PubMed Health⌕ Search

Biomedical subjects

Balázs Libisch

Publications and source records attributed to Balázs Libisch.

5 recordsLinked to original sources

Metallo-beta-lactamases as emerging resistance determinants in Gram-negative pathogens: open issues.

The rapid spread of acquired metallo-beta-lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.

Anti-Bacterial Agents↗

Establishing clonal relationships between VIM-1-like metallo-beta-lactamase-producing Pseudomonas aeruginosa strains from four European countries by multilocus sequence typing.

Ten multidrug-resistant Pseudomonas aeruginosa strains producing VIM-1-like acquired metallo-beta-lactamases (MBLs), isolated from four European countries (Greece, Hungary, Italy, and Sweden), were analyzed for genetic relatedness by several methodologies, including fliC sequence analysis, macrorestriction profiling of genomic DNA by pulsed-field gel electrophoresis (PFGE), random amplification of polymorphic DNA (RAPD), and multilocus sequence typing (MLST). The four approaches yielded consistent results overall but showed different resolution powers in establishing relatedness between isolates (PFGE>RAPD>MLST>fliC typing) and could usefully complement each other to address issues in the molecular epidemiology of P. aeruginosa strains producing acquired MBLs. In particular, the recently developed MLST approach was useful in revealing clonal relatedness between isolates when this was not readily apparent using RAPD and PFGE, and it suggested a common ancestry for some of the VIM-1-like MBL-positive P. aeruginosa strains currently spreading in Europe. The MBL producers belonged in three clonal complexes/burst groups (BGs). Of these, one corresponded to the previously described BG4 and included serotype O12 strains from Hungary and Sweden, while the other two were novel and included serotype O11 or nonserotypable strains from Greece, Sweden, and/or Italy. Comparison of the integrons carrying blaVIM-1-like cassettes of various isolates revealed a remarkable structural heterogeneity, suggesting the possibility that multiple independent events of acquisition of different blaVIM-containing integrons had occurred in members of the same clonal lineage, although a contribution of integrase-mediated cassette shuffling or other recombination mechanisms during the evolution of similar strains could also have played a role in determining this variability.

Bacterial Proteins↗

Molecular epidemiology of VIM-4 metallo-beta-lactamase-producing Pseudomonas sp. isolates in Hungary.

VIM metallo-beta-lactamase-producing serotype O11 or O12 Pseudomonas aeruginosa isolates infecting or colonizing 19 patients from seven hospitals in Hungary were characterized between October 2003 and November 2005. Macrorestriction analysis revealed the involvement of hospitals from three different towns in northwest Hungary in an outbreak caused by VIM-4-producing P. aeruginosa.

Base Sequence↗

Isolation of an integron-borne blaVIM-4 type metallo-beta-lactamase gene from a carbapenem-resistant Pseudomonas aeruginosa clinical isolate in Hungary.

The first integron-borne metallo-beta-lactamase gene was isolated in Hungary. The bla(VIM-4) gene is located on a class 1 integron that also carries a novel bla(OXA)-like gene. The integron is harbored by a serotype O12 Pseudomonas aeruginosa strain and shows high structural similarity to integrons isolated in Greece and Poland.

Amino Acid Sequence↗