WASHINGTON, DC – October 7, 2014 -- Yogurt containing probiotic bacteria successfully protected children and pregnant women against heavy metal exposure in a recent study. Working with funding from the Bill and Melinda Gates Foundation, Canadian and Tanzanian researchers created and distributed a special yogurt containing Lactobacillus rhamnosus bacteria and observed the outcomes against a control group. The work is published this week in mBio®, the online open-access journal of the American Society for Microbiology.
A research team from the Canadian Centre for Human Microbiome and Probiotics, led by Dr. Gregor Reid, studied how microbes could protect against environmental health damage in poor parts of the world. Their lab research indicated that L. rhamnosus had a great affinity for binding toxic heavy metals. Working with this knowledge, the team hypothesized that regularly consuming this probiotic strain could prevent metals from being absorbed from the diet.
Working with the Western Heads East organization, Dr. Reid had already established a network of community kitchens in Mwanza, Tanzania to produce a probiotic yogurt for the local population. Mwanza is located on the shores of Lake Victoria, which is known to be polluted with pesticides and toxic metals including mercury. The team utilized this network to produce and distribute a new type of yogurt containing L. rhamnosus. The special yogurt was distributed to a group of pregnant women and a group of children. The researchers measured the baseline and post-yogurt levels of toxic metals.
The team found a significant protective effect of the probiotic against mercury and arsenic in the pregnant women. This is important as “reduction in these compounds in the mothers could presumably decrease negative developmental effects in their fetus and newborns,” according to Dr. Reid. While the results obtained in the children studied showed benefits and lower toxin levels, the sample size and duration of treatment did not allow statistical significance.
The researchers were excited by the potential of basic foodstuffs to provide preventative protection for pregnant women worldwide. They are currently investigating lactobacilli with higher and even more specific mechanisms of sequestering mercury.
WASHINGTON, DC – OCTOBER 13, 2014 - A robust, broad spectrum antibiotic, and a gene that confers immunity to that antibiotic are both found in the bacterium Staphylococcus epidermidis Strain 115. The antibiotic, a member of the thiopeptide family of antibiotics, is not in widespread use, partly due to its complex structure, but the investigators, from Brigham Young University, Provo, Utah, now report that the mechanism of synthesis is surprisingly simple. “We hope to come up with innovative processes for large-scale production and derivitization so that new, and possibly more potent versions of the antibiotic can become available, says co-corresponding author Joel S. Griffitts. The research is published ahead of print in Journal of Bacteriology.
Strain 115 was originally discovered on turkeys that appeared to have enhanced immunity to bacterial infections. “The motivation behind our current work was a desire to understand the connection between Strain 115 and immunity to disease-causing bacteria,” says Griffitts.
It quickly became clear to the investigators that Strain 115 could produce a potent antibiotic that targets a large number of medically relevant bacteria, including those that cause staph infections, strep throat, and severe gastrointestinal diseases. “We wanted to know the identity of this antibiotic and the means by which Strain 115 protects itself from its own antibiotic’s deadly effects,” says Griffitts.
“We found that the genes for both antibiotic synthesis and self protection in Strain 115 are conveniently clustered on a compact DNA molecule [a plasmid] that replicates itself as a small circle within the cells of Strain 115,” says Griffitts. Among experiments they conducted to prove this, they engineered a version of Strain 115 that was missing the plasmid. That version failed to produce both the antibiotic and the immunity to the antibiotic.
The investigators then analyzed the mechanism of immunity. “Thiopeptide antibiotics kill cells by blocking a part of the ribosome,” Griffitts explains. Ribosomes, common to all living organisms, are the machines that read the genetic code, producing proteins based on the instructions therein. The plasmid, which directs the production of the thiopeptide antibiotic, also directs production of a spare part for the ribosome, a replacement for the part that is blocked by the antibiotic, which renders the ribosome insensitive to the antibiotic.
The investigation of Strain 115 began as an undergraduate project, after the bacteria had sat in a laboratory freezer for decades, says Griffitts. “It quickly grew into an effort involving two Ph.D. microbiologists, a talented graduate student, and several analytical biochemists.” Hopefully, he says, the research will ultimately enable production of a valuable antibiotic, in quantities sufficient to make a dent in the antibiotic crisis.
WASHINGTON, DC – August 19, 2014 – The American Society for Microbiology (ASM) announces that starting in 2016 the Society will co-locate its two major annual meetings, the General Meeting and the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). The first co-located GM /ICAAC will be held June 2016 in Boston.
WASHINGTON, DC – August 28, 2014 – The recently released 2013 Journal Citation Reports® confirm that the American Society for Microbiology (ASM) continues to be the authoritative source of high-impact research in microbiology. ASM publishes over 20% of all articles in the Microbiology category, while accounting for over 33% of all Microbiology citations. Four of the Top 5 most-cited journals in the field of Microbiology are ASM journals. ASM also has 3 titles ranked in the Top 20 by Impact Factor (#2 Clinical Microbiology Reviews®, #3 Microbiology and Molecular Biology Reviews®, and #12 mBio®).
WASHINGTON, DC – July 22, 2014 – In contrast to their negative reputation as disease causing agents, some viruses can perform crucial biological and evolutionary functions that help to shape the world we live in today, according to a new report by the American Academy of Microbiology.