Molecular Characterization of Carbapenemase-Producing Klebsiella pneumoniae Isolated from Egyptian Pediatric Cancer Patients Including a Strain with a Rare Gene-Combination of β-Lactamases

Purpose: Healthcare-associated infections caused by multi-drug-resistant (MDR) pathogens are a global threat. We aim to assess the clonal relatedness among carbapenemase-producing Klebsiella pneumoniae (CPKP) strains infecting Egyptian pediatric cancer patients.

Materials and methods: Identification and antimicrobial susceptibility testing of 149 Gram-negative isolates obtained from pediatric cancer patients were performed by VITEK 2. Genes encoding carbapenemases and extended-spectrum β-lactamases were detected by PCR and verified by DNA sequencing of representative samples. The transferability of the plasmids harboring bla _OXA-48, from representative clinical samples, was evaluated by performing a conjugation experiment followed by PCR and MIC shift determination. Clonal relationships among the bla _OXA-48-harboring K. pneumoniae isolates were determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR and pulsed-field gel electrophoresis (PFGE).

Results: Carbapenem resistance was observed in 59% of the isolates. The most prevalent species was K. pneumoniae (45.6%) and 57% of them were isolated from ICU. Fifty-nine % of the K. pneumoniae isolates were carbapenemase-producers and bla _OXA-48 was detected in (58%) of them. One isolate co-harbored bla _OXA-48, bla _NDM-1, and bla _IMP-1 genes for the first time in Egypt. PCR and meropenem MIC shift confirmed the success of the transferability of representative plasmids to E. coli K12. ERIC and PFGE identified 93% and 100% of the K. pneumoniae with a similarity coefficient ≥85%, respectively, including strains with indistinguishable patterns, suggesting possible clonal dissemination.

Conclusion: Our findings underline the dissemination of diverse clones of MDR CPKP among Egyptian pediatric cancer patients. Hence, routine molecular characterizations followed by strict implementation of infection control measures are crucial to tackling this threat.