Approbation of russian test strips for antimicrobial susceptibility testing of microorganisms by gradient diffusion method (E-test).

The most reliable criterion for the microorganisms antibiotic susceptibility is the value of the minimum inhibitory concentration (MIC). The gradient diffusion method (epsilometric test, e-test), carried out using test strips impregnated with an antimicrobial agent, allows to obtain the quantitative value of MIC, bypassing the time-consuming steps of the traditional method of serial dilutions. We tested strips for the epsilometric test, developed at Saint-Petersburg Pasteur Institute. The quality control, carried by testing the reference strains of E. coli ATCC 25922 and S. aureus 29213, confirmed compliance of the manufacturer's declared antibiotic concentration ranges. The MIC values obtained in the study of the antibiotic susceptibility of 101 clinical isolates of microorganisms of the ESKAPE group, isolated from patients of various hospitals in St. Petersburg, were compared to 8 antimicrobial agents using tested test strips and the corresponding M.I.C. Evaluator of the Oxoid (UK). A high percentage of compliance of MIC values was demonstrated, as well as full compliance of susceptibility categories for all microorganism/antibiotic combinations. The resulting divergences in the MIC values did not exceed one step of a double serial dilution, which is permissible according to GOST R ISO 20776-1-2010. The study showed that the test strips developed at the Saint-Petersburg Pasteur Institute DNT are an acceptable alternative to import tests and, after the registration certificate will be completed, can be offered to determine the susceptibility of microorganisms to antimicrobial agents in bacteriological laboratories.

INTERMOLECULAR INTERACTIONS IN THE SOLUTIONS OF SERUM ALBUMIN.

The mechanisms of intermolecular protein complex formation were studied by the example of monomers, oligomers and aggregates of bovine serum albumin (BSA) depending on the protein concentration, pH and urea concentration. Using dynamic light scattering (DLS), analytical ultracentrifugation (AUC) and PAG electrophoresis, we have shown that there is dynamic equilibrium between monomers and aggregates in BSA solution. Decreasing pH of the solution (4.0­1.0) resulted in increasing sizes of the aggregates. In the solutions with low urea concentrations (below 2 M), the sizes of aggregates decreased, while higher urea concentrations induced formation of larger aggregates due to the unfolding of the protein.

[Associations of PRLR/AluI gene polymorphism with reproductive, growth and meat quality traits in pigs].

The aim of this study was to determine associations between genotypes for the prolactin receptor (PRLR) gene and swine reproductive, growth and meat traits. 210 sows of three genetic groups: Large White (LW), Danish Landrace (LD) and Landrace x Yorkshire x Duroc (L x x Y x D) were included. The studied reproductive traits included the total number of born (TNB), number born alive (NBA). The growth traits were the number of days to 100-kg, average daily gains (ADG). The meat traits were the average backfat thickness (BFT), half carcass weight (HCW), area of M. longissimus dorsi (MLT) and lean meat content (LM). The polymorphism was detected using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method. It was shown that BB genotype is associated with the best NBA on 1.9 and 0.7 piglets at sows LW and LD, respectively. AB genotype is associated with best number of days to 100-kg at sows LD on 3.1 days and AA genotype with less BFT on 1.7 mm, bigger HCW on 0.5 kg and MLT on 5, 4 cm I at L x Y x D.

[Laboratory diagnosis of systemic chlamydiosis]. / Osobennosti laboratornoi diagnostiki khlamidiozov s sistemnymi proiavleniiami.

Modern methods for diagnosis of chlamydial infection are compared. In order to detect the total systems' manifestations in patients with chlamydial infection, the authors suggest to extend the list of clinical materials to be collected in patients with suspected chlamydial infection and to use direct immunofluorescent test, polymerase chain reaction, and ligase chain reaction in diagnostic studies.

[The role of mononuclear phagocytes in the immunopathogenesis of HIV infection]. / Rol' mononuklearnykh fagotsitov v immunopatogeneze VICh-infektsii.

The functional state of HIV-infected monocytes in 153 persons aged 20-59 years was studied. It was characterized by an increase in the production of monokines (TNF-alpha, IL1 beta) at stages IIB-IIIA, pronounced activation of the synthesis of DNA at stages IIB-IIC of the disease due to mass intracellular production of viral proteins. At the same stages an increase in the activity of lactate dehydrogenase and a decrease in the activity of succinate dehydrogenase were noted, which was indicative of an increase in the intensity of the process of anaerobic oxygenation at early of infection with the simultaneous decrease of the intensity of the tricarbon acid cycle and the subsequent suppression of the immunoregulating properties of monocytes.

[The genetic typing of Corynebacterium diphtheriae strains by the polymerase chain reaction with universal primers]. / Geneticheskoe tipirovanie shtammov Corynebacterium diphtheriae metodom polimeraznoi tsepnoi reaktsii s universal'nymi praimerami.

The use of polymerase chain reaction (UP-PCR with universal primers for the genetic typing of 85 C. diphtheriae strains, isolated from patients and carriers at the period of the epidemic, has shown that a single natural clone of biovar gravis seems to prevail in North Western Russia. UP-PCR is an effective too for the rapid intraspecific typing of strains on the molecular-genetic level and for the study of the circulation of C.diphtheriae epidemic clones.

[The epidemiological characteristics and laboratory diagnosis of viral hepatitides among the Federal troops on the territory of the Chechen Republic]. / Epidemiologicheskaia kharakteristika i laboratornaia diagnostika virusnykh gepatitov v federral'nykh voiskakh na territorii Chechenskoi Respubliki.

The items of information about epidemiologic peculiarities of virus hepatitis among military men of incorporated grouping of troops of MoD of RF in Republic of Chechnya and about creation of uniform system of laboratory diagnostics in interests of etiologic orientation of prophylaxis and control of these infections in military groups are submitted. Etiologic structure, the reasons and conditions of occurrence of virus hepatitis are established.