Performance and microbial community structure of a full-scale ANITATMMox bioreactor for treating reject water located in Finland.

The aim of this work was to study the operational performance and the microbial community dynamics during the start-up of ANITATMMox technology implemented at full-scale wastewater treatment plant in Finland to treat reject water from anaerobic digesters. The average ammonium removal in the studied setup reached around 90%, withstanding ammonium loads up to 0.13 g N m-2h-1. The nitrite concentration in the effluent did not exceed 10 mg L-1, and there was a slight accumulation of NO3--N during the operation which was controlled. Thus, the result showed a robust success to high ammonium loading in presence of organic matter. The sequencing showed a heterogeneous microbial population where Methanosaeta, WCHA1-57 genus, Sphingobacteriia, Chlorobia and diverse unknown fungi were found as dominant phylotypes. Moreover, members of the Brocadiaceae family were dominant in the adhered biomass, mostly represented by Candidatus Scalindua, rarely reported in WWTPs. Overall, the results demonstrated a drastic effect of region-specific operational conditions on carrier biofilm microbial communities as it was demonstrated by the microbial studies.

Embryonic stem cell/fibroblast hybrid cells with near-tetraploid karyotype provide high yield of chimeras.

Ten primary clones of hybrid cells were produced by the fusion of diploid embryonic stem (ES) cells, viz., line E14Tg2aSc4TP6.3 marked by green fluorescent protein (GFP), with diploid embryonic or adult fibroblasts derived from DD/c mice. All the hybrid clones had many characteristics similar to those of ES cells and were positive for GFP. Five hybrid clones having ploidy close to tetraploidy (over 80% of cells had 76-80 chromosomes) were chosen for the generation of chimeras via injection into C57BL blastocysts. These hybrid clones also contained microsatellites marking all ES cell and fibroblast chromosomes judging from microsatellite analysis. Twenty chimeric embryos at 11-13 days post-conception were obtained after injection of hybrid cells derived from two of three clones. Many embryos showed a high content of GFP-positive descendents of the tested hybrid cells. Twenty one adult chimeras were generated by the injection of hybrid cells derived from three clones. The contribution of GFP-labeled hybrid cells was significant and comparable with that of diploid E14Tg2aSc4TP6.3 cells. Cytogenetic and microsatellite analyses of cell cultures derived from chimeric embryos or adults indicated that the initial karyotype of the tested hybrid cells remained stable during the development of the chimeras, i.e., the hybrid cells were mainly responsible for the generation of the chimeras. Thus, ES cell/fibroblast hybrid cells with near-tetraploid karyotype are able to generate chimeras at a high rate, and many adult chimeras contain a high percentage of descendants of the hybrid cells.

[Protease and reverse transcriptase genetic polymorphism in HIV type 1 subtype A variants predominating in cis countries].

To define frequencies of drug resistance mutations among HIV-1 variants circulating within the territory of Russia, subtype A HIV-1 nucleotide sequences encoding protease and reverse transcriptase were analyzed. The analysis was carried out in 141 antiretroviral-naive individuals. Low frequency (less than 1%) of primary drug resistance mutations was shown. However, high frequencies of secondary mutations V77I in protease and A62V in RT (67% H 63%, respectively) linked to each other in most cases were observed. The HIV-1 isolates bearing both substitutions (MutV77I/A62V) were also characterized by the presence of several synonymous mutations, suggesting common origin for these viruses. HIV Biochip Hybridization microarray and/or Restriction fragment-length polymorphism analyses were performed to characterize gene pol polymorphism in additional 178 subtype A HIV-1 isolates. Among total 319 samples studied, Mutv77IA62V variant accounted for 56%, and was found to predominate in Russia in terms of both its geographical distribution and number of cases caused. Moreover, these viruses were prevalent in the regions known to have highest incidence of HIV-1 infection (Irkutsk, Samara, and Moscow regions). In addition, three other variants were found: viruses not containing the substitutions V77I or A62V, and variants bearing only one of them. Evolutional relationships between all four HIV-1 variants, as well as potential impact of the gene pol polymorphism on HIV-1 replicative fitness and drug resistance development are discussed.

[Visible and "cryptic" segregation of parental chromosomes in embryonic stem hybrid cells].

Chromosome segregation of the parental chromosomes was studied in 20 interspecific hybrid clones obtained by fusion of Mus musculus embryonic stem cells with Mus caroli splenocytes. FISH analysis with labeled species specific probes and microsatellite markers was used for identification of the parental chromosomes. Cytogenetic analysis has shown significant intra- and interclonal variability in chromosome numbers and ratios of the parental chromosomes in the hybrid cells: six clones contained all M. caroli chromosomes, nine clones showed moderate segregation of M. caroli chromosomes (from 1 to 7), and five clones showed extensive loss of M. caroli chromosomes (from 12 to complete loss of all M. caroli autosomes). Both methods demonstrated "cryptic" segregation of the somatic partner chromosomes. For instance, five clones with near-tetraploid chromosome sets contained only few M. caroli chromosomes (from 1 to 8). The data obtained suggest that the tetraploid chromosome set per se is not a sufficient criterion for conclusion on the absence of chromosome loss in the hybrid cells. Note that "cryptic" chromosome segregation occurred at a high frequency in the examined hybrid clones. Thus, "cryptic" segregation should be borne in mind for assessing pluripotency and genome reprogramming of embryonic stem hybrid cells.

[Polymorphism of herpes simplex virus type 1 and 2 DNA from laboratory strains and clinical material from patient with genital herpes]. / Polimorfizm DNK virusa prostogo gerpesa tipov 1 i 2 iz laboratornykh shtammov i klinicheskogo materiala ot patsientov s genital'nym gerpesom.

Polymerase chain reaction (PCR), that can amplify a fragment of the DNA-polymerase gene of 4 herpes viruses, i.e. herpes simplex viruses, type 1 (HSV-1), herpes simplex viruses, type 2 (HSV-2), Epstein-Barr virus and cytomegalovirus, was made use of to study the genetic polymorphism of HSV-1 and HSV-2 strains. The obtained amplicons were analyzed by the method of restriction-size fragments' polymorphism (RSFP) with restrictases Rsal, Taql and Hinfl. Four HSV-1 strains had an identical restriction profile. Strain G (HSV-2) also displayed the expected restriction profiles, however, contradictory results were obtained for strain BH (HSV-2): the restriction profiles with restrictases Hinfl and Rsal corresponded to HSV-2, and the restriction profile with Taql corresponded to HSV-1. The sequencing of appropriate fragments of strains G and BH revealed a dot-type mutation localized in Taql restriction site. The thus worked out PCR was used jointly with RSFP in the genotyping of 75 urogenital samples obtained from women with genital herpes who were treated at Moscow patient-care facilities. HSV-1 and HSV-2 were detected in 18 (24%) and 57 (76%) of samples, respectively. No changes were registered in the restriction profile for HSV-2 among the investigated samples and all of them had the restriction profile similar to that of strain G. The conclusion is that genital herpes associated with HSV-2 is genetically stable within its Moscow population.

[New R-plasmids in strains of Serratia marcescens with multiple drug resistance]. / Novye R-plazmidy u shtammov Serratia marcescens s mnozhestvennoi lekarstvennoi rezistentnost'iu.

In 4 S. marcescens polyresistant strains isolated from patients conjugative plasmids transferred to Escherichia coli have been detected. Two of these strains carry each one plasmid which codes resistance to 10 different antibiotics, including aminoglycosides which rarely occur in our country, and belongs to group IncC. The third strain is the host of 2 plasmids. One of them is similar to the above-mentioned 2 plasmids with respect to the incompatibility group and a set of markers, but additionally codes resistance to cephalosporins; the second plasmid has been determined as belonging to group IncM, unstable and capable of rendering the cells highly resistant only to aminoglycosides. And, finally, the fourth strain also carries 2 plasmids: one of them is unstable and belongs, supposedly, to group IncI alpha, and the second plasmid is stable and belongs to group IncM. The plasmid of group IncI alpha differs from all other plasmids of our Serratia by its capacity of rendering the cells highly resistant to chloramphenicol.

[Transfer to Escherichia coli of the mercury markers of new Pseudomonas aeruginosa plasmids]. / Peredacha kishechnoi palochke rtutnykh markerov novykh plazmid Pseudomonas aeruginosa.

A total of 5 new conjugative plasmids pLD can be transferred from one Ps. aeruginosa strain to other strains of this species, but not to E. coli. Only the markers of resistance to mercury can be transferred to E. coli by means of plasmids Inc P-1. The present work contains the data confirming that the mercury markers of 2 plasmids pLD 1017 and pLD 1051 behave similarly to transposons.

[Staphylococcal wound infection and the problems of antibacterial therapy]. / Stafilokokkovaia infektsiia ran i voprosy antibakterial'noi terapii.

An analysis of a qualitative composition of wound microflora grounded on the findings of the clinico-bacteriological examination of 315 cases with various pyo-inflammatory processes is presented here, and specific features of the species composition of wound microflora depending upon the character of a pyo-inflammatory process are shown. The sensitivity of staphylococcuses isolated from the wounds, to 19 antibacterial preparations is analyzed and recommendations on the most rational and differentiated use of antibacterial drugs in various forms of a purulent process of staphylococcal eti-logy are suggested.