Table 1.
Target overview of the microarray-based carbapenemases assay.
Table 2.
Carbapenemases genotyping results of the Microarray-based assay in comparison to the genotyping results of carbapenemases genes obtained from different reference laboratories that used standard PCR as Reference method.
Figure 1.
Linear multiplex DNA amplification, labeling and hybridization with the ArrayStrips.
(a) Linear Multiplex Amplification starting from clonal RNA-free genomic DNA. Extracted DNA is internally labeled with biotin (Label [L]) and amplified in a linear multiplex PCR reaction; (b) Hybridization: the internally biotin labeled, single-stranded DNA product hybridizes specifically under stringent conditions to the corresponding probes. The resulting duplex is detected using a horse-radish peroxidase (Enzyme [E]) – streptavidin conjugate, which causes the dye to precipitate ([S]). (c) Detection: the ArrayMate Reader (or ArrayTube Reader ATR 03) enables the visualization and subsequently automated analysis of the array image. The presence of a dark precipitated spot indicates successful hybridization; (d) Analysis: the assay specific software analysis script coming with the ArrayMate Reader (or ArrayTube Reader ATR 03), measures the signal intensity of each probe and determines which genes/alleles are present in the sample by means of an assay specific algorithm. (e) Genotype analysis: a software plugin coming with the ArrayMate Reader (or ArrayTube Reader ATR 03) analyzed the raw data automatically, finally a report is provided on the detected carbapenemases genes.
Table 3.
Additional lactamases detected by the microarray in comparison to conducted control PCRs.
Table 4.
Species genotyping results of the Microarray-based assay in comparison to the Reference method (phenotypic results were obtained from University Medical Center of Dresden, University Medical Center of Jena, German Collection of Microorganisms and Cell Cultures, Institut Pasteur and Friedrich-Loeffler-Institute).