The
European Medicines Agency (EMA) has recommended Holoclar, the first advanced
therapy medicinal product (ATMP) containing stem cells, for approval in the
European Union (EU). Holoclar is a treatment for moderate to severe limbal stem
cell deficiency (LSCD) due to physical or chemical burns to the eye(s) in
adults. It is the first medicine recommended for LSCD, a rare eye condition
that can result in blindness.
Pages
- Home
- About Dr. Tim Sandle
- Technical articles (free)
- Publications by Tim Sandle
- Microbiology books by Tim Sandle
- Other books by Tim Sandle
- Microbiology Sites
- Presentations by Tim Sandle
- Advertise here
- Write for us
- About this site
- Science and microbiology videos
- Pharmig Publications
- Privacy Policy
- Pharma Microbiology MSc
Friday, 13 February 2015
First stem-cell therapy recommended for approval in EU
Thursday, 12 February 2015
Adaptive pathways for drug development
Adaptive
pathways should be the preferred approach in the near future to bring new
medicines to patients according to the European Medicines Agency (EMA).
This
has been outlined in an article published in Clinical Pharmacology and
Therapeutics. The concept of adaptive pathways foresees an early approval of a
medicine for a restricted patient population based on small initial clinical
studies.
The
first approval is followed by progressive adaptations of the marketing
authorisation to expand access to the medicine to broader patient populations
based on data gathered from its use and additional studies.
EMA
launched a pilot project on adaptive pathways (formerly known as adaptive
licensing) in March 2014 to explore this approach with real medicines in
development.
As
of November 2014, the Agency had received and assessed 29 applications as part
of the pilot, nine of which had been selected for discussion with the
applicant.
Wednesday, 11 February 2015
Mitigating risks due to the use of antibiotics in animals
The
European Medicines Agency (EMA) has published recommendations to limit the
development of antimicrobial resistance (AMR) linked to the use of antibiotics
in animals, thereby minimising at source the risk of transmission of resistance
from animals to humans. The document reference is EMA/787672/2014.
The
proposed measures focus in particular on promoting the responsible use in
veterinary medicine of antibiotics that are critically important in human
medicine such as fluoroquinolones and third and fourth generation
cephalosporins.
Posted by Tim Sandle
Tuesday, 10 February 2015
Pharmacopeial Forum 40 (6)
The
USP Pharmacopeial Forum has a new update. This is Volume 40, No.6. Of interest
in the new issue is:
General Chapter
Chapter 790 Visible
Particulates in injections (Revision proposal target, USP39-NF34)
The
chapter has been edited to clarify intent, which is the need to control and
have acceptance criteria for extraneous particles, even for drug products that
contain inherent particles.
Chapter 851 Spectrophotometry and Light Scattering (Revision
proposal target, USP39-NF34)
This
general chapter is being replaced by a new series of chapters. The new chapters
are:
Chapter
852 Atomic Absorption Spectroscopy
Chapter
853 Fluorescence Spectroscopy
Chapter
854 Mid-Infrared Spectroscopy
Chapter
855 Nephelometry, Turbidimetry, and Visual Comparison
Chapter
857 Ultraviolet-Visible Spectroscopy
Chapter 855 Nephelometry,
Turbidimetry, and Visual Comparison [NEW] (Revision proposal target,
USP39-NF34)
A
replacement chapter for <851>Spectrophotometry and Light Scattering. The
majority of text in this new chapter is the same as <851>.
Chapter 1251 Weighing On An
Analytical Balance (Revision proposal target, USP39-NF34)
Posted by Tim Sandle
Monday, 9 February 2015
Industrial Pharmaceutical Microbiology: Standards & Controls (2015)
A
new edition of the essential microbiology book “Industrial Pharmaceutical
Microbiology: Standards & Controls” has been published.
This
publication covers the entire spectrum of industrial pharmaceutical
microbiology, as applicable to pharmaceuticals and healthcare and it has been
edited by Professor Geoff Hanlon and Dr. Tim Sandle.
The
contamination control of pharmaceutical and healthcare environments and
processes, together with pre-clinical drug development labs, requires a far
more holistic approach than simply choosing technologies and disinfectants.
Today the microbiologist is expected to understand industrial processes and
cleanrooms, and how to effectively evaluate microbial risks to products from
personnel and processes.
To
meet the latest regulatory expectations, the role of the microbiologist is
essential. In addition there is important input requirement from quality
assurance personnel, engineers, and process specialists. Whilst there is a
continuing need for monitoring of the environment and conducting standardised
laboratory tests, industrial pharmaceutical microbiology has moved on a great
deal in the past decade. It now has to embrace microbiological audits; rapid
microbiological methods; conducting risk assessments, both proactive in terms
of minimising contamination, and reactive in terms of addressing microbial data
deviations; and also ensuring that processes meet ‘quality by design’
principles. In this new 600 page book a team of 24 international authorities
will assist you in all your questions.
Industrial
Pharmaceutical Microbiology: Standards and Controls covers the
entire spectrum of industrial pharmaceutical microbiology, as applicable to
pharmaceuticals and healthcare. Connect instantly with regulations and current
best practices on everything from disinfectants to sterility testing;
environmental monitoring to hazard analysis; and from pharmaceutical processes
to biological indicators. All of this is developed from an international
perspective, where different regulations are compared and contrasted together
with insightful commentary as to best practices.
Industrial
Pharmaceutical Microbiology: Standards and Controls provides clear, practical
and up-to-date guidance for handling virtually every compliance and operational
challenge associated with pharmaceutical microbiology.
The
chapter list is:
Part A: The Role
of the Microbiologist and the Microbiology Laboratory
1.
Safety in Microbiology
Nigel
Silman and John V Daniels
2.
Best Practices in Microbiology Laboratory Training
Tim
Sandle
3.
The Use of Culture Media in Pharmaceutical Microbiology
Tim
Sandle
4.
Rapid Microbiological Methods and Process Analytical Technology (PAT)
Jeanne
Moldenhauer
5.
Microbial Risk Assessments for Operational Cleanrooms
Tim
Eaton
6.
The Role of the Qualified Person in Microbiological Quality Assurance
John
Dolman
7.
Auditing the Pharmaceutical Microbiology Department
Andy
Martin
Part B:
Microbiological Control and Industrial Processes
8.
Microbiological Environmental Monitoring
Rosamund
M Baird
9.
Selection and Use of Cleaning and Disinfection Agents in Pharmaceutical Manufacturing
Tim
Sandle
10
Microbiology of Pharmaceutical Grade Water
Tim
Sandle
11.
Biofilm Contamination in Pharmaceutical Facilities
Alex
P Blanchard
12.
Cleanrooms, Isolators and RABS: Basic Principles, Design, Testing, Operation and
Regulatory Aspects
John
Neiger
13.
Aseptic Process Simulations/Media Fills
Marco
Budini and Francesco Boschi
14.
Filtration
Claire
Jarmey-Swan
15.
Sterilisation Technologies
Eric
Dewhurst and Eamonn Hoxey
16.
Biological Indicators
Tim
Sandle
17.
Endotoxins and Dehydrogenation
Karen
Zinc McCullough
18.
Containment System Integrity: Microbial Challenges for Sterile Products
Tim
Sandle
19.
Challenges of Bacteriophage Therapy
Alexander
Sulakvelidze
Part C:
Regulatory Aspects of Industrial Pharmaceutical Microbiology
20.
Microbiological Quality and Regulatory Requirements for Biotherapeutics
Daniel
Galbraith
21.
The Microbiological Quality and Regulatory Requirements for Natural and Nutraceutical
Products
Martin
Dennison
22.
The Regulatory Control and Quality Assurance of Immunological products
Tim
Sandle
23.
Regulatory Guidelines (Microbiology) for Veterinary Medicinal Antimicrobial
Products
Klaus
Hellmann and Peter Silley
24.
Regulatory Expectations for Non-Sterile Manufacture of Pharmaceutical Dose
Forms
Edel
Fitzmaurice
25.
The Pharmacopoeias and Microbiology
V
Fenton-May
Posted by Tim Sandle
Gerpac pharmacy meeting review
"Tim Sandle (Head of Microbiology, Bio Products Laboratory Ltd, UK) and it is important to understand the different roles and properties of detergents and disinfectants when managing a clean room."
Hospital Pharmacy Europe have reviewed the conference, the review can be accessed here.
Posted by Tim Sandle
Sunday, 8 February 2015
Safe, effective meningitis A vaccine for infants
The World Health Organization (WHO) has opened the door to routine immunization of infants in sub-Saharan Africa by approving for use an innovative and affordable vaccine that has all but rid the meningitis belt of a major cause of deadly epidemics.
In the four years since its introduction in Africa, MenAfriVac® has had an immediate and dramatic impact in breaking the cycle of meningitis A epidemics, leading the safe, effective technology to be approved by WHO through its prequalification process for use in infants, and paving the way for protecting millions more children at risk of the deadly disease. The announcement was made today by the Meningitis Vaccine Project (MVP)—a partnership between the global health nonprofit PATH and WHO—and Serum Institute of India Ltd (SIIL), which manufactures the MenAfriVac® vaccine.
“Initial mass vaccination campaigns with MenAfriVac® have been highly effective in reducing the number of meningitis A cases,” said Dr. Marie-Pierre Préziosi, director of MVP. “But epidemics will return when rising numbers of unprotected newborns become a larger proportion of the total population over time. Now, with this decision, health officials will be able to ensure that population-wide protection is sustained by routinely immunizing infants.”
The WHO decision means that the new, 5 µg dose of the meningitis A vaccine meets international standards of quality, safety, and efficacy and can therefore be administered to children younger than one year of age in Africa. MenAfriVac® had previously been authorized for use in children and young adults, aged 1-29 years.
Before the introduction of MenAfriVac®, people living in countries of the meningitis belt, which stretches from Senegal in the west to Ethiopia in the east, were regularly struck by meningitis A epidemics in which sudden onset of symptoms could rapidly lead to death or permanent disability. One of the most devastating outbreaks ever recorded was in 1996-1997, when an epidemic wave infected more than 250,000 people and killed over 25,000 in just a few months. The only existing vaccine was insufficient to break the cycle.
In 2004, MVP partnered with SIIL to develop an affordable, tailor-made vaccine for use against meningitis A in sub-Saharan Africa. MenAfriVac® was developed in record time at less than 1 tenth the cost of a typical new vaccine. Since campaigns started in 2010, MenAfriVac® has been administered to over 215 million people in 15 countries of the African meningitis belt: Benin, Burkina Faso, Cameroon, Chad, Côte d’Ivoire, Ethiopia, Ghana, Mali, Niger, Mauritania, Nigeria, Senegal, Sudan, Togo, and The Gambia.
“Developing the MenAfriVac® vaccine fit exactly Serum’s ingrained philosophy of bringing down prices of vaccines so that under-privileged children of the world are protected,” said Dr. Cyrus Poonawalla, CEO of SIIL, headquartered in Pune, India. “We at Serum Institute are extremely proud of being part of an international partnership that brought an end to a public health issue that has been plaguing sub-Saharan Africa for more than a century.”
One year after large-scale vaccine introduction in late 2010, for example, experience from Burkina Faso provided early evidence that mass vaccination was associated with a significantly reduced risk of meningitis in the targeted population, as well as among the unvaccinated age groups, suggesting MenAfriVac® induced “community” protection. Findings were confirmed in a major way in Chad in 2012 where researchers reported a dramatic reduction in transmission and incidence of meningitis A, a drop of more than 90 percent following vaccination.
Support from Gavi, the Vaccine Alliance; the United Nations Children’s Fund (UNICEF); PATH; WHO; and national governments has been crucial for mass vaccination campaigns that are due to continue until 2016 to cover at-risk populations in all 26 countries where disease burden from meningitis A is greatest.
In parallel to the large-scale vaccination campaigns, clinical studies were designed and conducted to determine the safety, immunogenicity, and optimal dosage and immunization schedule for administering MenAfriVac® to infants and toddlers alongside other routine childhood vaccines in African meningitis belt countries.
Results from two infant clinical studies in Ghana and Mali and vaccine introduction impact data were presented to the WHO Strategic Advisory Group of Experts on Immunization (SAGE) in October 2014, and these SAGE experts concluded that a one-dose schedule at 9 months of age or older was recommended to achieve sustainable disease control following the initial mass campaigns in 1-29 year olds.
Specifically, the WHO prequalification that was announced today allows United Nations procurement agencies to purchase the vaccine for use in routine immunization programs in meningitis-belt countries while serving as an endorsement of quality for countries interested in adopting it.
WHO is already working with African countries to ensure a smooth transition from mass campaigns to routine immunization and so ensure sustainable disease control in the region. Seven countries (Burkina Faso, Cameroon, Chad, Ghana, Mali, Niger, and Nigeria) are in line to introduce MenAfriVac® in their routine systems as early as 2015, while mass vaccination campaigns will continue in remaining countries.
Created in June 2001 with the goal of eliminating epidemic meningitis as a public health problem in sub-Saharan Africa, MVP was one of the earliest product development partnerships funded by the Bill & Melinda Gates Foundation. MenAfriVac® was the first vaccine developed outside “traditional pharma,” and the only vaccine developed specifically for people in Africa.
“With MenAfriVac®, we created a revolutionary new model for vaccine development and now we stand on the brink of protecting an entire generation, and those to come, from a devastating disease,” said Dr. Kathy Neuzil, director of Vaccine Access and Delivery at PATH. “Our efforts began with a request by African leaders to address a major health challenge affecting hundreds of millions of people, and in less than a decade, we proved that a safe, effective vaccine could be developed and deployed across multiple countries at a price that was sustainable.”
“The benefits of childhood immunization last a lifetime and the MenAfriVac® vaccine is one of the greatest success stories that shows what partners can accomplish when we commit together to a compelling cause,” said Chris Elias, president of the Global Development program at the Bill & Melinda Gates Foundation. “Prequalification of the MenAfriVac® vaccine for infants clears the way for the routine immunization of every child before his or her first birthday to ensure long-term meningitis control.”
“We are more than halfway through with introducing the vaccine in meningitis-belt countries, and the first introductions have been a stunning success,” said Dr. Jean-Marie Okwo-Bele, director of the WHO Department of Immunization, Vaccines and Biologicals. “But we cannot yet declare a win on meningitis epidemics in sub-Saharan Africa. If we rest on our laurels and don’t finish the job, meningitis epidemics will return in a major way in the years to come. Elimination of meningitis epidemics will require meningitis belt countries’ political commitment to complete the mass campaigns and introduce the vaccine in the Expanded Programme on Immunization. Then and only then will we win the battle against meningitis.”
In the four years since its introduction in Africa, MenAfriVac® has had an immediate and dramatic impact in breaking the cycle of meningitis A epidemics, leading the safe, effective technology to be approved by WHO through its prequalification process for use in infants, and paving the way for protecting millions more children at risk of the deadly disease. The announcement was made today by the Meningitis Vaccine Project (MVP)—a partnership between the global health nonprofit PATH and WHO—and Serum Institute of India Ltd (SIIL), which manufactures the MenAfriVac® vaccine.
“Initial mass vaccination campaigns with MenAfriVac® have been highly effective in reducing the number of meningitis A cases,” said Dr. Marie-Pierre Préziosi, director of MVP. “But epidemics will return when rising numbers of unprotected newborns become a larger proportion of the total population over time. Now, with this decision, health officials will be able to ensure that population-wide protection is sustained by routinely immunizing infants.”
The WHO decision means that the new, 5 µg dose of the meningitis A vaccine meets international standards of quality, safety, and efficacy and can therefore be administered to children younger than one year of age in Africa. MenAfriVac® had previously been authorized for use in children and young adults, aged 1-29 years.
Before the introduction of MenAfriVac®, people living in countries of the meningitis belt, which stretches from Senegal in the west to Ethiopia in the east, were regularly struck by meningitis A epidemics in which sudden onset of symptoms could rapidly lead to death or permanent disability. One of the most devastating outbreaks ever recorded was in 1996-1997, when an epidemic wave infected more than 250,000 people and killed over 25,000 in just a few months. The only existing vaccine was insufficient to break the cycle.
In 2004, MVP partnered with SIIL to develop an affordable, tailor-made vaccine for use against meningitis A in sub-Saharan Africa. MenAfriVac® was developed in record time at less than 1 tenth the cost of a typical new vaccine. Since campaigns started in 2010, MenAfriVac® has been administered to over 215 million people in 15 countries of the African meningitis belt: Benin, Burkina Faso, Cameroon, Chad, Côte d’Ivoire, Ethiopia, Ghana, Mali, Niger, Mauritania, Nigeria, Senegal, Sudan, Togo, and The Gambia.
“Developing the MenAfriVac® vaccine fit exactly Serum’s ingrained philosophy of bringing down prices of vaccines so that under-privileged children of the world are protected,” said Dr. Cyrus Poonawalla, CEO of SIIL, headquartered in Pune, India. “We at Serum Institute are extremely proud of being part of an international partnership that brought an end to a public health issue that has been plaguing sub-Saharan Africa for more than a century.”
One year after large-scale vaccine introduction in late 2010, for example, experience from Burkina Faso provided early evidence that mass vaccination was associated with a significantly reduced risk of meningitis in the targeted population, as well as among the unvaccinated age groups, suggesting MenAfriVac® induced “community” protection. Findings were confirmed in a major way in Chad in 2012 where researchers reported a dramatic reduction in transmission and incidence of meningitis A, a drop of more than 90 percent following vaccination.
Support from Gavi, the Vaccine Alliance; the United Nations Children’s Fund (UNICEF); PATH; WHO; and national governments has been crucial for mass vaccination campaigns that are due to continue until 2016 to cover at-risk populations in all 26 countries where disease burden from meningitis A is greatest.
In parallel to the large-scale vaccination campaigns, clinical studies were designed and conducted to determine the safety, immunogenicity, and optimal dosage and immunization schedule for administering MenAfriVac® to infants and toddlers alongside other routine childhood vaccines in African meningitis belt countries.
Results from two infant clinical studies in Ghana and Mali and vaccine introduction impact data were presented to the WHO Strategic Advisory Group of Experts on Immunization (SAGE) in October 2014, and these SAGE experts concluded that a one-dose schedule at 9 months of age or older was recommended to achieve sustainable disease control following the initial mass campaigns in 1-29 year olds.
Specifically, the WHO prequalification that was announced today allows United Nations procurement agencies to purchase the vaccine for use in routine immunization programs in meningitis-belt countries while serving as an endorsement of quality for countries interested in adopting it.
WHO is already working with African countries to ensure a smooth transition from mass campaigns to routine immunization and so ensure sustainable disease control in the region. Seven countries (Burkina Faso, Cameroon, Chad, Ghana, Mali, Niger, and Nigeria) are in line to introduce MenAfriVac® in their routine systems as early as 2015, while mass vaccination campaigns will continue in remaining countries.
Created in June 2001 with the goal of eliminating epidemic meningitis as a public health problem in sub-Saharan Africa, MVP was one of the earliest product development partnerships funded by the Bill & Melinda Gates Foundation. MenAfriVac® was the first vaccine developed outside “traditional pharma,” and the only vaccine developed specifically for people in Africa.
“The benefits of childhood immunization last a lifetime and the MenAfriVac® vaccine is one of the greatest success stories that shows what partners can accomplish when we commit together to a compelling cause,” said Chris Elias, president of the Global Development program at the Bill & Melinda Gates Foundation. “Prequalification of the MenAfriVac® vaccine for infants clears the way for the routine immunization of every child before his or her first birthday to ensure long-term meningitis control.”
“We are more than halfway through with introducing the vaccine in meningitis-belt countries, and the first introductions have been a stunning success,” said Dr. Jean-Marie Okwo-Bele, director of the WHO Department of Immunization, Vaccines and Biologicals. “But we cannot yet declare a win on meningitis epidemics in sub-Saharan Africa. If we rest on our laurels and don’t finish the job, meningitis epidemics will return in a major way in the years to come. Elimination of meningitis epidemics will require meningitis belt countries’ political commitment to complete the mass campaigns and introduce the vaccine in the Expanded Programme on Immunization. Then and only then will we win the battle against meningitis.”
FDA's Margaret Hamburg Announces She Will Step Down in March 2015
Margaret Hamburg announced on Feb. 5, 2015 that after almost six years in her role as FDA Commissioner, she will step down from the position at the end of March 2015. According to Reuters, Hamburg announced in a note to staff that her time as FDA chief “has been the most rewarding of my career."
Dr. Stephen Ostroff, FDA’s chief scientist, will take the role as acting commissioner until the position is filled. A potential successor to Hamburg, Robert Califf, MD, a cardiologist and researcher from Duke University, was named by FDA to oversee its drug, medical device, and tobacco policy at the end of January 2015.
Under Hamburg, FDA increased inspection stringency of food and drugs originating from overseas, increased patient engagement in the drug development process, and introduced various measures to speed the development and review of new drugs. In addition to improving existing policies, FDA approved 51 new therapies in 2014, the most in almost 20 years. As noted in the press release on Reuters, Hamburg wrote in a blog post on Feb. 4, 2015 that it is “a testament ... to FDA's innovative approaches to help expedite development and review of medical products that target unmet medical needs."
"Commissioner Hamburg, from day one, has been committed to being a champion for patients. She has fostered the growth of science and innovation across the agency and really changed how FDA and industry collaborate,” said Ellen Sigal, founder and chair of Friends of Cancer Research, in the Reuters announcement.
Source:
ReutersSaturday, 7 February 2015
New understanding of virus vulnerability
A
new study has analyzed how genome mutations of RNA viruses tend to be lethal
for these infectious agents. It takes very little to make the RNA too messy and
bulky to fit into the capsid -- the shell that contains the viral genome -- and
by doing so disrupt the reproductive process. Lošdorfer Bochr('382')ichr('269').
To
get into the capsid, the "exoskeleton" of viruses, RNA must be well
combed and "packed," because otherwise it will not. The packing of
RNA is governed by the genome itself. Based on previous research that
demonstrated that viral RNA is normally optimized for packing (outside the
capsid it is only slightly bigger than the capsid itself).
Researchers
have verified what types of genome alterations preserve the optimization and
which instead render the RNA too bulky.
For
further details see:
Luca Tubiana, Anže Lošdorfer Božič, Cristian Micheletti,
Rudolf Podgornik. Synonymous Mutations Reduce Genome Compactness in
Icosahedral ssRNA Viruses. Biophysical Journal, 2015; 108
(1): 194 DOI: 10.1016/j.bpj.2014.10.070
Friday, 6 February 2015
New Pharmacovigilance Legislation
The
new EU 15 modules concerning pharmacovigilance are a major departure in terms
of the pharmacovigilance conducted over the last 6 years in Europe since the
introduction of Vol IXa. New pharmacovigilance legislation changes apply from April
2015..
The
requirements for information provided to Competent Authorities and the European
Medicines Agency (EMA) about the pharmacovigilance system(s) of marketing
authorisation holders (MAHs) change in several ways:
- Summary information only concerning the EU qualified person for pharmacovigilance (QPPV) and the location of a pharmacovigilance system master file will be contained in marketing authorisations.
- Full descriptive information about the pharmacovigilance system will have to be contained in a pharmacovigilance system master file, which should be made available to the National Competent Authorities upon request.
- Detailed requirements for the pharmacovigilance system master file concern its availability, structure, content and maintenance.
- The pharmacovigilance system master file will encompass the pharmacovigilance system and may therefore relate to one or more products, and changes to its content will not be automatically notifiable to the Competent Authorities. This differs from the current Detailed Description of the Pharmacovigilance system (DDPS), which will be phased out over the period from July 2012 to 2015.
Posted by Tim Sandle
Thursday, 5 February 2015
Safe use of sporicides
Since
their introduction, liquid sporicides have become one of the products of choice
for many biological research and production facilities wherever high-level
microbial control is critical. Although they are marketed as low-toxicity
products, appropriate care during use is essential to prevent potentially
dangerous conditions, exposures, and injuries.
This
forms part of an article by Vince McLeod for Laboratory Manager magazine. The
article goes onto state:
“The
class of liquid sporicidal disinfectants are popular non-bleach disinfectants
used for clean rooms and biosafety cabinets. Since their introduction, liquid
sporicides have become one of the products of choice for many biological
research and production facilities wherever high-level microbial control is
critical. These sporicides make up a category of liquid, cold, fast-acting
disinfectants/sterilants primarily used on hard, pre-cleaned surfaces. They
provide quick and effective microbial control, including the ability to destroy
bacterial spores. They are generally regarded as safe to use on stainless steel,
glass, plastics, walls, and floors. Most sporicides are available as a
ready-to-use premixed solution or a concentrate and can be applied by
immersion, spraying, fogging, or wiping. Although they are marketed as
low-toxicity products, appropriate care during use is essential to prevent
potentially dangerous conditions, exposures, and injuries.”
Wednesday, 4 February 2015
New antibiotic resistance mechanism
There
are two main families of bacteria: those that are surrounded by a single
membrane (or one outer wall) and those that are surrounded by two membranes (or
two outer walls).
Scientists
have examined a protein that is found between these two protective walls, known
as RcsF. When all is well, this protein is continually sent to the second outer
wall. However, if the bacterium is attacked (by an antibiotic, for instance)
the machinery that sends RcsF to the outer wall no longer works: instead of
being on the second outer wall, RcsF is stuck between the
two fortifications (membranes), from where it sends out an alarm signal. This
signal prompts the bacterium to trigger defence systems (by sending other
back-up proteins) so as to resist the attacking antibiotic.
In
this process, the researchers succeeded in discovering how the protein RcsF
manages to sound the alarm. In practical terms, when it is stressed, stuck
between the two walls, RcsF contacts another protein, IgaA. The interaction
between these two proteins raises the alarm.
For
further details see:
Seung-Hyun
Cho, Joanna Szewczyk, Christina Pesavento, Matylda Zietek, Manuel Banzhaf,
Paula Roszczenko, Abir Asmar, Géraldine Laloux, Ann-Kristin Hov, Pauline
Leverrier, Charles Van der Henst, Didier Vertommen, Athanasios Typas,
Jean-François Collet. Detecting Envelope Stress by Monitoring β-Barrel
Assembly. Cell, 2014; 159 (7): 1652 DOI: 10.1016/j.cell.2014.11.045
Tuesday, 3 February 2015
How Vibrio cholera steals DNA
Scientists
have uncovered the unconventional way that the cholera bacterium stabs and
kills other bacteria to steal their DNA, making it potentially more virulent.
This mechanism, known as "horizontal gene transfer," allows the
cholera bacterium to become more virulent by absorbing the traits of its prey.
The study is published in Science.
Cholera
is caused when the bacterium Vibrio
cholerae infects the small intestine. The disease is characterized by acute
watery diarrhea resulting in severe dehydration.
For
further details see:
S. Borgeaud, L. C. Metzger, T. Scrignari, M. Blokesch. The
type VI secretion system of Vibrio cholerae fosters horizontal gene transfer.
Science, 2015; 347 (6217): 63 DOI: 10.1126/science.1260064
Posted by Tim Sandle
Monday, 2 February 2015
Environmental Monitoring: a Comprehensive Handbook
This is volume 7 of the Environmental
Monitoring Handbook series. Each volume of this series discusses different
aspects of environmental monitoring. The appendix describes the various topics
and authors that can be found in volumes 1 through 6 of this series… There is a wealth of useful information that you can use
in establishing, maintaining and updating your environmental monitoring
program!
Foe details, see PDA
Tim Sandle has contributed a chapter. The chapter reference is:
Sunday, 1 February 2015
What types of bacteria are found in hailstones?
Researchers
have found a rich diversity of microbial life and chemicals in the ephemeral
habitat of a storm cloud, according to a study published in the journal PLOS
ONE by Tina Šantl Temkiv and colleagues from Aarhus University, Denmark.
The
researchers found that found that storm clouds carried several species of
bacteria typically found on plants and almost 3000 different compounds usually
found in soil. However, the hailstones had very few soil-associated bacteria or
chemicals that would usually occur in plants.
The
article reference is:
Tina
Šantl-Temkiv, Kai Finster, Thorsten Dittmar, Bjarne Munk Hansen, Runar
Thyrhaug, Niels Woetmann Nielsen, Ulrich Gosewinkel Karlson. Hailstones: A
Window into the Microbial and Chemical Inventory of a Storm Cloud. PLoS ONE,
2013; 8 (1)
Posted by Tim Sandle
Subscribe to:
Posts (Atom)
