A rapid evolutionary “arms race” between bacteria and killer viruses has been observed by a UNSW-led team of scientists in a sophisticated genetic study of the micro-organisms.
Associate Prof. Torsten Thomas, Kerensa McElroy and colleagues from the Centre for Marine Bio-Innovation and the School of Biotechnology and Biomolecular Sciences studied the evolution of Pseudomonas aeruginosa – bacteria that can cause chronic, often lethal lung infections in people with cystic fibrosis.
Researchers Decode Germs’ DNA to Fight Food Poisoning
Chances are you’ve heard of mapping genes to diagnose rare diseases, predict your risk of cancer and tell your ancestry. But to uncover food poisonings? The nation’s disease detectives are beginning a program to try to outsmart outbreaks by routinely decoding the DNA of potentially deadly bacteria and viruses.
The initial target is listeria, the third-leading cause of death from food poisoning and bacteria that are especially dangerous to pregnant women. Already, the government credits the technology with helping to solve a listeria outbreak that killed one person in California and sickened seven others in Maryland.
Bacterial Gold Extraction Suited for Rural Setting
A metallurgist based at Curtin Univ. has helped develop a hydrometallurgical method of extracting gold, palladium and platinum from crushed ores using bacteria and chemical leaching.
Prof. Jacques Eksteen, who was formerly the group consulting metallurgist at Lonmin Platinum in South Africa, says the research began as a way of addressing costs where conventional smelting methods are not economical.
If antimicrobial-resistant Salmonella is showing up in pigs, then are bacon-loving people also at risk? In his latest research, North Carolina State Univ. population health and pathobiology professor Sid Thakur looks at serotypes — or groups — of antibiotic-resistant Salmonella in people and pigs, to try to determine whether these strains are being passed from pork to people.
Sid Thakur is an expert on antimicrobial resistance in bacteria like Salmonella and Campylobacter, and how they may enter the food supply, particularly via pigs. For his latest study, he wanted to look at whether pigs and humans had the same types of antimicrobial-resistant Salmonella, which is a big public health concern. Thakur compared clinical human samples to samples he took from 30 North Carolina farms – from both the pigs and their surrounding environment, including everything from feed to floors – and found seven predominant serotypes of antimicrobial-resistant Salmonella, of which one, Salmonella Typhimurium, is also found in humans.
Research Sheds New Light on Sulfate-reducing Bacteria
Sulfate-reducing bacteria breathe sulfate rather than oxygen, reducing sulfate to hydrogen sulfide to meet their energy needs. Hydrogen sulfide is a toxic gas that smells like rotten eggs and can not only cause health problems by making its way into drinking water supplies, but also lead to metal corrosion of household plumbing as well as oil and gas pipelines. On the other hand, these bacteria can be used for environmental remediation efforts because they convert contaminants such as uranium, chromium and technetium from soluble to insoluble forms, reducing the risk of groundwater contamination with these metals. To predict and control the metabolic capabilities of these bacteria for beneficial environmental purposes, it’s necessary to have a detailed understanding of the biochemical pathways involved in sulfate reduction.
To address this issue, scientists from the Univ. of Missouri and Oak Ridge National Laboratory and examined electron transport required for sulfate reduction in bacteria. They tested the notion that sulfate reduction relies on pathways of electron flow from the periplasm — the outer portion of the cell — to the cytoplasm — the interior of the cell where sulfate reduction occurs.
Paleontologists studying fossilized feathers have proposed that the shapes of certain microscopic structures inside the feathers can tell us the color of ancient birds. But, new research from North Carolina State Univ. demonstrates that it is not yet possible to tell if these structures – thought to be melanosomes – are what they seem, or if they are merely the remnants of ancient bacteria.
Melanosomes are small, pigment-filled sacs located inside the cells of feathers and other pigmented tissues of vertebrates. They contain melanin, which can give feathers colors ranging from brownish-red to gray to solid black. Melanosomes are either oblong or round in shape, and the identification of these small bodies in preserved feathers has led to speculation about the physiology, habitats, coloration and lifestyles of the extinct animals, including dinosaurs, that once possessed them.
If you’ve run out of drinking water during a lakeside camping trip, there’s a simple solution: break off a branch from the nearest pine tree, peel away the bark and slowly pour lake water through the stick. The improvised filter should trap any bacteria, producing fresh, uncontaminated water.
In fact, an MIT team has discovered that this low-tech filtration system can produce up to four liters of drinking water a day — enough to quench the thirst of a typical person.
In a surprising new find, researchers have discovered that bacterial movement is impeded in flowing water, enhancing the likelihood that the microbes will attach to surfaces. The new work could have implications for the study of marine ecosystems, and for our understanding of how infections take hold in medical devices.
The findings, the result of microscopic analysis of bacteria inside microfluidic devices, were made by MIT postdoc Roberto Rusconi, former MIT postdoc Jeffrey Guasto (now an assistant professor of mechanical engineering at Tufts Univ.), and Roman Stocker, an associate professor of civil and environmental engineering at MIT.
Researchers Learn How Bacteria Makes Anti-greenhouse Gas
Univ. of Georgia marine scientists are uncovering the mechanisms that regulate the natural production of an anti-greenhouse gas. A new $2 million National Science Foundation grant will allow the UGA-led research group to further document how genes in ocean microbes transform sulfur into clouds in the Earth’s atmosphere.
Co-principal investigators on the grant are Franklin College of Arts and Sciences professors Mary Ann Moran of the department of marine sciences and William Whitman of the department of microbiology. The team is joined by Ronald Keine, a marine scientist at the Dauphin Island Sea Lab in Alabama, and James Birch and Chris Scholin, scientists from the Monterey Bay Aquarium Research Institute in California.
Like little factories, cells metabolize raw materials and convert them into chemical compounds. Biotechnologists take advantage of this ability, using microorganisms to produce pharmaceuticals and biofuels. To boost output to an industrial scale and create new types of chemicals, biotechnologists manipulate the microorganisms’ natural metabolism, often by “overexpressing” certain genes in the cell. But such metabolic engineering is hampered by the fact that many genes become toxic to the cell when overexpressed.
Now, Allon Wagner, Uri Gophna and Eytan Ruppin of Tel Aviv Univ.’s Blavatnik School of Computer Science and Department of Molecular Microbiology and Biotechnology, along with researchers at the Weizmann Institute of Science, have developed a computer algorithm that predicts which metabolic genes are lethal to cells when overexpressed. The findings, published in PNAS, could help guide metabolic engineering to produce new chemicals in more cost-effective ways.
The regular appearance of food poisoning in the news, including a recent event that led to the recall of more than 33,000 pounds of chicken, drives home the need for better bacterial detection long before meats and produce make it to the dinner table. On the horizon is a new approach for pathogen screening that is far faster than current commercial methods. Scientists are reporting the technique in the ACS journal Analytical Chemistry.
Clever Chemistry May Fight Antibiotic-Resistant Bacteria
As concerns about bacterial resistance to antibiotics grow, researchers are racing to find new kinds of drugs to replace ones that are no longer effective. One promising new class of molecules called acyldepsipeptides — ADEPs — kills bacteria in a way that no marketed antibacterial drug does — by altering the pathway through which cells rid themselves of harmful proteins.
Now, researchers from Brown Univ. and the Massachusetts Institute of Technology have shown that giving the ADEPs more backbone can dramatically increase their biological potency. By modifying the structure of the ADEPs in ways that make them more rigid, the team prepared new ADEP analogs that are up to 1,200 times more potent than the naturally occurring molecule.
Poison-breathing Bacteria May Aid Industry, Environment
Buried deep in the mud along the banks of a remote salt lake near Yosemite National Park are colonies of bacteria with an unusual property: they breathe a toxic metal to survive. Researchers from the Univ. of Georgia discovered the bacteria on a recent field expedition to Mono Lake in Calif., and their experiments with this unusual organism show that it may one day become a useful tool for industry and environmental protection.
The bacteria use elements that are notoriously poisonous to humans, such as antimony and arsenic, in place of oxygen, an ability that lets them survive buried in the mud of a hot spring in this unique saline soda basin.
Doctors may soon be able to diagnose stomach ulcers without taking tissue samples from the stomach. Researchers from the Univ. of Southern Denmark have developed a new, safer and noninvasive diagnostic technique for ulcers. The trick is to make the ulcer-causing bacteria in the gut light up in fluorescent green.
Each year, many patients are examined for ulcers, and this is often done by retrieving a tissue sample from the stomach. This requires that the doctor sends an instrument down into the patient´s stomach, and the patient must wait for the tissue sample to be analyzed before the doctor can give information about a possible ulcer.
Genetic systems run like clockwork, attuned to temperature, time of day and many other factors as they regulate living organisms. Scientists at Rice Univ. and the Univ. of Houston have opened a window onto one aspect of the process that has confounded researchers for decades: the mechanism by which genetic regulators adjust to changing temperature.
Until now, synthetic biologists have not been able to duplicate this marvel, but Rice biochemist Matthew Bennett and his team developed a robust synthetic genetic clock that allows Escherichia coli bacteria to accurately keep time in a wide temperature range. The clock, which regulates the production of proteins, does not speed up or slow down with changing temperatures, and offers one possible solution to a problem that has hindered the advance of synthetic biology. Read more: http://www.laboratoryequipment.com/videos/2014/01/genetic-clock-checks-thermometer