Development of antilipase immunoglobulin polymer diagnosticum for the detection of Vibrio cholerae eltor, possessing hemolytic and lipase activity

The possibility of using a heterogeneous, but structurally similar antigen--the commercial preparation of Pseudomonas sp. lipase (Sigma, USA)--for the development of polymer diagnosticum aimed at determination of lipase production in cholera vibrios was shown. The new diagnosticum (antilipase antibodies) on a polymer carrier was used in the serological volume agglomeration test for the detection of hemolytic atoxigenic V. eltor, obtained from environmental, objects, which produced lipase in 80% of cases. The differentiating capacity of the diagnosticum was confirmed on 120 V. eltor cultures isolated from environmental objects. The newly developed diagnosticum makes it possible to determine the lipase activity in cholera vibrios of different biovars and serovars.     

Specificity of lectin receptors of cholera vibrios

Spectrum of carbohydrate specificity of lectin receptors of epidemically significant cholera vibrios (ctx(+) tcp(+) Hly(-)) as well as non epidemic hemolytic variants with or without tcp A gene (ctx(-) tcp(-) Hly(+), ctx(-) tcp(+) Hly(+)) was studied under the carbohydrates-mediated inhibition of hemagglutination between human erythrocytes of four blood groups and sheep erythrocytes. It was demonstrated that in toxigenic cultures lectin receptors specific for glucose, mannose, sacharose, lactose dominate whereas receptors specific for aminosugars are virtually absent. The latter are detected in hemolytic vibrios that can explain their ecologic flexibility.     

Regulation of phenylacetic acid degradation genes of Burkholderia cenocepacia K56-2

Background  

Metabolically versatile soil bacteria Burkholderia cepacia complex (Bcc) have emerged as opportunistic pathogens, especially of cystic fibrosis (CF). Previously, we initiated the characterization of the phenylacetic acid (PA) degradation pathway in B. cenocepacia, a member of the Bcc, and demonstrated the necessity of a functional PA catabolic pathway for full virulence in Caenorhabditis elegans. In this study, we aimed to characterize regulatory elements and nutritional requirements that control the PA catabolic genes in B. cenocepacia K56-2.     

Type I interferon is required for T helper (Th) 2 induction by dendritic cells

Type 2 inflammation is a defining feature of infection with parasitic worms (helminths), as well as being responsible for widespread suffering in allergies. However, the precise mechanisms involved in T helper (Th) 2 polarization by dendritic cells (DCs) are currently unclear. We have identified a previously unrecognized role for type I IFN (IFN‐I) in enabling this process. An IFN‐I signature was evident in DCs responding to the helminth Schistosoma mansoni or the allergen house dust mite (HDM). Further, IFN‐I signaling was required for optimal DC phenotypic activation in response to helminth antigen (Ag), and efficient migration to, and localization with, T cells in the draining lymph node (dLN). Importantly, DCs generated from Ifnar1^?/? mice were incapable of initiating Th2 responses in vivo. These data demonstrate for the first time that the influence of IFN‐I is not limited to antiviral or bacterial settings but also has a central role to play in DC initiation of Th2 responses.     

Cholera vibrios lectins as main pathogenicity and persistence factors (biotechnological aspects of use)

Literature data and results of our studies of lectins are analyzed in the review. All the leading pathogenicity factors of cholera vibrios that possess enzymatic activity--cholera toxin, hemolysin, neuraminidase, chitinase have several lectin domains, that determine not only their pathogenetic role but also open perspectives for their use in medical practice. At the same time the variable receptor profile of cholera vibrios cells of various biovars and epidemical significance established with hemagglutination inhibition reaction by carbohydrates could be used to develop new principles of testing and typing of cholera vibrios.     

Adhesive and other properties of Vibrio cholerae tcp+ ctx- isolated from environmental objects in the Rostov region in 2002

The adhesive, hemolytic and triacylglycerol lipase activity of 4 V. cholerae ctp+ ctx- cultures, sensitive to bacteriophage ctx+, isolated from the Don and sewage water were tested. All these cultures were found to induce hemolysis of sheep red blood cells in the Greig test in 2 hours, possessed triacylglycerol lipase activity, but had no adhesive properties. By these parameters--atoxigenicity and the absence of adhesive properties--the isolated V. cholerae strains were characterized as avirulent and epidemically safe.     

Clustering protein sequences with a novel metric transformed from sequence similarity scores and sequence alignments with neural networks

Background  

The sequencing of the human genome has enabled us to access a comprehensive list of genes (both experimental and predicted) for further analysis. While a majority of the approximately 30000 known and predicted human coding genes are characterized and have been assigned at least one function, there remains a fair number of genes (about 12000) for which no annotation has been made. The recent sequencing of other genomes has provided us with a huge amount of auxiliary sequence data which could help in the characterization of the human genes. Clustering these sequences into families is one of the first steps to perform comparative studies across several genomes.