Introduction

The rapid detection of carbapenemase-producing organisms (CPOs) directly from blood cultures (BCs) positive for Gram-negative bacilli (GNB) may accelerate the appropriate treatment of at-risk patients.

Objective

To evaluate the performance of two commercial assays in the rapid detection of CPOs directly from BC positive for GNB.

Methods

BC positive for GNB were tested for the presence of CPOs with β CARBA® and NG-Test® CARBA 5. A subset of sterile BC samples was seeded with multidrug-resistant (MDR) GNB. Positive BCs from clinical and seeded samples were tested directly with β CARBA and CARBA 5 from BC pellets.

Results

Sixty-five samples were tested (30 clinical, 35 seeded). β CARBA had a sensitivity, specificity, NPV, and PPV of 100%, 65.7%, 100%, and 71.4%, respectively. CARBA 5 had a sensitivity, specificity, NPV, and PPV of 90.0%, 100%, 92.1%, and 100%. False negatives for CARBA 5 occurred with 1 GES, 1 VIM-1, and 1 IMP-14.

Conclusions

This study demonstrates that the detection of CPOs directly from positive BC can be accurately achieved. β CARBA had excellent sensitivity but suffered from poor specificity. CARBA 5 had good sensitivity and specificity but is unable to detect certain CPOs.

中文翻译：

---

直接从革兰氏阴性杆菌阳性的血液培养物中快速检测出产生碳青霉烯酶的生物。

介绍

直接从革兰氏阴性杆菌（GNB）阳性的血液培养物（BCs）中快速检测出产生碳青霉烯酶的生物（CPO），可能会加快对高危患者的适当治疗。

目的

为了评估直接从BC阳性的BC的CPO快速检测中两种商业检测方法的性能。

方法

用βCARBA®和NG-Test®CARBA 5测试了GNB阳性的BC是否存在CPO。将一部分无菌BC样品接种了耐多药（MDR）GNB。使用来自BC颗粒的βCARBA和CARBA 5直接测试来自临床和接种样品的阳性BC。

结果

测试了65个样本（30个临床样本，35个种子）。βCARBA的敏感性，特异性，NPV和PPV分别为100％，65.7％，100％和71.4％。CARBA 5的敏感性，特异性，NPV和PPV分别为90.0％，100％，92.1％和100％。CARBA 5的假阴性发生于1 GES，1 VIM-1和1 IMP-14。

结论

这项研究表明，可以准确地直接从阳性BC检测CPO。βCARBA具有极好的敏感性，但特异性较差。CARBA 5具有良好的敏感性和特异性，但无法检测某些CPO。