[Extended spectrum beta-lactamase types in Klebsiella pneumoniae strains isolated from blood cultures].

The aim of this study was to investigate and type the extended spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae strains isolated from blood cultures. Following the detection of antibiotic susceptibilities in 32 K. pneumoniae isolates, ESBL were detected in 13 (41%) of them by using double disc synergy test. Minimum inhibition concentrations for ceftazidime, cefotaxime, and aztreonam of ESBL positive strains were determined by E-test. After the extraction of the enzymes, the types of ESBLs were investigated by isoelectric focusing method. It was seen that, of all ESBL positive strains, one strain had four bands, one had three bands, six strains had two bands, and each of the others had only one beta-lactamase band. The results of polymerase chain reaction (PCR) revealed bla(SHV) in ten samples, bla(TEM) in six samples, and bla(SHV) with bla(TEM) in four samples. Ten SHV enzymes were typed as ESBL by PCR-RFLP (restriction fragment lenght polymorphism) method. The results of isoelectric focusing, PCR and RFLP performed in these ESBL positive K. pneumoniae isolates showed that the ESBL types could be SHV-2, SHV-5 and SHV-12 in the tested strains. It should always be taken into consideration that K. pneumoniae isolates could produce ESBLs and antibiotic treatment protocols should be adjusted in accordance.