[Comparative results of preimplantation genetic screening by array comparative genomic hybridization and new-generation sequencing].

Aneuploidies as quantitative chromosome abnormalities are a main cause of failed development of morphologically normal embryos, implantation failures, and early reproductive losses. Preimplantation genetic screening (PGS) allows a preselection of embryos with a normal karyotype, thus increasing the implantation rate and reducing the frequency of early pregnancy loss after IVF. Modern PGS technologies are based on a genome-wide analysis of the embryo. The first pilot study in Russia was performed to assess the possibility of using semiconductor new-generation sequencing (NGS) as a PGS method. NGS data were collected for 38 biopsied embryos and compared with the data from array comparative genomic hybridization (array-CGH). The concordance between the NGS and array-CGH data was 94.8%. Two samples showed the karyotype 47,XXY by array-CGH and a normal karyotype by NGS. The discrepancies may be explained by loss of efficiency of array-CGH amplicon labeling.

Comparison of the results of preimplantation genetic screening obtained by a-CGH and NGS methods from the same embryos.

Chromosomal aneuploidies are known for being the main cause of abnormal development of embryos with normal morphology, their implantation failure and early reproductive losses in IVF treatments. Preimplantation genetic screening (PGS) allows selecting embryos with normal chromosomal content and increases IVF treatment efficiency due to higher implantation rates and less frequent early pregnancy losses. New technologies used for PGS allow making genome-wide analysis of the presence of all chromosomes in embryos. This article presents our study of evaluation of two techniques used for PGS: previously developed and used in our laboratory a-CGH assay based on Agilent technology and newly tested semi-conductive NGS technique (Torrent technology).

[Genetic determinants of resistance of hospital-associated strains of Klebsiella pneumoniae to ß-lactam antibiotics isolated in neonates].

According to the results of analysis of whole genome sequencing, the presence of genes having resistance to ß-lactam antibiotics in hospital-associated strains of Klebsiella pneumoniae was studied. The strains were isolated from neonatal intensive care units. The data obtained were compared with the results of antimicrobial susceptibility testing of isolated microorganisms. Among other strains resistant to cephalosporins, the dominance of genes of CTX-M-type extended-spectrum ß-lactamases was shown. It was revealed that one of eight strains phenotypically resistant and moderately resistant to carbapenems have the blaOXA-48 carbapenemase gene.