 |
|
Pitt-led Researchers Find Source of Drug-Tolerant Tuberculosis Possibly Behind TB Relapses, Intensity of Treatment
June 12, 2008University of Pittsburgh-led researchers discovered that the primary bacteria behind tuberculosis can grow on surfaces and that drug-tolerant strains flourish in these bacterial communities, the research team recently reported in "Molecular Microbiology." The findings suggest a possible reason why human tuberculosis (TB) requires months of intensive antibiotic treatment and indicate a potential cause of the relapses that can nonetheless occur.
The researchers are the first to show that "Mycobacterium tuberculosis" can grow in surface-level bacteria clusters known as biofilms that are common in nature but never before shown for TB bacteria, explained the paper's senior author Graham Hatfull, chair and Eberly Family Professor of Biological Sciences in Pitt's School of Arts and Sciences. Hatfull collaborated and coauthored the paper with Professor William Jacobs Jr. of the Department of Microbiology and Immunology at the Albert Einstein College of Medicine in New York.
Hatfull, Jacobs, and their colleagues found that the biofilm bacteria are physiologically and genetically different from TB bacteria harvested in a lab-the type used in developing antibiotics. These variations result in a population of the bacteria that are "drug-tolerant and harbor persistent cells that survive high concentrations of anti-tuberculosis antibiotics," the team reports.
People with TB typically undergo six to nine months of treatment with multiple antibiotics and most of the bacteria generally die within the first two weeks. Yet the disease can recur, presumably because of drug-tolerant bacteria that have escaped the antibiotic. The source and location of these persistent cells are unknown, but Hatfull and Jacobs' research reveals a possible biofilm origin, Jacobs said.
"The nature of persisting "M. tuberculosis" cells has been an enigma for the entire field," Jacobs said. "Clearly "M. tuberculosis" cells in biofilms represent at least one class of persistent cells, and we are testing their biological relevance."
It is not yet known whether the biofilm actually factors into human TB infections, Hatfull said. He added that the only similar research regarding biofilm in living creatures showed the presence of biofilm-like or biofilm-related bacteria in guinea pigs.
"While our data does not show conclusively that biofilm formation in people gives rise to a drug-tolerant population, the fact that biofilms do so in the lab makes this an interesting and testable hypothesis," Hatfull said.
Other collaborators on the project include: Yann Guerardel and associate Xavier Trivelli of the Universite des Sciences et Technologies de Lille in France; Laurent Kremer and associate Anuradha Alahari of France's University of Montpellier; Pitt postdoctoral researcher Anil Ojha; and Jacobs' research associates Anthony Baughn, Dhinakaran Sambandan, and Tsungda Hsu.
The full paper can be read on the "Molecular Microbiology" Web site at www.blackwell-synergy.com/doi/full/10.1111/j.1365-2958.2008.06274.x
University of Pittsburgh
People with TB typically undergo six to nine months of treatment with multiple antibiotics and most of the bacteria generally die within the first two weeks. Yet the disease can recur, presumably because of drug-tolerant bacteria that have escaped the antibiotic. The source and location of these persistent cells are unknown, but Hatfull and Jacobs' research reveals a possible biofilm origin, Jacobs said.
"The nature of persisting "M. tuberculosis" cells has been an enigma for the entire field," Jacobs said. "Clearly "M. tuberculosis" cells in biofilms represent at least one class of persistent cells, and we are testing their biological relevance."
It is not yet known whether the biofilm actually factors into human TB infections, Hatfull said. He added that the only similar research regarding biofilm in living creatures showed the presence of biofilm-like or biofilm-related bacteria in guinea pigs.
"While our data does not show conclusively that biofilm formation in people gives rise to a drug-tolerant population, the fact that biofilms do so in the lab makes this an interesting and testable hypothesis," Hatfull said.
Other collaborators on the project include: Yann Guerardel and associate Xavier Trivelli of the Universite des Sciences et Technologies de Lille in France; Laurent Kremer and associate Anuradha Alahari of France's University of Montpellier; Pitt postdoctoral researcher Anil Ojha; and Jacobs' research associates Anthony Baughn, Dhinakaran Sambandan, and Tsungda Hsu.
The full paper can be read on the "Molecular Microbiology" Web site at www.blackwell-synergy.com/doi/full/10.1111/j.1365-2958.2008.06274.x
University of Pittsburgh
Microbiology Current Events and Microbiology News RSSDisinfectants can make bacteria resistant to treatment
Chemicals used in the environment to kill bacteria could be making them stronger, according to a paper published in the October issue of the journal Microbiology. Low levels of these chemicals, called biocides, can make the potentially lethal bacterium Staphylococcus aureus remove toxic chemicals from the cell even more efficiently, potentially making it resistant to being killed by some antibiotics.
Study reveals an oily diet for subsurface life
Thousands of feet below the bottom of the sea, off the shores of Santa Barbara, single-celled organisms are busy feasting on oil.
Scientists unmask key HIV protein, open door for more powerful AIDS drugs
University of Michigan scientists have provided the most detailed picture yet of a key HIV accessory protein that foils the body's normal immune response.
New way to make malaria medicine also first step in finding new antibiotics
University of Illinois microbiology professor William Metcalf and his collaborators have developed a way to mass-produce an antimalarial compound, potentially making the treatment of malaria less expensive.
New way to control protein activity could lead to cancer therapies
Investigators at the Stanford University School of Medicine have found a way to quickly and reversibly fine-tune the activity of individual proteins in cells and living mammals, providing a powerful new laboratory tool for identifying - more precisely than ever before - the functions of different proteins.
Advance offers revolution in food safety testing
Microbiologists at Oregon State University have developed a new technology to detect illness-causing bacteria - an advance that could revolutionize the food industry, improving the actual protection to consumers while avoiding the costly waste and massive recalls of products that are suspected of bacterial contamination but are perfectly safe.
New life found in ancient tombs
Life has been discovered in the barren depths of Rome's ancient tombs, proving catacombs are not just a resting place for the dead. The two new species of bacteria found growing on the walls of the Roman tombs may help protect our cultural heritage monuments.
Indian spice reduces size of hemorrhagic stroke
You might want to make curcumin part of your daily diet. This active ingredient of the Indian curry spice, turmeric, not only lowers your chances of getting cancer and Alzheimer's disease, but may reduce the size of a hemorrhagic stroke, say Medical College of Georgia researchers.
Pitt research indicates new virus is culprit, not bystander, in deadly skin cancer
University of Pittsburgh scientists are uncovering more evidence that a virus they recently discovered is the cause of Merkel cell carcinoma, an aggressive and deadly form of skin cancer.
Cancer-causing gut bacteria exposed
Normal gut bacteria are thought to be involved in colon cancer but the exact mechanisms have remained unknown. Now, scientists from the USA have discovered that a molecule produced by a common gut bacterium activates signalling pathways that are associated with cancer cells.
More Microbiology Current Events and Microbiology News Articles
 | Clinical Microbiology Made Ridiculously Simple (Medmaster) by Mark Gladwin A brief, clear, thorough, and highly enjoyable approach to clinical microbiology, brimming with mnemonics, humor, summary charts and illustrations, from AIDS to "flesh-eating bacteria" to ebola, mad cow disease, hantavirus, anthrax, smallpox, botulism, etc. Excellent Board... |
 | Microbiology: An Introduction, 9th Edition (Book & CD-ROM) by Gerard J. Tortora, Berdell R. Funke, Christine L. Case With this Ninth Edition, the “Number One” best-selling non-majors microbiology text extends its trusted and reliable approach with improved disease chapters that feature efficient new “Disease in Focus” boxes, a thoroughly revised immunity chapter (17), new options for the Microbiology Place website/CD-Rom, and a new Media Manager instructor presentation package with 30 multi-step... |
 | Microbiology: An Evolving Science by Joan L. Slonczewski, John W. Foster Microbiology: An Evolving Science promotes a clear understanding of this rapidly advancing field in two distinctive ways. First, an emphasis on current research, genomics, and molecular genetics enables students to learn how microbiologists think as they master the discipline's foundational topics. Second, a stunning and consistently executed art program helps students visualize key... |
 | Microbiology: A Systems Approach by Marjorie Kelly Cowan, Kathleen Park Talaro “Making Connections” Microbiology: A Systems Approach is a non-majors/allied health microbiology textbook that has quickly become known for its unique organization, engaging writing style, and instructional art program. Cowan’s “building blocks” approach establishes the big picture first and then gradually layers concepts onto this foundation. This logical structure helps students... |
 | Prescott/Harley/Klein's Microbiology by Joanne Willey, Linda Sherwood, Chris Woolverton The brand new author team of Prescott, Harley and Klein's Microbiology continues the tradition of past editions by providing a balanced, comprehensive introduction to all major areas of microbiology. Because of this balance, the Seventh Edition of Microbiology is appropriate for microbiology majors and mixed majors courses. The new authors have focused on readability, artwork, and the... |
 | Photographic Atlas For The Microbiology Lab by Michael J. Leboffe, Michael Leboffe, Burton E. Pierce |
| Medical Microbiology: with STUDENT CONSULT Online Access by Patrick R. Murray, Ken S. Rosenthal, Michael A. Pfaller The new edition of this popular text presents microbiology in a succinct, easy-to-use, and engaging manner. Clear discussions explain how microbes cause disease in humans, and review the updated vaccines and new antibiotics currently available to treat these diseases. Expert coverage of basic principles, the immune response, laboratory diagnosis, bacteriology, virology, mycology, and parasitology... | |
 | Microbiology: Principles and Explorations by Jacquelyn G. Black Microbiology: Principles and Explorations has been a best-selling textbook for several editions due to the author's engaging writing style where her passion for the subject shines through the narrative. The text's student-friendly approach provides readers with an excellent introduction to the study of Microbiology. This text is appropriate for non-major and mixed major microbiology courses,... |
 | Foundations in Microbiology by Kathleen Park Talaro Written with the non-major/allied health student in mind, Foundations in Microbiology offers an engaging and accessible writing style through the use of tools such as case studies and analogies to thoroughly explain difficult microbiology concepts. A taxonomic approach is used for the study of... |
 | Alcamo's Fundamentals of Microbiology, 8th Edition by Jeffrey C. Pommerville Alcamo s Fundamentals of Microbiology, Eighth Edition provides a firm foundation in microbiology with an emphasis on human disease. It is written for students in nursing and allied health programs and is appropriate for non-majors microbiology courses. The Eighth Edition of this classic text, revised by award winning educator Jeffrey Pommerville, retains the late Ed Alcamo s student friendly... |
| © 2008 BrightSurf.com |