Networking strategies in streptomyces coelicolor

We are interested the soil dwelling bacteria Streptomyces coelicolor because its cells grow end to end in a line. New branches have the potential to extend from any point along this line and the result is a network of branches and connections. This is a novel form of colonisation in the bacterial world and it is advantageous for spreading through an environment resourcefully. Networking protocols for communication technologies have similar pressures to be resourceful in terms of time, computing power, and energy. In this preliminary investigation we design a computer model of the biological system to understand its limitations and strategies for survival. The decentralised capacity for organisation of both the bacterial system and the model reflects well on the now-popular conventions for path finding and ad hoc network building in human technologies. The project will ultimately become a comparison of strategies between nature and the man-made

Metabolic modeling and analysis of the metabolic switch in Streptomyces coelicolor

Background The transition from exponential to stationary phase in Streptomyces coelicolor is accompanied by a major metabolic switch and results in a strong activation of secondary metabolism. Here we have explored the underlying reorganization of the metabolome by combining computational predictions based on constraint-based modeling and detailed transcriptomics time course observations. Results We reconstructed the stoichiometric matrix of S. coelicolor, including the major antibiotic biosynthesis pathways, and performed flux balance analysis to predict flux changes that occur when the cell switches from biomass to antibiotic production. We defined the model input based on observed fermenter culture data and used a dynamically varying objective function to represent the metabolic switch. The predicted fluxes of many genes show highly significant correlation to the time series of the corresponding gene expression data. Individual mispredictions identify novel links between antibiotic production and primary metabolism. Conclusion Our results show the usefulness of constraint-based modeling for providing a detailed interpretation of time course gene expression data

Detection of the inflammation biomarker C-reactive protein in serum samples: Towards an optimal biosensor formula

The development of an electrochemical immunosensor for the biomarker, C-reactive protein (CRP), is reported in this work. CRP has been used to assess inflammation and is also used in a multi-biomarker system as a predictive biomarker for cardiovascular disease risk. A gold-based working electrode sensor was developed, and the types of electrode printing inks and ink curing techniques were then optimized. The electrodes with the best performance parameters were then employed for the construction of an immunosensor for CRP by immobilizing anti-human CRP antibody on the working electrode surface. A sandwich enzyme-linked immunosorbent assay (ELISA) was then constructed after sample addition by using anti-human CRP antibody labelled with horseradish peroxidase (HRP). The signal was generated by the addition of a mediator/substrate system comprised of 3,3,5',5'-Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H2O2). Measurements were conducted using chronoamperometry at -200 mV against an integrated Ag/AgCl reference electrode. A CRP limit of detection (LOD) of 2.2 ng·mL-1 was achieved in spiked serum samples, and performance agreement was obtained with reference to a commercial ELISA kit. The developed CRP immunosensor was able to detect a diagnostically relevant range of the biomarker in serum without the need for signal amplification using nanoparticles, paving the way for future development on a cardiac panel electrochemical point-of-care diagnostic device

Reference values for glucose tolerance test in the urban Zimbabwean pregnant woman

A clinical study carried out in urban Zimbabwe on how to derive normal glucose values for the normal woman at different gestations of pregnancy.The oral glucose tolerance test is widely used as a screening test for impaired glucose tolerance. Criteria for abnormal results in pregnancy have been documented from different countries and in Zimbabwe, the North American values as proposed by O’Sulluvan and Mahan1 have been adopted. These standards were derived from populations on Western diets; also the glucose load was 100 g, the gestations were unselected and no allowance had been made for altered glucose tolerance with advancing gestation. The standards may also be inappropriate because of the differences in the nutritional status and the dietary habits of the two population groups. Others that have used a glucose load of 50 g have obtained significantly lower values than O’Sullivan and Mahan.2,3 Although in 1979 the WHO expert committee on diabetes4 recommended a standard glucose load of 75 g, many units, including ours, continue to use the 50 g load. The aim of this study was, therefore, to derive normal glucose values for the normal urban Zimbabwean woman at different gestations of pregnancy

Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom

Prevalence of three sulfonamide resistance genes, sul1, sul2 and sul3 and sulfachloropyridazine (SCP) resistance was determined in bacteria isolated from UK manured agricultural clay soils and slurry samples, over a two year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline (OTC) was used for manuring. Sul gene positive isolates were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in pig slurry and post application soil than in pre-application soil. Of 5isolates, 23 % carried sul1, 18 % sul2 and 9 % sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5 % and 11.7 % of sul positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8 % of sul1 positive isolates carried the intI1 gene. Sulfonamide resistant pathogens were identified in slurry amended soil and soil leachate, including Shigella flexneri, Aerococcus spp. and Acinetobacter baumanni, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotype sul1, sul2 and sul3 outside the Enterobacteriacae, and in the soil environment

Microbial imbalance in inflammatory bowel disease patients at different taxonomic levels

Background Inflammatory bowel disease (IBD), is a debilitating group of chronic diseases including Crohn’s Disease (CD) and ulcerative colitis (UC), which causes inflammation of the gut and affects millions of people worldwide. At different taxonomic levels, the structure of the gut microbiota is significantly altered in IBD patients compared to that of healthy individuals. However, it is unclear how these IBD-affected bacterial groups are related to other common bacteria in the gut, and how they are connected across different disease conditions at the global scale. Results In this study, using faecal samples from patients with IBD, we show through diversity analysis of the microbial community structure based on the 16S rRNA gene that the gut microbiome of IBD patients is less diverse compared to healthy individuals. Furthermore, we have identified which bacterial groups change in abundance in both CD and UC compared to healthy controls. A substantial imbalance was observed across four major bacterial phyla including Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria, which together constitute >98% of the gut microbiota. Next, we reconstructed a bacterial family co-abundance network based on the correlation of abundance profiles obtained from the public gut microbiome data of >22000 samples of faecal and gut biopsies taken from both diseased and healthy individuals. The data was compiled using the EBI metagenomics database [1]. By mapping IBD-altered bacterial families to the network, we show that the bacterial families which exhibit an increased abundance in IBD conditions are not well connected to other groups, implying that these families generally do not coexist together with common gut organisms. Whereas, the bacterial families whose abundance is reduced or did not change in IBD conditions compared to healthy conditions are very well connected to other bacterial groups, suggesting they are highly important groups of bacteria in the gut that can coexist with other bacteria across a range of conditions. Conclusions IBD patients exhibited a less diverse gut microbiome compared to healthy individuals. Bacterial groups which changed in IBD patients were found to be groups which do not co-exist well with common commensal gut bacteria, whereas bacterial groups which did not change in patients with IBD were found to commonly co-exist with commensal gut microbiota. This gives a potential insight into the dynamics of the gut microbiota in patients with IBD

Adopting innovative methods in the Ghanaian construction industry

Abstract: Increased demand for building infrastructure delivery advocates for innovative construction methods. This paper examines the concept and application of Modern Method of Construction used in the South-West UK, and the Innovative Building Technologies in South Africa. It assesses the methods, current use, off-site manufacturing; identifies and evaluates aspects of the construction process typically used with the aim of identifying and analysing the barriers and merits for the adoption in the Ghanaian construction industry. The research design adopts a qualitative method and case study of two housing projects as part of a broader study to determine an appropriate innovative construction method to meet project targets of time, cost, quality and improved delivery for the Ghanaian industry. The study finds; convenience; speed; reduced cost and improved delivery as the key success factors though there is less than 5% use of the innovative methods in the entire sector for mainly repetitive housing, schools and hospital projects. Negative end-users perception of building quality and low satisfaction; less government intervention through education; promotion; availability of off-site contractors and materials were also the barriers identified. Management contract is adopted in most cases hence the risk transferred to the management contractors. Lessons learnt are outlined and recommendation made for government action plans to mitigate the barriers during its implementation in the Ghanaian construction industry

Comments from the property industry on Masters Real Estate curricula in South Africa

Purpose: The aim of this paper is to report comments given in a survey of property professionals in the industry on Masters Real Estate (MRE) curricula in South Africa. Methodology: A questionnaire was administered to obtain comments from property professionals in the industry on MRE curricula in South Africa. Findings: The property industry survey revealed that MRE curricula in South Africa have both strengths and weaknesses. The main strength of the curricula noted by the property professionals is that the curricula are interdisciplinary. Weaknesses reported include lack of case studies and practical components in the curricula. Research limitations: Results of the survey will not directly influence change to the processes of curriculum development for postgraduate real estate education in South Africa. Curricula development will largely depend on outcomes of discussions of lecturing staff and university administrations implementing the courses. Value: The study will support processes of curricula improvement for MRE programmes in South Afric

Environmental monitoring of Mycobacterium bovis in badger feces and badger sett soil by real-time PCR, as confirmed by immunofluorescence, immunocapture, and cultivation

Real-time PCR was used to detect and quantify Mycobacterium bovis cells in naturally infected soil and badger faeces. Immunomagnetic capture, immunofluorescence and selective culture confirmed species identification and cell viability. These techniques will prove useful for monitoring M. bovis in the environment and for elucidating transmission routes between wildlife and cattle