scholarly journals Applications and integration of chromogenic culture media in clinical microbiology

2010 ◽  
Vol 31 (3) ◽  
pp. 127
Author(s):  
John Merlino

The ability to rapidly detect and identify micro-organisms is of paramount importance for many microbiology laboratories. The application of new classes of enzymatic-based chromogenic compounds has revolutionised traditional culture media, leading to the developments of a new generation of chromogenic media. Many studies have shown that the chromogenic agar has become more than an isolation media when compared to conventional culture media. A newer, faster, more cost-effective means in the presumptive identification or screening of microorganisms which are either genus, or in some cases species-specific, and allows superior differentiation of mixed micro-organisms in cultures. When supplemented with antibiotics or other agents, chromogenic media allows the screening for multidrug resistance and virulence in many micro-organisms and can be easily integrated with other automated and/or molecular-based methods.

2018 ◽  
Vol 24 (2) ◽  
pp. 128-135
Author(s):  
S Gul Nahar ◽  
M Bulbul Hasan ◽  
Mst Rokeya Khatun ◽  
M Nawshad Ali

Objective: The present study was done to compare the performance of chromogenic agar medium and conventional culture media for the isolation and presumptive identification of uropathogen.Methodology: A total 300 sample were collected from Rajshahi Medical College Hospital, Bangladesh during January to June, 2008. Urine samples of the suspected UTI cases, showing pus cells >5/HPF on microscopic examination were included for urine culture simultaneously onto 2 conventional media (Blood agar and MacConkey agar) and chromogenic agar medium (HiCrome UTI agar medium). Results: Culture yielded 139 (46.33%) bacterial growth among them, 133 (44.33%) showed single organism and remaining 06 (2.00%) showed mixed growth of two organisms in different combinations. It is evident from the present study that both HiCrome UTI agar and Blood agar (BA) media supported growth of all 145 bacteria, while MacConkey (MAC) agar yielded 133(91.72%) bacterial growths. The rate of presumptive identification of the isolates was found significantly higher (97.24%) on HiCrome UTI agar when compared with the MacConkey agar (80.68%) and Blood agar (27.58%) media. Out of 91 E. coli isolated, 88(96.70%) could be identified differentially on HiCrome UTI agar medium in contrast to 85(93.40%) on MacConkey agar and only 06(06.59%) on Blood agar. Again, all 06 (100%) of the isolate-pairs of mixed growth were identified distinctly on HiCrome UTI agar, whereas both Blood agar and MacConkey agar media could revealed only 01(16.66%) of the polymicrobial growth.Conclusion: HiCrome UTI agar medium has been documented for its very high yielding rate, rapid presumptive identification of both single and polymicrobial growths with greater precision and avoidance of biochemical tests for further identification of uropathogens. Thus it can be recommended as primary urine culture medium to be used by the clinical microbiology laboratories.TAJ 2011; 24(2): 128-135


2012 ◽  
Vol 39 (7) ◽  
pp. 629 ◽  
Author(s):  
Zachary H. Olson ◽  
Jeffrey T. Briggler ◽  
Rod N. Williams

Context Environmental DNA, or eDNA, methods are a novel application of non-invasive genetic sampling in which DNA from organisms is detected via sampling of water or soil, typically for the purposes of determining the presence or absence of an organism. eDNA methods have the potential to revolutionise the study of rare or endangered taxa. Aims We evaluated the efficacy of eDNA sampling to detect populations of an amphibian of conservation concern, the eastern hellbender (Cryptobranchus a. alleganiensis), indirectly from their aquatic environments. Methods We developed species-specific primers, validated their specificity and sensitivity, and assessed the utility of our methods in silico and in laboratory trials. In the field, we collected water samples from three sites with known densities of hellbenders, and from one site where hellbenders do not occur. We filtered water samples, extracted DNA from filters, and assayed the extraction products for hellbender DNA by using polymerase chain reaction (PCR) and gel electrophoresis. Key results Our methods detected hellbenders at densities approaching the lowest of reported natural densities. The low-density site (0.16 hellbenders per 100 m2) yielded two positive amplifications, the medium-density site (0.38 hellbenders per 100 m2) yielded eight positive amplifications, and the high-density site (0.88 hellbenders per 100 m2) yielded 10 positive amplifications. The apparent relationship between density and detection was obfuscated when river discharge was considered. There was no amplification in any negative control. Conclusion eDNA methods may represent a cost-effective means by which to establish broad-scale patterns of occupancy for hellbenders. Implications eDNA can be considered a valuable tool for detecting many species that are otherwise difficult to study.


2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.


Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.


2008 ◽  
Vol 53 (No. 3) ◽  
pp. 97-104 ◽  
Author(s):  
M. Zouhar ◽  
M. Marek ◽  
O. Douda ◽  
J. Mazáková ◽  
P. Ryšánek

<i>Ditylenchus dipsaci</i>, the stem nematode, is a migratory endoparasite of over 500 species of angiosperms. The main method of <i>D. dipsaci</i> control is crop rotation, but the presence of morphologically indistinguishable host races with different host preferences makes rotation generally ineffective. Therefore, a sensitive, rapid, reliable, as well as cost effective technique is needed for identification of <i>D. dipsaci</i> in biological samples. This study describes the development of species-specific pairs of PCR oligonucleotides for detection and identification of the <i>D. dipsaci</i> stem nematode in various plant hosts. Designed DIT-2 primer pair specifically amplified a fragment of 325 bp, while DIT-5 primer pair always produced a fragment of 245 bp in all <i>D. dipsaci</i> isolates. Two developed SCAR primer pairs were further tested using template DNA extracted from a collection of twelve healthy plant hosts; no amplification was however observed. The developed PCR protocol has proved to be quite sensitive and able to specifically detect <i>D. dipsaci</i> in artificially infested plant tissues.


Author(s):  
Rajeshwari Vittal ◽  
Juliet Roshini Mohan Raj ◽  
Ballamoole Krishna Kumar ◽  
Indrani Karunasagar

Abstract Legionella is a fastidious organism that is difficult to culture in the lab but is widely distributed in environmental, domestic, and hospital settings. The clinical manifestations due to Legionella infections range from mild fever to fatal pneumonia and multiorgan pathologies. Legionella outbreaks though prevalent globally are not reported in developing countries due to difficulties in isolating this organism and the lack of simple diagnostic protocols. Here, we review the literature from across countries to present various methods used to detect Legionella from environmental and clinical samples. We compare the sensitivity and the specificity of the conventional culture-based assays with the recent methods and discuss approaches to develop better detection and diagnostic tests. With better cost-effective detection techniques and regular monitoring of the susceptible sites, which may harbor Legionella colonies, most of the Legionella infections can be prevented. As a result, considerable burden, caused by Legionella infections, on the healthcare system, in especially economically weaker countries, can be mitigated.


Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 390
Author(s):  
Frank Kowalzik ◽  
Daniel Schreiner ◽  
Christian Jensen ◽  
Daniel Teschner ◽  
Stephan Gehring ◽  
...  

Increases in the world’s population and population density promote the spread of emerging pathogens. Vaccines are the most cost-effective means of preventing this spread. Traditional methods used to identify and produce new vaccines are not adequate, in most instances, to ensure global protection. New technologies are urgently needed to expedite large scale vaccine development. mRNA-based vaccines promise to meet this need. mRNA-based vaccines exhibit a number of potential advantages relative to conventional vaccines, namely they (1) involve neither infectious elements nor a risk of stable integration into the host cell genome; (2) generate humoral and cell-mediated immunity; (3) are well-tolerated by healthy individuals; and (4) are less expensive and produced more rapidly by processes that are readily standardized and scaled-up, improving responsiveness to large emerging outbreaks. Multiple mRNA vaccine platforms have demonstrated efficacy in preventing infectious diseases and treating several types of cancers in humans as well as animal models. This review describes the factors that contribute to maximizing the production of effective mRNA vaccine transcripts and delivery systems, and the clinical applications are discussed in detail.


2016 ◽  
Vol 97 (7) ◽  
pp. 1479-1482 ◽  
Author(s):  
Thomas J. Ashton ◽  
Meriem Kayoueche-Reeve ◽  
Andrew J. Blight ◽  
Jon Moore ◽  
David M. Paterson

Accurate discrimination of two morphologically similar species of Patella limpets has been facilitated by using qPCR amplification of species-specific mitochondrial genomic regions. Cost-effective and non-destructive sampling is achieved using a mucus swab and simple sample lysis and dilution to create a PCR template. Results show 100% concurrence with dissection and microscopic analysis, and the technique has been employed successfully in field studies. The use of highly sensitive DNA barcoding techniques such as this hold great potential for improving previously challenging field assessments of species abundance.


Author(s):  
Yan Cui ◽  
Wenqiao Wayne Yuan ◽  
Zhijian Pei

Continuous use of petroleum derived fuels is widely recognized as unsustainable due to depleting supplies and the accumulation of greenhouse gases in the environment. Renewable, carbon neutral transport fuels are needed for environmental and economic sustainabilities. Algae have been demonstrated to be one of the most promising sources for biofuel production. However, large-scale algae production and harvesting for energy manufacturing are too costly using existing methods. The approach of growing algae on solid carriers is innovative and can potentially lead to cost-effective manufacturing of algae biofuels. As cells approach to the solid surface, many factors come in to influence microbial attachment such as the surface wettability, free energy, polarity, roughness and topography. Surface wettability plays an important role in the initial cell attachment. For further contact, surface free energy and polarity are more directly related to cell-substratum attachment strength. Surface roughness and texture are species-specific parameters and have been applied widely in attachment studies.


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