Virulence Mechanisms and Antimicrobial Resistance in Invasive Klebsiella Pneumoniae Isolates

Abstract

Klebsiella pneumoniae has evolved to be a super-bug with the dual threat of antimicrobial resistance and virulence. Currently in India, given the high rates of XDR bacteria, the best choice for treatment is a combination of ceftazidime-avibactam and aztreonam which acts against both NDM and OXA48-like carbapenemase producing CRKp which is frequently seen. There is the emergence of carbapenem resistant-hypervirulent K. pneumoniae that carry mosaic plasmids coding for antimicrobial resistance and virulence. These strains are predominantly seen among nosocomial setting and hence pose a major public health challenge in India. Although a small proportion of CRhvKp infections are observed, they lead to fatal outcome. Other species such as K. quasipneumoniae are also acquiring the virulence traits and hence it is crucial to identify these species using molecular techniques. The genome plasticity of K. pneumoniae with an average of 5 plasmids per genome reveals the successful establishment of this pathogen. ST23, the international hypervirulent clone, has acquired multiple resistance plasmids from the endemic Indian clones. In India, the mechanism of carbapenem and colistin resistance and the prevalence of endemic clones are distinct from the global scenario. The convergence of AMR and virulence in MDR clones is challenging to manage. Recommendations: Surveillance studies are necessary to monitor the trend of carbapenemases and its genetic background. This will help in determining susceptibility to newer and#946;-lactam/ and#946;-lactamase agents. It is important to know the differences in resistance mechanisms among Enterobacterales while formulating therapeutic options since differences exist among the genera. Studies on monoclonal antibodies targeted against hypervirulent and carbapenem resistant K. pneumoniae are necessary. Since these antibodies target the capsular polysaccharide, knowledge on the differences in capsular types among hvKp and CRKp is necessary to formulate this therapeutic option.