Candida bloodstream infections in Serbia: First multicentre report of a national prospective observational survey in intensive care units.

Candida bloodstream infections (BSI) are a significant cause of mortality in intensive care units (ICU), hereof the prospective 12-months (2014-2015) hospital- and laboratory-based survey was performed at the Serbian National Reference Medical Mycology Laboratory (NRMML). Candida identification was done by a matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and a susceptibility test, according to the Clinical and Laboratory Standards Institute methodology. Among nine centres (265 beds; 10 820 patient admissions), four neonatal/paediatric (NICU/PICUs) and five adult centres (ICUs) participated, representing 89 beds and 3446 patient admissions, 166 beds and 7347 patient admissions respectively. The NRMML received 43 isolates, 17 from NICU/PICUs and 26 from adult ICUs. C. albicans dominated highly in NICU/PICUs (~71%), whereas C. albicans and C. parapsilosis were equally distributed within adults (46%, each), both accounting for ~90% of received isolates. The resistance to itraconazole and flucytosine were 25% and 2.4% respectively. In addition, the 2 C. albicans were azole cross-resistant (4.6%). The overall incidence of CandidaBSI was ~3.97 cases/1000 patient admissions (4.93 in NICU/PICU and 3.53 in adult ICU). The 30-day mortality was ~37%, most associated with C. tropicalis and C. glabrataBSI. Data from this national survey may contribute to improving the Balkan and Mediterranean region epidemiology of CandidaBSI within ICUs.

Serotype distribution, antimicrobial susceptibility and molecular epidemiology of invasive Streptococcus pneumoniae in the nine-year period in Serbia.

Streptococcus pneumoniae is one of the leading bacterial pathogens that can cause severe invasive diseases. The aim of the study was to characterize invasive isolates of S. pneumoniae obtained during the nine-year period in Serbia before the introduction of the pneumococcal conjugate vaccines (PCVs) into routine vaccination programs by determining: serotype distribution, the prevalence and genetic basis of antimicrobial resistance, and genetic relatedness of the circulating pneumococcal clones. A total of 490 invasive S. pneumoniae isolates were included in this study. The serotype, antimicrobial susceptibility, and ST of the strains were determined by the Quellung reaction, disk- and gradient-diffusion methods, and multilocus sequence typing (MLST), respectively. The most common serotypes in this study were 3, 19F, 14, 6B, 6A, 19A, and 23F. The serotype coverages of PCV10 and PCV13 in children less than 2 years were 71.3 and 86.1%, respectively, while PPV23 coverage in adults was in the range of 85-96%, depending on the age group. Penicillin and ceftriaxone-non-susceptible isolates account for 47.6 and 16.5% of all isolates, respectively. Macrolide non-susceptibility was detected in 40.4% of isolates, while the rate of multidrug- and extensive-drug resistance was 20.0 and 16.9%, respectively. The MLST analysis of 158 pneumococci identified 60 different STs belonging to the 16 Clonal Complexes (CCs) (consisting of 42 STs) and 18 singletons. The most common CC/ST were ST1377, CC320, CC15, CC273, CC156, CC473, CC81, and CC180. Results obtained in this study indicate that the pre-vaccine pneumococcal population in Serbia is characterized by high penicillin and macrolides non-susceptibility, worrisome rates of MDR and XDR, as well as a high degree of genetic diversity. These findings provide a basis for further investigation of the changes in serotypes and genotypes that can be expected after the routine introduction of PCVs.