New strategies for the treatment of infections caused by biofilm-producing Klebsiella pneumoniae

Treatment of Klebsiella pneumoniae infections is becoming increasingly challenging due to their multiple resistance to current antimicrobials. The ability to form biofilms is a critical virulence feature of K. pneumoniae. Biofilms are complex bacterial communities consisting of one or more species embedded in an extracellular matrix of proteins, carbohydrates, and DNA. Inhibition and killing of biofilm-producing strains with antibiotics often requires higher concentrations than those required to suppress planktonic bacteria. Dosage increases can vary significantly depending on many of their virulence factors. Therefore, alternative treatments have been sought recently. In this review, the literature was analyzed to gain insight into the major virulence factors with an emphasis on the role of biofilms in enhancing antimicrobial resistance, highlighting the importance of this mechanism for bacterial adaptation. The literature search was conducted using the electronic information resources PubMed, Google Scholar and eLibrary. The search depth was limited from 2000 to the present, the share of literature for the last 5 years was 63 %. The keywords used in the search were: Klebsiella pneumoniae, biofilm, virulence factors, infection treatment, combination therapy. The concepts of the difference between the pathotypes of K. pneumoniae, hypervirulent and classical, and their relationship with biofilm formation are revealed. The composition and regulation of biofilm are characterized, some factors influencing the structure of biofilm are briefly described. Some new combination strategies for the treatment of infections caused by biofilm-forming K. pneumoniae are also presented. Understanding the effect of antimicrobials on biofilms is of paramount importance for clinical practice due to the increased level of resistance and the spread of resistance among infectious agents.