Saturday, 19 August 2017

Bacteria on surfaces and strength of adhesion

Scientists have developed a method with which they can measure the contact area between a bacterium and the surface it is 'sitting' on. Interestingly a large contact area does not necessarily mean a large adhesive force. It turns out that specific features of the bacteria are the main reasons for the observed differences. These results can be used to optimize antibacterial materials.

Bacteria of the species Staphylococcus aureus are among the most widespread and dangerous pathogens of our time. One of the reasons for their effectiveness is their ability to adhere to both synthetic and natural surfaces, where they form very persistent biofilms. These biofilms effectively protect the individual pathogens making them very difficult to remove from a surface. This is why their presence on medical implants is so feared and why they are a major cause of post-operative infection. One approach to preventing infection is therefore to prevent the formation of the biofilm. But in order to be able to influence biofilm growth, scientists need to understand the mechanism by which the bacteria adhere to surfaces.

For example, it would be useful to know just what fraction of the surface area of a single bacterial cell is actually in contact with the surface. However, as these spherical bacteria are only a micrometer across (about one hundredth the thickness of a human hair), it was unlikely that conventional light microscopy could be used to determine the contact area.

The Saarland University team led by the experimental physicist Professor Karin Jacobs and the microbiologist Professor Markus Bischoff therefore made use of another property of the bacteria, namely that the strength of adhesion exhibited by different species of bacteria often depends strongly on the type of surface on which it is situated. For instance, the bacteria that were the focus of the present study adhere much more effectively to strongly hydrophobic surfaces than to wettable (hydrophilic) surfaces. The researchers therefore created a silicon-based surface that exhibited both properties -- strongly hydrophobic in one region, highly wettable in another -- within an extremely small area. The adhesive force exerted by individual bacteria on this specially prepared surface was then measured using a scanning atomic force microscope, known as a force spectroscope. The method involves bringing a single bacterial cell into minimal contact with the surface and then measuring the force required to detach the bacterium from that surface. This is the adhesive force.

On the hydrophobic (literally 'water hating') part of the surface, the force is roughly ten times greater than that needed when the bacterial cell adheres to the hydrophilic ('water loving') region. This procedure is then repeated with the bacterial cell located successively closer to the boundary between the hydrophobic and hydrophilic regions, then measuring the force with the bacterium located on the boundary itself and finally with the bacterium situated in the purely hydrophilic zone where the adhesive force is at its weakest. The measurement data relating the adhesive force of a single cell to its exact position on the specially customized surface, and therefore to the wettability of the surface, has allowed the Saarbrücken research team to infer the size of the contact area between the bacterium and the surface. The method can also be used for other measurements, such as determining the adhesive force of colloidal particles, which are also spherical in shape.

The research team discovered that the diameter of the contact area, which was assumed to be circular, was of the order of a few tens to several hundreds of nanometres (a thousand nanometres are equivalent to one thousandth of a millimetre) and that the size of the contact area can vary significantly between different individual cells of the same species Staphylococcus aureus. For the purposes of comparison, a non-pathogenic member of the genus Staphylococcus was also studied that adheres far less strongly to the surface than the pathogen Staphylococcus aureus.

It is particularly astonishing that the size of the contact area has absolutely no effect on the strength of adhesion between a bacterial cell and the surface. The researchers were also able to demonstrate that despite their spherical shape, the bacteria cannot be described simply as hard spheres when they interact with a surface. A more accurate description is to think of them as balls that are covered with a soft, shaggy and uneven coating of cell wall proteins and that this coat is the main factor determining adhesion between the cell and the surface. The pronounced local variability in the adhesive force reflects the different compositions of the groups of cell wall proteins, which determine how strongly a region of the cell's surface is able to adhere to a surface.

The approach used in the study can, in principle, be applied to all other species of bacterial pathogens no matter whether spherical or rod-like in shape. The results may well pave the way to developing surfaces whose morphology can be carefully adjusted to modify these adhesive forces, thus suppressing the adhesion of unwanted bacterial pathogens, or, alternatively, encouraging the adhesion of bacteria, such as those used in waste disposal, whose presence is desired.


Christian Spengler, Nicolas Thewes, Philipp Jung, Markus Bischoff, Karin Jacobs. Determination of the nano-scaled contact area of staphylococcal cellsNanoscale, 2017; DOI: 10.1039/c7nr02297b

Posted by Dr. Tim Sandle

Friday, 18 August 2017

Cranberries may aid the gut microbiome

Using the model beneficial bacterium bifidobacteria, researchers tested the hypothesis that cranberries might be a candidate for a new supplement to boost gut health. Bifidobacteria are found in adults to some degree but the highest concentrations are found in the gut microbiome of newborn, breast-fed babies.

This study provides the first evidence that certain bifidobacteria do consume xyloglucans, and the ones that do exhibit a special metabolism that is not typical. Specifically, these bifidobacteria produce formic acid while consuming xyloglucans and less lactic acid than is typically secreted.


Ezgi Özcan, Jiadong Sun, David C. Rowley, David A. Sela. A human gut commensal ferments cranberry carbohydrates to produce formateApplied and Environmental Microbiology, 2017; AEM.01097-17 DOI: 10.1128/AEM.01097-17

Posted by Dr. Tim Sandle

Thursday, 17 August 2017

Studying fungi to keep space travelers safe

Human presence in closed habitats that may one day be used to explore other planets is associated with changes in the composition of the fungal community - the mycobiome - that grows on surfaces inside the habitat, according to a new study.

Dr Kasthuri Venkateswaran, Senior Research Scientist at the NASA Jet Propulsion Laboratory, Caltech, and corresponding author of the study said: "Our study is the first report on the mycobiome of a simulated habitat meant for the future human habitation of other planets. We used the Inflatable Lunar/Mars Analog Habitat (ILMAH), a unique, simulated closed environment that mimics the conditions found on the International Space Station and possible human habitats on other planets. We showed that the overall fungal diversity changed when humans were present."

The researchers found that certain kinds of fungi -- including known pathogens that can colonize the human body and cause allergies, asthma and skin infections -- increased in number while humans were living inside the ILMAH. Prolonged stays in closed habitats might be stressful for inhabitants and thus lead to decreased immune response, making people more vulnerable to opportunistic pathogens like fungi.

Dr Venkateswaran said: "Fungi are extremophiles that can survive harsh conditions and environments like deserts, caves or nuclear accident sites, and they are known to be difficult to eradicate from other environments including indoor and closed spaces. Characterizing and understanding possible changes to, and survival of, fungal species in environments like the ILMAH is of high importance since fungi are not only potentially hazardous to the inhabitants but could also deteriorate the habitats themselves."
Knowing how fungal communities change in the presence of humans is thus necessary for the development of appropriate countermeasures to maintain habitats like the ILMAH or the ISS and to protect the health of the people who live there.


A. Blachowicz, T. Mayer, M. Bashir, T. R. Pieber, P. De León, K. Venkateswaran. Human presence impacts fungal diversity of inflated lunar/Mars analog habitatMicrobiome, 2017; 5 (1) DOI: 10.1186/s40168-017-0280-8

Posted by Dr. Tim Sandle

Wednesday, 16 August 2017

Helium ions reveal how viruses attack bacteria

Bacteria and viruses can be imaged with helium ions in contrast to electrons which are the standard workhorse in nanoscale microscopy, report scientists. Helium ions, being more massive than electrons, can be focused to a much tighter spot down to the atomic length scales. By measuring the electrons generated by the ion bombardment, an image can be formed from the sample with biological features visible below the nanometer (one billionth of a meter) length.

The novel technique, called helium ion microscopy (HIM), was used to image hard-to-see interaction between bacteria and viruses infecting bacteria, or so called bacteriophages. These phages are currently actively considered as a novel "smart weapon" against bacterial infections, which are becoming more and more difficult to treat with traditional antibiotics. The images demonstrated in clear images the different stages of how the phages in question attacked the bacteria (E. coli), for example showing the process where the virus has latched onto the bacterial surface, grabbing it with a tentacle like structure, and being in the process of injecting its genome into the bacterial cell.

In addition to imaging, the researchers also demonstrated that the ions can be used as a nanoscale scalpel, to cut portions off individual bacterial cells, or to reveal bacterial colonies under the surfaces of samples. They feel confident that HIM offers many more possibilities in the future to help to study microbes and viruses in their natural state, interacting with each other and other cells.


Miika Leppänen, Lotta-Riina Sundberg, Elina Laanto, Gabriel Magno de Freitas Almeida, Petri Papponen, Ilari J. Maasilta. Imaging Bacterial Colonies and Phage-Bacterium Interaction at Sub-Nanometer Resolution Using Helium-Ion MicroscopyAdvanced Biosystems, 2017; 1700070 DOI: 10.1002/adbi.201700070

Posted by Dr. Tim Sandle

Tuesday, 15 August 2017

Cleanroom summit

The Cleanroom Management Summit would like to highlight Annex 1 compliance, audit readiness and isolator technology as the essential topics for the pharmaceutical and healthcare industries. Included in the Summit’s Agenda they will result in overall industry development and shall help generate better understanding and expertise.

Annex 1, is an important industry requirement which requires compliance for sterile manufacturing of medicinal products. This standard is being revised in coming months, it is important that we understand the changes and how they would affect the manufacturing process. The Summit will highlight the new changes and our industry expert Mr Farguharson will provide guidance on how to maintain compliance.
Audits are very important in the drug manufacturing industry, they ensure the high quality standards, operational safety & efficiency and the regulatory requirements are achieved to ensure the safety of the customers, therefore preparation for auditing is essential, the Summit will look at this topic in detail with our industry leader giving insight and guidance on how to be Audit ready and how to achieve GMP excellence, these topics will provide essential information and would help your next industry audit go smoothly and incident free.

Isolator technology provides an easier and more cost effective solution for the cleanroom industry, the Summit will see how this technology can be implemented in pharmaceutical manufacturing and it's impact on the overall cleanroom industry.

Join the Cleanroom Management Summit in July and secure a 17.5% discount.

Special book offer:

Posted by Dr. Tim Sandle

Monday, 14 August 2017

Validation and Assessment of Computerized System Software in a Pharmaceutical Facility

Validation is an established approach within pharmaceuticals and healthcare, and the principles of validation extend to computerized systems. Validation concerns establishing documented evidence designed to produce a high degree of assurance that a process or system (including computer systems) will consistently operate according to pre-requisite specifications and quality attributes. Computerized system validation, as with other types of validation, is confirmed through a review of objective evidence to show the requirements for a specific application have been fulfilled. In other words it is proven that a system is fit for purpose. What differs are the specifics, and this paper draws out the main aspects.

A new paper of interest has been published:

The aim of this paper is to assess the current regulations relating to computer system validation, focusing on software (although reference is also made to hardware). The paper provides some best practice advice for the risk assessment of computerized systems.

The reference is:

Sandle, T. (2017) Validation and Assessment of Computerized System Software in a Pharmaceutical Facility, IVT Special Edition Utility Qualification Volume II, pp13-20

For further details, contact Tim Sandle

Posted by Dr. Tim Sandle

Sunday, 13 August 2017

Pharmig News

The latest edition of Pharmig News has been published. This is edition #68.

Inside the issue is part 1 of Pharmig’s survey of best practices for culture media, a regulatory news round-up, the chairman’s perspective, review of ‘Making Pharmaceuticals’, and news on training courses…and more!

Copies have been sent to member organizations. For details on how to get hold of a copy, please email:

Sandle, T. (2017) Industry practices relating to culture media use: The Pharmig survey (Part 1), Pharmig News, No. 68, pp2-7

Posted by Dr. Tim Sandle

FDA unveils plan to eliminate orphan designation backlog

U.S. Food and Drug Administration unveiled a strategic plan to eliminate the agency’s existing orphan designation request backlog and ensure continued timely response to all new requests for designation with firm deadlines. The agency’s Orphan Drug Modernization Plan comes a week after FDA Commissioner Scott Gottlieb committed to eliminating the backlog within 90 days and responding to all new requests for designation within 90 days of receipt during his testimony before a Senate subcommittee.

As authorized under the Orphan Drug Act, the Orphan Drug Designation Programprovides orphan status to drugs and biologics that are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases, which are generally defined as diseases that affect fewer than 200,000 people in the United States. Orphan designation qualifies the sponsor of the drug for various development incentives, including tax credits for clinical trial costs, relief from prescription drug user fee if the indication is for a rare disease or condition, and eligibility for seven years of marketing exclusivity upon approval. A request for orphan designation is one step that can be taken in the drug development process and is different than the filing of a marketing application with the FDA.

Currently, the FDA has about 200 orphan drug designation requests that are pending review. The number of orphan drug designation requests has steadily increased over the past five years. In 2016, the FDA’s Office of Orphan Products Development received 568 new requests for designation – more than double the number of requests received in 2012. The increased interest in the program is a positive development for those with rare diseases and under this new plan, the agency remains committed to advancing the program to ensure it can efficiently and adequately review these requests.

This is the first element of several efforts the FDA will undertake under its new “Medical Innovation Development Plan,” which is aimed at ensuring that the FDA’s regulatory tools and policies are modern, risk based, and efficient. The goal of the plan is to seek ways the FDA can help facilitate the development of safe, effective and transformative medical innovations that have the potential to significantly impact disease and reduce overall health care costs.

This is an edited version of the FDA press release, full details can be found here.

Posted by Dr. Tim Sandle

Pharmig News #67

Posted by Dr. Tim Sandle

Saturday, 12 August 2017

Single Entity Injectable Drug Products

The FDA is requiring the removal of ratio expressions of strength from the labeling of single-entity injectable drug products (i.e., drug products that contain only one active ingredient) and replacement with the amount per unit of volume (e.g., mg/mL).

For example, Epinephrine Injection 1:1,000 will now be labeled as Epinephrine Injection 1 mg/mL. The FDA is requiring the changes to help prevent medication errors related to strength being expressed as a ratio on labeling. There have been several reports of medication errors indicating that ratio expressions are confusing to health care providers and contributed to the errors. Some of the medication errors resulted in serious adverse outcomes, including death. The United States Pharmacopeia (USP) instituted a new labeling standard in an effort to reduce medication errors related to confusion with ratio expressions.

This revision affects Epinephrine Injection, Isoproterenol Hydrochloride Injection, and Neostigmine Methylsulfate Injection.

For further details see: FDA

Posted by Dr. Tim Sandle

Friday, 11 August 2017

Designing cleanrooms for particulate control (Turkish)

Tim Sandle has written an article for the Turkish Cleanroom News publication - Designing cleanrooms for particulate control (Turkish: Parçacık kontrolü için temiz oda tasarımı).

The reference is:

Sandle, T. (2017) Designing cleanrooms for particulate control, Cleanroom News, Issue 2, pp22-23 (Turkish publication: "Parçacık kontrolü için temiz oda tasarımı"). 

The article can be found here: Cleanroom News

Posted by Dr. Tim Sandle

Thursday, 10 August 2017

Supply Chain Security Toolkit for Medical Products

News from the FDA:

Protecting the integrity of the medical product supply chain is complex and requires a global approach. FDA led a collaboration within Asia Pacific Economic Cooperation (APEC) economies to create a Supply Chain Security Toolkit for Medical Products to maximize available global resources and to deliver quality trainings and best practices and for securing the global supply chain for medical products. The toolkit covers the entire supply chain and lifecycle of medical products from raw materials to use by patients. It focuses on developing — and implementing through training programs — processes, procedures, and tools directed at enhancing global medical product quality and supply chain security.

For further details see: FDA

Posted by Dr. Tim Sandle

Wednesday, 9 August 2017

GMP Short Notice and Unannounced Inspections

An interesting blog post from the UK MHRA:

The Human Medicines Regulations 2012 as amended; regulation 325 ‘Rights of Entry’ states that an inspector may at any reasonable time enter premises. This allows for the MHRA to perform inspections both at short notice (may be a few days) or unannounced (no notice given). The use of these inspection types allows us to investigate issues that pose a significant risk to public health without obstruction and to work efficiently. We spend a lot of time planning and scheduling inspections but unfortunately there are times when things don’t go to plan and we can find ourselves with the following scenarios:
  1. There are times when we have no choice for logistical or health & safety reasons but to cancel or postpone a planned inspection at very short notice (for example because an inspector can no longer travel and there is no other available staff to back fill).
  2. A planned inspection finishes early or is postponed at the last minute (for example if a site is found not to ready to be inspected or an incident at the site means we can no longer inspect).
  3. Risk information dictates a change to the prioritisation of an inspection.
  4. A last-minute change to meeting requirements means some inspectors are then free to inspect.
See more at: MHRA

Posted by Dr. Tim Sandle

Tuesday, 8 August 2017

Guidance for stem cell therapies in animals

The European Medicines Agency (EMA) has published the first ever guidance document for stem cell therapies in animals. The guidance addresses concerns raised by manufacturers and authorities in regard to the sterility (absence of bacteria, fungi and mycoplasma) of allogenic stem cell therapies in the veterinary sector.

Allogenic stem cell-based veterinary medicines originate from tissues (such as bone marrow or fat) from a donor from the same species of animal, not from the recipient of the cells. These products are manufactured in large batches which need to be sterile as they are administered by injection directly into the body.

Microbiological contamination can occur at various steps, from the initial sampling of the cells and tissues, up to the final product packaging into containers such as vials, syringes or bottles. A crucial step is the sourcing and collection of the stem cells as it is not always possible to fully implement aseptic techniques at this stage. Control for the absence of microorganisms is also key in manufacturing process controls and quality controls of cell preparations at selected stages of production. The guidance provides answers to eight main issues identified by ADVENT to support manufacturers in ensuring sterile and safe stem cell-based therapies for veterinary use.

For further details see: EMA

Posted by Dr. Tim Sandle

Monday, 7 August 2017

New book: Aseptic and Sterile Processing: Control, Compliance and Future Trends

New book: Aseptic and Sterile Processing: Control, Compliance and Future Trends. Edited by Tim Sandle and Edward C. Tidswell.

Sterile medical products comprise of medical devices, drugs, and biologics. Some are completed  by a terminal sterilization step, thousands of the sterile products found in hospitals, clinics and pharmacies are manufactured by aseptic processing.  These are products intended for patients who have weak or compromised immune systems. This means a contaminated product will the patient’s condition worse or result in death. This places a considerable emphasis upon environmental control and sterility assurance. Despite this concerns of regulatory agencies suggest weaknesses in adequately determining the risk factors that are presented to aseptic and sterile products processing.

To help to check against this rise in regulator concerns, DHI and PDA have published the most important text discussing aseptic and sterile manufacturing to be published in the last decade. The book considers the state of sterile products manufacturing both today and tomorrow. The book is edited by two leading experts in aseptic and sterile products manufacture: Dr. Tim Sandle and Dr. Edward Tidswell.

To produce this comprehensive text the editors sought out leading industry and academic figures to help reassess current risks and technologies, and to represent new developments in the field. The aim was to produce a book that was foremost practical, but also grounded in sound science. Among the subjects covered are contamination risks, regulations, bioburden control, endotoxin control, water systems, depyrogenation, filtration, microbial contamination risks to cleanrooms, environmental monitoring, aseptic process simulations, single-use disposable technology, disinfection, sterility testing, cleanroom operator controls, risk assessment, human error and rapid methods.

Among the subject matter experts enlisted are: David Hussong, James Agalloco, James Akers, Maik W. Jornitz, Teri C. Soli, James Vesper, Hal Baseman, Anne Marie Dixon-Heathman, Michael Miller, Mark Trotter, Karen Zink McCullough, Matts Ramstorp, Crystal Booth, Mark Hunter and others highly experienced in their specialist subjects.

The lessons from the leading practitioners are aimed squarely at those involved with aseptic and sterile processing. Such readers will be able take away many learning points and apply these principles to aseptic and sterile processing within the pharmaceutical and healthcare sectors. The book will also appeal to students of pharmaceutical sciences.

A central theme with the new book is that it is time for a new paradigm in relation to our understanding sterility, given that many microorganisms cannot be cultured. This places a renewed emphasis upon assurance and controls; a thorough science-based risk assessment of processes; and by taking advantage of the best available technologies.

Aseptic and Sterile Processing: Control, Compliance and Future Trends is available from the PDA Bookstore, at: