Table 2. Dynamic changes in annual resistance of MRSA and MSSA to several antimicrobial agents from 2008 to 2017 (rate of resistance, %).
| Antimicrobial agent | 2008 | 2010 | 2011 | 2012 | 2015 | 2016 | 2017 | P-valuea | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | MRSA | MSSA | |
| PEN | 100% | 93% | 100% | 92% | 100% | 92% | 100% | 92% | 100% | 90% | 100% | 89% | 100% | 85% | / | 0.0398 |
| GEN | 85% | 14% | 81% | 14% | 85% | 8% | 73% | 8% | 57% | 5% | 70% | 8% | 57% | 4% | <0.0001 | 0.0026 |
| CZO | 99% | 0% | 96% | 1% | 97% | 0% | 92% | 1% | 93% | 0% | 86% | 0% | 85% | 2% | <0.0001 | 0.3159 |
| ERY | 96% | 55% | 91% | 42% | 85% | 53% | 48% | 91% | 70% | 35% | 87% | 38% | 81% | 35% | 0.0014 | 0.0012 |
| FOS | 38% | 1% | 46% | 3% | 47% | 1% | 32% | 32% | 44% | 2% | 63% | 1% | 52% | 2% | 0.0056 | >0.9999 |
| RIP | 27% | 5% | 29% | 3% | 37% | 1% | 12% | 10% | 6% | 1% | 5% | 1% | 5% | 1% | <0.0001 | 0.0831 |
| SXT | 25% | 0% | / | 12% | 0% | 6% | 7% | 5% | 3% | 3% | 2% | 2% | 0% | <0.0001 | 0.8644 | |
| LVX | / | 95% | 11% | 95% | 20% | 91% | 9% | 89% | 15% | 85% | 14% | 76% | 17% | <0.0001 | 0.5392 | |
| LZD | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | / | / |
| VAN | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | / | / |
Notes: Blank cells indicate not tested. MRSA: methicillin-resistant S. aureus; MSSA: methicillin-susceptible S. aureus; PEN: penicillin; GEN: gentamicin; CZO: cefazolin; ERY: erythromycin; FOT: fosfomycin; RIF: rifampin; SXT: trimethoprim/sulfamethoxazole; LVX: levofloxacin; LZD: linezolid; VAN: vancomycin.
aP-value by chi-square test for trend, for detecting whether the increasing or decreasing trend in resistance rates among MRSA or MSSA existed over the past decade. A p-value below .05 was considered to be significantly different and is indicated in bold face.