Method of isolating conditionally-pathogenic Gram-negative microorganisms, agents of intrahospital infections, from air

The possibility of detecting Pseudomonas aeruginosa and other Gram-negative bacteria in the air of the burn department at the Institute of Surgery was studied. The investigation of large volumes of air (0.5-1 m3) in the wards and the corridor with the use of a new bacteriological aerosol sampler, model IIAB-5, resulted in the detection of Pseudomonas aeruginosa. Besides, in a number of other rooms Klebsiella, Proteus, Citrobacter and Enterobacter were detected in the air. The possibility of the spread of Gram-negative opportunistic bacteria through the air in hospital conditions is discussed.     

Taxonomic identification of gram-negative nonfermenting microorganisms in environmental research

The scheme for the identification of Gram-negative nonfermenting microorganisms is proposed. The scheme comprises the most important key signs, such as the cytochrome oxidase reaction determined by the method of Gaby and Hadley, the oxidation/fermentation test, maltose oxidation and motility, as well as additional key signs, among them gelatinase activity, the oxidation of 10% lactose, nitratase activity with the liberation of free nitrogen, the utilization of the sources of carbon and energy (glucose and sodium acetate) in limited media containing ammonium salts and nitrates as the sources of nitrogen. Additional tests for the identification of nonfermenting microorganisms similar in their main key signs are also recommended.     

The medium for determining the gelatinase activity of non-fermenting gram-negative microorganisms

To determine the gelatinase activity of Gram-negative nonfermenting microorganisms, a double-layer medium containing 2% of agar in the lower layer and 10-20% of gelatin in the upper layer has been developed. The medium ensures free access of atmospheric oxygen, possibility of rapid (24-42 h) determination of gelatinase activity at 22-25 degrees C, efficacy of the test. simultaneous determination of gelatin hydrolysis by 8-12 strains in one dish.     

Subcellular Localization of Oxaloacetate Decarboxylase and Its Isolation from Maize Leaves

The activity of oxaloacetate decarboxylase was revealed in leaves of a C₄ plant, maize (Zea mays L.). This activity was unrelated to decarboxylase activities of other enzymes, e.g., NAD-malate dehydrogenase (EC 1.1.1.38) or NADP-malate dehydrogenase (EC 1.1.1.40), and was located in chloroplasts (83.1%). Using a four-step purification procedure, an electrophoretically pure enzyme preparation of oxaloacetate decarboxylase was obtained from maize leaves. The specific activity of the enzyme was 3.150 EU/mg protein, the factor of purification was 40.4, and the yield was 11.0%. The enzyme exhibited Michaelis–Menten kinetics with K _m for oxaloacetate 30 ± 5 M and pH optimum 7.1 ± 0.5. The metabolite-mediated regulation of oxaloacetate decarboxylase activity has been investigated. It is found that sodium chloride (1.0 mM) activates the enzyme, whereas ATP inhibits the enzyme activity.     

Investigation of the possibility of exceeding the Greenwald density limit during ECRH in T-10

In T-10 experiments, attempts were made to significantly exceed the Greenwald limit $\bar n_{Gr} $ during high-power (P _ab=750 kW) electron-cyclotron resonance heating (ECRH) and gas puffing. Formally, the density limit $(\bar n_e )_{\lim } $ exceeding the Greenwald limit $({{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }} = 1.8)$ was achieved for q _L=8.2. However, as q _L decreased, the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ also decreased, approaching unity at q _L≈3. It was suggested that the “current radius” (i.e., the radius of the magnetic surface enclosing the bulk of the plasma current I _p), rather than the limiter radius, was the parameter governing the value of $(\bar n_e )_{\lim } $ . In the ECRH experiments, no substantial degradation of plasma confinement was observed up to $\bar n_e \sim 0.9(\bar n_e )_{\lim } $ regardless of the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ . In different scenarios of the density growth up to $(\bar n_e )_{\lim } $ , two types of disruptions related to the density limit were observed.     

Phylogenetic analysis of a microbial community involved in anaerobic oxidation of ammonium nitrogen

The phylogenetic diversity of a microbial community involved in anaerobic oxidation of ammonium nitrogen in the DEAMOX process was studied. Analysis of clone libraries containing 16S rRNA gene inserts of Bacteria, (including Planctomycetes) and Archaea revealed the presence of nucleotide sequences of the microorganisms involved in the main reactions of the carbon, nitrogen, and sulfur cycles, including nitrifying, denitrifying, and ANAMMOX bacteria. In the bacterial clone library, 16S rRNA gene sequences of representatives of the phyla Proteobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Verrucomicrobia, Lentisphaerae, Spirochaetales, and Planctomycetes, as well as of some new groups, were detected. In the archaeal clone library, nucleotide sequences of methanogens belonging to the orders Methanomicrobiales, Methanobacteriales, and Methanosarcinales were found. It is possible that both ANAMMOX bacteria and bacteria of the genus Nitrosomonas are involved in anaerobic ammonium oxidation in the DEAMOX reactor. Many sequences were similar to those from the clone libraries obtained previously from the ANAMMOX community of marine sediments. It is also probable that the DEAMOX reactions occur in natural ecosystems (in marine and freshwater sediments and the oceanic water column), thereby providing for the coupling of the nitrogen and sulfur cycles.     

Hormonal Sex Inversion and Some Aspects of Its Genetic Determination in Chicken

Different mechanisms of genetic sex determination in birds are considered. Special emphasis is placed on the influence of external factors (reduction of estrogen synthesis, inactivation of DNA methylases) on expression of key sex determining genes. The possibility of sex inversion in domestic chicken by aromatase inhibition, genomic DNA demethylation, and the effect of estrogen analogs on estrogen receptors was demonstrated. The results of these effects were analyzed and their effect on the development of gonads in one-day embryos was demonstrated. A suggestion on earlier aromatase activity in chicken embryos, weak effect of DNA demethylation with 5-azacytidine, and different mechanisms of the effect of estrogens and their analogs (tamoxifen) on the gonad development in chicken was made.     

Influence of Mirabegron,Adrenaline, and Ascorbic Acid on the Intensity of Iron-Induced Biochemiluminescence of Erythrocytes in Whole Blood in Men

Human Physiology - Taking into account the prospects of using the selective β3 -adrenergic receptors (β3-AR) agonist mirabegron (Betmiga) for the prevention and treatment of obesity, we...