Genotypic and Phenotypic Screening of Carbapenemase Mediated Resistance in Klebsiella pneumoniae Clinical Isolates: A Hospital Based Study.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has been reported increasingly all over
the world and it is usually resistant to multiple antimicrobial agents. Is to detect the frequency
and distribution of carbapenemase genes in CRKP at Al-Zahraa University hospital, Cairo,
Egypt, and to compare between the performance of Rapidec Carba NP and modified
carbapenemase inactivation (mCIM) phenotypic methods for early and reliable recovery of
carbapenemase production in Klebsiella. pneumoniae (KP) clinical isolates. Sixty K.
pneumoniae isolates were recovered in our Microbiology laboratory. Carbapenemase
production by these isolates was assessed using antimicrobial sensitivity testing, Rapidec
Carba NP, modified carbapenemase inactivation methods (mCIM) and detection of
carbapenemase genes by PCR. CRKP was implicated in several types of healthcare associated
infections with frequency of 46.7 (28/60). The frequency of carbapenemase genes was 13
(54.2) for blaNDM, 7 (29.2%) for blaOXA-48 and 1(4.1%) for blaKPC. 3 (12.5%) isolates
carried both blaNDM and blaOXA-48. All isolates were negative for blaIMP, the sensitivity
and specificity of Rapidec Carba NP test were (100%) and (91.7%) respectively, while
sensitivity and specificity of mCIM were (66.7%) and (88.9 %) respectively, in comparison to
the PCR test which is used as the gold standard test. The Carbapenem resistance is frequently
encountered in K. pneumoniae isolates at our hospital. Rapidec carba NP and mCIM tests have
high performance and applicability in detection of carbapenemases. However, The Rapidec
carba NP was found to be rapid and with higher sensitivity.