Whole-Genome Sequencing of Russian Neisseria Gonorrhoeae Isolates Related to ST 1407 Genogroup.

The whole-genome sequencing data of three N. gonorrhoeae strains isolated in the Russian Federation in 2015 are presented. According to the NG-MAST protocol, these strains are related to the globally spread ST 1407 genogroup. The analysis of their resistomes showed the absence of ermA/B/C/F genes and the presence of wild-type alleles of rpsE, rrs, rrl, rplD, rplV, macAB, and mefA genes, and these patterns explain the susceptibility of the sequenced strains to aminocyclitols (spectinomycin) and macrolides (azithromycin). Conjugative resistance determinants (blaTEM, tetM) were absent in the genomes, and the penC/ pilQ, parE, and norM alleles were shown to be wild-type, whereas single or multiple nucleotide substitutions were identified in the genes encoding targets for ß-lactams (ponA, penA), tetracyclines (rpsJ), and fluoroquinolones (gyrA, parC). The additional mutations were found in porB gene and the promoter of mtrR gene, which nonspecifically reduced the susceptibility to antimicrobials due to the membrane permeability decrease and efflux pump overexpression. The diversity of mutations observed in the analyzed genomes prompted a revision of the phylogenetic relationships between the strains by comparing more than 790 groups of housekeeping genes. A high homology between the N. gonorrhoeae ST 1407 and N. gonorrhoeae ST 12556 genomes was confirmed; the latter had probably diverged from a common ancestor as a result of single mutation events. On the other hand, N. gonorrhoeae ST 12450 was an example of phenotypic convergence which appeared in the emergence of new drug resistance determinants that partially coincide with those of the ST 1407 genogroup.

Do Mitochondria Have an Immune System?

The question if mitochondria have some kind of immune system is not trivial. The basis for raising this question is the fact that bacteria, which are progenitors of mitochondria, do have an immune system. The CRISPR system in bacteria based on the principle of RNA interference serves as an organized mechanism for destroying alien nucleic acids, primarily those of viral origin. We have shown that mitochondria are also a target for viral attacks, probably due to a related organization of genomes in these organelles and bacteria. Bioinformatic analysis performed in this study has not given a clear answer if there is a CRISPR-like immune system in mitochondria. However, this does not preclude the possibility of mitochondrial immunity that can be difficult to decipher or that is based on some principles other than those of CRISPR.

[Effect of Long-Term Application of Agrotechnical Techniques and Crops on Soil Microbial Communities].

Effects of long-term application ofvarious fertilizers and crops on soil microbiomes an a long-term field experiment were investigated using the library of the 16S rRNA gene sequences obtained by high-throughput sequencing of the total DNA. The communities exhibited high diversity, with 655 microbial genera belonging to 34 phyla detected (31 bacterial and 3 archaeal ones). For analysis of the effect of the studied factors on community structure, a linear model was developed in order to simplify interpretation of the data of high-throughput sequencing and to obtain biologically important information. Liming was shown to modulate the effect of mineral fertilizers on the structure of microbial populations. The differences in the structure and alpha-diversity of microbial communities were shown to depend more on the crops and liming, rather than on the fertilizers applied. Interaction between the crop factor and liming expressed as an ambiguous effect of liming on the microbiome in the presence of different plants was reliably demonstrated. Thus, in the case of barley and clover, liming resulted in increased taxonomic diversity of the community, while in the case of potato and flax it had an opposite effect.