The Quest for Better Bandages Turns to Nanofibers

Our skin is a protective barrier to bacterial infection, but damage to the skin allows bacteria to enter. Normally, our immune system kills the bacteria and allows wounds to heal. However, certain diseases can overload the immune system and lead to heavy infection. Antibiotics are commonly used to treat heavy bacterial infection, but bacteria can develop drug resistance after too much exposure. A team at … Continue reading The Quest for Better Bandages Turns to Nanofibers

Bacteria snatch up foreign material using specialized arm-like structures

In order to adapt to their environments, it is important that bacteria be able to mix up their genetic code. One way that bacteria do this is by taking up bits of free-floating foreign DNA that can be released by other kinds of bacteria into their environments when they die. This process is called ‘transformation.’ The pieces of DNA can occasionally encode components that make … Continue reading Bacteria snatch up foreign material using specialized arm-like structures

Colonies 5

The colonies in this image display some of the diversity of pigment production in Pseudomonas aeruginosa. The blue-green colonies contain a pigment called pyocyanin, which is known to be toxic to human cells and helps the bacteria establish a niche during infections. The colonies containing a brown halo produce the brown pigment pyomelanin, which is thought to help the bacteria scavenge for iron, an essential … Continue reading Colonies 5

Colonies 4

To get around, Pseudomonas aeruginosa bacterium use a number of motility strategies, such as twitching and gliding. In this image, we see a special kind of bacterial motility behavior known as swarming, where a mass of bacteria moves collectively across a surface.  This is an example of singled celled bacterial species acting in a multicellular way. For a group of cells to swarm, the bacterium … Continue reading Colonies 4

Colonies 3

It may be hard to believe, but this sea of shiny, donut-shaped colonies are Pseudomonas aeruginosa colonies. These Pseudomonas colonies have a genetic mutation that causes many of the bacteria’s genes to be shut off. The donut-shape of these colonies may indicate a two-step growth phase where the younger cells on the outside edge of the colony grow towards more nutrients while the older cells in … Continue reading Colonies 3

Colonies 1 and 2

No one likes to be in crowded spaces, so when colonies reach a critical cell density, cells within the colony begin to lyse, dramatically changing the architecture of the colony. The colony on the left is a wild-type colony, while the colony on the right is a genetic mutant that exhibits an autolytic phenotype, that is the bacterium’s own enzymes “eat up” its cells. The … Continue reading Colonies 1 and 2

Colonies on a Plate

A single bacterial cell is invisible to the naked eye. As that single cell grows and divides into new cells, however, it forms a visible pile of bacteria. In microbiology, we call this pile of bacteria a colony. A colony’s appearance can indicate a lot about the bacterial cells within, such as how they utilize nutrients, if they carry genetic mutations, and how the bacterial … Continue reading Colonies on a Plate


The adaptation of the opportunistic human pathogen Pseudomonas aeruginosa often produces phenotypic diversity. Here, mutants isolated from a genetic screen show notable differences in phenotype: the production of pigments, size, shape, and texture. The blue-green pigmentation seen in some mutants results from the production of pyocyanin, an excreted toxin that kills other microbes and mammalian cells. Whereas, the brown pigmentation is caused by the exocellular pigment, pyomelanin, which … Continue reading Pseudomonads

Nature’s Living Magnets: An unexpected tool to treat disease

by Saman Hussain figures by Daniel Utter All living organisms have developed ways to move to places that are beneficial for them. Even tiny organisms like bacteria need to move towards food sources. Finding food becomes much easier if information from the environment is used to help in the search. For example, if you are looking for free pizza in your workplace, relying on randomly … Continue reading Nature’s Living Magnets: An unexpected tool to treat disease

Antibiotic Resistance: Old genes, new problems

by Alexandra Cantley figures by Joy Jiao and Shannon McArdel Over the last several years, antibiotic resistance has gripped the attention of the public. Recently, newspapers have alerted us to a “superbug” in China and detailed the struggles of Daniel Fells, a Giants team member who is facing surgery for a persistent MRSA infection [1,2]. Yet, a recent survey conducted by the World Health Organization … Continue reading Antibiotic Resistance: Old genes, new problems