Journal of clinical microbiology
-
J. Clin. Microbiol. · Jun 2008
Outbreak of OXY-2-Producing Klebsiella oxytoca in a renal transplant unit.
We describe a Klebsiella oxytoca infection outbreak in a renal transplant unit that involved seven patients. All strains belonged to a single pulsed-field gel electrophoresis pattern and were resistant to amoxicillin-clavulanate, cefuroxime, piperacillin-tazobactam, and aztreonam but susceptible to ceftriaxone, ceftazidime, cefepime, and imipenem. Chromosomal beta-lactamase hyperproduction was caused by a point mutation in the bla(OXY-2) gene promoter region.
-
J. Clin. Microbiol. · Jun 2008
Comparative StudyEvaluation of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry in comparison to 16S rRNA gene sequencing for species identification of nonfermenting bacteria.
Nonfermenting bacteria are ubiquitous environmental opportunists that cause infections in humans, especially compromised patients. Due to their limited biochemical reactivity and different morphotypes, misidentification by classical phenotypic means occurs frequently. Therefore, we evaluated the use of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for species identification. ⋯ MALDI-TOF MS identified 67 of the 78 isolates (85.9%) included, in agreement with the results of the reference method; 9 were misidentified and 2 were unidentified. The identities of 10 randomly selected strains were 100% correct when three different mass spectrometers and four different cultivation media were used. Thus, MALDI-TOF MS-based species identification of nonfermenting bacteria provided accurate and reproducible results within 10 min without any substantial costs for consumables.