Aupaix Antoine, Lamraoui Kamila, Rodriguez-Villalobos Hector, Anantharajah Ahalieyah, Verroken Alexia
Microbiology Department, Cliniques universitaires Saint-Luc, Brussels, Belgium.
Front Microbiol. 2024 Oct 16;15:1480687. doi: 10.3389/fmicb.2024.1480687. eCollection 2024.
Antimicrobial susceptibility testing (AST) using broth microdilution (BMD) is usually the reference method to obtain accurate minimum inhibitory concentrations and optimally manage infections with resistant organisms. Several commercial dry BMD are available for AST in clinical laboratories.
Two commercial BMD panels for testing of multidrug-resistant Gram-negative bacteria were compared: the Thermo Scientific™ Sensititre DKMGN and the Beckman Coulter NMDRM1, for 17 antimicrobial agents.
A total of 207 isolates were tested: three ATCC strains and one NCTC strain, six quality control strains from the Belgian National Antimicrobial Committee, and 197 clinical isolates, including carbapenem-resistant , , and . The European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2023 breakpoints version 13.1 were used to assign susceptibility categories.
Overall, the categorical agreement (CA) and essential agreement (EA) were both above 90%, but several useful antibiotics for the treatment of multi-resistant organisms showed CA and EA under 90%, that is, meropenem, imipenem, and colistin for and and colistin for . For , the NMDRM1 panel showed a significantly higher resistance rate for meropenem, imipenem, amikacin, and colistin. For carbapenems, the minimal inhibitory concentrations (MICs) were underestimated by the DKMGN panel, as already pointed out by a warning on the EUCAST website. To better assess carbapenem susceptibility in carbapenem-resistant organisms, the DKMGN panel now requires the use of a higher inoculum in the insert kit. However, for a given isolate whose susceptibility to carbapenems is not known, there is a risk of underestimating the MIC values. Our results show that colistin testing remains a challenge, highlighting the urgent need for the development of more accurate commercial methods. The use of a single commercial method cannot guarantee good precision in the determination of the MIC value for colistin.
使用肉汤微量稀释法（BMD）进行抗菌药物敏感性试验（AST）通常是获得准确最低抑菌浓度并优化耐药菌感染管理的参考方法。临床实验室中有几种用于AST的商业干式BMD。
比较了两种用于检测多重耐药革兰氏阴性菌的商业BMD板：赛默飞世尔科技™ Sensititre DKMGN和贝克曼库尔特NMDRM1，用于检测17种抗菌药物。
共检测了207株菌株：3株ATCC菌株和1株NCTC菌株、6株来自比利时国家抗菌委员会的质量控制菌株以及197株临床分离株，包括耐碳青霉烯类的 、 和 。采用欧洲抗菌药物敏感性试验委员会（EUCAST）2023年第13.1版的折点来划分敏感性类别。
总体而言，分类一致性（CA）和基本一致性（EA）均高于90%，但几种用于治疗多重耐药菌的常用抗生素的CA和EA低于90%，即美罗培南、亚胺培南和黏菌素用于 以及黏菌素用于 。对于 ，NMDRM1板显示美罗培南、亚胺培南、阿米卡星和黏菌素的耐药率显著更高。对于碳青霉烯类药物，如EUCAST网站上的一则警告所指出的，DKMGN板低估了最低抑菌浓度（MIC）。为了更好地评估耐碳青霉烯类菌中的碳青霉烯类药物敏感性，DKMGN板现在需要在插入试剂盒中使用更高的接种量。然而，对于一株对碳青霉烯类药物敏感性未知的特定分离株，存在低估MIC值的风险。我们的结果表明，黏菌素检测仍然是一项挑战，凸显了开发更准确商业方法的迫切需求。使用单一商业方法无法保证在测定黏菌素的MIC值时具有良好的精密度。
