Service de Bactériologie-Virologie, INSERM U914 Emerging Resistance to Antibiotics, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris Sud, Le Kremlin-Bicêtre, France.
J Clin Microbiol. 2011 Feb;49(2):718-21. doi: 10.1128/JCM.01773-10. Epub 2010 Dec 1.
Enterobacterial isolates expressing the carbapenemase NDM-1 are emerging worldwide. Twenty-seven NDM-1-positive isolates of worldwide origin were included in this study to identify these strains as not only pathogens but also colonizers of normal flora for infection control screening. Although susceptibility to carbapenems varied, a combined test (IMP/IMP + EDTA), the Etest MBL, and automated susceptibility testing by Vitek2 (bioMérieux) identified those NDM-1 producers as verified by PCR using specific primers. Screening for carriers of NDM-1 producers may be based on media such as the ChromID ESBL culture medium routinely used to screen for extended-spectrum β-lactamase producers, which gives excellent detection levels with low limits of detection ranging from 8 × 10(0) to 5 × 10(2) CFU/ml. The CHROMagar KPC culture medium had higher limits of detection (1 × 10(1) to 5 × 10(5) CFU/ml) and may be proposed for the follow-up of outbreaks of infections with NDM-1 producers. Colonies growing on these screening media can be verified as NDM-1 producers with molecular methods as described herein.
产 NDM-1 肠杆菌科细菌在全球范围内不断出现。本研究纳入了 27 株来自世界各地的 NDM-1 阳性分离株，目的是不仅将这些菌株鉴定为病原体，也鉴定为正常菌群的定植者，以进行感染控制筛查。尽管对碳青霉烯类药物的敏感性存在差异，但联合检测（IMP/IMP+EDTA、Etest MBL 和 Vitek2 自动药敏试验[生物梅里埃]），以及使用特定引物的 PCR 检测，可鉴定出这些 NDM-1 产生菌。NDM-1 产生菌携带者的筛查可能基于常规用于筛选产超广谱β-内酰胺酶菌的培养基，如 ChromID ESBL 培养基，该培养基对低检测限（8×10(0)至 5×10(2)CFU/ml）的检测水平非常出色。CHROMagar KPC 培养基的检测限较高（1×10(1)至 5×10(5)CFU/ml），可能适用于 NDM-1 产生菌感染暴发的后续监测。用本文所述的分子方法可验证在这些筛选培养基上生长的菌落是否为 NDM-1 产生菌。
