Vancomycin Resistant Enterococci (VRE) are a major cause of nosocomial infections. The purpose of this study was the investigation of the genetic background of vancomycin resistance in VRE strains isolated from various clinical sources in a major hospital in Bucharest. Identification of Enterococcus faecium and E. faecalis at the species level was performed using multiplex PCR for species specific ddl (D-alanine-D-alanine ligase) genes, as for 64% of the strains the VITEK system revealed only the genus of the strains. We used a multiplex PCR approach, using primers targeting the vanA, vanB, vanC, vanD, vanE, vanG genes, revealing the presence of vanA and vanB genes, To the best of our knowledge, this is the first description of vanA and vanB genes in Romania. This specific and sensitive technique allows detection of glycopeptide-resistant strains, that may escape phenotypebased automated rapid methods.

Candida albicans is a commensal yeast that often colonizes various parts of humans, mainly epithelial, dermal or mucosal (oral cavity, gastrointestinal and genital tract etc.) tissues, but also an opportunistic pathogen that can be involved in a wide range of asymptomatic to severe, invasive infections in immunodeficient individuals. It exhibits certain unique properties such as phenotypic switching (crucial for avoiding the immune system), unique mating pattern (both asexual and sexual) and haploinsufficiency. This fungus has been also known to be a major cause of oral and skin infections, with a higher number of cases occurring in HIV positive individuals. Strains isolated from different parts of the body exhibit certain differences in their morphology and properties, among which, biofilms formation ability needs to be better understood in order to design efficient antifungal strategies. This review paper gives a brief description of various aspects of Candida albicans pathogenesis.

In recent years, a significant number of epidemiological variations have been observed for fungal infections. In immunocompromised patients, Candida albicans is crucially involved in invasive infections, mostly originating in respiratory tract colonization. The global rise in candidiasis has led researchers to investigate possible correlations between fungal strains virulence profiles and their pathogenic potential, among the most investigated genes being those involved in adherence and biofilm development. In this study, we established the adherence gene profiles of C. albicans strains isolated from respiratory tract secretions in patients hospitalized for cardiovascular diseases and correlated them with the ability of the respective strains to colonize the epithelial cells and form biofilms on the inert substratum. The strains isolated from the lower respiratory tract exhibited the highest adherence capacity and were intensive biofilm producers. The SAP9, ALS3, ALS5, and ALS6 genes were the most frequently detected. There was a significant association between the presence of ALS 3 gene and the cellular substrate colonizing potential of the harboring strains. We also found that the strains expressing SAP9 were more virulent in the phenotypic assays. Detecting the presence of adherence genes from different clinical isolates is a cost-effective tool that would allow researchers to predict the virulence of a certain strain and estimate its potential to adhere to host cells and develop biofilms.

A total number of 35 strains (n=23 of K. pneumoniae and n=12 of E.coli) were isolated in May 2017 from patients with UTI, hospitalized in the National Institute for Cardiovascular Diseases Prof. C.C. Iliescu and from community infections (CA) diagnosed in Central Reference Synevo-Medicover Laboratory from Bucharest. The hospital strains were identified by BD Phoenix and the CA ones by mass spectrometry using MALDI Biotyper. The antibiotic susceptibility was determined by agar disk diffusion (CLSI, 2017) and automated methods (BD Phoenix and Vitek II system). For molecular characterization, all strains were analyzed be using PCR amplification. The investigated strains revealed the presence of tetracycline resistance gene, i.e. tet(A) (67% in E. coli and 45% of K. pneumoniae strains), tet(D) (8% of E. coli and 5% of K. pneumoniae strains), carbapenemase genes (blaOXA-48 in 40% of the K. pneumoniae strains); blaTEM (25% of E. coli strains and 10% of K. pneumoniae strains).

Adherence of Candida albicans to the cellular and inert substratum contributes to its commensal status, but also plays an essential role in the development of fungal infections, particularly in hospitalized and immunodepressed patients. This study evaluated the adherence capacity and biofilm formation of 109 C. albicans strains isolated from upper respiratory tract secretions, wound secretions, urine culture, blood culture and stool culture taken from patients hospitalized for cardiovascular surgery. The strains were originally identified as C. albicans, based on their morphological characteristics and then confirmed by the Vitek II automatic system. All tested strains adhered to the cellular substratum, the isolates from stool culture, urine and thrush secretion exhibiting the most intensive adhesion capacity, the predominant adherence pattern being the aggregative one. Patient age and gender did not exhibit a significant influence on the adhesion process. The strains with the highest biofilm production capacity were the ones isolated from respiratory tract secretions and urine cultures. Statistically significant correlations could be established among a high number of yeast cells adhered to HeLa cells and i) the aggregative adherence pattern and ii) the moderate to high capacity to form biofilms on the inert substratum. These results could suggest the implication of common fungal structures in the colonization of inert and cellular substrata, while the elucidation of the molecular mechanisms involved in these processes could bring an important benefit to the appropriate management of fungal infections, depending on the isolation source.