RESUMO
The vanC1 gene, which is chromosomally located, confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Enterococcus faecium TJ4031 was isolated from a blood culture and harbours the vanC1gene. Polymerase chain reaction (PCR) assays were performed to detect vanXYc and vanTc genes. Only the vanXYc gene was found in the E. faecium TJ4031 isolate. The minimum inhibitory concentrations of vancomycin and teicoplanin were 2 µg/mL and 1 µg/mL, respectively. Real-time reverse transcription-PCR results revealed that the vanC1and vanXYc genes were not expressed. Pulsed-field gel electrophoresis and southern hybridisation results showed that the vanC1 gene was encoded in the chromosome. E. faecalis isolated from animals has been reported to harbour vanC1gene. However, this study is the first to report the presence of the vanC1gene in E. faecium of human origin. Additionally, our research showed the vanC1gene cannot serve as a species-specific gene of E. gallinarum and that it is able to be transferred between bacteria. Although the resistance marker is not expressed in the strain, our results showed that E. faecium could acquire the vanC1gene from different species.
Assuntos
Humanos , Proteínas de Bactérias/genética , Enterococcus faecium/genética , Genes Bacterianos/genética , Enterococos Resistentes à Vancomicina/genética , Antibacterianos/farmacologia , Southern Blotting , Proteínas de Bactérias/sangue , Eletroforese em Gel de Campo Pulsado , Enterococcus faecalis/genética , Enterococcus faecium/efeitos dos fármacos , Enterococcus/efeitos dos fármacos , Enterococcus/genética , Hibridização In Situ/métodos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Família Multigênica/fisiologia , Reação em Cadeia da Polimerase , Teicoplanina/farmacologia , Resistência a Vancomicina/genética , Vancomicina/farmacologiaRESUMO
Oleaginous microbial strains were cultivated to identify the best oil-producing strain amongst Yarrowia lipolytica (CGMCC 2.1398), Lipomyces starkeyi (CGMCC 2.1608), Rhodosporidium toruloides (CGMCC 2.1389), Mortierella isabellina (CGMCC 3.3410), Cunninghamella blakeleana (CGMCC 3.970), and Mycobacterium QJ311. A method for rapid determination of oil content and fatty acid composition was established to identify the optimum oil-producing strains. This method had a relative standard deviation of 4.09%, an average recovery ratio of 97.09% and a detection limit of 0.1–1.0 g. Mortierella isabellina CGMCC 3.3410 was identified as the best oil-producing strain amongst the six strains tested, with a total biomass of 75 g/10 L and a lipid content of 35%. A rapid screening method of oleaginous microorganisms is discussed for the first time.