Inactivation of Chromosomal Genes in Serratia marcescens

© 2016, Springer Science+Business Media New York.Gram-negative bacterium Serratia marcescens is a well-known environmental microorganism and the accepted clinical pathogen causing nosocomial infections. It attracts more attention in recent years due to the emergence of strains with multiple drug resistance. Standard recombinant techniques are difficult to apply to S. marcescens due to the presence of numerous hydrolytic enzymes, in particular, extracellular nuclease and restriction endonuclease, which degrade transforming DNAs. We overcame this obstacle by utilizing restrictionless nuclease-deficient mutant strain S. marcescens TT392. As a proof of principal, in this genetic background, we generated a knockout strain with deletion of macAB locus using lambda red technology. The resulting mutation could be easily moved to a new genetic background by generalized phage transduction. This strategy provides a good tool for evaluation of S. marcescens pathogenic potential

Inactivation of Chromosomal Genes in Serratia marcescens

© 2016, Springer Science+Business Media New York.Gram-negative bacterium Serratia marcescens is a well-known environmental microorganism and the accepted clinical pathogen causing nosocomial infections. It attracts more attention in recent years due to the emergence of strains with multiple drug resistance. Standard recombinant techniques are difficult to apply to S. marcescens due to the presence of numerous hydrolytic enzymes, in particular, extracellular nuclease and restriction endonuclease, which degrade transforming DNAs. We overcame this obstacle by utilizing restrictionless nuclease-deficient mutant strain S. marcescens TT392. As a proof of principal, in this genetic background, we generated a knockout strain with deletion of macAB locus using lambda red technology. The resulting mutation could be easily moved to a new genetic background by generalized phage transduction. This strategy provides a good tool for evaluation of S. marcescens pathogenic potential

Inactivation of Chromosomal Genes in Serratia marcescens

© 2016, Springer Science+Business Media New York.Gram-negative bacterium Serratia marcescens is a well-known environmental microorganism and the accepted clinical pathogen causing nosocomial infections. It attracts more attention in recent years due to the emergence of strains with multiple drug resistance. Standard recombinant techniques are difficult to apply to S. marcescens due to the presence of numerous hydrolytic enzymes, in particular, extracellular nuclease and restriction endonuclease, which degrade transforming DNAs. We overcame this obstacle by utilizing restrictionless nuclease-deficient mutant strain S. marcescens TT392. As a proof of principal, in this genetic background, we generated a knockout strain with deletion of macAB locus using lambda red technology. The resulting mutation could be easily moved to a new genetic background by generalized phage transduction. This strategy provides a good tool for evaluation of S. marcescens pathogenic potential

Inactivation of Chromosomal Genes in Serratia marcescens

© 2016, Springer Science+Business Media New York.Gram-negative bacterium Serratia marcescens is a well-known environmental microorganism and the accepted clinical pathogen causing nosocomial infections. It attracts more attention in recent years due to the emergence of strains with multiple drug resistance. Standard recombinant techniques are difficult to apply to S. marcescens due to the presence of numerous hydrolytic enzymes, in particular, extracellular nuclease and restriction endonuclease, which degrade transforming DNAs. We overcame this obstacle by utilizing restrictionless nuclease-deficient mutant strain S. marcescens TT392. As a proof of principal, in this genetic background, we generated a knockout strain with deletion of macAB locus using lambda red technology. The resulting mutation could be easily moved to a new genetic background by generalized phage transduction. This strategy provides a good tool for evaluation of S. marcescens pathogenic potential

Interim results of the Ph-negative acute lymphoblastic leukemia treatment in adult patients (results of Russian research group of ALL treatment (RALL))

An interim analysis of long-term treatment results for 202 patients with acute lymphoblastic leukemia (ALL), aged 15–60 years, received therapy according protocol ALL-2009 was shown. The basic principle of ALL-2009 was non-aggressive, but continued cytostatic exposure, as well as the reproducibility in a regional hematology centers. Long-term treatment results of ALL-2009 are 2 times higher than the previously obtained in adult ALL patients within the Russian clinical multicenter studies of adult ALL. The 5‑year overall survival of patients younger than 30 years was 73.6 %, relapse-free survival (RFS) – 71.5 %, compared with 52.7 % and 61.8 % in patients aged 30 years and older, respectively. In patients with B-precursor ALL with normal karyotype of blast cells significantly higher 5‑year RFS (82.1 %) compared to patients with abnormal karyotype (58.8 %) was registered. For T-ALL cytogenetic characteristics of blast cells had no prognostic significance. For patients with T-ALL important to perform autologous stem cell transplantation as a later consolidation, as this significantly reducerelapse rate (from 33 to 0 %).</p

Interim results of the Ph-negative acute lymphoblastic leukemia treatment in adult patients (results of Russian research group of ALL treatment (RALL))

An interim analysis of long-term treatment results for 202 patients with acute lymphoblastic leukemia (ALL), aged 15–60 years, received therapy according protocol ALL-2009 was shown. The basic principle of ALL-2009 was non-aggressive, but continued cytostatic exposure, as well as the reproducibility in a regional hematology centers. Long-term treatment results of ALL-2009 are 2 times higher than the previously obtained in adult ALL patients within the Russian clinical multicenter studies of adult ALL. The 5‑year overall survival of patients younger than 30 years was 73.6 %, relapse-free survival (RFS) – 71.5 %, compared with 52.7 % and 61.8 % in patients aged 30 years and older, respectively. In patients with B-precursor ALL with normal karyotype of blast cells significantly higher 5‑year RFS (82.1 %) compared to patients with abnormal karyotype (58.8 %) was registered. For T-ALL cytogenetic characteristics of blast cells had no prognostic significance. For patients with T-ALL important to perform autologous stem cell transplantation as a later consolidation, as this significantly reducerelapse rate (from 33 to 0 %)