by Francesca Tomasi figures by Aparna Nathan Too Much of a Good Thing? Ninety years ago, Alexander Fleming happened upon the chemical compound penicillin and sparked a medical revolution. It was a serendipitous occasion – Fleming had been growing plates of bacteria in his lab when he noticed some mold growing on one of them. Just some classic contamination, he probably thought, ready to discard … Continue reading Less of the Same: Rebooting the antibiotic pipeline
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
Is this apple safe to eat? Did that course of antibiotics work? To answer these types of questions we often need to know how to find and count illness-causing bacteria. Several bacteria counting techniques already exist. However, these approaches are slow and sensitive to laboratory conditions. Sam Nugen and his team from Cornell University are streamlining this process using a type of virus called phages, … Continue reading Viruses to the Rescue: Can we use viruses to find bacteria in our environment?
by Jenny Zheng figures by Rebecca Clements With winter soon coming to an end (hopefully), many of us have been plagued by seemingly endless hacking that’s accompanied by phlegm, a type of mucus produced by the respiratory tract. The body starts feeling better after a week of sickness, but even after that “hell-week,” one final foe has to be dealt with: the phlegm. It’s such … Continue reading All About That Mucus: How it keeps us healthy
Antibiotic resistance is a rampant problem around the world. More than 23,000 deaths a year in the US are a result of antibiotic resistant bacteria. Bacteria become resistant to antibiotics in several ways. The antibiotic itself can be broken down, or the components of bacteria targeted by antibiotics can mutate. Over prescription leads to the development of further resistance. With each year there are increasing numbers … Continue reading Have antibiotic resistant bacteria met their match? A new method for antibiotic discovery that could change the arms race.
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
by Veerasak “Jeep” Srisuknimit figures by Jovana Andrejevic Our time with antibiotics is running out. In 2016, a woman in Nevada died from a bacterial infection caused by Klebsiella pneumoniae that was resistant to all available antibiotics. Bacteria that is resistant to colistin, an antibiotic of last resort, has been discovered on pig farms in China. Bacteria have been evolving to resist antibiotics faster than … Continue reading Bacteriophage: A solution to our antibiotics problem?
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
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
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