Detection and characterization of OXA-48-producing Klebsiella pneumoniae originated in Bulgaria.

We report the identification of OXA-48-producing Klebsiella pneumoniae, causing peritonitis in a cancer patient admitted to the Oncology Hospital in Sofia. The isolate had reduced susceptibility to carbapenems but remained susceptible to extended-spectrum cephalosporins. PCR and sequencing confirmed the presence of blaOXA-48 gene flanked by two intact copies of IS1999 on truncated ΔTn1999.

First detection of OXA-24 carbapenemase-producing Acinetobacter baumannii isolates in Bulgaria.

This report describes the first identification of OXA-24 carbapenemase-producing Acinetobacter baumannii isolates from Bulgaria. According to national surveillance data A. baumannii along with Pseudomonas aeruginosa are the most troublesome microorganisms in hospital environment with high rates of acquired carbapenem resistance.

Molecular epidemiology and multidrug resistance mechanisms of Pseudomonas aeruginosa isolates from Bulgarian hospitals.

A panel of 29 multidrug-resistant (MDR) Pseudomonas aeruginosa isolates recovered from seven hospitals as part of a country-wide surveillance of antimicrobial resistance in Bulgarian hospitals was studied. Molecular typing through multiple-locus variable number tandem-repeat analysis (MLVA6) yielded 23 different profiles. Phenotypic and genotypic tests for the detection of acquired carbapenemases yielded negative results in all cases.

Total internal reflection imaging of microorganism adhesion using an oil immersion objective.

In this paper, we report the results of total internal reflection microscopy investigations of the interaction of two types of microorganisms: Saccharomyces cerevisiae and Escherichia coli with substrates. It is shown that with this method qualitative and quantitative information about cells-substrate interaction can be obtained. One can easily make a difference between attached and non-attached as well as between dead and alive cells, and more generally can follow the dynamics of the process of cells' attachment to substrates.

Plasmon microscopy and imaging ellipsometry of Artrobacter oxydans attached on polymer films.

The attachment of Artrobacter oxydans 1,388 on a newly synthesized biodegradable copolymer of poly-(hexanlactam)-co-block-poly-(delta-valerolactone) is investigated by optical, microscopic and biochemical methods. The potentials of surface plasmon microscopy and imaging ellipsometry for detecting microorganisms when Al films are used to excite plasmons is assessed by comparing images obtained by these methods with dark field microscopy pictures. The experimental results demonstrate that in this case imaging ellipsometry and plasmon microscopy in transmission are promising methods and can be used in optical sensors for monitoring cell adhesion.

Tularemia outbreak, Bulgaria, 1997-2005.

The 1997-2005 tularemia outbreak in Bulgaria affected 285 people. Ten strains were isolated from humans, a tick, a hare, and water. Amplified fragment length polymorphism typing of the present isolates and of the strain isolated in 1962 suggests that a new genetic variant caused the outbreak.

Tularaemia outbreak in Bulgaria.

During the last 40 y, 2 large tularaemia outbreaks occurred in Bulgaria. We report the second outbreak, in 1998--2003, including a total of 262 laboratory confirmed cases. The majority of the patients presented with oropharyngeal tularaemia (89.