Syndicate content

Archive - Jul 9, 2015

Chromosomal Location Couples Sporulation Genes to Replication Cycle in Spore-Forming Bacteria

In spore-forming bacteria, chromosomal locations of genes can couple the DNA replication cycle to critical, once-in-a-lifetime decisions about whether to reproduce or form spores. The new finding by Rice University bioengineers and colleagues at the University of California at San Diego and the University of Houston was published online on July 9, 2015 in the journal Cell. The article is titled “Chromosomal Arrangement of Phosphorelay Genes Couples Sporulation and DNA Replication.” As most microorganisms, Bacillus subtilis bacteria are single-celled creatures with one goal: to reproduce by making copies of themselves. But survival isn't always that simple. For example, when food gets scarce, B. subtilis must decide between two possible paths: shut down, form a dormant spore (image) -- a process called "sporulation" -- and wait for better times, or split into two cells and gamble that there is enough food for at least one more generation. "The decision about whether to form a spore and when is a very important one for B. subtilis," said Dr. Oleg Igoshin, Associate Professor of Bioengineering at Rice and one of the lead researchers on the new study. "If the organism waits too long, it can starve before it finishes transforming into a spore. If it acts too early and forms a spore too soon, it can be overwhelmed and out-reproduced by competitors." Dr. Igoshin's lab specializes in describing the workings of the complex genetic regulatory networks that cells use to make such decisions. He said dozens of studies over the past 25 years have identified a network of more than 30 genes that B. subtilis uses to bring about sporulation. When food is plentiful, this network is largely silent. But during times of starvation the genes work in concert to form a spore. B.

Oral Cholera Vaccine (Shancol) That Is Two Doses and Low Cost Protects Against Endemic Disease in Highly Populated Urban Setting, Lancet Study Shows; Trial in Bangladesh Funded by Bill & Melinda Gates Foundation

In an announcement published on July 9, 2015, the International Centre for Diarrheal Disease Research in Dhaka, Bangladesh (ICDDR,B) reported that The Lancet had published an article online on July 8, 2015, by ICDDR,B scientists, demonstrating that a double-dose, low-cost oral cholera vaccine can substantially reduce hospitalizations and deaths from cholera in densely populated urban settings. The article is titled “Feasibility and Effectiveness of Oral Cholera Vaccine in an Urban Endemic Setting in Bangladesh: A Cluster Randomized Open-Label Trial.” This Lancet article is accompanied by a commentary that is titled “Oral Cholera Vaccines in Endemic Countries.” Links to these articles in The Lancet are provided below, as are links to many of the popular press stories on this major advance. While oral cholera vaccines have previously been shown to be effective in trial settings, this is the first study to prove their effectiveness and feasibility in a real-life situation. The findings lend support to the vaccine’s use in routine mass vaccination programs to help to control cholera in endemic countries. Cholera exacts a tremendous toll on public health globally – 91,000 deaths and 2.8 million cases of cholera are reported every year and over 1 billion people are estimated to be at risk. Approximately half the deaths occur in children under 5 years of age. The burden of cholera is greatest in the developing countries of Africa and South Asia where a large number of people live in unsanitary conditions without access to clean water, factors which are critical to the spread of cholera. While environmental factors can take a long time to improve, an oral cholera vaccine can provide a much-needed alternative in these settings. The study by Dr.

Existing OTC Antacid Drug Lansoprazole (Prevacid®) Found to Be Highly Promising Anti-Tuberculosis Medication; TB Is Currently World’s Second Leading Single-Agent Killer After AIDS

Testing thousands of approved drugs, EPFL scientists have identified an unlikely anti-tuberculosis drug: the over-the-counter antacid lansoprazole (Prevacid®). Tuberculosis (TB) continues to be a global pandemic, second only to AIDS as the greatest single-agent killer in the world. In 2013 alone, the TB bug Mycobacterium tuberculosis caused 1.5 million deaths and almost nine million new infections. Resistance to TB drugs is widespread, creating an urgent need for new medicines. EPFL (École Polytechnique Fédérale de Lausanne) scientists in Switzerland have now identified lansoprazole, a widely used, over-the-counter antacid, as an excellent candidate against tuberculosis. The study was published online on July 9, 2015 in an open-access article in Nature Communications. The article is titled “Lansoprazole Is an Antituberculous Prodrug Targeting Cytochrome bc1.” It takes well over ten years for a new tuberculosis drug to complete these trials and be approved for human use. Meanwhile, traditional antibiotics have led many strains of tuberculosis bacteria to evolve multi-drug resistance (MDR). Millions of new chemical compounds have been tested for their ability to disrupt the growth of M. tuberculosis in the test tube, but discouragingly few are currently in clinical trials. But this process up can be sped up. Compounds that have already been approved for use in humans could be repurposed as anti-tuberculosis medications, and cut down both on the time and the cost of new drug development. This is the strategy adopted by Dr. Stewart Cole's lab at EPFL. The assay uses a robotized system that gives candidate drugs to cultured lung cells that have been infected with M. tuberculosis.