Hypervirulent Klebsiella pneumoniae: Epidemiology, virulence factors, and antibiotic resistance

Human infections induced by Klebsiella pneumoniae (K. pneumoniae) include pneumonia; urinary tract infections, liver abscesses, bacteremia, and others. The introduction and spread of the hypervirulent K. pneumoniae (hvKp) strains have raised the number of persons who are already susceptible to infections, including those who are healthy or immune-compromised. Infections can occur worldwide; however, they are particularly prevalent in the Asia-Pacific area. Virulence plasmids as well as other conjugal components contain the genetic material that gives hvKp its hypervirulence phenotype. Although the vast majority of hvKp isolates are antibiotic-susceptible, the incidence of virulent as well as resistant isolates, such as carbapenem-resistant hvKp isolates, is continuously growing. Multidrug resistance (MDR) and increased virulence of these strains may be the cause of the subsequent clinical crisis. This study aimed to review and analyse the epidemiology, the factors associated with hypervirulence, and the mechanisms of antibiotic resistance of the hvKp strains in order to provide a better understanding of the basic biology of these strains.