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!

 

New Social Media Tidbits and Insights

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.

A new study released last Thursday by the Pew Research Center found that about 8 per cent of active American Internet users are also enthusiastic about Twitter. Of the 8 per cent, 2 percent indicated that they are extremely active and use it daily as a source of new content and links to other websites and services. Further, it appears that black and Latino persons are twice as likely as compared with whites to use Twitter. Whether or not Twitter can increase its use among all Americans still remains to be seen.

Facebook is still the 800 lb gorilla in the room and without a doubt the world’s largest online networking site. However, Facebook growth is starting to slow a bit and issue surrounding privacy and free speech considerations are starting to take its toll. There is no doubt that Facebook is a content-generating machine. According to an article in the NY Times, Facebook’s “more than 500 million users upload more than 1.0 billion pieces of content a day.” Unfortunately, because of Facebook’s expansive size, it is becoming increasingly difficult to find relevant and useful content on the site. Interestingly, Facebook users are turning to the site to gain access or find information to “ebooks.” Finally, roughly 70 per cent of recruiters and hiring managers are using Facebook (and other networking sites like LinkedIn) to source job candidates or conduct background checks on prospective new hires.

Until next time...

Good Luck and Good Job Hunting!!!!!

 

A Troubling Trend: Genital Herpes Infections are on the Rise

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 very troubling article about the infection rates and incidence of genital herpes among sexually active Americans. Here are some of the facts gleaned from a recent CDC report on genital herpes:

  1. One in six Americans aged 14 to 49 are infected with genital herpes, making the virus — herpes simplex 2 — one of the most common sexually transmitted diseases in the United States
  2. Research shows that people with genital herpes are two to three times as likely to acquire H.I.V. as those without herpes
  3. H.I.V.-infected individuals also infected with genital herpes are more likely to transmit H.I.V. to others
  4. Infection rates for women are almost twice the rate of men
  5. Blacks are three times as likely to be infected as whites
  6. Black women have the highest rates of infection, with almost half infected

Looking back, it is understandable why HIV/AIDS took precedent over genital herpes infections. After all, most people usually don’t die from genital herpes. However, the rising infection rates of the disease suggest that the American public needs to be better educated the spread and prevention of genital herpes infections. There is no question that discussions about STDs are embarrassing and often difficult. However, these days, they can be the difference between live and death!

Until next time…

Good Luck and Good Job Hunting!!!!!!!!!!!

 

The Curious Case of Wrinkles, Botox and FDA

One day after the US Food and Drug Administration (FDA) approved Dysport, a new product that will compete with Botox, the agency ordered that labels for all botulinal toxin-based drugs must carry a black box safety warning. For those of you who may not know, that is the most stringent kind of safety warning label—viewed by many in the industry as “the kiss of death”— that the agency can order to appear on the products that it regulates. 

Black boxes (literally a black box with bold-face risk information) are typically reserved for medications that are know to have serious or life-threatening side effects or risks. For example, many antidepressants—most recently serotonin re uptake inhibitors (SRIs)—carry black box warnings of increased danger of suicidal thoughts and actions. 

Over the last 20 years FDA approved Botox to treat crossed eyes, eyelid spasm, severe underarm sweating and cervical dystonia (a painful and severe neck condition that can cause an abnormal head position) Cosmetic Botox was approved to treat skin folds and wrinkles in 2002. Allergan, the company that manufactures Botox, reported $1.3 billion in worldwide sales of the drug in 2008. 

Botox and Dysport are injectible products made from the highly paralytic toxins produced by the bacterium Clostridium botulinum. Botulinal toxins interfere with muscle contractions and patients with botulism food poisoning exhibit what is known as “flaccid paralysis.” Afflicted individuals cannot breather and will die without early intervention. FDA order the black box safety warning labels because there were numerous reports of serious health problems, complications and deaths caused by the drug spreading from the site of injection to other parts of the body. 

Most of the problems with Botox resulted from the overuse of Botox for unapproved treatments like limb spasticity in children with cerebral palsy (although misuse of the product for cosmetic purposes may have also contributed to the problems). The agency will now require that all botulism-based products carry a black box warning explaining that the medication has the potential to spread from the site of injection to other body sites—with the potential to cause serious problems like difficulties swallowing or breathing. Also, it will require manufacturers of botulinal products [Allergan (Botox) and Ipsen/Medicis Pharmaceuticals (Dysport)] to send physicians letters warning of the risks and to craft medical guides given to patients at the time of injection. 

The new warning labels will likely do little to discourage the rampant use of Botox and Dysport for cosmetic indications. After all, beauty will always come before safety! 

Until next time... 

Good Luck and Good Job Hunting (looking younger may help)

 

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FDA Adds Black Box Safety Warning to EPO Drugs

Amgen announced today that US regulators added black box warnings to its erythropoietin drugs, Epogen and Aranesp. Similar warnings were also added to Johnson and Johnson’s Procrit which is licensed from Amgen. For those of you who don’t know, getting a black box warning on a drug label is like getting the “kiss of death” from a marketing and sales perspective. It certainly will not help sales of these products!

The new warnings approved by the Food and Drug Administration warn that the company's drugs increased death and accelerated tumor growth in patients with several types of cancer, including breast and cervical. Prior labeling warned of similar risks in other types of cancers.

The actions taken by the agency were not unexpected but suffice it to say there are a lot of unhappy Amgen and Johnson & Johnson employees in a Thousand Oaks, CA and New Brunswick, NJ

Until next time….

Good Luck and Good Job Hunting!!!!!!!

Hot Off the Press: "May Cause Heart Attack" Added to GSK's Avandia Label

The FDA ruled today that GlaxoSmithKline’s blockbuster diabetes drug Avandia will now carry as part of its label a warning advising that its use might raise the risk of suffering a heart attack.

A black box warning is the sternest warning a drug can carry and still remain on the market in the U.S. Avandia already carries a black box warning advising it could cause or exacerbate congestive heart failure in some patients.

With 2006 sales of almost $3 billion, Avandia has been a major revenue driver for Glaxo.

Look for continued corporate right sizing at GSK through 2008.

Until next time….

Good Luck and Good Job Hunting!!!!!!!!