Abstract
Plasmid-mediated AmpC-producing Escherichia coli and Klebsiella pneumoniae have been associated with poor clinical outcomes, but they are not readily identified in hospital microbiology laboratories. We tested 753 gram-negative bloodstream isolates for AmpC by using the EDTA disk test and the modified Hodge test (n = 172) and the modified Hodge test alone (n = 581). The 30-day mortality for the AmpC group was 9% (2/23) and was 6% (3/51) for the control group. The clinical response was similar: Afebrile on day 2 (AmpC group, 16/23 [70%]; control group, 32/45 [71%]) and on day 4 (AmpC group, 19/22 [86%]; control group, 37/44 [84%]). Patients with isolates in the AmpC group were more likely to be in an intensive care unit at the time of the positive blood culture (P = 01) and more likely to be intubated (P = 05) than patients with isolates in the control group. Effective antibiotic treatment within the first 48 hours was given to 47 (92%) of 51 patients with isolates in the control group but to only 14 (61%) of 23 patients with isolates in the AmpC group (P = 001).The modified Hodge test and the EDTA disk test did not identify patients at risk for a poor outcome from AmpC-producing bacterial infections.
Original language | English (US) |
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Pages (from-to) | 572-576 |
Number of pages | 5 |
Journal | American journal of clinical pathology |
Volume | 135 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2011 |
Externally published | Yes |
Keywords
- AmpC β-lactamase
- Bacteremia outcome
- EDTA disk test
- Modified Hodge test
ASJC Scopus subject areas
- Pathology and Forensic Medicine