Breakpoint beware: reliance on historical breakpoints for Enterobacteriaceae leads to discrepancies in interpretation of susceptibility testing for carbapenems and cephalosporins and gaps in detection of carbapenem-resistant organisms
Breakpoint beware: reliance on historical breakpoints for Enterobacteriaceae leads to discrepancies in interpretation of susceptibility testing for carbapenems and cephalosporins and gaps in detection of carbapenem-resistant organisms
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DOI：
10.1007/s10096-019-03711-y
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发表时间：
2019-11-02
影响因子：
4.5
通讯作者：
Burnham, Carey-Ann D.
中科院分区：
文献类型：
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作者：
Yarbrough, Melanie L.;Wallace, Meghan A.;Burnham, Carey-Ann D.
耐碳青霉烯类肠杆菌科（CRE）是一个重要的公共卫生和感染预防威胁。CRE通常通过表型抗菌药物敏感性试验（AST）检测，近年来对其解释标准进行了修改。我们的目的是测量断点变化对CRE AST解释的影响。评价了1年内从临床培养物中回收的肠杆菌科分离株（n = 10，183）的纸片扩散AST的条带大小以及来自美国和巴基斯坦的临床和环境来源的CRE（n = 342）。根据历史（CLSI M100-S19）和当前（CLSI M100-S29）折点解释结果。根据FDA定义计算判读误差。使用当前折点作为参考标准，使用肠杆菌科临床分离株的历史折点，头孢吡肟发生了56例（17%）非常重大（假敏感性）错误，美罗培南解释发生了13例（45%）非常重大错误，对应于1年期间遗漏的12例产碳青霉烯酶CRE。对于确认的bla（KPC）CP-CRE临床和环境分离株（n = 149），头孢吡肟、美罗培南、亚胺培南和厄他培南的历史折点的非常重大错误率分别为8%、30%、63%和0%。对于bla（KPC）分离株，使用历史折点将导致42份（28%）美罗培南假敏感性报告。未能采用更新的AST折点可能导致对常用于治疗革兰氏阴性菌感染的抗菌药物的假敏感性报告，并妨碍对CRE的识别。这些错误可能会对患者护理产生负面影响，并妨碍感染控制和公共卫生工作。
Carbapenem-resistant Enterobacteriaceae (CRE) are an important public health and infection prevention threat. CRE are typically detected via phenotypic antimicrobial susceptibility testing (AST), for which interpretive standards were modified in recent years. Our objective was to measure the impact of breakpoint changes on AST interpretation for CRE. Zone sizes from disk diffusion AST for Enterobacteriaceae isolates recovered from clinical cultures over a 1-year period (n = 10,183) and CRE from clinical and environmental sources from the USA and Pakistan (n = 342) were evaluated. Results were interpreted according to historical (CLSI M100-S19) and current (CLSI M100-S29) breakpoints. Interpretive errors were calculated according to the FDA definitions. Using current breakpoints as the reference standard, 56 (17%) very major (false susceptibility) errors occurred for cefepime and 13 (45%) very major errors for meropenem interpretation using historical breakpoints in clinical isolates of Enterobacteriaceae, corresponding to 12 carbapenemase-producing CRE that would have been missed during the 1-year period. For confirmed bla(KPC) CP-CRE clinical and environmental isolates (n = 149), the very major error rate for historic breakpoints was 8%, 30%, 63%, and 0% for cefepime, meropenem, imipenem, and ertapenem, respectively. For bla(KPC) isolates, the use of historical breakpoints would have led to 42 (28%) reports of false susceptibility to meropenem. Failure to adopt updated AST breakpoints may lead to reports of false susceptibility for antimicrobials commonly used to treat Gram-negative infections and preclude recognition of CRE. Such errors could negatively impact patient care and hamper infection control and public health efforts.