Evaluation of Boronic Acid Disk Tests for Differentiating KPC-Possessing Klebsiella pneumoniae Isolates in the Clinical Laboratory
| Autor: | Aggeliki Poulou, Katerina Themeli-Digalaki, Danai Sofianou, Athanassios Tsakris, Ioulia Kristo, Alexandros Ikonomidis, Dimitra Petropoulou, Spyros Pournaras |
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| Rok vydání: | 2009 |
| Předmět: |
Microbiology (medical)
Carbapenem Imipenem Klebsiella pneumoniae medicine.medical_treatment Cefepime Microbial Sensitivity Tests beta-Lactams Sensitivity and Specificity Meropenem beta-Lactam Resistance beta-Lactamases Microbiology chemistry.chemical_compound polycyclic compounds medicine Humans False Positive Reactions Cefoxitin Bacteriological Techniques biology Bacteriology biochemical phenomena metabolism and nutrition bacterial infections and mycoses biology.organism_classification Boronic Acids Virology Anti-Bacterial Agents chemistry Beta-lactamase Ertapenem medicine.drug |
| Zdroj: | Journal of Clinical Microbiology. 47:362-367 |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.01922-08 |
| Popis: | The worldwide increase in the occurrence and dissemination of KPC β-lactamases among gram-negative pathogens makes critical the early detection of these enzymes. Boronic acid disk tests using different antibiotic substrates were evaluated for detection of KPC-possessing Klebsiella pneumoniae isolates. A total of 57 genotypically confirmed KPC-possessing K. pneumoniae isolates with varying carbapenem MICs were examined. To measure the specificity of the tests, 106 non-KPC-possessing isolates (89 K. pneumoniae and 17 Escherichia coli isolates) were randomly selected among those exhibiting reduced susceptibility to cefoxitin, expanded-spectrum cephalosporins, or carbapenems. As many as 56, 53, and 40 of the non-KPC-possessing isolates harbored extended-spectrum β-lactamases, metallo-β-lactamases, and plasmid-mediated AmpC β-lactamases, respectively. By use of CLSI methodology and disks containing imipenem, meropenem, or cefepime, either alone or in combination with 400 μg of boronic acid, all 57 KPC producers gave positive results (sensitivity, 100%) whereas all 106 non-KPC producers were negative (specificity, 100%). The meropenem duplicate disk with or without boronic acid demonstrated the largest differences in inhibition zone diameters between KPC producers and non-KPC producers. By use of disks containing ertapenem, all isolates were correctly differentiated except for five AmpC producers that gave false-positive results (sensitivity, 100%; specificity, 95.3%). These practical and simple boronic acid disk tests promise to be very helpful for the accurate differentiation of KPC-possessing K. pneumoniae isolates, even in regions where different broad-spectrum β-lactamases are widespread. |
| Databáze: | OpenAIRE |
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