antibiotics

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A Case of the Missing Microbes

Most animals depend on their gut microbes for digestive help. The caterpillar, however, seems to lack resident gut microbes all together.

By characterizing the microbial composition across 124 species of caterpillars from North America and Costa Rica, Tobin Hammer and colleagues at the University of Colorado Boulder found that caterpillars do not have microbial friends living in their gut. Fecal material from the caterpillars contained several orders of magnitude fewer microbes compared to other organisms. (more…)

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Meet a Microbiologist: Erica Hartmann

Erica’s foray into science didn’t specifically begin with microbiology. Her father worked at NASA and while accompanying him to work on “Take Your Daughter to Work Day” every year, she’s tried all sorts of things, even astronaut ice cream. She’s read a lot about science and her interest grew. “The Hot Zone especially scared the bejeezus out of me but was also fascinating,” she recalls. She grew up near Reston, Virginia, where Reston Virus (causes Ebola symptoms in non-human primates) was discovered. While she was in high school, she closely followed the race to sequence the human genome. “It felt hugely important and revolutionary, and I wanted to be a part of it,” Erica says. (more…)

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Why are pathogens rarely resistant to vaccines?

We have all heard the horrifying tales of incurable bacterial infections due to antibiotic resistance. But why don’t we see pathogens becoming resistant to vaccines? Intuitively, it seems that vaccines, like antibiotics, put selective pressure on pathogens. The selective force should drive the evolution of vaccine resistance, right? David Kennedy and Andrew Read explore this quandary in their recent publication in the Proceedings of the Royal Society.

Historically, when vaccine resistance arises, it takes much longer compared to antibiotic resistance. Vaccines created as early as the 1920s are still effective today while resistance to a new antibiotic can develop within a few years. Because the evolution of vaccine resistance is so rare, vaccines may be a solution to the drug resistance problems we face today. Vaccines reduce the need for antibiotic treatment and also decrease the number of cases and spread of infections. (more…)

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Bacteria’s toxic addiction to DNA

For bacteria, addiction to DNA can be a life or death situation. Lose that DNA and the bacterium suffers an unfortunate toxic death.

Many bacteria easily transfer DNA amongst themselves in the forms of plasmid DNA. Plasmids are mobile genetic elements that replicate independently of the chromosome. These small circular pieces of DNA often contain genes that provide its carrier a survival advantage under specific environmental conditions. For example, if a bacterium contains a plasmid with an antibiotic resistance gene, it can survive antibiotic treatment. But, the plasmid is not beneficial to its host cell in all situations and poses a metabolic burden for the host. So why do these plasmids exist and remain in bacteria? (more…)

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A year of microbes

Of course there are way too many microbiology stories than I can blog about. Here are some other fascinating finds throughout the year:

A bacteria that eats plastic: Poly(ethylene terephthalate) (PET) is a component of many plastic products that have accumulated in large quantities in the environment. Researchers have isolated a bacterium that uses PET as its main energy and carbon source. This bacterium can be further developed to efficiently degrade or ferment PET waste products. (more…)