Teaching Hospital of Clermont-Ferrand, Clermont-Ferrand, France.
M2ISH, UMR 1071 Inserm 1071 Usc INRAE 1382, Université Clermont Auvergne, Clermont-Ferrand, France.
Eur J Clin Microbiol Infect Dis. 2024 Jun;43(6):1181-1192. doi: 10.1007/s10096-024-04829-4. Epub 2024 Apr 25.
The MAST® D72C test is a phenotypical test which can detect ESBL and AmpC production in Enterobacterales. It can also identify the suspected presence of carbapenemase. The aim of the present study was to assess the sensitivity and specificity of this test and to discuss its usefulness in laboratories, especially those that use only an automated AST system.
The performance of the MAST® D72C test was assessed against a collection of 119 non-redundant Enterobacterales isolates characterized for their content in β-lactamases, and compared with that of the reference double disk synergy test. β-lactamase content was established from phenotypic and genotypic analyses to collect a broad diversity of resistance mechanisms and bacterial strains, including 30 ESBL-producing strains, 32 strains overproducing chromosomal AmpC, 10 strains producing plasmid-encoded AmpC, 12 carbapenemase-producing strains, 13 strains combining the production of several β-lactamases, and 22 strains that produced other β-lactamases.
The sensitivity and specificity for ESBL-detection were comparable with those of the synergy test, 75 versus 72.5%, and 94.9 versus 93.7%, respectively. The sensitivity and specificity for AmpC-detection were 71.7% and 100%, respectively, and sensitivity reached 78.7% if we excluded carbapenem-resistant isolates. Carbapenemase-detection sensitivity was 90%.
These results show that the MAST® D72C test can be a useful tool for the detection of ESBL- and AmpC-production in clinical laboratories.
MAST® D72C 测试是一种表型测试，可检测肠杆菌科中 ESBL 和 AmpC 的产生。它还可以鉴定碳青霉烯酶的可疑存在。本研究的目的是评估该测试的灵敏度和特异性，并讨论其在实验室中的实用性，特别是那些仅使用自动化 AST 系统的实验室。
对 119 种非冗余肠杆菌科分离株进行了 MAST® D72C 测试的性能评估，这些分离株的β-内酰胺酶含量特征与参考双碟协同试验进行了比较。通过表型和基因型分析确定β-内酰胺酶含量，以收集广泛的耐药机制和细菌菌株，包括 30 株产 ESBL 株、32 株染色体 AmpC 过度产生株、10 株产质粒编码 AmpC 株、12 株产碳青霉烯酶株、13 株联合产生多种β-内酰胺酶株和 22 株产生其他β-内酰胺酶株。
ESBL 检测的灵敏度和特异性与协同试验相当，分别为 75%和 72.5%，94.9%和 93.7%。AmpC 检测的灵敏度和特异性分别为 71.7%和 100%，如果排除耐碳青霉烯的分离株，灵敏度可达 78.7%。碳青霉烯酶检测的灵敏度为 90%。
这些结果表明，MAST® D72C 测试可以成为临床实验室检测 ESBL 和 AmpC 产生的有用工具。
