Table 2 Comparison of detection methods by factors influencing decision to adopt a specific test
Variable | Assay | ||
|---|---|---|---|
CHROMagar MRSA | Cepheid Xpert SA Complete | Hain GenoQuick | |
Initial investment cost (equipment, accessories) | US $14,400 | US $43,000 | US $23,900 |
Cost per test | US $6.50–7.50 | US $45–50 | US $10–15 |
Hands-on time per sample | 4–5 min | < 1 min | ~ 15 min |
Number of Samples per Run | 1 sample per plate | 4 samples per run | 12 samples per run |
Testing time | 18–48 h | < 1 h (50 mins) | 2.5 h |
Total turn-around-time | 18–48 h | 1.25 h | 3.5 h |
Human resource considerations | Technically demanding | Not technically demanding | Technically demanding |
Challenges | Definite identification as MRSA requires confirming isolates as S. aureus with a coagulase test, which is not included in the test kit nor specified by the manufacturer | High failure rate –sample debris can clog pre-filter with particulates, leading to cartridge failure. No sample preparation is recommended by the manufacturer | Extraction, amplification and detection processes are cumbersome and hands-on. Assay needed to be optimized by doubling the amount of DNA extract, which was not specified by the manufacturer |