Bernabeu Sandrine, Ratnam Kayaththiry Caroline, Boutal Hervé, Gonzalez Camille, Vogel Anaïs, Devilliers Karine, Plaisance Marc, Oueslati Saoussen, Malhotra-Kumar Surbhi, Dortet Laurent, Fortineau Nicolas, Simon Stéphanie, Volland Hervé, Naas Thierry
Team Resist, UMR1184, School of Medicine of Université Paris-Saclay-INSERM-CEA, LabEx Lermit, 94276 Le Kremlin-Bicêtre, France.
Bacteriology-Hygiene Unit, APHP, Hôpital Bicêtre, 94270 Le Kremlin-Bicêtre, France.
Diagnostics (Basel). 2020 Sep 28;10(10):764. doi: 10.3390/diagnostics10100764.
We have developed a lateral flow immunoassay (LFIA), named NG-Test CTX-M MULTI (NG-Test), to detect group 1, 2, 8, 9, 25 CTX-M producers from agar plates and from positive blood cultures in less than 15 min. The NG-Test was validated retrospectively on 113 well-characterized enterobacterial isolates, prospectively on 102 consecutively isolated ESBL-producers from the Bicêtre hospital and on 100 consecutive blood cultures positive with a gram-negative bacilli (GNB). The NG-Test was able to detect all CTX-M producers grown on the different agar plates used in clinical microbiology laboratories. No false positive nor negative results were observed. Among the 102 consecutive ESBL isolates, three hyper mucous isolates showed an incorrect migration leading to invalid results (no control band). Using an adapted protocol, the results could be validated. The NG-Test detected 99/102 ESBLs as being CTX-Ms. Three SHV producers were not detected. Among the 100 positive blood cultures with GNB tested 10/11 ESBL-producers were detected (8 CTX-M-15, 2 CTX-M-27). One SHV-2-producing- was missed. The NG-Test CTX-M MULTI showed 100% sensitivity and specificity with isolates cultured on agar plates and was able to detect 98% of the ESBL-producers identified in our clinical setting either from colonies or from positive blood cultures.
我们开发了一种名为NG-Test CTX-M MULTI（NG-Test）的侧向流动免疫分析方法，可在不到15分钟的时间内从琼脂平板和阳性血培养物中检测出第1、2、8、9、25组CTX-M产生菌。NG-Test在113株特征明确的肠杆菌分离株上进行了回顾性验证，在Bicêtre医院连续分离的102株产超广谱β-内酰胺酶（ESBL）菌株以及100株革兰氏阴性杆菌（GNB）血培养阳性样本上进行了前瞻性验证。NG-Test能够检测出临床微生物实验室使用的不同琼脂平板上生长的所有CTX-M产生菌。未观察到假阳性或假阴性结果。在102株连续的ESBL分离株中，有3株高黏液分离株显示迁移不正确，导致结果无效（无对照带）。采用改良方案后，结果可得到验证。NG-Test检测出102株ESBL中有99株为CTX-M型。3株SHV产生菌未被检测到。在100株GNB血培养阳性样本中，检测出10/11株产ESBL菌（8株CTX-M-15，2株CTX-M-27）。1株产SHV-2的菌株未被检测到。NG-Test CTX-M MULTI对琼脂平板上培养的分离株显示出100%的敏感性和特异性，并且能够检测出我们临床环境中从菌落或阳性血培养物中鉴定出的98%的产ESBL菌。
