Fluorothiazinon inhibits the virulence factors of uropathogenic Escherichia coli involved in the development of urinary tract infection.

Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacterium associated with urinary tract infection. Due to the development of antibiotic resistance and MDR, UPEC infection has become a serious problem in the last decade. In order to combat resistance, it is necessary to develop innovative antimicrobial agents that act by different mechanisms than conventional antibiotics. Among the new therapeutic strategies, suppression of pathogen virulence has become a promising alternative, since it fundamentally reduces selective pressure and the development of resistance. In our study, we showed that the compound Fluorothiazinon suppressed UPEC's ability to form biofilms and to move using the flagellum, as well as to penetrate into cells. Prophylactic use with subsequent treatment of FT in rodent models led to an improvement in survival and significantly reduced the bacterial load in the organs of the urinary system, thereby inhibiting the development of ascending infection and preventing the development of pathological changes in prostate tissues. These results suggest that FT affects several UPEC virulence factors at once and if similar results can be found in clinical trials it can potentially be used as a new drug against UPEC.

[Single-domain adapted antibodies against Chlamydia trachomatis, preserving the development of chlamidic infection in vitro]. / Odnodomennye adaptirovannye antitela protiv Chlamydia trachomatis, podavliaiushchie razvitie khlamidiinoi infektsii v usloviiakh in vitro.

The technology for the generating of single-domain recombinant monoclonal antibodies (nanoantibodies) based on the immunization of a camel, cloning of induced sequences encoding single-domain antigen-recognizing fragments of non-canonical camel antibodies, as well as functional selection of clones of nanoantibodies by the phage display method, was used to obtain new effective tools for more efficient diagnostics of Chlamydia infection and to develop new approaches for effective therapy. Two promising nanoantibodies were obtained. They showed effective binding to extracellular and intracellular forms of C. trachomatis, and also had activity that inhibited the development of chlamydial infection in vitro.

Role of Chlamydia in Multiple Sclerosis.

Chlamydia and antibodies to them were detected by serological, molecular biological, and culture methods in the sera and cerebrospinal fluid of patients with multiple sclerosis and in the reference groups of subjects without neurological diseases. Correlations between the agent presence in the biological fluids of patients and clinical characteristics of the disease were analyzed. C. pneumoniae were more incident in the biological liquids of patients with multiple sclerosis than in healthy volunteers. On the other hand, the incidence of the agent in the patients was not high and its presence did not correlate with the clinical manifestations. C. trachomatis was equally rare in the patients and volunteers. The studies indicated the existence of a group of patients infected by C. pneumoniae in the cohort of patients with multiple sclerosis, but the impact of this agent for the disease course remains unclear.

[Modern aspects of diagnostics of chronic chlamydiosis caused by persisting forms of Chlamydia].

AIM: To study the possible hematogenic route of dissemination of Chlamydia trachomatis and to analyze efficacy of methods of pathogen detection in clinical specimens (sera and scraping material). MATERIALS AND METHODS: Cultural method, electron microscopy, real-time PCR, immunofluorescent assay. RESULTS: C. trachomatis was detected in blood by using 2 tests (culture and PCR) in 95.2% of patients with confirmed Chlamydia infection. Chlamydia isolated from blood had infectious properties that could point to the presence of weakly studied hematogenic route of dissemination of C. trachomatis in host's organism. Study of diagnostic value of pathogen detection in serum showed that in case of chronic diseases of urogenital tract as well as extragenital diseases, rate of C. trachomatis detection in serum was significantly higher (61.1% of cases compared to 16.7% in scraping material). CONCLUSION: It is the first time when data about possible circulation of C. trachomatis in blood of patients was obtained. Detection of C. trachomatis in serum of patients with chronic and complicated forms of chlamydiosis provides essentially new approach for direct identification of the pathogen irrespectively from localization of infection's locus.

Structure of human pro-matrix metalloproteinase-2: activation mechanism revealed.

Matrix metalloproteinases (MMPs) catalyze extracellular matrix degradation. Control of their activity is a promising target for therapy of diseases characterized by abnormal connective tissue turnover. MMPs are expressed as latent proenzymes that are activated by proteolytic cleavage that triggers a conformational change in the propeptide (cysteine switch). The structure of proMMP-2 reveals how the propeptide shields the catalytic cleft and that the cysteine switch may operate through cleavage of loops essential for propeptide stability.

Three-dimensional structure of human tissue inhibitor of metalloproteinases-2 at 2.1 A resolution.

The three-dimensional structure of human tissue inhibitor of metalloproteinases-2 (TIMP-2) was determined by X-ray crystallography to 2.1 A resolution. The structure of the inhibitor consists of two domains. The N-terminal domain (residues 1-110) is folded into a beta-barrel, similar to the oligonucleotide/oligosaccharide binding fold otherwise found in certain DNA-binding proteins. The C-terminal domain (residues 111-194) contains a parallel stranded beta-hairpin plus a beta-loop-beta motif. Comparison of the structure of uncomplexed human TIMP-2 with that of bovine TIMP-2 bound to the catalytic domain of human MMP-14 suggests an internal rotation between the two domains of approximately 13 degrees upon binding to the protease. Furthermore, local conformational differences in the two structures that might be induced by formation of the protease-inhibitor complex have been found. The most prominent of these involves residues 27-40 of the A-B beta-hairpin loop. Structure-based alignment of amino acid sequences of representatives of the TIMP family maps the sequence differences mainly to loop regions, and some of these differences are proposed to be responsible for the particular properties of the various TIMP species.

[Isolation of isoforms and crystallization of endonucleases of Serratia marcescens]. / Razdelenie izoform i kristallizatsiia éndonukleazy Serratia marcescens.

Two isoforms of an extracellular endonuclease, nuclease Sm1 and nuclease Sm2, were isolated from the culture filtrate of Serratia marcescens strain B10 M1 by the ligand-exchange chromatography on iminodiacetate-agarose in Cu2(+)-form, and chromatography on phosphocellulose and DEAE-Toyopearl 650S. The pI for nucleases Sm1 and Sm2 were found to be 7.1 and 6.7, respectively. The amino acid analysis and N-terminal amino acid sequencing of the proteins showed a significant degree of homology between the enzymes. The secondary structure of nuclease Sm2 was calculated. Crystals of nuclease Sm2 were obtained with the space group P2(1)2(1)2(1), a 69.0; b 106.7; c 74.8 A.