BackgroundThe number of studies regarding the incidence of multidrug resistant strains and distribution of genes encoding virulence factors, which have colonized the post-Soviet states, is considerably limited. The aim of the study was (1) to assess the Staphylococcus (S.) aureus nasal carriage rate, including Methicillin Resistant S. aureus (MRSA) strains in adult Ukrainian population, (2) to determine antibiotic resistant pattern and (3) the occurrence of Panton Valentine Leukocidine (PVL)-, Fibronectin-Binding Protein A (FnBPA)- and Exfoliative Toxin (ET)-encoding genes.MethodsNasal samples for S. aureus culture were obtained from 245 adults. The susceptibility pattern for several classes of antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The virulence factor encoding genes, mecA, lukS-lukF, eta, etb, etd, fnbA, were detected by Polymerase Chain Reaction (PCR).ResultsThe S. aureus nasal carriage rate was 40%. The prevalence of nasal MRSA carriage in adults was 3.7%. LukS-lukF genes were detected in over 58% of the strains. ET-encoding genes were detected in over 39% of the strains and the most prevalent was etd. The fnbA gene was detected in over 59% of the strains. All MRSA isolates tested were positive for the mecA gene. LukS-lukF genes and the etd gene were commonly co-present in MRSA, while lukS-lukF genes and the fnbA gene were commonly co-present in Methicillin Sensitive S. aureus (MSSA) isolates. No significant difference was detected between the occurrence of lukS-lukF genes (P > 0.05) and the etd gene (P > 0.05) when comparing MRSA and MSSA. The occurrence of the fnbA gene was significantly more frequent in MSSA strains (P < 0.05).ConclusionsIn Ukraine, S. aureus is a common cause of infection. The prevalence of S. aureus nasal carriage in our cohort of patients from Ukraine was 40.4%. We found that 9.1% of the strains were classified as MRSA and all MRSA isolates tested positive for the mecA gene. We also observed a high prevalence of PVL- and ET- encoding genes among S. aureus nasal carriage strains. A systematic surveillance system can help prevent transmission and spread of drug resistant toxin producing S. aureus strains.

Porenczuk A, Grzeczkowicz A, Maciejewska I, et al. An initial evaluation of cytotoxicity, genotoxicity and antibacterial effectiveness of a disinfection liquid containing silver nanoparticles alone and combined with a glass-ionomer cement and dentin bonding systems.

The purpose of the study was to establish the prevalence of new Candida glabrata complex species: Candida nivariensis and Candida bracarensis isolated from clinical material, evaluate their phenotypes and the prevalence of gene family encoding extracellular glycosylphosphatidylinositol-linked aspartyl proteases, crucial for C. glabrata virulence. Study material included 224 C. glabrata clinical strains. Candida glabrata phenotypes were identified using CHROMagar Candida medium. Strains were analysed by using C. glabrata-specific PCR for the internal transcribed spacer region to confirmed the identification. To identify C. nivariensis and C. bracarensis strains, the D1/D2 region of 26S rRNA was sequenced. The prevalence of YPS-family proteases genes was detected using standard PCR method. Candida nivariensis amounted about 6% among the total number of C. glabrata strains. Candida nivariensis strains had a white phenotype on chromogenic agar media and assimilated two sugars - trehalose and glucose. Among the 13 C. nivariensis strains, 10 did not present any YPS-family protease genes. Coexistence of all detected YPS-family protease genes was specific for C. glabrata species. This study identified C. nivariensis strains; however, no C. bracarensis strains were identified. The white phenotype of C. nivariensis was confirmed. Most strains of the new species do not present any of the tested YPS genes.

In the past years opportunistic fungal infections have seriously increased, mainly in immunocompromised patients. The aim of the study was to determine the prevalence of yeast-like fungi in invasive candidiasis and to estimate its susceptibility to chosen antifungal agents. One hundred and sixty strains of yeast-like fungi were cultured from various clinical material: samples from lower respiratory tract, blood, the peritoneal cavity and others. The susceptibility tests were established according to the quantitative E-test method. The Candida genus represented the main etiological factor of invasive candidiasis. The predominant species were: C. glabrata (71/160), C. albicans (34/160), C. krusei (17/160), C. tropicalis (14/160). All tested strains were the most resistant to itraconazole. Candida glabrata presented the 100% susceptibility to amphotericin B and caspofungin and was the least susceptible to itraconazole, posaconazole and voriconazole. Candida albicans was the most susceptible species to all antymicotics.

Culturing strains from clinical samples is the main method to diagnose invasive pulmonary aspergillosis. Detecting the galactomannan antigen in serum samples is an auxiliary examination. The goal of this study was to determine the frequency with which Aspergillus fumigatus was cultured in clinical samples taken from patients hospitalized in the the Infant Jesus Teaching Hospital in Warsaw, Poland, in the period of 2013-2014. Specimens from the respiratory tract and blood were cultured for mycological and serological assessments. Strain isolation was performed in chloramphenicol Sabouraud agar. Species identification was based on morphological traits in macro-cultures and on microscopic examination. The galactomannan antigen was detected by ELISA method. Out of 2000 clinical samples with positive mycological results, 200 were obtained from the respiratory tract. A. fumigatus was cultured in 13 cases from the respiratory group. Ten cases were cultured out of tracheal aspirates and three from bronchoalveolar lavage fluid. The galactomannan antigen was detected in a serum sample from only one out of the 13 patients with cultures positive for A. fumigatus. It also was detected in serum samples of three other patients in whom A. fumigatus culture yielded a negative result. We conclude that culture-confirmed invasive pulmonary aspergillosis represents a scarce finding. A. fumigatus cultured from clinical samples may not always be confirmed by ELISA assay and vice versa a positive ELISA result does not attest the successful culture.