Table 1.
Clinical data and phenotypic and genotypic identification results of the Klebsiella pneumoniae and Enterobacter aerogenes isolates used in this study
| Strain | Sample | Motilityb | Ornithine decarboxylaseb | API Code | API Identificationc | Vitek2d Phoenixd | tDNA-PCRe | Clonef |
| Group 1 | ||||||||
| LBV268 | + | + | 5305773 | E. aerogenes | E. aerogenes | E. aerogenes | BEI | |
| MN1 | Aspirate | + | + | 5305773 | E. aerogenes | NT | E. aerogenes | BEII |
| BEI 166 | + | + | 5305773 | E. aerogenes | NT | E. aerogenes | BEI | |
| BEII 169 | + | + | 5305773 | E. aerogenes | NT | E. aerogenes | BEII | |
| Group 2 | ||||||||
| BG | Blood culture | - | - | 5005763 | K. pneumoniae/K. terrigena | K. pneumoniae | K. pneumoniae | K1 |
| DHJ2 | Aspirate | - | - | 5215773 | K. pneumoniae | K. pneumoniae | K. pneumoniae | K2 |
| Group 3 | ||||||||
| GA1 | Wound | (-) | (-) | 5205773 | Weak | NT | E. aerogenes | BEI |
| GA2 | Urine | (-) | (-) | 5205773 | Weak | NT | E. aerogenes | BEI |
| GA3 | Urine | (-) | (-) | 5205773 | Weak | K. pneumoniae | E. aerogenes* | BEI |
| MN2 | Ascites | (-) | (-) | 5205773 | Weak | K. pneumoniae | E. aerogenes | BEI |
| MN3 | Urine | (-) | (-) | 5205773 | Weak | NT | E. aerogenes* | BEI |
| VGM | Sputum | (-) | (-) | 5205773 | Weak | K. pneumoniae | E. aerogenes | BEII-related |
| DHJ1 | Urine | (-) | (-) | 5205753 | No identification | NT | E. aerogenes* | BEII-related |
| DHJ3 | Blood culture | (-) | (-) | 5205753 | No identification | NT | E. aerogenes | BEII-related |
| RA | Throat isolate | (-) | (-) | 5204673 | K. terrigena | NT | E. aerogenes* | Non-related |
| DBH | Urine | (-) | (-) | 5204673 | K. terrigena | NT | E. aerogenes* | BEI |
a: Data for genuine E. aerogenes isolates are presented first (group 1). Clinical isolate LBV268 was used as control for analysis on automated phenotypical identification systems. The isolates BEI 166 and BEII 169 were shown previously [4] to belong to the two major E. aerogenes clones (BEI and BEII) in Belgium. Group 2 presents data for genuine K. pneumoniae. Clinical isolate BG was used as control for analysis on automated phenotypical identification systems. The third group presents the data for the phenotypically aberrant E. aerogenes isolates.
b: +, positive; -, negative; (-), negative after standard incubation time, only positive after subculturing and/or retesting with prolonged incubation periods.
c: Weak: Weak identification with possibilities: E. aerogenes, K. pneumoniae or R. planticola.
d: NT: not tested.
e: * indicates that identification was confirmed by 16S rDNA sequence analysis.
f: Clonal relationships were determined using RAPD-analysis.