Understanding Klebsiella pneumoniae carbapenem resistant profile recovered in a Brazilian university hospital

Problem: Carbapenem-resistant strains of K. pneumoniae (CRKP) represent 70 to 90% of public health infections. Considering the difficulty in launching new pharmacological options, and the imminent threat of outbreaks, new studies are necessary. Objectives: To investigate antimicrobial resistance and virulence factors of CRKP strains recovered in the Clinical Hospital from the Federal University of Minas Gerais State, from October 2016 to January 2018. Methodology: Medical records of twenty-five patients were included and age ranged from 18 to 76 years old. 26 CRKP isolates were identified by MALDI-TOF. The antimicrobial susceptibility profile was determined by broth microdilution or disk-diffusion tests. The modified carbapenem inactivation method searched for carbapenemase, and the string test for hypermucoviscous phenotypes. Biofilm production was evaluated by quantitative assay, and the irp2, mrkD, fimH, and blaKPC genes were screened by conventional PCR. Results: Medical records showed previous use of antibiotics (92%), ICU hospitalization (44%), use of invasive medical devices (72%), and the presence of comorbidities (96%). Charlson comorbidity index (CCI) among patients ranged from 0-12 with an average score of 4.7. The highest score observed (12) was in a 75yo patient who was diagnosed with chronic kidney disease, and other comorbidities. The prevalence of blaKPC among the CRKP strains was 92%. Conclusions: Although no strains showed the hypervirulence phenotype, all of them presented important virulence factors and genetic diversity. A small number of chains of microbial transmission apparently related to biofilm production evidenced the persistence and transfer of multiresistant CRKP strains in the hospital environment.