This Week in Microbiology (TWiM) Episode #2: The Plague, Microbial Virulence and the Gut Microbiome
On episode #2 of the podcast This Week in Microbiology, Vincent, Cliff, and Michael review a fatal laboratory acquired Yersinia pestis infection, and how gut bacteria which are part of the normal flora of all animals control body weight and metabolic activity.
For those of you who may not know, bubonic plague—which killed thousands of people during outbreaks in the Middle Ages —still occurs at a low level in many places through out the world including sporadic cases in the Western US! About 10 to 20 Americans catch plague each year, and 1 to 3 die of it, according to the Centers for Disease Control and Prevention. Nowadays, most cases are in the Four Corners area, where Utah, Arizona, New Mexico and Colorado meet, and most victims live in rodent-infested rural housing. Despite the fear that the word plague induces in most people, the infection is easily treated with antibiotics if caught earlier enough (modern antibiotics were discovered in the 1940s starting with penicillin).
"Bring out your dead"from Monty Python and The Holy Grail
Y. pestis, the bacterium that causes bubonic plague, lives in the blood of infected prairie dogs and ferrets and other rodents and can be transmitted to human via bites from infected fleas (which are commonly found in wild rodent populations) that have previously had a blood meal on -infected animals. Interestingly, an article appeared in the NY Times last Fall, which linked climate change (aka global warning) to a reduction in the incidence Y. pestis infections in the Western US.
The article cited a study in the American Journal of Tropical Medicine and Hygiene, which tracked climatic conditions in 195 counties in 13 Western states, from Washington to Texas, that reported even one plague case since 1950.
Cases of plague have dropped over time, and authors of the study concluded that rising nighttime temperatures since 1990 may have helped to reduce the incidence of plague. They suggested that warmer nights melt winter snow packs earlier than in the past, leading to drier soil in rodent burrows. When the soil gets too dry, fleas die and plague can no longer be transmitted from infected rodents to human hosts. Talk about an upside for global warming!!!!!!
While this may be good news for potential plague victims, the incidence of plague in the US is so low that the public health benefits offered by climate change may be nominal as compared with the damage that global warming will cause if continues unchecked. That said, who knew that climate change and bacterial pathogenesis were interconnected?
To learn more about the less well known interrelationships between bacteria, animals and the planet we invite you to continue to listen to TWiM. You can subscribe to TWiM (free) at the Zune Marketplace, via RSS feed, by email or listen on your mobile device with the Microbeworld app.
Until next time...
Good Luck and Good Listening!
.jpg)
At present, 74 percent of adult Americans use the Internet according at a recent Pew survey. While Twitter continues to be one of the hottest new social media tools and Facebook still dominates the social web, do both really live up to the media hype? Let’s start with Twitter.
While studying the pathogenesis of Neisseria gonorrhoeae in Portland, OR in the early 1980s, genital herpes had replace gonorrhea as the scourge of the sexually transmitted disease community. To help to combat the spread of genital herpes, my labmates and I joined the Portland Venereal Disease Action Committee, a grass roots organization that provided public outreach and education about sexually transmitted diseases (STDs). A few years later, the Regan Administration finally admitted to the American public that HIV/AIDS was real and that HIV infections were likely to reach epidemic proportions. While genital herpes can be painful, uncomfortable and often emotionally debilitating, the unprecedented morbidity and mortality of HIV/AIDS almost pushed genital herpes into infectious diseases obscurity. Now that HIV/AIDS is more treatable than ever before, epidemiologists and sexually transmitted diseases experts have begun to reexamine the infection rates and incidence of other STDs (including herpes, gonorrhea, Chlamydia and syphilis) among Americans. To that end, I read today a .jpg)
One day after the US Food and Drug Administration (FDA) approved Dysport, a new product that will compete with Botox, the 
The FDA 