肠杆菌科中检测质粒介导和染色体编码的黏菌素耐药性方法的比较。

Comparison of methods for detection of plasmid-mediated and chromosomally encoded colistin resistance in Enterobacteriaceae.

机构信息

Laboratory of Bacteriology, Bordeaux University Hospital, France; CNRS UMR5234, University of Bordeaux, Bordeaux, France; Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland; INSERM European Unit (LEA, IAME), Paris, France.

Emerging Antibiotic Resistance Unit, Medical and Molecular Microbiology, Department of Medicine, University of Fribourg, Fribourg, Switzerland; INSERM European Unit (LEA, IAME), Paris, France; University of Lausanne and University Hospital Center, Lausanne, Switzerland.

出版信息

Clin Microbiol Infect. 2018 Feb;24(2):175-179. doi: 10.1016/j.cmi.2017.06.002. Epub 2017 Jun 9.

DOI:10.1016/j.cmi.2017.06.002

PMID:28606644

Abstract

OBJECTIVES

Because of the emergence of plasmid-mediated (mcr-1 and mcr-2 genes) and chromosomally encoded colistin resistance, reliable methods for detecting colistin resistance/susceptibility in routine laboratories are required. We evaluated the respective performances of the BD Phoenix automated system, the newly developed Rapid Polymyxin NP test and the broth microdilution (BMD) reference method to detect colistin resistance in Enterobacteriaceae, and particularly those producing mcr-1 and mcr-2.

METHODS

Colistin susceptibility of 123 enterobacterial clinical isolates (40 colistin-susceptible and 83 colistin-resistant isolates) was tested with the BD Phoenix automated system, the Rapid Polymyxin NP test and the BMD method. Molecular mechanisms responsible for plasmid-mediated and chromosomally encoded colistin resistance mechanisms were investigated by PCR and sequencing.

RESULTS

Considering BMD as a reference method, the BD Phoenix system failed to detect ten colistin-resistant isolates (one Escherichia coli, one Klebsiella pneumoniae, seven Enterobacter species and one Salmonella enterica). The Rapid Polymyxin NP test failed to detect the same single E. coli isolate. Those two latter methods detected the 16 E. coli, K. pneumoniae and S. enterica isolates producing the plasmid-encoded mcr-1 and mcr-2.

CONCLUSIONS

The BD Phoenix system and the Rapid Polymyxin NP test are reliable techniques for detecting plasmid-mediated mcr-1 and mcr-2-related colistin resistance. However, a high rate of false susceptibility was observed with the BD Phoenix system, indicating that susceptibility results obtained with that system should be confirmed by BMD method. By contrast, the Rapid Polymyxin NP test showed a good agreement with the BMD method, and results were obtained rapidly (within 2 hours). The BMD method should be performed if minimum inhibitory concentration values are needed.

摘要

目的

由于质粒介导（mcr-1 和 mcr-2 基因）和染色体编码的多粘菌素耐药性的出现，需要在常规实验室中使用可靠的方法来检测多粘菌素耐药性/敏感性。我们评估了 BD Phoenix 自动化系统、新开发的 Rapid Polymyxin NP 检测和肉汤微量稀释（BMD）参考方法在检测肠杆菌科中的多粘菌素耐药性的各自性能，特别是那些产生 mcr-1 和 mcr-2 的肠杆菌科。

方法

使用 BD Phoenix 自动化系统、Rapid Polymyxin NP 检测和 BMD 方法检测 123 株肠杆菌临床分离株（40 株多粘菌素敏感和 83 株多粘菌素耐药分离株）的多粘菌素敏感性。通过 PCR 和测序研究了质粒介导和染色体编码的多粘菌素耐药机制的分子机制。

结果

以 BMD 为参考方法，BD Phoenix 系统未能检测到 10 株多粘菌素耐药分离株（1 株大肠埃希菌、1 株肺炎克雷伯菌、7 株肠杆菌属和 1 株肠炎沙门菌）。Rapid Polymyxin NP 检测未能检测到相同的单一 E. coli 分离株。这两种方法检测到 16 株产质粒编码 mcr-1 和 mcr-2 的大肠埃希菌、肺炎克雷伯菌和肠炎沙门菌分离株。

结论

BD Phoenix 系统和 Rapid Polymyxin NP 检测是检测质粒介导的 mcr-1 和 mcr-2 相关多粘菌素耐药性的可靠技术。然而，BD Phoenix 系统观察到较高的假敏感性率，表明该系统获得的药敏结果应通过 BMD 方法确认。相比之下，Rapid Polymyxin NP 检测与 BMD 方法具有良好的一致性，并且结果可以在 2 小时内快速获得。如果需要最小抑菌浓度值，则应进行 BMD 方法。