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M Iu Kirillov

Publications and source records attributed to M Iu Kirillov.

At least 19 recordsLinked to original sources

[A molecular-and-genetic analysis of species and strain diversity of bifidobacteria in early childhood].

The species and strain composition of bifidobacteria in 29 children both sexes, aged 8 to 16 months, was studied. Species-specific primers and PCR were used to determine to which species the predominant strains of bifidobacteria, isolated from feces by cultural methods, belonged. Bifidobacteria were found in 28 (96.5%) children; their number was 10.2 +/- 0.7 ECU per a gram of the material. B. longum and B. bifidum were frequent (71.4 and 53.5%, respectively). The level of quantitative detection used in the study also allowed revealing of B. catenulatum (17.9%) and B. breve (14.4%). A high titer of B. dentium was found in one case (3.6%). B. adolescentis and B. angulatum were not found in any patient. The average number of species found in one child was 1.7 +/- 0.7. RAPD-PCR and investigation of plasmid profile were used to determine possible belonging of the isolates to different strains. The average number of strains per one sample was 2.3 +/- 1.2. Nine unique plasmid bifidobacterial strains were isolated from 7 children. In 3 children the intestinal tract was found to be colonized by both plasmid and non-plasmid-carrying strains of one bifidobacterial species.

Age Factors↗

[Wild small mammals are the reservoir hosts of the Bartonella genus bacteria in the south of Moscow region].

A total of 103 blood samples collected from wild small mammals captured in the Prioksko-Terrasny Reserve on the south of Moscow region were studied to determine the bartonellae prevalence. The examined species were the yellow-necked mice Apodemus flavicollis (35 samples), the European wood mouse Apodemus uralensis (10 samples), the bank vole Clethrionomys glareolus (51 samples), the house mouse Mus musculus (3 samples), the common vole Microtus arvalis (2 samples), and the shrew Sorex araneus (2 samples). Initially, we obtained 76 bacterial Bartonella-like isolates after plating onto the surface of the solid nutrient media. 66 of them were PCR-positive at least for three of four targets, gltA, ftsZ, ribC and 16S RNA. Thus, the percentage of the infection in the studied community was 64%. Subsequent RFLP assay showed that obtained isolates belonged to the Bartonella grahamii and/or B. taylorii species. In 7 cases we found both bartonellae species in one animal. These data were confirmed by direct sequencing of four ftsZ, four ribC and two gltA amplicons. According to our data, there is no any marked host specificity for these bartonellae species. Now we have laid the bartonellae strain collection consisting of 31 isolates. To our knowledge, this is the first investigation of the bartonellae prevalence in wild small mammals performed in Russia. The comparison of our data with those obtained by European researchers and issues of coinfection by different bartonellae species and host specificity are discussed.

Animals↗

[Methods of Helicobacter pylori detection].

There is the HP diagnostic methods review. The classification of main methods is presented. Diagnostic significance and defects of all these methods were demonstrated. There are own data of HP and its strains revealing in the patients with duodenal peptic ulcer.

Duodenal Ulcer↗

[A mobile genetic element on a Bordetella pertussis chromosome stimulates cointegrate formation in Escherichia coli strains].

This work continues a series of reports devoted to the study of a repeated sequence isolated from the Bordetella pertussis chromosome (RSBP--Repeated Sequence of Bordetella Pertussis). The RSBP was earlier demonstrated to have a structure similar to IS elements and exhibit some properties of mobile genetic elements. The results of this work demonstrate the ability of this novel genetic element to stimulate the formation of cointegrates between independent replicons. We have studied the structure of five cointegrates formed by integration of a resident RSBP-containing plasmid into three different sites of a recipient replicon. The studied cointegrates are capable of resolution with the release of a resident plasmid independent of the host cell RecA function.

Bordetella pertussis↗

[Identification of genes controlling the transition of Salmonella typhimurium bacteria to a non-culturable state].

Mutants of Salmonella typhimurium with an impaired process of transition to the nonculturable state were tainted. Mutants were divided into four phenotypic groups. In four mutants (representatives of each phenotypic group), genes with TnPhoA transposon insertions were cloned; these insertions caused a disturbance in the process of mutant cell transition to the nonculturable state. Nucleotide sequences of mutant gene fragments were determined. Comparison of nucleotide sequences obtained with a data bank on DNA nucleotide sequences of enterobacterial genomes allowed the identification of four genes involved in the control of nonculturable form generation in salmonellae.

Base Sequence↗

[Nucleotide sequence and properties of a transposon-like structure cloned from a Bordetella pertussis chromosome].

The 2.3 kb BamHI-EcoRI subclone has been isolated and sequenced from the 15 kb BamHI chromosomal fragment of Bordetella pertussis comprising also the vir gene. The sequence contained one copy of a transposon-like structure, very similar to the RSs of B. pertussis recently characterized, the unique sequence of B. pertussis chromosomal DNA and an inverted sequence complementary to 402 bp of 3' end of the B. pertussis RS element. The fragment of plasmid pUC4K containing the gene for kanamycin resistance (Km) was integrated in the XhoI site of the unique portion of the transposon-like structure of plasmid DNA (Ap(r), Km(r)). The clones in amount of 2% tested had the Ap-S phenotype. The recombinant plasmid from the Ap(s) phenotype clones lost one of the repeats and a portion of the gene bla as a result of deletion. The conclusion is drawn that RSs of B. pertussis stimulate the formation of deletions.

Ampicillin Resistance↗

[Nucleotide sequence and properties of an inverted repeating element of a Bordetella pertussis chromosome].

The repeated sequence from Bordetella pertussis chromosome was cloned using the method described by Ohtsubo. The sequences of the characterized B. pertussis chromosome are homologous to the previously described sequences and analogous in the structure to the already known IS elements. The parental recombinant plasmids containing the RS were unstable and segregated to the plasmids of different structure. The segregants' structure is characterized in this paper. It is shown in our study that the RS element is able to stimulate intragenomic rearrangements, such as deletions. It is shown that at least one deletion begins precisely after 3' end of RS and terminates with the sequence which is completely homologous to ten terminal nucleotides of this one. Probably, RSs stimulate at high frequency the formation of deletions, which appear to be the result of recA-independent site-specific recombination between short direct repeats.

Base Sequence↗

[Mobile element RSBP1 of Bordetella pertussis].

A number of repeated sequences was identified in the chromosome of Bordetella pertussis by the electron microscopic analysis of the chromosomal DNA of this microorganism. One of the sequences was cloned on the vector plasmid pHC79. It is shown to consist of two elements RSBP1 and RSBP2. The first elements is probably identical to an RS-element described previously. The cloned RSBP1 element is shown to stimulate the deletion formation in the genome of the plasmid pMKII and is able to transpose into the chromosome of Escherichia coli. The latter properties permit one to classify RSBP1 as an element belonging to a class of migrating genetical elements.

Bordetella pertussis↗

[Structural organization of a segment of chromosome, containing the vir gene of Bordetella pertussis].

To study the structural arrangement of the chromosomal region containing vir genes of Bordetella pertussis the corresponding 15 kb fragment of Bordetella pertussis chromosomal DNA has been cloned. The sequence homology to an earlier characterized Bordetella pertussis genetical element RSBP1 and flanked by two 400 bp inverted repeats has been shown to be located at an end of a BamHI fragment. The restriction map of Bordetella pertussis 475 coincides with the previously published maps of Bordetella pertussis Tohama and 18323 permitting one to conclude the definite conservatism of the cloned sequence. The preliminary data obtained make possible mapping of the RSBP1 homologous sequence adjacent to adenylate cyclase, agglutinin 2 and pertussis toxin genes. The possible role of RSBP1 elements in the regulation of Bordetella virulence is suggested.

Bordetella pertussis↗