Isolate B17 from Kombucha was estimated to be an efficient producer of bacterial cellulose (BC). The isolate was deposited under the number P 1463 and identified as Komagataeibacter rhaeticus by comparing a generated amplified fragment length polymorphism (AFLP™) DNA fingerprint against a reference database. Static cultivation of the K. rhaeticus strain P 1463 in Hestrin and Schramm (HS) medium resulted in 4.40 ± 0.22 g/L BC being produced, corresponding to a BC yield from glucose of 25.30 ± 1.78 %, when the inoculum was made with a modified HS medium containing 10 g/L glucose. Fermentations for 5 days using media containing apple juice with analogous carbon source concentrations resulted in 4.77 ± 0.24 g/L BC being synthesised, corresponding to a yield from the consumed sugars (glucose, fructose and sucrose) of 37.00 ± 2.61 %. The capacity of K. rhaeticus strain P 1463 to synthesise BC was found to be much higher than that of two reference strains for cellulose production, Komagataeibacter xylinus DSM 46604 and Komagataeibacter hansenii DSM 5602T, and was also considerably higher than that of K. hansenii strain B22, isolated from another Kombucha sample. The BC synthesised by K. rhaeticus strain P 1463 after 40 days of cultivation in HS medium with additional glucose supplemented to the cell culture during cultivation was shown to have a degree of polymerization of 3300.0 ± 122.1 glucose units, a tensile strength of 65.50 ± 3.27 MPa and a length at break of 16.50 ± 0.83 km. For the other strains, these properties did not exceed 25.60 ± 1.28 MPa and 15.20 ± 0.76 km.

Surgical site infection is the second most common nosocomial (health-care associated) infection among hospitalized patients and is a significant public health problem worldwide. Infections caused by multiresistant microorganisms are of special concern because of difficulties to treat them. From 1484 clinical samples, we isolated 1117 cultures of different gram-positive and gram-negative microorganisms. The leading agents were S. aureus and coagulase-negative Staphylococci. Methicillin resistance among S. aureus was low, while it exceeded 50% in CoNS. From gram-negative bacteria, representatives of the family Enterobacteraceae and non-fermenting rods were isolated in similar amounts. ESBL producers among E. coli and K. pneumoniae were not registered.

Coagulase-negative Staphylococci (CoNS) form a part of the skin flora and commonly cause nosocomial bloodstream and catheter- related infections. According to their relatively low virulence, it is important to detect the virulence factors of clinical isolates. The production of extracellular polymers and formation of biofilms belong to virulence factors. We studied clinical isolates of CoNS and compared them with isolates from the healthy skin. The species distribution did not differ significantly. Slime production in clinical strains was more often and more intense. A comparison of methicillin-resistant (MR) and methicillinsensitive (MS) clinical strains has revealed that slime production is more active in MR strains.