Monday, 24 April 2017

Efficient microbial fuel cell made from paper


Fuel cells are one of the renewable sources of energy being actively worked on by scientists. The basis of many fuel cells are specific bacteria, and a new breakthrough has been made using a paper-based system.
The search for alternative forms of energy is an important part of technological research. Of the different energy sources being examined, microbial-powered fuel cells are considered one of the most promising clean energy alternatives. A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction. This is the subject of research from the University of Rochester. Not only have scientists made significant progress, they have constructed a fuel cell that relies on bacteria found in wastewater.
One problem limiting fuel cells that use wastewater is corrosion of electrodes. This happens because electrodes have consisted of metal. An alternative type of electrode, made from carbon felt, has also proved limiting because carbon felt is porous and therefore prone to clogging. The solution to this has been to look towards the use of paper; that is a special type of paper coated with carbon paste. The paste is formed from a mixture of graphite and mineral oil.
In terms of how the cell works, the carbon paste attracts electrons emitted by bacteria, of the species Shewanella oneidensis MR-1. This bacterium consumes toxic heavy metal ions in the wastewater and ejects electrons. The electrons are attracted to the carbon coating on the positive electrode (anode), and then proceed to flow to the negative electrode (a platinum cathode), triggering an electrochemical reaction.
In trials the electrode has proved efficient, at twice the density of the carbon-based model. It is also cost-effective and relatively easy to prepare. The research is published in the journal of the American Chemical Society Energy Letters, and it is titled "Extracellular Electron Transfer on Sticky Paper Electrodes: Carbon Paste Paper Anode for Microbial Fuel Cells."
In related news, Digital Journal has reported about a new disposable battery has been developed. The battery remarkably folds like an origami ninja star, and it runs on only a few drops of water.


Posted by Dr. Tim Sandle

Sunday, 23 April 2017

Medical technologists find cheaper way to make essential medicine


Medical technologists have found a means to create an anti-fungal medication, designed to combat Cryptococcal meningitis, less expensively. The drug is intended for use in parts of Africa.
A fungal form of meningitis causes a major problem in parts of Africa, and it can lead to in-excess of 600,000 deaths each year. The aggressive disease accounts for close to 20 percent of deaths associated with AIDS related Human Immunodeficiency Virus (HIV) infections globally, based on U.S. Centers for Disease Control and Prevention figures.
To combat incidences of the fungal infection, medics have profiled that an existing medicine could help. However, the medication is prohibitively expensive for health systems in many parts of Africa. As a solution, medical researchers have come up with a low-cost way of manufacturing the drug. This should lead to greater use of the drug in those parts of the world that need it the most.
The drug in question is the anti-fungal drug flucytosine. The drug has been used in countries like the U.S. for several decades. The World Health Organization, in 2011, made the recommendation that patients with Cryptococcal meningitis, an infection associated with those infected with HIV take flucytosine (in combination with another medication called amphotericin B) as a first line of defense. the primary agent of infection is Cryptococcus neoformans.
To make the medication at a lower cost, PharmPro reports that Dr. Graham Sandford from Durham University (U.K.) has come up with a new method. This is make flucytosine out of readily available, naturally occurring cytosine. This is by pumping inexpensive fluorine gas and a solution of cytosine in formic acid through a steel tube, where flucytosine is produced by later recrystallization.
The development of the alternative medication is described in the American Chemical Society journal Organic Process Research & Development. The research paper is titled "One-Step Continuous Flow Synthesis of Antifungal WHO Essential Medicine Flucytosine Using Fluorine."


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Posted by Dr. Tim Sandle

Saturday, 22 April 2017

Teixobactin: A Powerful Tool for Combating Resistant Strains


Resistance to antibiotics has grown out to be serious health dilemma. Despite this serious health crisis, no new antibiotics have been revealed since last 30 y. A new ray of hope in the form of teixobactin has come out of the dark which can prove to be effective in defeating resistance. This new antibiotic has an interesting mechanism of action against bacteria. The discovery of this wonderful compound has evolved as major breakthrough especially in this era of antibiotic catastrophe. This review article highlights various facets of teixobactin. Its chemistry, mode of action, in vitro and in vivo aspects have been thrown light upon in this review. Though the compound has not undergone clinical trial studies but its effect in mice models has given a hope for overpowering resistance. This article has been mainly communicated with an objective to provide information about teixobactin which has emerged as ray of hope for fighting antibiotic resistance.

This relates to a new paper of interest, see: IJPS

Friday, 21 April 2017

Preparation, production, storage and performance testing of culture media


Spotlight on ISO 11133:2014 “Microbiology of food, animal feed and water -- Preparation, production, storage and performance testing of culture media.”

Culture media is of fundamental importance for most microbiological tests: to obtain pure cultures, to grow and count microbial cells, and to cultivate and select microorganisms. Without high-quality media, the possibility of achieving accurate, reproducible, and repeatable microbiological test results is reduced.

ISO 11133:2014 defines terms related to quality assurance of culture media and specifies the requirements for the preparation of culture media intended for the microbiological analysis of food, animal feed, and samples from the food or feed production environment as well as all kinds of water intended for consumption or used in food production. These requirements are applicable to all categories of culture media prepared for use in laboratories performing microbiological analyses.

ISO 11133:2014 also sets criteria and describes methods for the performance testing of culture media. It applies to producers such as:

  • commercial bodies producing and/or distributing ready-to-use or semi-finished reconstituted or dehydrated media;
  • non-commercial bodies supplying media to third parties;
  • microbiological laboratories preparing culture media for their own use.

For details see: ISO

Posted by Dr. Tim Sandle

Thursday, 20 April 2017

Light rain can spread soil bacteria far and wide


Using high-resolution imaging, researchers from MIT's Department of Mechanical Engineering observed the effect of raindrops falling on dry soil laden with bacteria. When falling at speeds mimicking those of a light rain, at temperatures similar to those in tropical regions, the drops released a spray of mist, or aerosols. Each aerosol carried up to several thousand bacteria from the soil. The researchers found the bacteria remained alive for more than an hour afterward.

If this airborne bacteria were lofted further by wind, it could travel a good distance before settling back on the ground to colonize a new location. The researchers estimated that the total number of bacteria dispersed by raindrops can range from 10,000 trillion to 800,000 trillion cells per year. As a result, global precipitation may contribute to releasing 1.6 to 25 percent of the total amount of bacteria from land.

See:

Young Soo Joung, Zhifei Ge, Cullen R. Buie. Bioaerosol generation by raindrops on soil. Nature Communications, 2017; 8: 14668 DOI: 10.1038/ncomms14668

Posted by Dr. Tim Sandle

Wednesday, 19 April 2017

Faster, more accurate detection of food- and water-borne bacteria


Recently, Charles S. Henry and colleagues developed a paper-based method to detect Salmonella, Listeria and E. coli in food and water samples. In their latest study, Henry's team wanted to see if it would be feasible to use this paper-based technique in conjunction with electrochemical analysis to produce more refined results.


To simulate contaminated food, the researchers exposed clean alfalfa sprouts to E.coli and Enterococcus faecalis bacteria. They also collected unfiltered water from a nearby lagoon. For colorimetric detection, the team built a simple light box, which served as a substitute for a laboratory plate reader. Then they used a smartphone to take a series of images of the 84 paper-based well plates over time. For the electrochemical portion of the experiment, they used a series of electrodes printed onto plastic transparency sheets. Both approaches used the same assays to successfully detect harmful bacteria in the samples within 4 to 12 hours, and both produced complementary findings. They conclude that combining their paper-based technique with electrochemistry could lead to a simpler, yet more comprehensive way to detect bacterial contaminants in food and water.

See:

Jaclyn A. Adkins, Katherine Boehle, Colin Friend, Briana Chamberlain, Bledar Bisha, Charles S. Henry. Colorimetric and Electrochemical Bacteria Detection Using Printed Paper- and Transparency-Based Analytic Devices. Analytical Chemistry, 2017; DOI: 10.1021/acs.analchem.6b05009

Posted by Dr. Tim Sandle

Tuesday, 18 April 2017

Visualizing the genome: First 3-D structures of active DNA created


Researchers from the University of Cambridge and the MRC Laboratory of Molecular Biology used a combination of imaging and up to 100,000 measurements of where different parts of the DNA are close to each other to examine the genome in a mouse embryonic stem cell. Stem cells are 'master cells', which can develop -- or 'differentiate' -- into almost any type of cell within the body.

Most people are familiar with the well-known 'X' shape of chromosomes, but in fact chromosomes only take on this shape when the cell divides. Using their new approach, the researchers have now been able to determine the structures of active chromosomes inside the cell, and how they interact with each other to form an intact genome. This is important because knowledge of the way DNA folds inside the cell allows scientists to study how specific genes, and the DNA regions that control them, interact with each other. The genome's structure controls when and how strongly genes -- particular regions of the DNA -- are switched 'on' or 'off'. This plays a critical role in the development of organisms and also, when it goes awry, in disease.

The researchers have illustrated the structure in accompanying videos, which show the intact genome from one particular mouse embryonic stem cell. In the film, above, each of the cell's 20 chromosomes is coloured differently.


In a second video regions of the chromosomes where genes are active are coloured blue, and the regions that interact with the nuclear lamina (a dense fibrillar network inside the nucleus) are coloured yellow. The structure shows that the genome is arranged such that the most active genetic regions are on the interior and separated in space from the less active regions that associate with the nuclear lamina. The consistent segregation of these regions, in the same way in every cell, suggests that these processes could drive chromosome and genome folding and thus regulate important cellular events such as DNA replication and cell division.

For further details see:

Stevens, TJ et al. 3D structures of individual mammalian genomes studied by single-cell Hi-C. Nature, 3 March 2017 DOI: 10.1038/nature21429

Posted by Dr. Tim Sandle

Monday, 17 April 2017

Understanding the Importance of Safety in Pharmaceutical Manufacturing and Transportation


Pharmaceutical manufacturing and transportation is an industry that requires a high level of oversight to make sure the medications being manufactured meet the required specifications and that they are being transported correctly to ensure maximum efficacy upon delivery. For many patients, these medications can do everything from improve the quality of their life to ensure their survival, which is what makes these regulations so important.

Special guest post by Megan Ray Nichols

What do you need to understand about safety in pharmaceutical manufacturing and transportation?

Manufacturing

The first step in pharmaceutical safety happens in the manufacturing stage. In the United States, manufacturers are constantly under scrutiny by the FDA (Food and Drug Administration) to ensure each batch of a medication meets the same quality and efficacy standards as the previous batches.
Pharmaceutical companies that produce their products in the United States are subject to the FDA’s Current Good Manufacturing Practice, or CGMP. These practices ensure the company is using the highest-quality raw products as well as up-to-date manufacturing technology to provide a standard level of quality across all of their products.

This is essential, especially for over-the-counter medications, because most customers don’t have the skills or equipment necessary to test their medication and make they’re safe and effective. For a bottle of Tylenol, for example, most people don’t look closely enough to see anything other than they’ve got the proper number of pills in hand. It’s not laziness on the consumer’s part, but rather a sign of the trust they’ve placed in the manufacturer.

Transportation

Safety plays a significant role in the transportation of medications. Once the medication is complete and safe to transport, the problem becomes a logistical one. A number of different variables have to be taken into account, including:

·         Form: In what form are these drugs being transported? Solid — in the form of pills or powder — or liquid, in IV bags or sterile bottles? Are they gaseous substances that need to be transported in pressurized containers?

·         Type: Security for the shipment of controlled substances should be much higher because they are most likely to be stolen and sold on the street.

·         Requirements: Do the medications have to be kept at a certain temperature to maintain safety and efficacy?

·         Destination: Where are the medications going? Will there be multiple transport changes (such as truck to plane) for final delivery, or will the products remain in the same vehicle for their entire journey?
These variables and many more have to be taken into account when planning the best way to produce and deliver pharmaceutical products. Items that have to be kept at a low temperature, for example, will need to be more carefully monitored than those that can be stored at room temperature.
Security at loading and unloading points is also a necessity — especially for controlled substances at risk for theft.

Customer Expectations

Customer expectations are higher than they’ve ever been, in part because they know they can put their trust in these companies and that there are laws in place to ensure every Tylenol or Excedrin they take is going to be close to identical. That trust comes from experience — they know that if there is a problem, the product will be removed until it can be fixed, like the cross-contamination problem that Novartis experienced in 2012 with Excedrin and four of its other over-the-counter products.

The applicable safety regulations are the key to making sure the trust of these consumers is not misplaced.

Regulations concerning the safety of pharmaceutical manufacturing and transportation aren’t there just to pacify bureaucrats and legislators — they’re in place to ensure that safe and effective medication is available to patients around the world. By ensuring this safety throughout both the manufacturing and shipping processes, we can help to ensure that no matter their destination, all of these medications arrive where they’re needed most in time to help.

Microbial swab recovery


Swabs are commonly used as part of microbiological environmental monitoring programmes and it is important to understand the suitability of the swabs used and their limitations.

A new paper by Ravikrishna Satyada and Tim Sandle looks into this issue. The abstract for the paper reads:

Surface monitoring by using swabs forms a regular part of environmental monitoring of cleanrooms. There are different factors that affect swab recovery, from tip type to enumeration method. One factor, for swabs where the microorganisms are detached from the swab tip and which are then membrane filtered, is the period of vortex mixing. This paper discusses microbial surface sampling, and the factors that affect swab recovery. The paper presents some experimental data where vortex times are considered for a range of microorganisms. The study outcome indicates that 15 seconds vortex mixing is sufficient to obtain microbial recoveries from the swab tip above 50%.

The reference is:

Satyada, R. and Sandle, T. (2016) Releasing capacity of pre-sterile cotton swabs for discharging sampled microorganisms, European Journal of Parenteral and Pharmaceutical Sciences, 21 (4): 121-128

For further details please contact Tim Sandle

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Posted by Dr. Tim Sandle

Sunday, 16 April 2017

'Smart' bacteria remodel their genes to infect our intestines


Infectious diarrhea, a common disease of children, is responsible for over 2 million infant deaths annually in developing counties alone. A primary cause of this and other devastating conditions is enteropathogenic bacteria, which attack the intestinal tract when contaminated food is consumed.

The infection process involves hundreds of genes and proteins, both in the infectious bacteria and the human host. However, the processes by which the pathogens establish themselves in our gut are poorly understood.

Now, a new study published in the journal Science, by researchers at the Hebrew University of Jerusalem's Faculty of Medicine, describes how pathogens sense their host, and tailor their gene expression to exploit their host to cause disease. The research was led by led by Prof. Ilan Rosenshine, the Etta Rosensohn Professor of Bacteriology at the Hebrew University.


Working with a pathogenic strain of E. coli, the researchers found that the bacteria can sense attachment to the human intestinal cells and activate gene expression in response. This was demonstrated by engineering one of these genes to express a protein that stains the expressing bacteria to appear green under the microscope. Under microscopic examination, the researchers observed that only the attached bacteria fluoresce in bright green, whereas non-attached bacteria remain dark.

The researchers also deciphered how upon sensing that it has attached to intestinal cells, the pathogen reorganizes its gene expression, including genes involved in virulence and metabolism, to exploit the host cell. These findings may lead to the development of new strategies to combat bacterial infection.

See:

Naama Katsowich, Netanel Elbaz, Ritesh Ranjan Pal, Erez Mills, Simi Kobi, Tamar Kahan, Ilan Rosenshine. Host cell attachment elicits posttranscriptional regulation in infecting enteropathogenic bacteria. Science, 2017; 355 (6326): 735 DOI: 10.1126/science.aah4886



Posted by Dr. Tim Sandle

Saturday, 15 April 2017

Proposed New USP General Chapter: The Analytical Procedure Lifecycle ⟨1220⟩


The following may be of interest to readers:

An analytical procedure must be demonstrated to be fit for its intended purpose. It is useful to consider the entire lifecycle of an analytical procedure, i.e., its design and development, qualification, and continued verification. The current concepts of validation, verification, and transfer of procedures address portions of the lifecycle but do not consider it holistically. The purpose of this proposed new chapter is to more fully address the entire procedure lifecycle and define concepts that may be useful. This approach is consistent with the concept of quality by design (QbD) as described in International Council for Harmonisation (ICH) Q8-R2, Q9, Q10, and Q11. The lifecycle approach can potentially be applied to all procedures, although the level of effort should be consistent with the complexity and criticality of the procedure.

For further details see: USP

Posted by Dr. Tim Sandle

Friday, 14 April 2017

Humidity Measurement for Effective Manufacturing


The purpose of this free eBook is to share humidity theory, tools and practical examples of how measuring humidity, moisture and dew point brings value to different manufacturing processes.

The eBook includes some of our most popular and requested humidity assets, such as:
  • Humidity calculator (direct link to the online/offline version)
  • Humidity Formulas
  • Measurement specification glossary
  • Intrinsic safety knowledge
  • ...and much more
You are welcome to download the free eBook (one click to open) and save as a handy tool for later use.

Thursday, 13 April 2017

3-D tissue culture models to mimic human gut infections


Central to the development of tissue models that can better predict how humans respond to infection is the understanding that cells and tissues in our bodies function in a three-dimensional (3-D) context. Accordingly, cell-based models of tissues made in the laboratory must be developed with the same appreciation for the 3-D tissue microenvironment encountered by pathogens in the body.

While this research concept has long been appreciated by the cancer and regenerative medicine world, the infectious disease world has been slower to get on board.

Now, an ASU Biodesign Institute team has developed and applied 3-D tissue models to study bacterial infectious disease nearly two decades ago -- and spearheaded the adoption of 3-D tissue models as a new paradigm to study infectious disease -- has reported their latest advancement in 3-D intestinal model development.

The new study, a collaboration between Arizona State University and NASA's Johnson Space Center, was led by Cheryl Nickerson, a researcher at ASU's Biodesign Institute and professor in the School of Life Sciences.

Their united goal is to develop more realistic models of intestinal tissue to thwart Salmonella, a leading cause of food poisoning and systemic disease worldwide with many varieties causing severe and sometimes fatal infections with an economic impact in the billions of dollars.

Interestingly, the response of this new model to infection with the different types of Salmonella was very different for each strain, thus demonstrating the model's ability to distinguish between these closely related pathogens based on their infection characteristics. Specifically, important differences were observed between the bacterial strains in model colonization (adherence, invasion and intracellular survival) and intracellular co-localization patterns in epithelial and immune cells.

See:

Jennifer Barrila, Jiseon Yang, AurĂ©lie CrabbĂ©, Shameema F. Sarker, Yulong Liu, C. Mark Ott, Mayra A. Nelman-Gonzalez, Simon J. Clemett, Seth D. Nydam, Rebecca J. Forsyth, Richard R. Davis, Brian E. Crucian, Heather Quiriarte, Kenneth L. Roland, Karen Brenneman, Clarence Sams, Christine Loscher, Cheryl A. Nickerson. Three-dimensional organotypic co-culture model of intestinal epithelial cells and macrophages to study Salmonella enterica colonization patterns. npj Microgravity, 2017; 3 (1) DOI: 10.1038/s41526-017-0011-2


Posted by Dr. Tim Sandle

Wednesday, 12 April 2017

Useful links updated


The list of useful links to science and regulatory organizations on the site has been updated. Please check through, there will be something of interest.


Posted by Dr. Tim Sandle