Wednesday, 20 November 2019

Modulation of the microbiome

A Nature Review has been issued, covering the gut microbiota’s role in colorectal cancer.

According to new experimental evidence from Jun Yu’s group at The University of Hong Kong, the gut microbiota is a key cog in the formation and progression of colorectal cancer. Gut bacteria play a role in preventing adverse effects of treatment too. Clinical data demonstrated that clear changes in the number of specific bacteria are detected in patients and can even serve as a biomarker for disease screening to help to inform a patient’s response to a certain treatment. It’s clear that modulation of the gut microbiota is an excellent strategy to enhance treatment efficacy and reduce adverse effects of colorectal cancer therapies.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Tuesday, 19 November 2019

What Technologies Will Have the Biggest Impact on Pharma?

Medical science has come a long way since the days of leeches and trepanning, but new technologies are emerging every day that will change the way we look at pharmaceutical science. Here are the ones that will have the most significant impact on pharma, once the industry learns to adopt them.

A guest post by Megan Ray Nichols

Machine Learning and Analytics

Machine learning, or programming computers to learn and grow from the information they're given, is a stepping stone between the digital networks we use today and true artificial intelligence. This technology may still be in its infancy, but its applications in the industry are growing by the day. One potential use in the pharmaceutical industry is in drug discovery and manufacturing.

Drug discovery is typically slow and expensive. Pharmaceutical researchers start by selecting a target and analyzing millions of compounds before they might discover one that proves to be a viable potential treatment. Half a dozen steps later, it might make it to clinical trials, and then after a decade of additional testing, it could be made available to consumers.

Machine learning programs can consolidate many of these steps, from target selection through pre-clinical stages. While it will never replace the need for clinical trials, it could reduce time and money spent on drug discovery while still producing new viable medications. According to industry experts, these applications could save the health care sector $150 billion a year by 2026.

IoT and Networked Sensors

The Internet of Things (IoT) is showing up in nearly every industry. If you've got any smart devices in your home, from an Amazon Echo to a smart garage door opener, you're already part of it. This technology could become an invaluable part of the pharmaceutical industry once adopted by existing companies.

These sensors are capable of sending and receiving information, can be networked to a central hub, and may be programmed to do nearly anything. In the pharmaceutical sector, IoT sensors are becoming popular for real-time equipment monitoring, environmental monitoring and control in manufacturing plants. They also watch the supply chain once medications leave the factory en route to pharmacies and hospitals around the country.

IoT requires additional equipment and IT professionals to install it and keep it running. Once adopted, it could address many of the problems — such as a lack of transparency — that the pharmaceutical industry is currently facing.

Automation and Robotics

Automation isn't a new concept in manufacturing, but many pharmaceutical companies are starting to turn to autonomous practices to create medications and medical technology. It's already used in the filling, packing and inspection in more than one-third of pharmaceutical factories.

More recently, companies have started incorporating a process known as Raman Spectroscopy to analyze drugs before they're shipped. Ramen spectroscopy uses single-frequency lasers to examine the vibrational frequency of the molecular bonds in the medications. The drugs are tested by the computer to determine whether they're safe to ship.

Automation is also making an appearance in lab settings. The ACAPELLA-1K is a DNA prep system that uses automation and highly specialized fluid processing systems to prepare 1,000 samples of DNA for sequencing in less than eight hours. The ACAPELLA system can aspirate, dispense, mix, transport, and heat or cool the fluids as necessary to get them ready for sequencing, all with the press of a button. 

3D Printing

3D printing started as a toy for hobbyists and CAD designers to turn their designs into reality, but it's started to make an appearance in nearly every industry. There's even a 3D printer on the International Space Station. Millions of people use pills and capsules every single day — and many of them are difficult to swallow or taste terrible. 3D printing might be the solution to these problems. Instead of using the same size and shape of a pill for everyone, 3D printing would enable pharmaceutical companies to customize their medications for the needs of each patient.

The first 3D printed drug to receive FDA approval was Spritam, a medication from Aprecia Pharmaceuticals used to treat epilepsy in 2016. It created new technology to build each pill, one layer at a time, to make a dissolvable pill that's easier to swallow. While 3D printing isn't more efficient than traditional pill-making methods, it can help make taking your medicine easier and less uncomfortable. 

Looking Forward

Medical technology is changing the way we do everything from how we manufacture pills to how we discover new drugs and treatments. These technological advances will alter the very foundation of the pharmaceutical industry, once current pharma companies adopt them. It might not be too long before you take a pill that was discovered and designed by a machine learning program and created by a 3D printer before being delivered to your door.

Pharmaceutical Microbiology Resources (

Monday, 18 November 2019

Cleanroom regulatory trends: A review of FDA warning letters

Cleanrooms remain a central focus of regulatory inspections and it is good practice for those working within pharmaceuticals and healthcare to assess regulatory trends. This task is difficult within Europe, where only broad overviews are released (due to data privacy restrictions) and it becomes complex when assessing output from U.S. FDA, given the hundreds of warning letters issued. To assist with this process, this article assesses recent FDA warning letters and draws out the main trends and significant non-compliances relating to cleanroom design, testing and operations.

Tim Sandle has written a new article:

Sandle, T. (2019) Cleanroom regulatory trends: A review of FDA warning letters, Clean Air and Containment Review, Issue 38, pp20-24

For details, please contact Tim Sandle

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Sunday, 17 November 2019

Supplier Oversight and Quality Control for Patient Safety

Tim Sandle has taken part in a podcast with the Institute of Validation Technology as part of their ‘Voices In Validation’ series.

Stacey Bruzzese talks to Dr. Tim Sandle, the Head of Microbiology and Sterility Assurance at Bio Products Laboratory Limited.

Stacey and Tim cover a variety of topics:

  • For pharma manufactures, how does fewer employees, smaller inventory, less space and reduced time impact patient safety?
  • What type of supplier oversite is necessary?
  • As supply chains become more and more digital, how does IoT impact processes and programs controlling quality?
  • How do Big Data and Cloud Computing relate to patient safety, accessibility and affordability?
  • What does Dr Sandle see as the next major shift in supply chain migration?

To access the podcast, see:

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Saturday, 16 November 2019

New fluorescence method reveals signatures of individual microbes

When viewed with specialized microscopes, microbial cells show an individual fluorescence pattern, or signature, that depends on the mixture of biomolecules contained within the cells. That complex mixture, with its telltale signature, in turn depends on the type of microbe and its physiological state, such as whether it is growing or what it is consuming as a food source.
University of Tsukuba researchers have developed a new method, named CRIF (Confocal Reflection microscopy-assisted single-cell Innate Fluorescence), to detect the fluorescence signatures of individual microbial cells. The method is non-destructive, meaning the cells remain alive, and allows cells to be studied in realistic three-dimensional environments. Importantly, the new method can be used to view individual cells within mixtures of different types of microbe, unlike many standard techniques that work best with "pure" populations where the cells are all alike. The team recently published their findings in Applied and Environmental Microbiology.

"We used a confocal microscope, which can generate images from three-dimensional materials -- rather like comparing a sequence of slices to build up an image of a whole intact structure. This enabled us to find the locations of the microbial cells within the sample," says lead and co-corresponding author Yutaka Yawata. "Combining this with spectroscopy to measure a set of fluorescence signals under the microscope, we were able to see the different types of microbes within the sample, and read their signatures to identify the individual cells."

The team went on to train computer models to read the fluorescence signatures and distinguish different types of cells. The models learned to recognize cells automatically, even when looking at different cells with very similar shapes and sizes, and analyze the images for cell signatures to identify the cells according to their type and physiological state.
"Our technique to recognize and track the innate fluorescence signatures of each of the individual cells within three-dimensional samples opens up exciting new opportunities to explore mixed microbial populations, as found in natural environments," says co-corresponding author Nobuhiko Nomura. "It will help researchers understand how microbes grow and interact with each other in the real world."


Yutaka Yawata, Tatsunori Kiyokawa, Yuhki Kawamura, Tomohiro Hirayama, Kyosuke Takabe, Nobuhiko Nomura. Intra- and Interspecies Variability of Single-Cell Innate Fluorescence Signature of Microbial Cell. Applied and Environmental Microbiology, 2019; 85 (18) DOI: 10.1128/AEM.00608-19

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Friday, 15 November 2019

Antibiotic resistant genes prevalent in groundwater

With climate change comes increasing water shortages, and potentially longer periods of drought. As policymakers look urgently to wastewater recycling to stem the gap in water resources, the question is -- how best to reuse water and ensure public safety. New and emerging contaminants like antibiotic resistant genes (ARGs) pose a potential hazard to public safety and water security. One concern is the spread of ARGs through the water system and an increase in development of antibiotic-resistant super bugs.

Researchers from the University of Southern California studied and compared samples from an advanced groundwater treatment facility in Southern California and groundwater aquifers to detect differences in ARG concentrations. While they found that the advanced groundwater treatment facility reduced nearly all targeted ARGs to below detection limits, groundwater samples had a ubiquitous presence of ARGs in both control locations and locations recharged with water from the advanced water treatment facility.
Historically, indirect reuse treatment methods in which an environmental barrier is an intermediary step in the water cleaning process have been more popular than the direct "toilet to tap" process. While indirect methods of water reuse treatment were, from a public perception and appetite, considered more reliable, it is actually direct reuse "toilet to tap" approaches which do not introduce an environmental buffer that produce safer, more pure water for potability. The reason for this lies in the way ARGs in the environment can contaminate potable reuse water.

While some ARGs are naturally occurring in microbial communities, antibiotics, ARGs and antibiotic resistant pathogens are on the rise in water sources as a result of the overuse of antibiotics in general. In a typical water treatment cycle, wastewater is treated first at a wastewater treatment facility. The study found that this water remains high in ARGs, as they persist throughout the treatment process. From here, water intended for potable reuse is further purified using advanced physical and chemical techniques including reverse osmosis -- a process that uses a partially permeable membrane to purify drinking water.

Since wastewater treatment plants are not generally designed for removal of micropollutants like antibiotics, they tend to persist in treatment systems, leading to high densities of ARG resistant bacteria at different stages of treatment. When this water is introduced into an aquifer, where ARGs are already naturally occurring, it can become contaminated with ARGs and antibiotic resistant bacteria. To further complicate the issue, ARGs are easily transferred through horizontal gene transfer, increasing the risk for antibiotic resistant pathogens.


Moustapha Harb, Phillip Wang, Ali Zarei-Baygi, Megan H. Plumlee, Adam L. Smith. Background Antibiotic Resistance and Microbial Communities Dominate Effects of Advanced Purified Water Recharge to an Urban Aquifer. Environmental Science & Technology Letters, 2019; DOI: 10.1021/acs.estlett.9b00521

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Thursday, 14 November 2019

Potential to use CRISPR to alter the microbiome

Researchers at Western University have developed a new way to deliver the DNA-editing tool CRISPR-Cas9 into microorganisms in the lab, providing a way to efficiently launch a targeted attack on specific bacteria. The study opens up the possibility of using CRISPR to alter the makeup of the human microbiome in a way that could be personalized and specific from person to person. It also presents a potential alternative to traditional antibiotics to kill bacteria like Staphyloccous aureus (Staph A) or Escherichia coli (E. coli).

The technology has the potential for development of next generation antimicrobial agents that would be effective even for bacteria that are resistant to all known antibiotics. This technology could also be used to help 'good' bacteria produce compounds to treat diseases caused by protein deficiencies.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats and can be programmed to target specific stretches of genetic code and to edit DNA at precise locations. Researchers use CRISPR to permanently modify genes in living cells and organisms.
In this way, CRISPR can be programmed to kill bacteria, but until now there wasn't a way to efficiently and specifically target certain bacterial strains.

The delivery system developed at Western uses bacteria's natural ability to replicate -- called bacterial conjugation -- to deliver CRISPR to specific bacteria, in order to alter its DNA and kill it.


Thomas A. Hamilton, Gregory M. Pellegrino, Jasmine A. Therrien, Dalton T. Ham, Peter C. Bartlett, Bogumil J. Karas, Gregory B. Gloor, David R. Edgell. Efficient inter-species conjugative transfer of a CRISPR nuclease for targeted bacterial killing. Nature Communications, 2019; 10 (1) DOI: 10.1038/s41467-019-12448-3

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Wednesday, 13 November 2019

Digital transformation of pharmaceuticals - what's new?

Here is my article on digital transformation of pharmaceuticals - "Becoming Pharma 4.0: How Digital Transformation Is Reshaping Pharmaceuticals".

The digital transformation of biopharmaceutical manufacturing is continuing at a rapid pace as companies attempt to mine the sources of data available. Innovations include predictive analytics, big data analytics, and creating the digital plant. Digital transformation offers a mechanism to revise its business model, to improve production processes, to design new drugs faster by using artificial intelligence to screen compounds and to increase responsiveness to customers. Furthermore, the volume of data processed by pharmaceutical firms shows no sign of slowing down. This means pharmaceutical companies must act quickly in terms of building core internal digital capabilities and moving beyond their traditional IT functions to all areas of the business.

See :

Tuesday, 12 November 2019

New defensive mechanism against bacterial wound infections

Wound inflammation which results in impaired wound healing can have serious consequences for patients. Researchers from Charité -- Universitätsmedizin Berlin have discovered a new defensive mechanism which enables our skin to actively kill bacteria. Central to this mechanism is a cellular messenger molecule known as 'interleukin 6', whose mode of action may be used in the future to prevent wound infections.

Skin wound colonization by bacteria or other pathogens can lead to severe inflammation. In the worst cases, this can result in septicemia or amputation. Prompt treatment is therefore essential. However, growing numbers of bacteria developing antibiotic resistance have resulted in treatment options becoming increasingly limited.

The researchers investigated the hypothesis that the skin's host defense against pathogens might include 'mast cells', a type of defensive immune system cell which is known to play a major role in allergies. Mast cells are responsible for the body's response to otherwise harmless substances, producing symptoms such as runny nose or itching. However, researchers suspect that their role goes beyond this mediation of abnormal immune responses, with some results suggesting that they play a role in our body's defense against pathogens.

Using an animal model, the researchers studied the effects of an absence of mast cells on wound healing after infection. The researchers observed that, on day five after infection, the total number of bacteria present in the wound was 20 times higher if mast cells were absent. This resulted in the infected wound taking several days longer to close. According to the researchers' findings, the mast cells' bacteria-killing effect is a product of the release of the messenger molecule interleukin 6. This molecule stimulates cells within the superficial layer of the skin, prompting them to release 'antimicrobial peptides', short protein chains which kill bacteria, viruses and fungi.

The study demonstrated the nature and extent of mast cell involvement in the skin's host defense mechanism against bacteria. Exploiting their knowledge of interleukin 6 and its key function, the researchers found that the application of interleukin 6 to the wound prior to infection resulted in an improved defense against bacteria, even in animals with intact immune systems.

The researchers were also able to replicate this effect in human tissue.


C. Zimmermann, D. Troeltzsch, V. A. Giménez-Rivera, S. J. Galli, M. Metz, M. Maurer, F. Siebenhaar. Mast cells are critical for controlling the bacterial burden and the healing of infected wounds. Proceedings of the National Academy of Sciences, 2019; 201908816 DOI: 10.1073/pnas.1908816116

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Monday, 11 November 2019

Auditing and Assessing The Quality Control Laboratory

The concept of quality is central to the delivery of laboratory services and this is achieved through the incorporation of quality systems, quality control and quality assurance in all aspects of laboratory practice. Essential to all aspects of laboratory results is to ensure that they are accurate, reliable and delivered in a timely fashion. To ensure that these requirements are in place and that they are consistently being met, audits should be regularly undertaken. Quality audits play an essential role in the Quality Management System and these are typically a systematic examination of a system, discrete operate, product or process. In pharmaceuticals and healthcare, the analytical laboratory function plays an important role in testing products and samples against defined acceptance criteria and this information is used for release purposes. Such laboratories tend to be organized along specific disciplines (such as chemistry or microbiology) and fall within a generalized control laboratory (or quality control laboratory) unit.

Audits of the laboratory will be performed at predefined time intervals, assessing whether the laboratory complies with the defined quality system processes and this can involve procedural or results-based assessment criteria. Such audits (sometimes called ‘assessments’) can be internal (from within the company) or external (such as conducted by customers or inspectors from regulator bodies or standards / certification agencies for accreditation purposes or where inspections are performed by regulatory agencies).

In relation to how audits should be applied to Quality Control Laboratories, Tim Sandle has written an article.

The reference is:

Sandle, T. (2019) Auditing and Assessing The Quality Control Laboratory, Journal of GXP Compliance, 23 (4): 1-10

For a copy, please contact Tim Sandle

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Sunday, 10 November 2019

Weak spot in pathogenic bacteria

Antibiotics are still the most important weapon for combatting bacterial infections. But medical science is running out of "ammunition" because of more and more frequently occurring resistances. Scientists from the Technical University of Munich and the Max Planck Institute of Molecular Physiology has now elucidated the structure of the proteolytic complex ClpX-ClpP. This is a key to development of innovative antibiotics which target the degradation process of defective proteins in bacteria.

Almost 700,000 people in Europe suffer from infections every year through antibiotic-resistant pathogens; approximately 33,000 of them die. Despite this enormous and globally increasing danger, very few new antibiotics have been developed and approved in the past few decades.

There is no improvement in sight. That is why it is urgently necessary to find new points of attack in pathogenic bacteria and to develop new antibiotics which exploit these weak spots.
New mechanism of action destroys bacteria

A particularly promising point of attack for antibacterial therapies is the proteolytic enzyme ClpP: on the one hand it plays an important role in bacterial metabolism, and on the other hand it ensures the controlled degradation of defective proteins.

But for this purpose it requires the ClpX protein as a starting aid. In the complex with ClpP, ClpX identifies proteins which should be degraded, unfurls them and guides them into its barrel-like degradation chamber.

Scientists in the groups led by Prof. Stephan Sieber, Technical University of Munich (TUM) and Prof. Stefan Raunser, Director at the Max Planck Institute of Molecular Physiology in Dortmund, have now elucidated the three-dimensional structure of the ClpX-ClpP proteolytic complex for the first time and thereby established an important basis for future pharmacological strategies.

A new class of potential antibiotics -- the so-called acyldepsipeptide (ADEP) antibiotics -- also brings about an uncontrolled degradation through ClpP without the support of ClpX. As a result also vital proteins are destroyed -- with lethal consequences for the bacteria.
This unique mechanism of action has considerable innovation potential in the fight against pathogenic bacteria. Whereas common antibiotics act through the inhibition of vital processes, in this case the antibacterial effect is achieved through the activation of a process.

In addition to the degradation of defective proteins, ClpP is also a decisive regulator in the production of an arsenal of bacterial toxins which are primarily responsible for the pathogenic effect of many pathogens.


Christos Gatsogiannis, Dora Balogh, Felipe Merino, Stephan A. Sieber, Stefan Raunser. Cryo-EM structure of the ClpXP protein degradation machinery. Nature Structural & Molecular Biology, 2019; 26 (10): 946 DOI: 10.1038/s41594-019-0304-0

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Saturday, 9 November 2019

Real-time view into the kinetics of viral assembly

Researchers have captured images of the formation of individual viruses, offering a real-time view into the kinetics of viral assembly. The research provides new insights into how to fight viruses and engineer self-assembling particles.

"Structural biology has been able to resolve the structure of viruses with amazing resolution, down to every atom in every protein," said Vinothan Manoharan, the Wagner Family Professor of Chemical Engineering and Professor of Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences. "But we still didn't know how that structure assembles itself. Our technique gives the first window into how viruses assemble and reveals the kinetics and pathways in quantitative detail."

Manoharan and his team focused on single-stranded RNA viruses, the most abundant type of virus on the planet. In humans, RNA viruses are responsible for, among others, West Nile fever, gastroenteritis, hand, foot, and mouth disease, polio, and the common cold.

These viruses tend to be very simple. The virus Manoharan and his team studied, which infects E. coli bacteria, is about 30 nanometers in diameter and has one piece of RNA, with about 3600 nucleotides, and 180 identical proteins. The proteins arrange themselves into hexagons and pentagons to form a soccer-ball-like structure around the RNA, called a capsid.
How those proteins manage to form that structure is the central question in virus assembly. Until now, no one had been able to observe viral assembly in real time because viruses and their components are very small and their interactions are very weak.

To observe the viruses, the researchers used an optical technique known as interferometric scattering microscopy, in which the light scattered off an object creates a dark spot in a larger field of light. The technique doesn't reveal the virus's structure but it does reveal its size and how that size changes with time.

The researchers attached viral RNA strands to a substrate, like stems of a flower, and flowed proteins over the surface. Then, using the interferometric microscope, they watched as dark spots appeared and grew steadily darker until they were the size of full-grown viruses. By recording intensities of those growing spots, the researchers could actually determine how many proteins were attaching to each RNA strand over time.

The researchers compared these observations to previous results from simulations, which predicted two types of assembly pathways. In one type of pathway, the proteins first stick randomly to the RNA and then rearrange themselves into a capsid. In the second, a critical mass of proteins, called a nucleus, must form before the capsid can grow.


Rees F. Garmann, Aaron M. Goldfain, Vinothan N. Manoharan. Measurements of the self-assembly kinetics of individual viral capsids around their RNA genome. Proceedings of the National Academy of Sciences, 2019; 201909223 DOI: 10.1073/pnas.1909223116

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Friday, 8 November 2019

Household bleach inactivates chronic wasting disease prions

A 5-minute soak in a 40% solution of household bleach decontaminated stainless steel wires coated with chronic wasting disease (CWD) prions, according to a new study by National Institutes of Health scientists. The scientists used the wires to model knives and saws that hunters and meat processors use when handling deer, elk and moose -- all of which are susceptible to CWD. The research was conducted at Rocky Mountain Laboratories (RML) in Hamilton, Mont., USA.

CWD is a brain-damaging and fatal prion disease in cervids, members of the deer family. To date CWD has never been found in people. However, other prion diseases can affect people, therefore scientists, wildlife managers and public health agencies have suggested handling CWD cervid tissues with caution. CWD is spreading in North America, increasing the potential for human exposure. The disease has been found in cervids in 26 states and three Canadian provinces, as well as in Norway, Finland and South Korea. Not all animals infected with CWD will show signs of disease, but those that do appear weak and thin.

Infectious prions -- types of proteins found in mammals that when misfolded can cause disease -- are extremely difficult to inactivate, which led the scientists to seek a practical, low-cost CWD decontamination method. Bleach has been proven as a decontaminant against other types of prions but had never been tested against CWD.

CWD prions adhere readily to stainless steel and can contaminate knives, saws and other equipment. For hunters and others who want to be cautious when handling potentially CWD-infected animals, the ability to decontaminate equipment is one approach to reducing potential exposure.

The researchers worked with CWD-infected brains from white-tailed and mule deer. They tested various bleach concentrations and soak times to determine the most effective combination to eliminate prion seeding. Notably, the study failed to find an effective method to decontaminate CWD-infected solid tissue. Pieces of CWD-infected brain retained prion activity even after a 30-minute soak in 100% bleach. Investigators note that bleach fails to penetrate tissues and should be used only as a surface decontaminant.

The scientists hope that public health and wildlife agencies will consider this study when making formal recommendations for decontamination of CWD prions.


Katie Williams, Andrew G. Hughson, Bruce Chesebro, Brent Race. Inactivation of chronic wasting disease prions using sodium hypochlorite. PLOS ONE, 2019; 14 (10): e0223659 DOI: 10.1371/journal.pone.0223659

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Thursday, 7 November 2019

Blue laser light inhibits biofilm formation by inducing oxidative stress

An emerging, novel approach to control antibiotic-resistant bacterial infections is based on the use of light, in particular of blue wavelengths (400–470 nm). A new research paper of interest, concerning biofilm elimination by inducing oxidative stress. Here s the abstract:

Resolution of bacterial infections is often hampered by both resistance to conventional antibiotic therapy and hiding of bacterial cells inside biofilms, warranting the development of innovative therapeutic strategies. Here, we report the efficacy of blue laser light in eradicating Pseudomonas aeruginosa cells, grown in planktonic state, agar plates and mature biofilms, both in vitro and in vivo, with minimal toxicity to mammalian cells and tissues. Results obtained using knock-out mutants point to oxidative stress as a relevant mechanism by which blue laser light exerts its anti-microbial effect. Finally, the therapeutic potential is confirmed in a mouse model of skin wound infection. Collectively, these data set blue laser phototherapy as an innovative approach to inhibit bacterial growth and biofilm formation, and thus as a realistic treatment option for superinfected wounds.

The link to the research can be found here.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Wednesday, 6 November 2019

Update on disinfectant test standards

Two European disinfectant test standards have been updated this year.

EN 1276: 2019 Phase 2 / Step 1 – Quantitative Bactericidal Suspension Test

This involves at least two Gram-positive bacteria (Staphylococcus aureus and Enterococcus hirae) and at least two Gram-negative organisms (Pseudomonas aeruginosa and Escherichia coli), with the provision for additional test organisms if desired.

Incorporated into the test procedure are interfering substances to simulate clean and dirty conditions using different levels of Bovine Serum Albumin (BSA) and the effect of water hardness. Temperatures and contact times can be incorporated based on manufacturer’s recommendations.

Three disinfectant concentrations are included to cover the active and non-active range; this is to provide some control on the test method (i.e. the non-active concentration would be expected to fail the test). There are also additional controls to ensure that the test procedures are satisfactory, to demonstrate that the neutralisation procedure is effective and to ensure that the neutralisation agents do not themselves inactivate the test organisms.

The basic requirement is at least a 5-log reduction of all the test organisms.

This test is intended to take account of some of the environmental parameters (e.g. water hardness, organic load) as well as the effect of the contact time, all of which may influence the efficacy of the disinfectant under in-use conditions. However, it should be noted that ready to use disinfectants will be disadvantaged in comparison to concentrated disinfectants when tested according to this method, as some dilution is always produced by the addition of inoculum and interfering substance. Ready to use products can only be tested at a concentration of 97% or less.

EN 1650: 2019  Phase 2 / Step 1 - Quantitative Fungicidal Suspension Test

This test procedure serves a similar function to the Quantitative Bacterial Suspension Test (EN 1276) but is intended to cover fungicidal activity.

This test utilises the same two organisms as used in the Phase 1 Basic Fungicidal Test (Candida albicans and Aspergillus brasiliensis) with the provision for additional test organisms if desired. It incorporates the same interfering substances and test controls as in the Quantitative Bactericidal Suspension Test and has the same limitation regarding testing of ready to use products. The temperature and contact time are recommended by the disinfectant manufacturer.

The basic requirement is at least a 4-log reduction for all the test organisms . This requirement is less stringent than that required for the quantitative bacterial suspension test and reflects the expected reduced susceptibility of fungi to disinfectant preparations compared to bacteria.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Tuesday, 5 November 2019

US environmental agency to end animal testing by 2035

The US Environmental Protection Agency will phase out animal testing of chemical products by 2035, in favour of computer-based and in vitro tissue models.

As part of efforts to “aggressively peruse a reduction in animal testing”, the agency will reduce requests for and funding of mammal studies by 30% by 2025. Any mammal studies requested or funded by EPA after 2035 will require administrator approval on a case-by-case basis, it said.

EPA Administrator Andrew Wheeler said in a memo: “Scientific advancements exist today that allow us to better predict potential hazards for risk assessment purposes without the use of traditional methods that rely on animal testing.

“Through scientific innovation and strategic partnerships, we can protect human health and the environment by using cutting-edge, ethically sound science in our decision-making that efficiently and cost-effectively evaluates potential effects without animal testing.

The EPA is also awarding $4.25 million to five US universities for R&D into alternative test methods.

Kristie Sullivan at Physicians Committee for Responsible Medicine said: “This measure will mean a safer environment as well as scientific methods that are technically better and more humane.

“We have been pleased to see the progress EPA has made to adopt newer and better test methods, and we are excited to witness the agency making a commitment to move more fully towards non-animal tests that will better protect human health and the environment.”

From December 2011 to May 2018, the EPA deferred more than 1,000 pesticide toxicity studies, saving more than 200,000 laboratory animals and $300 million in the process.

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

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