Hypervirulent Klebsiella pneumoniae as a hospital-acquired pathogen in the intensive care unit in Mansoura, Egypt

Introduction Hypervirulent Klebsiella pneumoniae (hvKP) are variants of K. pneumoniae that come up worldwide. hvKP is known in community-acquired infections but little is known about its role in hospital-acquired (HA) infections. The aim of this study was to evaluate the frequency of hvKP among HA K. pneumoniae infections in the intensive care unit (ICU) and to compare virulence and antibiotic susceptibility between hvKP and classical K. pneumoniae (cKP). Methods String test, biofilm formation, serum bactericidal assay, capsular polysaccharide genes (K1, K2, K5, K20, K54, K57), virulence genes: rmpA, rmpA2, iucA, iroB and antimicrobial susceptibility were assessed in HA K. pneumoniae strains isolated from the ICU in Mansoura, Egypt. Results Probable hvKP represented 4 out of 65 (6.2%) K. pneumoniae. K1 and K2 genes were present in 2 and 1 isolate respectively in probable hvKP. rmpA genes were significantly associated with hvKP; at the same time biofilm production and serum resistance were not significantly associated with the hypervirulent group. There was no significant difference between hvKP and cKP strains in terms of resistance pattern. Conclusion hvKP in critically ill patients from the ICU may form a new threat especially in the presence of antibiotic resistance. Although the validity of the string test in detecting metastatic Klebsiella is questionable, it is a simple and easy test that can be done in any laboratory indicating the presence of this organism. Serotypes and genomic background may provide helpful and confirmatory tools to diagnose hvKP.