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Development of an algorithm for phenotypic screening of carbapenemase-producing Enterobacteriaceae in the routine laboratory.
- Source :
-
BMC infectious diseases [BMC Infect Dis] 2017 Jan 17; Vol. 17 (1), pp. 78. Date of Electronic Publication: 2017 Jan 17. - Publication Year :
- 2017
-
Abstract
- Background: Carbapenemase-producing Enterobacteriaceae (CPE) are difficult to identify among carbapenem non-susceptible Enterobacteriaceae (NSE). We designed phenotypic strategies giving priority to high sensitivity for screening putative CPE before further testing.<br />Methods: Presence of carbapenemase-encoding genes in ertapenem NSE (MIC > 0.5 mg/l) consecutively isolated in 80 French laboratories between November 2011 and April 2012 was determined by the Check-MDR-CT103 array method. Using the Mueller-Hinton (MH) disk diffusion method, clinical diameter breakpoints of carbapenems other than ertapenem, piperazicillin+tazobactam, ticarcillin+clavulanate and cefepime as well as diameter cut-offs for these antibiotics and temocillin were evaluated alone or combined to determine their performances (sensitivity, specificity, positive and negative likelihood ratios) for identifying putative CPE among these ertapenem-NSE isolates. To increase the screening specificity, these antibiotics were also tested on cloxacillin-containing MH when carbapenem NSE isolates belonged to species producing chromosomal cephalosporinase (AmpC) but Escherichia coli.<br />Results: Out of the 349 ertapenem NSE, 52 (14.9%) were CPE, including 39 producing OXA-48 group carbapenemase, eight KPC and five MBL. A screening strategy based on the following diameter cut offs, ticarcillin+clavulanate <15 mm, temocillin <15 mm, meropenem or imipenem <22 mm, and cefepime <26 mm, showed 100% sensitivity and 68.1% specificity with the better likelihood ratios combination. The specificity increased when a diameter cut-off <32 mm for imipenem (76.1%) or meropenem (78.8%) further tested on cloxacillin-containing MH was added to the previous strategy for AmpC-producing isolates.<br />Conclusion: The proposed strategies that allowed for increasing the likelihood of CPE among ertapenem-NSE isolates should be considered as a surrogate for carbapenemase production before further CPE confirmatory testing.
- Subjects :
- Anti-Bacterial Agents pharmacology
Bacterial Proteins metabolism
Carbapenems pharmacology
Cefepime
Cephalosporins pharmacology
Clavulanic Acids pharmacology
Enterobacteriaceae drug effects
Enterobacteriaceae genetics
Enterobacteriaceae physiology
Ertapenem
Humans
Imipenem metabolism
Imipenem pharmacology
Meropenem
Microbial Sensitivity Tests
Penicillanic Acid analogs & derivatives
Penicillanic Acid pharmacology
Penicillins pharmacology
Tazobactam
Thienamycins metabolism
Thienamycins pharmacology
Ticarcillin pharmacology
beta-Lactamases metabolism
beta-Lactams metabolism
beta-Lactams pharmacology
Algorithms
Bacterial Proteins analysis
Carbapenems metabolism
Drug Resistance, Bacterial
Enterobacteriaceae metabolism
beta-Lactamases analysis
Subjects
Details
- Language :
- English
- ISSN :
- 1471-2334
- Volume :
- 17
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- BMC infectious diseases
- Publication Type :
- Academic Journal
- Accession number :
- 28095794
- Full Text :
- https://doi.org/10.1186/s12879-016-2174-y