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Solving the plasmid paradox: evolutionary advantages of multicopy plasmids

Today marks the end of 2016's World Antibiotic Awareness Week, aimed to increase awareness of antibiotic resistance and to advocate for the prudent use of these drugs.

One of the key drivers of antibiotic resistance is how rapidly bacteria acquire DNA from the environment or from other bacteria. Resistance elements are often carried on mobile elements, DNA that can move around the genome or be transferred to other genomes. The almost universal rapid assimilation of DNA by bacteria leads to the acquisition of multiple antibiotic resistance genes in a variety of bacterial species. One such example of a DNA mobile element is the plasmid, small circular DNA that replicates independently of the chromosome and can be transferred from bacterium to bacterium during cell division, transformation, and conjugation. (more…)

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Microbes in costumes trick the immune system

Halloween has finally arrived and everyone around you has been busy working on their costumes in anticipation for this glorious day of tricks and treats. Come Halloween night, you may not even recognize the faces behind the costumes. How would you tell apart friends with a sweet tooth from foes ready for some tricks?

For some bacteria, putting on costumes is an everyday event when it comes to tricking the immune system. The immune system distinguishes the body's own cells from those of invading bacteria and viruses. Since the microbe's outer membrane is usually the first thing the immune system sees, the body takes advantage of molecules found on the outer membrane┬áto generate an immune response. This seems like a wise defense mechanism but microbes have several tricks up their sleeves; they disguise themselves from the immune response by changing molecules on their outer membrane (antigenic variation) or by turning on and off expression of genes encoding for surface molecules (phase variation). (more…)

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The buzz about the honey bee microbiome

Imagine you are at a picnic on a nice sunny day. Several bees stop by buzzing around your food particularly intrigued by a bowl of fruit. Though bees may be a nuisance on this particular day, they serve an essential role in the production of much of the food we eat. They produce honey, beeswax and other products we enjoy. Bees are also crucial in pollination and without honey bees, we may not be able to enjoy fruits, nuts, and vegetables that we do today.

In the past decades, the honey bee population have declined rapidly. Between April 2015 and March 2016, beekeepers lost 44.1% of their colonies. This decline in the honey bee population could be due to many reasons including pesticides, parasites, and disease. More curiously, many colonies have fallen to colony collapse disorder (CCD), where adult worker bees die-off and surprisingly, no dead bees are found in or around the hives. The exact cause of CCD is not completely known thought many have attributed pesticides, pathogens, antibiotics, and climate change as the cause. (more…)

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The Unseen Cloud Makers from the Ocean

The ocean is teeming with microscopic life that despite their minuscule size, greatly impact our world's ecosystem and climate. A large majority of these organisms are considered planktonic, those that are suspended in the ocean waters and rely on the current for movement. Phytoplankton are a type of plankton that are autotrophic and use just photosynthesis as a carbon source. Not only do they serve as a food source for larger organisms, phytoplankton also produce the majority of the world's oxygen and also play roles in cloud formation. (more…)

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Multitudes of life in Ed Yong's I Contain Multitudes

"Remember that animals emerged in a world that had already been teeming with microbes for billions of years. They were the rulers of the planet long before we arrived." -Ed Yong

Last week, I was able to attend Ed Yong's book talk at MIT. At his talk, Yong took us on a journey through his recently published book, I Contain Multitudes: The Microbes Within Us and a Grander View of Life. In this microbial tour de force, Yong describes the diverse ways microbes interact with plants, animals, humans, and basically anything on this earth. Microbes are ubiquitous and Yong explores the ways microbes may shape our global ecosystem and vice versa. (more…)