Review Article
Development of New Tools to Detect Colistin-Resistance among Enterobacteriaceae Strains
Table 5
Comparison of detection methods for polymyxin resistance.
| Method | Principle | Time | Manual (M); automated (A) | Detection | ColR | mcr | HR | MIC |
| Phenotypic | | | | | | | | Selective agar | Selective growth | 18 h | M | + | − | + | − | Rapid polymyxin NP | pH change | 4 h | M | + | − | − | − | Micromax | Cell wall lysis detection by fluorescence | 3 h | M/A | + | − | − | − | MALDI-TOF MS | Specific peak detection | 1 h | A | + | + | − | − | MCR-1 inhibition | Chelation with | 18 h | M | + | + | ± | + | Colistin MAC | Dipicolinic acid | | | | | | | EDTA assays | EDTA | | | | | | |
| AST | | | | | | | | BMD (UMIC, Micronaut-MIC, Sensitest, Micronaut-S, and Sensititre) | Growth inhibition | 18 h | M/A | + | − | ± | + | Agar diffusion | Measure of growth inhibition zone | 18 h | M | | | | | Disk diffusion | | | | − | − | + | − | Gradient strip | | | | − | − | + | + | ColiSpot | | | | + | − | ND | − | Agar dilution | Growth inhibition | 18 h | M | − | − | + | + | Automatized system | Growth detection | | | | | | | MicroScan | Fluorimetry | 3.5–7 h | A | + | − | − | − | Vitek 2 | Algorithm | 4–10 h | A | + | − | − | − | Phoenix | Oxidoreduction | 6–16 h | A | + | − | − | − |
| Genotypic | | | | | | | | Standard PCR | Amplification | 3 h | A | + | + | − | − | RT-PCR | Amplification | 1 h | A | + | + | − | − | LAMP (Eazyplex, etc.) | Amplification | 20 min | A | + | − | − | − | Microarray | DNA hybridization | 6.5 h | A | + | − | − | − | NGS | Whole-genome sequencing | | | | | | | Illumina | | 4–56 h | A | + | + | − | − | PacBio RS II | | 0.5–3 h | A | + | + | − | − |
|
|
ColR: colistin resistance; HR: heteroresistance; +: yes; −: no; ±: sometimes.
|