A hybrid strain of Klebsiella pneumoniae called Carbapenem-Resistant Hypervirulent K. pneumoniae (CR-hvKP) has become a concerning public health issue in China. This strain is multidrug-resistant, hypervirulent, and highly transmissible, posing a significant challenge to public health, especially in clinical settings across Asia. The emergence of CR-hvKP is a result of the convergence of two types of Klebsiella pneumoniae, leading to the development of a highly dangerous pathogen that is both resistant to antibiotics and highly virulent.
Carbapenem-resistant K. pneumoniae (CRKP) strains have become a predominant concern in Chinese healthcare settings, constituting a majority of clinical carbapenem-resistant Enterobacteriaceae (CRE) infections. The rise of CR-hvKP is due to the acquisition of plasmids carrying both the carbapenem-resistance gene and the virulence gene. The widespread use of antimicrobials has provided a selective advantage, contributing to the alarming development of CR-hvKP.
The virulence factors of CR-hvKP play a crucial role in its pathogenicity. The hypermucoviscosity (HMV) phenotype, characterized by a thick capsule, acts as a physical barrier hindering the transfer of genes and makes strains with hypercapsules less prone to harboring antimicrobial resistance genes. Siderophores and other virulence factors further enhance the pathogenicity of CR-hvKP.
The clinical impacts of CR-hvKP are diverse, ranging from pyogenic liver abscesses, endophthalmitis, and meningitis to hospital-acquired urinary tract infections, pneumonia, septicemias, and soft tissue infections. The morbidity and mortality associated with CR-hvKP infections are high, particularly in cases of bloodstream infections (BSI). Patients with underlying comorbidities, such as diabetes mellitus, are at a higher risk of CR-hvKP infection.
China has been identified as the epicenter of the CR-hvKP epidemic, with a significant rise in reported cases since 2012. The prevalence of CR-hvKP varies across regions, with certain areas reporting higher incidence rates. The most common carbapenem-resistance determinant in CR-hvKP is the blaKPC-2 gene. Understanding the epidemiology and genetic backgrounds of CR-hvKP is crucial for effective surveillance and management.
The emergence of CR-hvKP in China poses a severe threat to public health and requires urgent attention and comprehensive strategies for containment. Efforts should focus on developing strategies to curb the proliferation of K. pneumoniae virulence plasmids and combat carbapenem resistance. Enhanced infection control measures, robust surveillance systems, and the development of novel treatment options are necessary to tackle this emerging healthcare threat. Continued research into the epidemiology, genetic backgrounds, and clinical impacts of CR-hvKP is crucial to stay ahead of this evolving public health challenge.