A Global Overview of β-lactam Resistance Genes in Klebsiella pneumoniae

Abstract

Klebsiella pneumoniae is a gram-negative bacillus of the Enterobacteriaceae family, commonly associated with nosocomial infections. This pathogen is a serious public health problem as some of its strains are resistant to about 95% antimicrobials of the pharmaceutical market. This resistance is promoted by the production of the β-lactamase extended spectrum (ESBL) enzymes, one of the major causes of therapeutic failure. This review evaluated the incidence and distribution of resistance genes from Klebsiella pneumoniae to β-lactams worldwide. Our study was conducted with the subject the organism K. pneumoniae and β-lactamic resistance. The most reported genes were blaSHV-12, blaCTX-M-2 and blaSHV-5; with blaSHV-12 being the most described. The last two were present in all continents, characterizing its cosmopolitan profiles. The greatest genetic diversity was observed in the Asian and Oceania, where 41 different genes were isolated. Additionally, our review points out the coexistence of different classes of β-lactamases in a single bacterial isolate. Finally, knowledge of mechanisms associated with resistance of K. pneumoniae is of great public interest and the verification of resistance genes shows a variation over time and location highlights the importance of evaluating the mechanisms or strategies by which these variations occur.