Tag: Bacteria

Posted on

The Irresistible Resistome: How Infant Diapers Might Help Combat Antibiotic Resistance (sort of)

by and
5 comments
Gautam Dantas
Credit: Pablo Tsukayama, Ph.D.,
Washington University School of Medicine
Gautam Dantas
Born: Mumbai, India
Most proud of: His family, which brings him joy and pride
Favorite lab tradition: OOFF! Official Optional Formal Fridays, when members of his lab can dress up, eat bread—made in the lab’s own bread machine—and drink beer and wine together at the end of the day
When not in the lab, he: Enjoys home brewing, pickling and canning, and spending time with his wife and children. He also attends musical performances, including those of his wife, who sings in the St. Louis Symphony Chorus
Advice to aspiring scientists: Pursue hobbies, take risks, explore beyond your comfort zone. “You can do a Ph.D., but also have other experiences.” He says his own outside activities refine his focus in the lab, keep him grounded and help him be an empathetic mentor to his students. Plus, he met his wife while singing in the chorus of Macalester College in St. Paul, Minnesota

When I Grow Up…

Gautam Dantas remembers the day in 10th grade when he first wanted to be a scientist. It was the day he had a new biology teacher, a visiting researcher from the U.S. The teacher passionately described his own biochemical studies of how organisms live together in communities. By the end of the class, Dantas had resolved to earn a Ph.D. in biochemistry.

He ended up doing much more—gaining expertise in computational biology, protein design and synthetic biology. He now combines his skills and knowledge in multifaceted research that spans four departments at Washington University in St. Louis. His goal: to better understand and help combat a vital public health threat—drug-resistant bacteria.

“Our motivation is that we are living in the antibiotic era, and antibiotic resistance is getting out of control,” Dantas says. “We have very few new antibiotics we can use, so we’re kind of scrambling [to find new ways to treat bacterial diseases].”

His research focuses on one of the groups most vulnerable to bacterial infections—newborn babies.

According to his lab’s website Exit icon, the research is “at the interface of microbial genomics, ecology, synthetic biology, and systems biology,” and it aims “to understand, harness, and engineer the biochemical processing potential of microbial communities.” They do it by scrounging around in infant diapers.

Antibiotic Angst

Since their introduction in the 1940s, antibiotic drugs have saved countless lives. Simultaneously, they weeded out strains of bacteria easily killed by the drugs, allowing drug-resistant strains to thrive. Every year, at least 2 million people in the U.S. become infected and at least 23,000 die from drug-resistant bacteria, according to the Center for Disease Control and Prevention. Continue reading “The Irresistible Resistome: How Infant Diapers Might Help Combat Antibiotic Resistance (sort of)”

Posted on

Newly Identified Cell Wall Construction Workers: A Novel Antibiotic Target?

by
0 comments
SEDS

A family of proteins abbreviated SEDS (bright, pink) help build bacterial cell walls, so they are a potential target for new antibiotic drugs. Credit: Rudner lab, Harvard Medical School.

Scientists have identified a new family of proteins that, like the targets of penicillin, help bacteria build their cell walls. The finding might reveal a new strategy for treating a range of bacterial diseases.

The protein family is nicknamed SEDS, because its members help control the shape, elongation, division and spore formation of bacterial cells. Now researchers have proof that SEDS proteins also play a role in constructing cell walls. This image shows the movement of a molecular machine that contains a SEDS protein as it constructs hoops of bacterial cell wall material.

Any molecule involved in building or maintaining cell walls is of immediate interest as a possible target for antibiotic drugs. That’s because animals, including humans, don’t have cell walls—we have cell membranes instead. So disabling cell walls, which bacteria need to survive, is a good way to kill bacteria without harming patients.

This strategy has worked for the first antibiotic drug, penicillin (and its many derivatives), for some 75 years. Now, many strains of bacteria have evolved to resist penicillins—and other antibiotics—making the drugs less effective.

According to the Centers for Disease Control and Prevention, drug-resistant strains of bacteria Exit icon infect at least 2 million people, killing more than 20,000 of them in the U.S. every year. Identifying potential new drug targets, like SEDS proteins, is part of a multi-faceted approach to combating drug-resistant bacteria.

Posted on

CRISPR Serves Up More than DNA

by
0 comments
Marine bacterium Marinomonas mediterranea
The marine bacterium Marinomonas mediterranea uses a CRISPR system to spot invading RNAs and store a memory of the invasion event in its genome. Research team member Antonio Sanchez-Amat was the first to isolate and characterize this bacterial species. Credit: Antonio Sanchez-Amat, University of Murcia.

A new study has added another twist to the CRISPR story. As we’ve highlighted in several recent posts, CRISPR is an immune system in bacteria that recognizes and destroys viral DNA and other invading DNA elements, such as transposons. Scientists have adapted CRISPR into an indispensable gene-editing tool now widely used in both basic and applied research.

Many previously described CRISPR systems detect and cut viral DNA, insert the DNA pieces into the bacterial genome and then use them as molecular “mug shots” to flag and destroy the virus if it attacks again. But various viruses use RNA, not DNA, as genetic material. Although research has shown that some CRISPR systems also can target RNA, how these systems can archive harmful RNA encounters in the bacterial genome was unknown. Continue reading “CRISPR Serves Up More than DNA”

Posted on

Cool Video: Watching Bacteria Turn Virulent

by
1 comment

Researchers created an apparatus to study quorum sensing, a communication system that allows some bacteria to cause dangerous infections. Their findings suggest that blocking bacterial communication might lead to a new way to combat such infections. Credit: Minyoung Kevin Kim and Bonnie Bassler, Princeton University.

If you’ve ever felt a slimy coating on your teeth, scrubbed grime from around a sink drain or noticed something growing between the tiles of a shower, you’ve encountered a biofilm. Made up of communities of bacteria and other microorganisms, biofilms thrive where they can remain moist and relatively undisturbed. As they enlarge, biofilms can block narrow passages like medical stents, airways, pipes or intestines. Continue reading “Cool Video: Watching Bacteria Turn Virulent”

Posted on

Finding Adventure: Blake Wiedenheft’s Path to Gene Editing

by
1 comment
Blake Wiedenheft
Blake Wiedenheft
Grew up in: Fort Peck, Montana
Fields: Microbiology, biochemistry, structural biology
Job site: Montana State University
Secret talent: Being a generalist; enjoying many different subjects and activities
When not in the lab, he’s: Running, biking, skiing or playing scrabble with his grandmother

Scientific discoveries are often stories of adventure. This is the realization that set Blake Wiedenheft on a path toward one of the hottest areas in biology.

His story begins in Montana, where he grew up and now lives. Always exploring different interests, Wiedenheft decided in his final semester at Montana State University (MSU) in Bozeman to volunteer for Mark Young, a scientist who studies plant viruses. Even though he majored in biology, Wiedenheft had spent little time in a lab and hadn’t even considered research as a career option. Continue reading “Finding Adventure: Blake Wiedenheft’s Path to Gene Editing”

Posted on

Bacterial Biofilms: A Charged Environment

by
1 comment
Bacillus subtilis biofilm
A Bacillus subtilis biofilm grown in a Petri dish. Credit: Süel Lab, UCSD.

Last summer, we shared findings from Gürol Süel Exit icon and colleagues at the University of California, San Diego, that bacterial cells in tight-knit microbial communities called biofilms expand in a stop-and-go pattern. The researchers concluded that this pattern helps make food at the nutrient-rich margin available to the cells in the starved center, but they didn’t know how. They’ve now shown that the cells use electrochemical signaling to communicate and cooperate with each other.

Because nutrients and other signals cells use to sense each other and their environment move rather slowly, the researchers looked for a faster, more active communication system in biofilms of the bacterium B. subtilis. They focused on electrical signaling via potassium, a positively charged ion that, for example, our nerve and muscle cells use to send or receive signals. Continue reading “Bacterial Biofilms: A Charged Environment”

Posted on

Cool Images: A Halloween-Inspired Cell Collection

by and
3 comments

As Halloween approaches, we turned up some spectral images from our gallery. The collection below highlights some spooky-sounding—but really important—biological topics that researchers are actively investigating to spur advances in medicine.

Cell Skeleton
Fibroblast
The cell skeleton, or cytoskeleton, is the framework that gives a cell its shape, helps it move and keeps its contents organized for proper function. A cell that lacks a cytoskeleton becomes misshapen and immobile. This fibroblast, a cell that normally makes connective tissues and travels to the site of a wound to help it heal, is lacking a cytoskeleton. Researchers have associated faulty cytoskeletons and resulting abnormal cell movement with birth defects and weakened immune system functioning. See fibroblasts with healthy skeletons.

Continue reading “Cool Images: A Halloween-Inspired Cell Collection”

Posted on

Bacterial ‘Fight Clubs’ and the Search for New Medicines

by
1 comment
Competition encourages bacteria to produce secondary metabolites with therapeutic potential that they would otherwise hold in reserve. Credit: Michael Smeltzer, Vanderbilt University.

Bacteria hold a vast reservoir of compounds with therapeutic potential. They use these compounds, known as secondary metabolites, to protect themselves against their enemies. We use them in many antibiotics, anti-inflammatories and other treatments.

Scientists interested in developing new medicines have no shortage of places to look for secondary metabolites. There are an estimated 120,000 to 150,000 bacterial species on Earth. Each species is capable of producing hundreds of secondary metabolites, but often only under specific ecological conditions. The challenge for researchers is figuring out how to coax the bacteria to produce these compounds.

Now, Brian Bachmann and John McLean of Vanderbilt University and their teams have shown that by creating “fight clubs” where bacteria compete with one another, they can trigger the bacteria to make a wide diversity of molecules, including secondary metabolites. Continue reading “Bacterial ‘Fight Clubs’ and the Search for New Medicines”

Posted on

The Simple Rules Bacteria Follow to Survive

by
1 comment
Left: Football stadium. Right: Colored contoured lines showing the periodic stops in the growth of a bacterial colony
Football image credit: Stock image. The colored contoured lines show the periodic stops in the growth of a bacterial colony. Credit: Süel Lab, UCSD.

What do these images of football fans and bacterial cells have in common? By following simple rules, each individual allows the group to accomplish tasks none of them could do alone—a stadium wave that ripples through the crowd or a cell colony that rebounds after antibiotic treatment.

These collective behaviors are just a few examples of what scientists call emergent phenomena. While the reasons for the emergence of such behavior in groups of birds, fish, ants and other creatures is well understood, they’ve been less clear in bacteria. Two independent research teams have now identified some of the rules bacterial cells follow to enable the colony to persist. Continue reading “The Simple Rules Bacteria Follow to Survive”

Posted on

Meet Sarkis Mazmanian and the Bacteria That Keep Us Healthy

by
1 comment
Sarkis K. Mazmanian
Credit: New York Academy of Sciences
Sarkis K. Mazmanian, Ph.D.
Born in: The country of Lebanon, moved to Los Angeles when he was 1
Fields: Microbiology, immunology, neuroscience
Works at: California Institute of Technology
Awards won: Many, including the MacArthur Foundation “Genius” grant
Most proud of: The success of his trainees! “There’s nothing that comes close to the gratification and joy I feel when a student or research fellow goes on to be an independent scientist.”
When not in the lab or mentoring students, he’s: Spending time with his family, including his 1-year-old-son or going for an occasional run

As a child, Sarkis Mazmanian frequently took things apart to figure out how they worked. At the age of 12, he dismantled his family’s entire television set—to the dismay of his parents and the unsuccessful TV repairman.

“I wasn’t aware of this at the time, but maybe that was some sort of a foreshadowing that I would enjoy science,” Mazmanian says. “Scientists take biological systems apart to understand how they work.”

Mazmanian never thought he’d become a microbiologist, let alone a leading expert in the field. He began studying microbiology at the University of California, Los Angeles (UCLA), because it was the major that allowed him to do the most hands-on research. But as soon as he entered the field, he fell in love with the complexities of microbial organisms and the efficiency of their functions. Continue reading “Meet Sarkis Mazmanian and the Bacteria That Keep Us Healthy”