The adaptation of human immunodeficiency virus type-1 (HIV-1) to an array of physiologic niches is advantaged by the plasticity of the viral genome, encoded proteins, and promoter. CXCR4-utilizing (X4) viruses preferentially, but not universally, infect CD4+ T cells, generating high levels of virus within activated HIV-1-infected T cells that can be detected in regional lymph nodes and peripheral blood. By comparison, the CCR5-utilizing (R5) viruses have a greater preference for cells of the monocyte-macrophage lineage; however, while R5 viruses also display a propensity to enter and replicate in T cells, they infect a smaller percentage of CD4+ T cells in comparison to X4 viruses. Additionally, R5 viruses have been associated with viral transmission and CNS disease and are also more prevalent during HIV-1 disease. Specific adaptive changes associated with X4 and R5 viruses were identified in co-linear viral sequences beyond the Env-V3. The in silico position-specific scoring matrix (PSSM) algorithm was used to define distinct groups of X4 and R5 sequences based solely on sequences in Env-V3. Bioinformatic tools were used to identify genetic signatures involving specific protein domains or long terminal repeat (LTR) transcription factor sites within co-linear viral protein R (Vpr), trans-activator of transcription (Tat), or LTR sequences that were preferentially associated with X4 or R5 Env-V3 sequences. A number of differential amino acid and nucleotide changes were identified across the co-linear Vpr, Tat, and LTR sequences, suggesting the presence of specific genetic signatures that preferentially associate with X4 or R5 viruses. Investigation of the genetic relatedness between X4 and R5 viruses utilizing phylogenetic analyses of complete sequences could not be used to definitively and uniquely identify groups of R5 or X4 sequences; in contrast, differences in the genetic diversities between X4 and R5 were readily identified within these co-linear sequences in HIV-1-infected patients.
Aim. Confirmation of taxonomic position of Lactobacillus fermentum 90 TC-4 strain using phenotypic (classic microbiological, MALDI TOF mass-spectrometry) and genetic (16S rRNA gene segment sequencing and full genome sequencing) methods. Materials and methods. Object of the study - Lactobacillus fermentum 90 TC-4 strains from various collections. Mass-spectrometric analysis was carried out using Autoflex MALDI TOF mass-spectrometer (Bruker Daltonics, Germany), study of biochemical properties of the strain was carried out using API 50 CHL strips (Biomerueux, France), “DNA-sorb B” kit was used for isolation ofgenome DNA (CRIE, Moscow). Sequencing of the accumulated fragments of 16S rRNA gene was carried out using GenomeLab GeXP sequencing (Beckman Coulter, USA), full genome sequencing was carried out in MiSeq platform (Illumina). Assembly ofgenome and bioinformation analysis was carried out using BLAST program (www.blast.ncbi.nlm.nih.gov/blast.cgi), «CLC Bio Assembly» and genome server RAST (rast.nmpdr.org). Results. L. fermentum 90 TC-4 strain was established to be contaminated by L. plantarum culture in a series of cases. As a result of identification of a pure culture of L. fermentum 90 TC-4 strain using a specter of high-technology methods, membership of the strain in L. fermentum species has been proven. Conclusion. Taxonomic status of L. fermentum 90 TC-4 strain was confirmed.
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