Antimicrobial Susceptibility and Molecular Characterization of Carbapenemase-Producing Enterobacter spp. Community Isolates in Belgrade, Serbia.

Antimicrobial resistance represents the emerging problem of modern medicine. Despite the fact that Enterobacter spp. is one of the most resistant pathogens, there has been a paucity of data on molecular epidemiology and antimicrobial susceptibility of community isolates in European countries as well as in Serbia. This study was conducted in 2016 and 2017 with the aim to investigate the prevalence of carbapenem-resistant Enterobacter spp. community isolates, molecular determinants of carbapenem resistance, and their genetic relatedness. Seventeen (1.6%) of 1,040 isolates that were positive for carbapenemase screening in accordance with European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations were included in the study. Minimum inhibitory concentrations for selected antimicrobials were determined by broth microdilution and by disk diffusion for chloramphenicol. Multiplex polymerase chain reactions (PCRs) for blaKPC, blaNDM, blaIMP, blaVIM, and blaOXA-48-like carbapenemase genes were performed. Clonality was assessed by enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis. All isolates were multidrug resistant. The most frequent carbapenemase gene found was blaNDM (70.6%), followed by isolates coharboring blaNDM and blaOXA-48-like genes (23.5%) and a single isolate with the blaOXA-48-like gene (5.9%). ERIC-PCR molecular typing showed six different clusters (A-F) with clonal relatedness among isolates from the same institution and association of clusters E and F with the blaNDM carbapenemase gene. Our results indicate the need for Enterobacter spp. surveillance both in the community and hospitals to prevent spreading of multiresistant clones.

Differences in antimicrobial consumption, prescribing and isolation rate of multidrug resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii on surgical and medical wards.

In order to provide guidance data for clinically rational use of an antibiotics consuption, prescribing and prevalence of multidrug resistant (MDR) Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii were monitored on the surgical (S) and medical (M) wards of the University Hospital Center "Dr. Dragisa Misovic-Dedinje" (Belgrade, Serbia), in the study period from 2012 to 2015. Appropriateness of antimicrobial use was evaluated using the Global-Prevalence Survey method designed by the University of Antwerp. The percentages of MDR pathogens relative to the total number of isolates of K. pneumoniae and P. aeruginosa were higher on the S (86.2% and 49.1%) than on the M (63.2% and 36.9%) wards. The percentage of MDR A. baumannii was not different between S (93.7%) and M (79.5%) wards. An overall antibiotics consumption (defined daily doses/100 bed-days) during study was 369.7 and 261.5 on the S and M wards, respectively. A total of 225 prescriptions of antimicrobials were evaluated in138 adults admitted to wards on the day of the survey. The percentage of antimicrobials prescribed for prophylaxis on the M and S wards were 0% and 25%, respectively. Therapies were more frequently empiric (S, 86.8% and M, 80%). The percentages of medical errors on the S and M wards were 74.6% and 27.3%, respectively. The quality indicators for antibiotic prescribing on the S and M wards were as follows: the incorrect choice of antimicrobials (35.6% vs. 20.0%), inappropriate dose interval (70.6% vs. 16.9%) or duration of therapy (72.5% vs. 23.1%), a non-documented stop/review data (73.6% vs. 16.9%) and divergence from guidelines (71.9% vs. 23.1%). Treatment based on biomarkers was more common on the M wards as compared to the S wards. The increasing prevalence of MDR pathogens, a very high consumption and incorrect prescribing of antimicrobials need special attention, particularly on the S wards.