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."



See:


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.

See:

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.


See:

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 : https://www.biopharmatrend.com/post/109-becoming-pharma-40-how-digital-transformation-is-reshaping-pharmaceuticals/

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.

See:

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.

See:

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.

See:

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.

See:

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

Monday, 4 November 2019

Creating ‘smart’ microbial bionsensors: An interview with a Los Alamos National Laboratory researcher


New research shows that protein-based biosensors can detect the presence of a desired enzyme target and respond by physically lighting up and enabling researchers to immediately identify cells with increased overall enzyme yield.

The new approach, which comes from Los Alamos National Laboratory, can be translated to screening of metagenomic samples, rational enzyme design, or
directed evolution of known enzymes. The technology is adaptable to a single enzyme, or a pathway, or global optimization of an industrial strain.

Tim Sandle has conducted an interview with Dr. Ramesh Jha of the Los Alamos National Laboratory to discover more.

The reference is:



Sandle, T. (2019) Creating ‘smart’ microbial bionsensors: An interview with a Los Alamos National Laboratory researcher, Pharmig News, 75, pp2-3

For details, contact Tim Sandle

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Sunday, 3 November 2019

Good Distribution Practice: A Handbook for Healthcare Manufacturers and Suppliers

An excellent new two-volume book has been published, vital for those working in pharmaceuticals and healthcare:

Good Distribution Practice: A Handbook for Healthcare Manufacturers and Suppliers - Edited by Siegfried Schmitt.

A two-volume reference publication, discussing in detail global regulations and practices. Over 30 professionals and experts share their knowledge, interpret the regulations and provide a plethora of best-practice examples.

Volume 1
Following an introduction into the subject of Good Distribution Practice (GDP), the key topics covered in this volume relate to:
  • The applicable GDP regulations globally, including serialization
  • Qualified Person (QP) and Responsible Person (RP) in GDP
  • GDP as part of the Quality Management System (QMS)
  • Good Distribution Practice - the industry perspective
  • GDP Checklist
Volume 2

Following an introduction into the subject of Good Distribution Practice (GDP), the key topics covered in this volume relate to:
  • De-risking the supply chain
  • Serialisation and Packaging in Practice
  • Other chapters provide details about packaging materials. 
The authors not only introduce the readers to the options available, but more importantly help assure that the selection of packaging materials is linked to shipping routes, pharmaceutical material properties and lastly costs. 

The book is available from the PDA Bookstore:



Or from Amazon :


Volume 2

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Researchers find way to kill pathogen resistant to antibiotics


Researchers have demonstrated a new strategy in fighting antibiotics resistance: the use of artificial haem proteins as a Trojan horse to selectively deliver antimicrobials to target bacteria, enabling their specific and effective sterilization. The technique killed 99.9% of Pseudomonas aeruginosa, a potentially deadly, antibiotic-resistant bacterium present in hospitals. The strategy should also work for other dangerous bacteria.

Pseudomonas aeruginosa is a dangerous bacterium that causes infections in hospital settings and in people with weakened immune systems. It can cause blood infections and pneumonia, while severe infections can be deadly. Highly resistant to antibiotic treatment, P. aeruginosa is one of the most critical pathogens urgently requiring alternative treatment strategies, according to the World Health Organization.

This bacterium is one of many that have evolved a system that allows them to acquire difficult-to-access iron from the human body. Iron is essential for bacterial growth and survival, but in humans, most of it is held up within the 'haem' complex of haemoglobin. To get hold of it, P. aeruginosa and other bacteria secrete a protein, called HasA, which latches onto haem in the blood. This complex is recognized by a membrane receptor on the bacterium called HasR, permitting haem entry into the bacterial cell, while HasA is recycled to pick up more haem.

Bioinorganic chemist Osami Shoji of Nagoya University and collaborators have found a way to hijack this 'haem acquisition system' for drug delivery. They developed a powder formed of HasA and the pigment gallium phthalocyanine (GaPc), which, when applied to a culture of P. aeruginosa, was consumed by the bacteria.

"When the pigment is exposed to near-infrared light, harmful reactive oxygen species are generated inside the bacterial cells," explains Shoji. When tested, over 99.99% of the bacteria were killed following treatment with one micromolar of HasA with GaPc and ten minutes of irradiation.


The strategy also worked on other bacteria with the HasR receptor on their membranes, but not on ones without it. The haem acquisition system is so essential to these bacteria's survival that it is not expected to change, making it unlikely the bacteria will develop resistance to this drug strategy, the researchers believe.

"Our findings support the use of artificial haem proteins as a Trojan horse to selectively deliver antimicrobials to target bacteria, enabling their specific and effective sterilization, irrespective of antibiotic resistance," the team reports in their study.

See:

Yuma Shisaka, Yusuke Iwai, Shiho Yamada, et al. Hijacking the Heme Acquisition System of Pseudomonas aeruginosa for the Delivery of Phthalocyanine as an Antimicrobial. ACS Chemical Biology, 2019; 14 (7): 1637 DOI: 10.1021/acschembio.9b00373

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Saturday, 2 November 2019

Alcohol-producing gut bacteria could cause liver damage even in people who don't drink



Non-alcoholic fatty liver disease (NAFLD) is the build-up of fat in the liver due to factors other than alcohol. It affects about a quarter of the adult population globally, but its cause remains unknown. Now, researchers have linked NAFLD to gut bacteria that produce a large amount of alcohol in the body, finding these bacteria in over 60% of non-alcoholic fatty liver patients.

Researchers discovered the link between gut bacteria and NAFLD when they encountered a patient with severe liver damage and a rare condition called auto-brewery syndrome (ABS). Patients with ABS would become drunk after eating alcohol-free and high-sugar food. The condition has been associated with yeast infection, which can produce alcohol in the gut and lead to intoxication.

By analyzing the patient's feces, the team found he had several strains of the bacteria Klebsiella pneumonia in his gut that produced high levels of alcohol. K. pneumonia is a common type of commensal gut bacteria. Yet, the strains isolated from the patient's gut can generate about four to six times more alcohol than strains found in healthy people.

Moreover, the team sampled the gut microbiota from 43 NAFLD patients and 48 healthy people. They found about 60% of NAFLD patients had high- and medium-alcohol-producing K. pneumonia in their gut, while only 6% of healthy controls carry these strains.

To investigate if K. pneumonia would cause fatty liver, researchers fed germ-free mice with high-alcohol-producing K. pneumonia isolated from the ABS patient for 3 months. These mice started to develop fatty liver after the first month. By 2 months, their livers showed signs of scarring, which means long-term liver damage had been made. The progression of liver disease in these mice was comparable to that of mice fed with alcohol. When the team gave bacteria-fed mice with an antibiotic that killed K. pneumonia, their condition was reversed.


Their findings could help develop a screening method for early diagnosis and treatment of non-alcoholic fatty liver.

See:

Jing Yuan, Chen Chen, Jinghua Cui, et al. Fatty Liver Disease Caused by High-Alcohol-Producing Klebsiella pneumoniae. Cell Metabolism, 2019; DOI: 10.1016/j.cmet.2019.08.018

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

Friday, 1 November 2019

How fungal biofilm structure impacts lung disease



Findings from an innovative new study led by researchers at Dartmouth's Geisel School of Medicine and published this week in Nature Microbiology reveal that the way in which human fungal pathogens form colonies can significantly impact their ability to cause disease.

Highly diverse and adaptable, these colonies, known as biofilms, allow invasive fungal pathogens such as Aspergillus fumigatus to grow and thrive, infecting the lungs of patients, even under demanding environmental circumstances.

In the study the researchers sought to assess how an important environmental stressor impacts disease progression in invasive aspergillosis, a disease caused by the mold Aspergillus fumigatus, and to identify fungal genetic factors involved in this process.

The research found that the appearance of the organism can actually tell medics something about how it is going to behave in the lung -- in this case, how this particular morphology gives the organism the ability to be more virulent and to cause more host damage.


See:

Caitlin H. Kowalski, Joshua D. Kerkaert, Ko-Wei Liu, Matthew C. Bond, Raimo Hartmann, Carey D. Nadell, Jason E. Stajich, Robert A. Cramer. Fungal biofilm morphology impacts hypoxia fitness and disease progression. Nature Microbiology, 2019; DOI: 10.1038/s41564-019-0558-7

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology

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