Strålin Kristoffer, Rothman Richard E, Özenci Volkan, Barkataki Kieron, Brealey David, Dhiman Neelam, Poling Lara, Kurz Michael C, Limaye Ajit P, LoVecchio Frank, Lowery Kristin, Miller Loren G, Moran Gregory J, Overcash J Scott, Parekh Amisha, Peacock W Frank, Rivers Emanuel P, Sims Matthew, Stubbs Amy M, Sundqvist Martin, Ullberg Måns, Carroll Karen C
Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden.
J Clin Microbiol. 2020 Aug 24;58(9). doi: 10.1128/JCM.01860-19.
Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the United States ( = 13) and Europe ( = 3). First, on testing of 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true-positive and 97.2% true-negative results. Second, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC positive and PCR/ESI-MS negative, 4.3%; BC positive and PCR/ESI-MS positive, 10.3%; BC negative and PCR/ESI-MS positive, 15.3%; and BC negative and PCR/ESI-MS negative, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and species, 83%. The specificities were >94% for all individual species. Patients who had received prior antimicrobial medications ( = 603) had significantly higher PCR/ESI-MS positivity rates than patients without prior antimicrobial treatment-31% versus 22% ( < 0.0001)-with pronounced differences for Gram-negative bacteria and species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics to be used with whole blood for detection of bloodstream microorganisms in sepsis.
血培养（BC）常常无法检测出脓毒症患者血流中的微生物。然而，分子诊断技术具有巨大潜力。分子方法聚合酶链反应/电喷雾电离质谱法（PCR/ESI-MS）能够检测全血中数百种不同微生物的DNA。本研究的目的是在一项多中心研究中评估该方法的性能，该研究涵盖了美国的13家教学医院和欧洲的3家教学医院。首先，在对2754份添加或未添加微生物的人工合成全血样本进行检测时，PCR/ESI-MS产生了99.1%的真阳性结果和97.2%的真阴性结果。其次，在1460例疑似脓毒症（脓毒症-2定义）患者中，全血的BC和PCR/ESI-MS检测结果阳性率分别为14.6%和25.6%，结果组合如下：BC阳性且PCR/ESI-MS阴性，占4.3%；BC阳性且PCR/ESI-MS阳性，占10.3%；BC阴性且PCR/ESI-MS阳性，占15.3%；BC阴性且PCR/ESI-MS阴性，占70.1%。与BC相比，PCR/ESI-MS显示出以下敏感性（不包括凝固酶阴性葡萄球菌）：革兰氏阳性菌为58%；革兰氏阴性菌为78%；酵母菌为83%。所有单个菌种的特异性均>94%。接受过先前抗菌药物治疗的患者（n = 603）的PCR/ESI-MS阳性率显著高于未接受过先前抗菌治疗的患者，分别为31%和22%（P < 0.0001），革兰氏阴性菌和酵母菌的差异尤为明显。总之，PCR/ESI-MS在人工合成样本上表现出色。在临床样本上，它显示出高特异性，对革兰氏阴性菌和酵母菌具有中等偏高的敏感性，并且在抗菌治疗期间阳性率升高。这些有前景的结果鼓励进一步开发用于全血检测脓毒症患者血流中微生物的分子诊断技术。
