Bacteria Made Of Star Stuff

One of the best at explaining science was Carl Sagan. One recurring theme in Sagan’s works can be seen in the quote below:

And we who embody the local eyes and ears and thoughts and feelings of the cosmos we’ve begun, at last, to wonder about our origins. Star stuff, contemplating the stars organized collections of 10 billion-billion-billion atoms contemplating the evolution of matter tracing that long path by which it arrived at consciousness here on the planet Earth and perhaps, throughout the cosmos.

Or consider the video below:

Eeek! Run For Your Lives! The Asphalt Eating Bacteria are Coming

The bacteria were found in the Rancho La Brea tar pits, according to Science Daily. Several things serve to make this story interesting. First:

Out of Africa With Helicobacter pylori

I don’t know how I missed this, but Science Daily has an interesting story on the Out of Africa theory.

Global Warming: Unintended Consequences

A lot has been written about the impact of global warming, but an article on ABC News discusses an aspect I had never thought about before. The article discusses the public health aspects of global warming. The article mentions a number of cases that can be directly or indirectly linked to global warming. For example, what was thought to be an outbreak of the Norfolk virus, on an Alaskan cruise ship, turned out to be due to “…a type of cholera-like bacteria, Vibrio parahaemolyticus…” How is this possible?

More on DNA from Ocean Bacteria

A while back I wrote this post on efforts to sequence the DNA of sea going bacteria. Research in that area has continued and new findings have recently been reported. They are quite fascinating – so much so I am putting off several other posts (one of these days I’ll get that post on the evolution of voltage gated sodium channels written) so I can blog about it (since I have been blogging about bacteria a lot I have been getting this strange compulsion to change the name of my blog to Aetiology Jr. – nah!)

MRSA and Amoebas

By now, most of us are familiar with MRSA or methicillin resistant Staphylococcus aureus. The staph bacteria is pretty common on human skin but doesn’t become a problem until it finds an entry through the flesh [afarensis had an old scar from a car accident get infected with staph, fortunately not MRSA, and spent about four days in the hospital last summer] at which point it becomes a problem. MRSA is mainly found in hospitals, although there have always been a number of cases where the person had never visited a hospital. Recent research may have uncovered why. According to Science Daily MRSA use amoeba to evade measures designed to halt their spread:

Scientists from the University of Bath have shown that MRSA infects and replicates in a species of amoeba, called Acanthamoeba polyphaga, which is ubiquitous in the environment and can be found on inanimate objects such as vases, sinks and walls.
As amoeba produce cysts to help them spread, this could mean that MRSA maybe able to be ‘blown in the wind’ between different locations.

MRSA and Amoebas

By now, most of us are familiar with MRSA or methicillin resistant Staphylococcus aureus. The staph bacteria is pretty common on human skin but doesn’t become a problem until it finds an entry through the flesh [afarensis had an old scar from a car accident get infected with staph, fortunately not MRSA, and spent about four days in the hospital last summer] at which point it becomes a problem. MRSA is mainly found in hospitals, although there have always been a number of cases where the person had never visited a hospital. Recent research may have uncovered why. According to Science Daily MRSA use amoeba to evade measures designed to halt their spread:

Scientists from the University of Bath have shown that MRSA infects and replicates in a species of amoeba, called Acanthamoeba polyphaga, which is ubiquitous in the environment and can be found on inanimate objects such as vases, sinks and walls.
As amoeba produce cysts to help them spread, this could mean that MRSA maybe able to be ‘blown in the wind’ between different locations.

I Wonder What Tara Would Make of This?

John J. Dennehy (Yale University), Nicholas A. Friedenberg (Dartmouth College), Robert D. Holt (University of Florida), and Paul E. Turner (Yale University), “Viral ecology and the maintenance of novel host use”
http://www.journals.uchicago.edu/cgi-bin/resolve?id=doi:10.1086/499381
Infectious diseases often mysteriously appear and disappear in populations. On some occasions small outbreaks rapidly die out; on others, epidemics ensue. Dennehy et al. explore the dynamics of pathogen emergence using viruses and their host bacteria as a study system. A mathematical model was constructed from basic demographic data to predict transmission rates required for persistence of viruses on their native and novel hosts. The model was validated with serial passage experiments revealing a range of transmission rates where virus populations were sustained on the native host, but went extinct on the novel host. In this critical region, periodic exposure to native hosts allowed the viruses to survive on novel hosts, an unanticipated result. The mechanism behind this phenomenon may be a “host legacy” effect. Dennehy et al. observe that viruses previously reared on the native host showed greater productivity on the novel host than did viruses previously reared on the novel host. This experimental demonstration of a host legacy effect has important implications. The capacity of a virus to propagate upon a novel host apparently is conditional on the recent experience of preceding generations. This is intrinsically interesting, suggesting a kind of complexity in pathogen population dynamics that has not been widely regarded. Second, given this host legacy effect, the total viral population size experiencing the novel environment is greater than would otherwise be expected. Because the amount of genetic variation that can be exposed to selection via novel mutations should scale with population size, this provides a more fertile ground for adaptive evolution to the new host.
Just Curious…

Lateral Transfer of Toxin Gene between Bacteria and Spiders?

This is fascinating:

It’s a case of evolutionary detective work. Biology researchers at Lewis & Clark College and the University of Arizona have found evidence for an ancient transfer of a toxin between ancestors of two very dissimilar organisms–spiders and a bacterium. But the mystery remains as how the toxin passed between the two organisms. Their research is published this month in the journal Bioinformatics, 22(3): 264-268, in an article titled “Lateral gene transfer of a dermonecrotic toxin between spiders and bacteria.”

More on Magnetic Bacteria

Those of my readers who followed me from my old blog may remember this post on magnetic bacteria. In it I discuss how a new technique called cyroelectron tomography has allowed researchers to gain new insights into how magnetosomes are arranged in some bacteria.

Above is a picture of magnetosome chains.