Stories tagged antibiotics


Disease Detectives
Disease DetectivesCourtesy Disease Detectives
Earlier this year I got the chance to work as the crew of high school staff in the Kitty Andersen Youth Science Center ( at the museum to create a series of web-based videos about infectious diseases for the Disease Detectives exhibit. We worked from January through August learning video production skills, learning about different infectious disease topics, talking to experts and folks on the museum floor. We're just getting the videos online now, and all of our videos will be on the exhibit website soon ( but I wanted to share them here as well.

For this video, titled "Got Beef? The Story Behind Antibiotics and Livestock" the crew to a slaughter house on in South St. Paul, the Minnesota Department of Health, U of M St. Paul (at 7AM to see the cows grazing), Mississippi Market Co-op, and did hours of research, prep, and post production.
Got Beef? The Story Behind Antibiotics and Livestock from Disease Detectives on Vimeo.

You can check out the video here.


Pretty bacteria: Do not be fooled by the pastel colors- these things will kill you.
Pretty bacteria: Do not be fooled by the pastel colors- these things will kill you.Courtesy esterase
I bet regular bacteria have posters of their favorite superbug hung on their bedroom walls. I mean superbugs are just so much cooler than regular bacteria; they’re kind of the bad boys of the bacteria world. Regular bacteria do what they are told: they keel over when exposed to disinfectants and antibiotics. But not those rebellious superbugs. Superbugs have some kind of genetic mutation that allows them to survive in hostile, antimicrobial environments. Basic principles of natural selection come into play: the mutant bacterium survives in the presence of the antibiotic/disinfectant and then goes on to produce other bacteria with the same mutation, ultimately creating a new resistant colony. In this scenario, exposure to the antimicrobial agent (the antibiotic or disinfectant) is imperative. However, scientists now think that another scenario exists; one in which exposure is not required. In a recent study, these scientists found that the use of disinfectants in hospitals can lead to bacterial resistance to antibiotics, even if the bacteria haven’t been exposed to the antibiotics.

Researchers from the National University of Ireland added increasing amounts of disinfectant to petri dishes full of Pseudomonas aeruginosa (a bug that causes pneumonia in hospital patients, among other things) and the bug became immune not only to the disinfectant, but also to ciprofloxacin- the antibiotic used to treat the bug. Superbugs are essentially using their exposure to disinfectants as “teachable moments” for resisting antibiotics.

This is significant because now it seems that bacteria have one less hurdle to overcome in their mission to cause serious harm to patients (that’s not really their “mission,” I say that for dramatic effect). If superbugs can resist the disinfectant slathered on the countertops and doorknobs of hospitals, it’s possible that they could go on to infect patients who “for some reason” won’t respond to the antibiotics. Man, regular bacteria must be so jealous.

Farm animals often carry germs that can get into our food supply. And pumping the animals full of antibiotics can cause other problems, such as breeding super bugs that are immune to the drugs. But researchers in South Carolina are taking a new approach. They are adding nanoparticles to chicken feed. The particles imitate chicken cells and attract the germs. The germs get stuck to the particles, and then get expelled harmlessly the next time the chicken poops.


Escherichia coli
Escherichia coliCourtesy National Institutes of Health

Gut buddies

Bacteria are everywhere. Human intestines are loaded with bacteria (more than a trillion of them). Research findings are showing that humans have a symbiotic relationship with their intestinal flora. Our health depends upon certain bacteria in our gut.
Good bacteria help us digest our food, repress the growth of yeast and other harmful microbes, promote growth of cells lining the intestines, trains the early immune system in fighting harmful bacteria yet leaving the helpful species alone. Bacteria are also implicated in preventing allergies, an overreaction of the immune system to non-harmful antigens.

Study ties gut bacteria to good health

In a recent paper, Dennis Kasper at Harvard Medical School proposed

"that molecules of the bacterial microbiota can mediate the critical balance between health and disease" Nature: 29 May, 2008; A microbial symbiosis factor prevents intestinal inflammatory disease.

Colitis in mice due to lack of good gut bacteria

Bacteroides fragilis is a common bacterium found in the human gut that produces a molecule called Prostate Specific Antigen (PSA). Mouse studies suggest that PSA can influence the development of immune cells called T cells. Experiments in mice showed that PSA inhibited the production of chemicals by intestinal immune cells that usually trigger inflammation in response to infection with H. hepaticus. Read more about the study in New Scientist

What happens when broad spectrum antibiotics kill off your good gut bacteria?

I would like to challenge readers to answer this question using our comments feature, and to also suggest what you need to do to regain your "gut buddies".

Have you ever wondered what antibiotic resistance really means? And who is resistant to those drugs? For a very good explanation read the blog entry Drug Resistance, Explained in the New York Times. I enjoyed the History of Medicine at the end too.

Did you find this explanation helpful? Did you learn anything that surprised you?

Some microbes are resistant to antibiotics. Researchers in England have developed a way to change the molecular structure of antibiotics to make them more effective against these “superbugs.”

A compound, platensimycin, found in soil microbes may be the source of a powerful new antibiotic. In the lab, it wiped out strains of Staphylococcus aureus and Enterococcus that were resistant to our most powerful current drugs. The drug won't be ready for human use for years, but if it passes all safety and efficacy tests, it will be the third new antibiotic to reach patients in the last 40 years. And the strongest.