• MeSH
• emigranti a imigranti MeSH
• lidé MeSH
• vakcinace * statistika a číselné údaje   MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Ukrajina MeSH

The genus Aeromonas comprises primarily aquatic bacteria and also serious human and animal pathogens with the occurrence in clinical material, drinking water, and food. Aeromonads are typical for their complex taxonomy and nomenclature and for limited possibilities of identification to the species level. According to studies describing the use of MALDI-TOF MS in diagnostics of aeromonads, this modern chemotaxonomical approach reveals quite high percentage of correctly identified isolates. We analyzed 64 Aeromonas reference strains from the set of 27 species. After extending the range of analyzed Aeromonas species by newly described ones, we proved that MALDI-TOF MS procedure accompanied by Biotyper tool is not a reliable diagnostic technique for aeromonads. We obtained quite high percentage of false-positive, incorrect, and uncertain results. The identification of newly described species is accompanied with misidentifications that were observed also in the case of pathogenic aeromonads.

• MeSH
• Aeromonas chemie   klasifikace   izolace a purifikace   MeSH
• fylogeneze MeSH
• gramnegativní bakteriální infekce mikrobiologie   veterinární   MeSH
• lidé MeSH
• mikrobiologie životního prostředí MeSH
• potravinářská mikrobiologie MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• techniky typizace bakterií metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH

RATIONALE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling of bacteria is often used to distinguish isolates beyond the species level, even to the level of individual strains. However, the influence of bacterial growth conditions on the discriminatory power of the method to the strain level has not yet been properly evaluated. METHODS: For the purpose of this study, we used an extraction protocol recommended for clinical laboratories for MALDI-TOF MS profiling of bacteria. Seventeen closely related strains of the Lactobacillus acidophilus group were cultivated under various growth conditions (growth medium, time, and temperature) and analyzed. RESULTS: Out of a total of 327 samples, 80 % were correctly assigned to the species level and 13 % only to the genus level. When using data obtained from strains cultured for lengthy periods (7 days), the identification success rate was reduced due to poor signal quality, whereas with shorter cultivation times there was no influence of growth conditions on the assignment of particular strains to their corresponding species. However, variations in certain cultivation parameters were found to influence identification and differentiation of most of the examined strains. Strain discrimination was frequently found to be dependent on the selection of culture conditions. MALDI-TOF MS data treatment (strain-specific peak detection, BioTyper scoring, subtyping, or cluster analysis) also contributed to the discriminatory power of the method. CONCLUSIONS: When MALDI-TOF MS profiling of bacteria is used for strain discrimination, the cultivation conditions should be properly optimized and controlled as they significantly contribute to the discriminatory power of the method.

• MeSH
• čas MeSH
• fylogeneze MeSH
• kultivační média MeSH
• Lactobacillus acidophilus klasifikace   genetika   růst a vývoj   izolace a purifikace   MeSH
• reprodukovatelnost výsledků MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• techniky typizace bakterií * metody   normy   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH