Morrissey S M, Nielsen M, Ryan L, Al Dhanhani H, Meehan M, McDermott S, O'Sullivan N, Doyle M, Gavin P, O'Sullivan N, Cunney R, Drew R J
Irish Meningitis and Sepsis Reference Laboratory, Temple Street Children's University Hospital, Dublin 1, Ireland.
Department of Microbiology, University Hospital Waterford, Co. Waterford, Ireland.
Eur J Clin Microbiol Infect Dis. 2017 Jul;36(7):1317-1324. doi: 10.1007/s10096-017-2938-3. Epub 2017 Mar 1.
The aim of this study was to compare an in-house real-time PCR assay, with bacterial culture as the reference, for the diagnosis of late onset group B Streptococcal (GBS) disease. This was a retrospective review. All children aged 7-90 days presenting to four paediatric centres that had a blood or CSF sample tested by GBS PCR were included. Of 7,686 blood and 2,495 cerebrospinal fluid (CSF) samples from patients of all ages received for PCR testing, 893 and 859 samples were eligible for the study, respectively. When compared to culture, the sensitivity of blood PCR was 65% (13/20) in comparison to the CSF PCR test which was 100% (5/5). Ten of 23 PCR-positive blood samples and 17 of 22 PCR-positive CSF samples were culture negative. The median threshold Ct values for culture-positive/PCR-positive CSF samples was lower than that of culture-negative/PCR-positive CSF samples (p = 0.08). Clinical details of 17 available cases that were culture negative/PCR positive were reviewed; seven were deemed to be definite cases, eight were probable and two were possible. The results showed that detection of GBS by PCR is useful for CSF samples from infants aged 7-90 days with suspected meningitis; however, analysis of blood samples by PCR is of limited value as a routine screening test for late onset GBS sepsis and should not replace bacterial culture.
本研究的目的是比较一种内部实时聚合酶链反应（PCR）检测方法与作为参考的细菌培养法，用于诊断晚发型B族链球菌（GBS）疾病。这是一项回顾性研究。纳入了所有在四个儿科中心就诊、其血液或脑脊液样本接受GBS PCR检测的7至90日龄儿童。在所有年龄患者接受PCR检测的7686份血液样本和2495份脑脊液（CSF）样本中，分别有893份和859份样本符合本研究要求。与培养法相比，血液PCR检测的灵敏度为65%（20例中的13例），而脑脊液PCR检测的灵敏度为100%（5例中的5例）。23份PCR阳性血液样本中有10份以及22份PCR阳性脑脊液样本中有17份培养结果为阴性。培养阳性/PCR阳性脑脊液样本的Ct值中位数阈值低于培养阴性/PCR阳性脑脊液样本（p = 0.08）。对17例培养阴性/PCR阳性的现有病例的临床细节进行了回顾；7例被判定为确诊病例，8例为疑似病例，2例为可能病例。结果表明，对于7至90日龄疑似脑膜炎婴儿的脑脊液样本，通过PCR检测GBS是有用的；然而，通过PCR分析血液样本作为晚发型GBS败血症的常规筛查试验价值有限，不应取代细菌培养。
