The Stephan Angeloff Institute of Microbiology

Sofia, Bulgaria

The Stephan Angeloff Institute of Microbiology

Sofia, Bulgaria
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De Soyza A.,Newcastle University | Hall A.J.,University of Liverpool | Mahenthiralingam E.,University of Cardiff | Drevinek P.,Charles University | And 18 more authors.
MicrobiologyOpen | Year: 2013

Pseudomonas aeruginosa is a major opportunistic pathogen in cystic fibrosis (CF) patients and causes a wide range of infections among other susceptible populations. Its inherent resistance to many antimicrobials also makes it difficult to treat infections with this pathogen. Recent evidence has highlighted the diversity of this species, yet despite this, the majority of studies on virulence and pathogenesis focus on a small number of strains. There is a pressing need for a P. aeruginosa reference panel to harmonize and coordinate the collective efforts of the P. aeruginosa research community. We have collated a panel of 43 P. aeruginosa strains that reflects the organism's diversity. In addition to the commonly studied clones, this panel includes transmissible strains, sequential CF isolates, strains with specific virulence characteristics, and strains that represent serotype, genotype or geographic diversity. This focussed panel of P. aeruginosa isolates will help accelerate and consolidate the discovery of virulence determinants, improve our understanding of the pathogenesis of infections caused by this pathogen, and provide the community with a valuable resource for the testing of novel therapeutic agents. © 2013 The Authors.


Eneva R.T.,The Stephan Angeloff Institute of Microbiology | Engibarov S.A.,The Stephan Angeloff Institute of Microbiology | Petrova P.,The Stephan Angeloff Institute of Microbiology | Abrashev R.,The Stephan Angeloff Institute of Microbiology | And 3 more authors.
Applied Biochemistry and Biotechnology | Year: 2015

Vibrio cholerae neuraminidase (VCNA) is widely used in biochemical and medical research, in processes for preparing homogenous sialoconjugates, and in the pharmaceutical industry. Its production by non-toxigenic strains is quite desirable, in order to avoid the expensive safety measures. Here, we report the first method for highly effective production of a novel, purified V. cholerae extracellular neuraminidase from a non-toxigenic strain. The enzyme is highly active, and its properties, as well as the responsible gene nanH, are practically identical with those of the toxigenic strains. It cleaves α,2 → 3 and α,2 → 6 glycosidic bonds with highest affinity (KM 1.7 × 10−5 μM) for human transferrin. The deduced amino acid sequence of the enzyme reveals three binding sites for Ca2+ and one for sialic acid. The sequence analysis of the nanH gene, being the first for a V. cholerae non-O1 strain, shows 99 % identity with a new nanH allele of an O1 Vibrio strain. The simple laboratory technology for efficient production of the new VCNA is based on the use of common and cheap nutrient media and easily available inducer—glycomacropeptide. The rapid purification consists of salting-out and diethylaminoethanol (DEAE) and Q-Sepharose chromatography steps. Purified preparation contains no aldolase and protease, which gives the production scheme a great potential for industrial application. © 2015, Springer Science+Business Media New York.


PubMed | The Stephan Angeloff Institute of Microbiology
Type: Journal Article | Journal: Applied biochemistry and biotechnology | Year: 2015

Vibrio cholerae neuraminidase (VCNA) is widely used in biochemical and medical research, in processes for preparing homogenous sialoconjugates, and in the pharmaceutical industry. Its production by non-toxigenic strains is quite desirable, in order to avoid the expensive safety measures. Here, we report the first method for highly effective production of a novel, purified V. cholerae extracellular neuraminidase from a non-toxigenic strain. The enzyme is highly active, and its properties, as well as the responsible gene nanH, are practically identical with those of the toxigenic strains. It cleaves ,2 3 and ,2 6 glycosidic bonds with highest affinity (K M 1.7 10(-5) M) for human transferrin. The deduced amino acid sequence of the enzyme reveals three binding sites for Ca(2+) and one for sialic acid. The sequence analysis of the nanH gene, being the first for a V. cholerae non-O1 strain, shows 99% identity with a new nanH allele of an O1 Vibrio strain. The simple laboratory technology for efficient production of the new VCNA is based on the use of common and cheap nutrient media and easily available inducer--glycomacropeptide. The rapid purification consists of salting-out and diethylaminoethanol (DEAE) and Q-Sepharose chromatography steps. Purified preparation contains no aldolase and protease, which gives the production scheme a great potential for industrial application.

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