection may be advantageous for identification of pathogens. To assess the value of mNGS using pus in patients with sepsis, thirty-five samples were collected. Pathogen identification and mixed infection diagnosis obtained by use of mNGS or cultivation methods were compared. Fifty-three aerobic or facultative anaerobes, 59 obligate anaerobes and 7 fungi were identified by the two methods. mNGS increased the accuracy rate of diagnosing aerobic or facultative anaerobic infections from 44.4% to 94.4%; mNGS also increased the sensitivity of diagnosing obligate anaerobic infections from 52.9% to 100.0%; however, mNGS did not show any advantage in terms of fungal infections. Culture and mNGS identified 1 and 24 patients with mixed infection, respectively. For obligate anaerobes, source of microorganisms was analyzed. The odontogenic bacteria all caused empyema (n = 7) or skin and soft tissue infections (n = 5), whereas the gut-derived microbes all caused intra-abdominal infections (n = 7). We also compared the clinical characteristics of non-obligate anaerobic and obligate anaerobic infection groups. The SOFA score [9.0 (7.5, 14.3) vs. 5.0 (3.0, 8.0), P = 0.005], procalcitonin value [4.7 (1.8, 39.9) vs. 2.50 (0.7, 8.0), P = 0.035], the proportion of septic shock (66.7% vs. 35.3%, P = 0.044) and acute liver injury (66.7% vs. 23.5%, P = 0.018) in the non-obligate anaerobic infection group were significantly higher than those in the obligate anaerobic infection group. In patients with sepsis caused by purulent infection, mNGS using pus from the primary lesion may yield more valuable microbiological information.
摘要：
血液宏基因组下一代测序(mNGS)的阳性检出率仍然太低,不能满足临床需要,而来自原发感染部位的脓液可能有利于病原体的鉴定。评估脓毒症患者使用脓液的mNGS的价值，收集了35个样本。比较了使用mNGS或培养方法获得的病原体鉴定和混合感染诊断。53个需氧或兼性厌氧菌，通过两种方法鉴定出59种专性厌氧菌和7种真菌。mNGS将诊断需氧或兼性厌氧菌感染的准确率从44.4%提高到94.4%；mNGS还将诊断专性厌氧菌感染的敏感性从52.9%提高到100.0%；mNGS在真菌感染方面没有显示任何优势。培养和mNGS确定了1例和24例混合感染患者，分别。对于专性厌氧菌，对微生物来源进行了分析。牙源性细菌均引起脓胸（n=7）或皮肤和软组织感染（n=5），而肠道来源的微生物均引起腹腔感染（n=7）。我们还比较了非专性厌氧和专性厌氧感染组的临床特征。SOFA得分[9.0（7.5，14.3）vs.5.0(3.0,8.0),P=0.005],降钙素原值[4.7（1.8，39.9）与2.50(0.7,8.0),P=0.035],感染性休克的比例(66.7%vs.35.3%,P=0.044）和急性肝损伤（66.7％vs.23.5%,非专性厌氧菌感染组P=0.018)明显高于专性厌氧菌感染组。在化脓性感染引起的败血症患者中，使用原发病灶脓液的mNGS可能会产生更有价值的微生物学信息。
