Microbiology Laboratory, CUB-Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
Laboratoire de Microbiologie, CHU Mont-Godinne, Université Catholique de Louvain, 5530, Yvoir, Belgium.
Eur J Clin Microbiol Infect Dis. 2018 Jan;37(1):109-116. doi: 10.1007/s10096-017-3108-3. Epub 2017 Sep 27.
The purpose of this study was evaluation of the VAPChip assay based on the "Rapid-Array-PCR-technology" which targets 13 respiratory pathogens and 24 β-lactam resistance genes directly on respiratory clinical specimens. The first step included analysis of 45 respiratory specimens in order to calibrate and determine the threshold for target genes. The second prospective step involved 85 respiratory samples from patients suspected of nosocomial pneumonia collected in two academic hospitals over an 8-month period. Results of the VAPChip assay were compared to routine methods. The first step showed a large proportion of positive signals for H. influenzae and/or S. pneumoniae. For identification, discrepancies were observed in seven samples. Thresholds were adapted and two probes were re-designed to create a new version of the cartridge. In the second phase, sensitivity and specificity of the VAPchip for bacterial identification were 72.9% and 99.1%, respectively. Seventy (82%) pathogens were correctly identified by both methods. Nine pathogens detected by the VAPChip were culture negative and 26 pathogens identified by culture were VAPChip negative. For resistance mechanisms, 11 probes were positive without identification of pathogens with an antimicrobial-susceptibility testing compatible by culture. However, the patient's recent microbiological history was able to explain most of these positive signals. The VAPChip assay simultaneously detects different pathogens and resistance mechanisms directly from clinical samples. This system seems very promising but the extraction process needs to be automated for routine implementation. This kind of rapid point-of-care automated platform permitting a syndromic approach will be the future challenge in the management of infectious diseases.
本研究的目的是评估基于“快速阵列-PCR 技术”的 VAPChip 检测方法，该方法直接针对呼吸道临床标本中的 13 种呼吸道病原体和 24 种β-内酰胺类耐药基因。第一步包括分析 45 个呼吸道标本，以校准和确定靶基因的阈值。第二步包括在 8 个月的时间里，从两所学术医院疑似医院获得性肺炎的 85 个呼吸道样本。VAPChip 检测结果与常规方法进行了比较。第一步显示了流感嗜血杆菌和/或肺炎链球菌的阳性信号比例较大。为了进行鉴定，在 7 个样本中观察到了差异。阈值进行了调整，两个探针被重新设计，以创建一个新的试剂盒版本。在第二阶段，VAPchip 对细菌鉴定的敏感性和特异性分别为 72.9%和 99.1%。两种方法均正确识别了 70（82%）种病原体。VAPChip 检测到的 9 种病原体培养阴性，而培养鉴定的 26 种病原体 VAPChip 检测阴性。对于耐药机制，11 个探针呈阳性，而培养物与抗菌药物敏感性试验相兼容的病原体未被识别。然而，患者最近的微生物病史能够解释大多数这些阳性信号。VAPChip 检测方法可直接从临床样本中同时检测不同的病原体和耐药机制。该系统似乎很有前途，但提取过程需要自动化，以便常规实施。这种快速床边自动化平台允许进行综合征方法将是传染病管理未来的挑战。
