Volume 8, Number 5—May 2002
Dispatch
Cefepime MIC as a Predictor of the Extended-Spectrum β-Lactamase Type in Klebsiella pneumoniae, Taiwan
Table
Distribution of pIa values in 110 isolates of extended-spectrum β-lactamase-producing Klebsiella pneumoniae, stratified by cefepime MIC level,b Taiwan
| Cefepime MIC (mg/L) (n=110) | pI 5.4 (n=89) | pI 6.3 (n=7) | pI 7.6 (n=92) | pI 7.8 (n=4) | pI 7.9 (n=40) | pI 8.2 (n=62) | pI 8.4 (n=43) | pI 8.8 (n=3) |
|---|---|---|---|---|---|---|---|---|
| >32 (n=38) | 38 | 0 | 31 | 0 | 29c | 20d | 18c | 2 |
| 16 (n=6) | 6 | 0 | 5 | 0 | 5c | 3e | 5d | 0 |
| 8 (n=26) | 20 | 2f | 22 | 0 | 6g | 8h | 12g | 0 |
| 4 (n=19) | 9 | 4f | 17 | 1f | 0 | 12h | 6g | 1g |
| 2 (n=10) | 7 | 1f | 8 | 3f | 0 | 8h | 2g | 0 |
| <1 (n=11) | 9 | 0 | 9 | 0 | 0 | 11h | 0 | 0 |
apI, Isoelectric point. Each strain may have multiple pIs.
bMIC test, reference broth microdilution method according to National Committee for Clinical Laboratory Standards.
cTen of 34 isolates having a cefepime MIC >16 mg/L did not have enzymes with pI values of 8.2 or 8.4.
d Eight of 23 isolates (cefepime MIC >16 mg/L) were not coexistent with pI 8.2 or 7.9.
e All 23 isolates were simultaneously coexistent with pI 7.9, 8.4, or 8.8 (12 with pI 7.9 plus 8.4; 9 with pI 7.9; and 2 with pI 8.8).
fAll the 11 isolates (pI 7.8 or 6.3) were coexistent with pI 8.2.
gCeftazidime MIC <8 mg/L; ceftriaxone MIC <32 mg/L.
hCeftazidime MIC <16 mg/L.