Tag: host-microbe interaction
Move over flu season, there’s an entire epidemic calendar
Flu season is upon us, but there are actually “seasons” for many other infectious diseases. Chickenpox outbreaks peak each spring and polio transmission historically occurred in the summer. In fact, at least 69 infectious diseases vary seasonally.
Micaela Elvira Martinez, assistant professor in the Department of Environmental Health Sciences at Columbia University, found this out by systematically querying the data of 69 infectious diseases for seasonality. She chose the diseases to study based on those that were of public health interest (including neglected tropical diseases). She searched the literature for a disease name + season and/or disease name + season + human and collected information from the publications found. When needed, she searched for disease name + “seasonality.”
What she found was that seasons matter – but it’s more complicated than cold weather keeping everyone cooped up indoors. Martinez categorizes the impact of seasonality into four factors: environmental, host behavior, life cycle events, and exogenous biotic factors. What’s more, all of these factors can influence disease epidemiology at many levels: from hosts, to reservoirs, and to vectors. (more…)
Acute Oak Decline: A Modern Adaptation of Koch’s Postulates
In the UK, thousands of oak trees are “bleeding,” oozing dark liquid from cracks on their bark. What lies underneath are fluid-filled necrotic cavities that disrupts their life force by impeding the normal flow of nutrients and water. Taking advantage of the weakened state of the trees, are bark-boring beetles, which lay their eggs in the cracks of the bark. These are the characteristic signs of Acute Oak Decline, a disease that can kill a tree within four or five years of symptom onset.
Acute Oak Decline made its appearance in 2008. Now, scientists have found that Acute Oak Decline is caused by a polymicrobial infection – in this case, a simultaneous infection of three bacterial species: Brenneria goodwinii, Gibbsiella quercinecans, and Rahnella victoriana. With the microbes (B. goodwinii and G. quercinecans) and beetle larvae in hand, the researchers were able to replicate the characteristic signs of Acute Oak Decline. (more…)
Zombie Worms and Microbes Come Together for a Deep Sea Meal
Deep within the ocean, scientists and explorers alike have discovered all sorts of creatures almost unfathomable to our terrestrial minds. Giant octopus, electric eels, and anglerfish have all tickled our imagination over the past several centuries, and left us in awe of the capabilities of life.
A more recent discovery is that of the bone-eating worms. On one end of the worms are feathery plumes that act as gills to extract oxygen from the water. On the opposite end are root-like structures that dig deep below the bone surface. These newly discovered zombie worms were called Osedax, meaning “bone eating” in Latin. (more…)
There’s a Fungus Among Us and It’s Making Peppers Spicy
Though the heat of the chili pepper has taken our culinary adventures to great heights, the spiciness of chili peppers was not designed to attract hungry diners. Spiciness actually evolved to defend the plant against fungal predators.
Peppers, like many fruits, are colorful, sweet, and appetizing, designed to attract animals that help bring seeds to new ground. But along with inviting animals beneficial to the plant’s survival, fruits also lure consumers that destroy seeds. Thus, fruit chemistry hangs in a delicate balance. The chemicals produced by the fruit must keep predators at bay, but must also not negatively affect seed dispersers. (more…)