Butler-Laporte Guillaume, Yansouni Cedric P, Paquette Katryn, Lawandi Alexander, Stabler Sarah N, Akhter Murtaza, Davidson Adam C, Gavric Marko, Jinah Rehman, Saeed Zahid, Demir Koray, Sangsari Sassan, Huang Kelly, Mahpour Amirali, Shamatutu Chris, Caya Chelsea, Troquet Jean-Marc, Clark Greg, Wong Titus, Lee Todd C, Stenstrom Robert, Sweet David, Cheng Matthew P
Divisions of Infectious Diseases and Medical Microbiology, McGill University Health Centre, Montréal, Québec, Canada.
McGill Interdisciplinary Initiative in Infection and Immunity, McGill University, Montréal, Québec, Canada.
Open Forum Infect Dis. 2020 Aug 23;7(9):ofaa371. doi: 10.1093/ofid/ofaa371. eCollection 2020 Sep.
Of all microbiological tests performed, blood cultures have the most impact on patient care. Timely results are essential, especially in the management of sepsis. While there are multiple available blood culture systems on the market, they have never been compared in a prospective study in a critically ill population.
We performed an analysis of the FABLED study cohort to compare culture results and time to positivity (TTP) of 2 widely used blood culture systems: BacT/Alert and BACTEC. In this multisite prospective study, patients with severe manifestations of sepsis had cultures drawn before antibiotics using systematic enrollment criteria and blood drawing methodology allowing for minimization of pre-analytical biases.
We enrolled 315 patients; 144 had blood cultures (47 positive) with BacT/Alert and 171 with BACTEC (53 positive). Patients whose blood cultures were processed using the BacT/Alert system were younger (median, 64 vs 70 years; = .003), had a higher proportion of HIV (9.03% vs 1.75%; = .008) and a lower qSOFA ( = .003). There were no statistically significant differences in the most commonly identified bacterial species. TTP was shorter for BACTEC (median [interquartile range {IQR}], 12.5 [10-14] hours) compared with BacT/Alert (median [IQR], 17 [14-21] hours; < .0001).
In this large prospective multi-centre study comparing the two blood culture systems among patients with severe manifestations of sepsis, and using a rigorous pre-analytical methodology, the BACTEC system yielded positive culture results 4.5 hours earlier than BacT/Alert. These results apply to commonly isolated bacteria. However, our study design did not allow direct comparison of TTP for unusual pathogens nor of clinical sensitivity between systems. More research is needed to determine the clinical implications of this finding.
在所有进行的微生物学检测中，血培养对患者护理的影响最大。及时获得结果至关重要，尤其是在脓毒症的管理中。虽然市场上有多种可用的血培养系统，但从未在危重症人群中进行过前瞻性研究比较。
我们对FABLED研究队列进行了分析，以比较2种广泛使用的血培养系统（BacT/Alert和BACTEC）的培养结果和阳性时间（TTP）。在这项多中心前瞻性研究中，患有严重脓毒症表现的患者在使用抗生素之前进行培养，采用系统的纳入标准和采血方法，以尽量减少分析前偏倚。
我们纳入了315例患者；144例使用BacT/Alert进行血培养（47例阳性），171例使用BACTEC进行血培养（53例阳性）。使用BacT/Alert系统处理血培养的患者更年轻（中位数，64岁对70岁；P = 0.003），HIV比例更高（9.03%对1.75%；P = 0.008），qSOFA更低（P = 0.003）。在最常鉴定出的细菌种类方面没有统计学显著差异。与BacT/Alert（中位数[四分位间距{IQR}]，17[14 - 21]小时；P < 0.0001）相比，BACTEC的TTP更短（中位数[IQR]，12.5[10 - 14]小时）。
在这项大型前瞻性多中心研究中，对患有严重脓毒症表现的患者比较了两种血培养系统，并采用了严格的分析前方法，BACTEC系统比BacT/Alert早4.5小时获得阳性培养结果。这些结果适用于常见分离细菌。然而，我们的研究设计不允许直接比较不常见病原体的TTP或系统之间的临床敏感性。需要更多研究来确定这一发现的临床意义。
