Carbapenem Resistance and Hypervirulence in Pediatric Klebsiella pneumoniae Sepsis

Background: Klebsiella pneumoniae is a major etiological agent of pediatric sepsis. The emergence and dissemination of carbapenem-resistant K. pneumoniae (CRKP) and hypervirulent strains (hvKp) represent an escalating global health concern. However, data regarding the coexistence of carbapenem resistance and hypervirulence in pediatric populations, especially in low- and middle-income countries, remain limited. Objectives: This study aimed to determine the prevalence of carbapenem resistance and hypervirulence-associated genes among pediatric K. pneumoniae bloodstream infections in Egypt and to assess their association. Methods: A cross-sectional study was conducted involving 100 pediatric patients with culture-confirmed K. pneumoniae sepsis at Mansoura University Children’s Hospital between January 2023 and January 2025. Clinical and laboratory data were collected. Antimicrobial susceptibility testing was performed using standard disc diffusion and carbapenemase inhibition assays. Polymerase chain reaction (PCR) was employed to detect carbapenemase genes (including blaNDM for New Delhi metallo-β-lactamase, blaOXA-48 for oxacillinase-48, blaKPC for K. pneumoniae carbapenemase, blaVIM for Verona integron-encoded metallo-β-lactamase, and blaIMP for imipenemase). Hypervirulence genes tested included iucA (aerobactin siderophore synthesis), iroN and iroB (salmochelin siderophore cluster), and peg-344 (putative transporter). Genotypic hvKp was defined as the presence of two or more hypervirulence-associated genes. Results: Carbapenem resistance was identified in 64% of isolates, with blaNDM (New Delhi metallo-β-lactamase) and blaOXA-48-like (oxacillinase-48) genes being the most prevalent carbapenemase determinants. Hypervirulence-associated genes were detected in 86% of isolates, which were classified as genotypic hvKp, most frequently iucA (aerobactin system) and peg-344 (putative transporter). No significant demographic or inflammatory differences were observed between CRKP and carbapenem-susceptible groups. Hypervirulence was present at similarly high frequencies in CRKP (87%) and carbapenem-susceptible K. pneumoniae (84%) isolates, with no significant association between these traits ( p = 0.782). Logistic regression analysis did not identify any clinical predictors of hypervirulent infection. Conclusion: The detection of multidrug-resistant K. pneumoniae isolates harboring multiple hypervirulence-associated genes highlights the potential convergence of resistance and virulence determinants. However, further phenotypic and functional studies are required to confirm the hypervirulent phenotype and assess its clinical significance.