High Prevalence of Multidrug-Resistant Klebsiella pneumoniae Harboring Several Virulence and β-Lactamase Encoding Genes in a Brazilian Intensive Care Unit

<i>Klebsiella pneumoniae</i> is an important opportunistic pathogen that commonly causes nosocomial infections and contributes to substantial morbidity and mortality. We sought to investigate the antibiotic resistance profile, pathogenic potential and the clonal relationships between <i>K. pneumoniae</i> (<i>n</i> = 25) isolated from patients and sources at a tertiary care hospital's intensive care units (ICUs) in the northern region of Brazil. Most of <i>K. pneumoniae</i> isolates (<i>n</i> = 21, 84%) were classified as multidrug resistant (MDR) with high-level resistance to β-lactams, aminoglycosides, quinolones, tigecycline, and colistin. All the 25 isolates presented extended-spectrum beta-lactamase-producing (ESBL), including carbapenemase producers, and carried the <i>bla</i> _KPC (100%), <i>bla</i> _TEM (100%), <i>bla</i> _SHV variants (<i>n</i> = 24, 96%), <i>bla</i> _OXA-1 group (<i>n</i> = 21, 84%) and <i>bla</i> _CTX-M-1 group (<i>n</i> = 18, 72%) genes. The K2 serotype was found in 4% (<i>n</i> = 1) of the isolates, and the K1 was not detected. The virulence-associated genes found among the 25 isolates were <i>mrk</i>D (<i>n</i> = 24, 96%), <i>fim</i>H-1 (<i>n</i> = 22, 88%), <i>ent</i>B (100%), <i>iut</i>A (<i>n</i> = 10, 40%), <i>ybt</i>S (<i>n</i> = 15, 60%). The genes related with efflux pumps and outer membrane porins found were <i>AcrAB</i> (100%), <i>tol</i>C (<i>n</i> = 24, 96%), <i>mdt</i>K (<i>n</i> = 22, 88%), <i>Omp</i>K35 (<i>n</i> = 15, 60%), and <i>Omp</i>K36 (<i>n</i> = 7, 28%). ERIC-PCR was employed to determine the clonal relationship between the different isolated strains. The obtained ERIC-PCR patterns revealed that the similarity between isolates was above 70%. To determine the sequence types (STs) a multilocus sequence typing (MLST) assay was used. The results indicated the presence of high-risk international clones among the isolates. In our study, the wide variety of MDR <i>K. pneumoniae</i> harboring β-lactams and virulence genes strongly suggest a necessity for the implementation of effective strategies to prevent and control the spread of antibiotic resistant infections.