[Occurrence of AmpC-positive Klebsiella pneumoniae strains in patients with haematological malignancies].
BACKGROUND
Currently, important bacterial beta-lactamases of increasing clinical significance include AmpC enzymes. The aim was to assess their occurrence in Klebsiella pneumoniae strains isolated from patients with haematological malignancies in a prospective study.


METHODS
Over a 2-month period, strains of the species were isolated from clinical material obtained from patients hospitalized at the Department of Haemato-Oncology of the University Hospital Olomouc. The strains were identified using standard microbiological techniques and the Vitek 2 automated system. Production of AmpC beta-lactamases was roughly determined by phenotypic tests and subsequently confirmed by PCR detection of genes encoding these enzymes.


RESULTS
During the above-mentioned period, a total of 35 K. pneumoniae isolates were collected. In 7 of them, production of AmpC beta-lactamases was preliminarily detected by phenotypic test. The multiplex PCR method confirmed phenotyping and determined DHA types in all the isolates.


CONCLUSIONS
All AmpC-positive isolates were false-susceptible to at least one of the tested third-generation cephalosporins. In one patient, clinically apparent infection caused by this strain was documented. The reported results suggest the possibility of occurrence of AmpC-beta-lactamases in K. pneumoniae strains with clinical significance.
Chromá
Magdaléna
M
Institute of Microbiology Faculty of Medicine UP Olomouc, Olomouc, Czech Republic. magdalena.chroma@centrum.cz
Kolár
Milan
M
Sauer
Pavel
P
Faber
Edgar
E
Stosová
Tatána
T
Koukalová
Dagmar
D
Indrák
Karel
K
D000208:Acute Disease; D001426:Bacterial Proteins / Q000378:metabolism*; D006801:Humans; D007711:Klebsiella pneumoniae / Q000201:enzymology / Q000302:isolation & purification*; D007938:Leukemia / Q000382:microbiology*; D001618:beta-Lactamases / Q000378:metabolism*
D001426:Bacterial Proteins; C048795:AmpC beta-lactamases; D001618:beta-Lactamases