Abstract：
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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%.
CONCLUSIONS: These results show that the MAST® D72C test can be a useful tool for the detection of ESBL- and AmpC-production in clinical laboratories.
METHODS: 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.
RESULTS: 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%.
CONCLUSIONS: These results show that the MAST® D72C test can be a useful tool for the detection of ESBL- and AmpC-production in clinical laboratories.
摘要：
目的：MAST®D72C测试是一种表型测试，可以检测肠杆菌中ESBL和AmpC的产生。它还可以识别怀疑存在碳青霉烯酶。本研究的目的是评估该测试的敏感性和特异性，并讨论其在实验室中的有用性。特别是那些只使用自动AST系统的。
方法：MAST®D72C测试的性能是针对一组119个非冗余肠杆菌分离株进行评估的，这些分离株的β-内酰胺酶含量为特征，并与参考双盘协同试验进行了比较。通过表型和基因型分析建立β-内酰胺酶含量，以收集广泛的抗性机制和细菌菌株，包括30个产生ESBL的菌株，32株过量生产染色体AmpC，10株产生质粒编码的AmpC，12个产生碳青霉烯酶的菌株，13个菌株结合了几种β-内酰胺酶的生产，和22株产生其他β-内酰胺酶的菌株。
结果：ESBL检测的灵敏度和特异性与协同试验相当，75对72.5%，和94.9对93.7%，分别。AmpC检测的敏感性和特异性分别为71.7%和100%,分别,如果我们排除耐碳青霉烯类分离株，敏感性达到78.7%。碳青霉烯酶检测灵敏度为90%。
结论：这些结果表明，MAST®D72C测试可以成为临床实验室中检测ESBL-和AmpC-产生的有用工具。
方法：MAST®D72C测试的性能是针对一组119个非冗余肠杆菌分离株进行评估的，这些分离株的β-内酰胺酶含量为特征，并与参考双盘协同试验进行了比较。通过表型和基因型分析建立β-内酰胺酶含量，以收集广泛的抗性机制和细菌菌株，包括30个产生ESBL的菌株，32株过量生产染色体AmpC，10株产生质粒编码的AmpC，12个产生碳青霉烯酶的菌株，13个菌株结合了几种β-内酰胺酶的生产，和22株产生其他β-内酰胺酶的菌株。
结果：ESBL检测的灵敏度和特异性与协同试验相当，75对72.5%，和94.9对93.7%，分别。AmpC检测的敏感性和特异性分别为71.7%和100%,分别,如果我们排除耐碳青霉烯类分离株，敏感性达到78.7%。碳青霉烯酶检测灵敏度为90%。
结论：这些结果表明，MAST®D72C测试可以成为临床实验室中检测ESBL-和AmpC-产生的有用工具。
