Phenotypic and molecular detection of nosocomial carbapenem-resistant blaOXA-48 Klebsiella pneumoniae isolated from Al-Azhar Assiut University Hospital ICUs

Abstract

Purpose The aim were to detect the prevalence of blaOXA-48 carbapenem-resistant Klebsiella pneumoniae (CRKP) (K. pneumoniae) among the K. pneumoniae isolates isolated from the ICUs of Al-Azhar Assiut University Hospital by phenotypic and molecular methods and to investigate susceptibility of other alternative drugs for CRKP strains.Patients and methods This was a hospital-based cross-sectional study that was conducted on 63 isolates of K. pneumoniae isolated from clinical samples of patients .All isolates were subjected to phenotypic and genotypic susceptibility for carbapenem resistance. For identification of K. pneumoniae, it was done using conventional methods. The test for antibiotic susceptibility was done using disc diffusion method. Strains were resistant for carbapenems, with antibiotic sensitivity testing being investigated for confirmation of carbapenem resistance. Phenotypic confirmation was done using modified Hodge test, whereas the molecular confirmation was done using PCR.Results K. pneumoniae isolates were most frequently seen in sputum (38%) followed by blood (20%) and sputum (16%). Of 63 K. pneumoniae isolates, 24 (38%) isolates were carbapenem resistant by disc diffusion method. By using modified Hodge test, 22 (91.7%) isolates were positive by modified-Hodge test and two (8.3%) isolates were negative, which was confirmed by PCR for blaOXA-48, giving results that 22 (91.7%) isolates were positive and two (8.3%) were negative.Conclusion OXA-48 gene is a common source of carbapenem resistance in CRKP in the hospital environment in our country. Antibiotic susceptibility testing by disc diffusion method and modified Hodge test are cost-effective and suitable methods for the initial detection of CRKP, especially when molecular detection methods are not available.