Salmonella species are frequent human pathogens. An incredibly diverse genus, different types of Salmonella infect an enormous variety of species, from mammals to fish to invertebrates. They are typically acquired via ingestion of contaminated food or water, and the bacteria then seed the intestine and replicate there. These gram-negative organisms are the cause of typhoid fever (Salmonella enterica serovar typhi) and can also cause acute gastroenteritis (multiple types, including Salmonella enterica serovars enteritidis and typhimurium).

Of these types, S. typhi is the most deadly, and generally the best known. Typhoid fever, while no longer common in developed countries, is still a significant burden in developing areas, where ingestion of S. typhi leads quickly to fever, nausea, and vomiting. The bacterium can also spread from the intestine to the blood and other organs, causing a systemic infection that can rapidly be fatal. Here in the U.S., however, S. enteritis and S. typhimurium are more common–indeed, they rank among the most common food-borne pathogens here. These bacteria also are ingested and cause gastrointestinal symptoms, but disease is typically more mild than with S. typhi. The victim becomes symptomatic ~12-48 hours after ingestion of the bacteria, experiencing vomiting, nausea, abdominal cramping, and diarrhea. The illness can last from 3-7 days in healthy individuals; in the very young or old or those with other types of compromised immune systems, symptoms may be prolonged and more severe, and more frequently result in death.

There has been much work over the past 50 years examining factors that allow Salmonella to cause disease, and to characterize the bacterium’s interaction with its hosts. However, a novel study takes this research to another level, quite literally–looking at how space travel affects the virulence of Salmonella typhimurium in a mouse model of disease. More after the jump…
Continue reading “Germs….in…..SPACE!”

DonorsChoose 2007–final call!

Edited to add: we’ve reached our goal! Thank you so much to all who participated; if others would still like to donate, Janet has a list of other blogger challenges–and remember that every completed challenge gets a 10% completion bonus from DonorsChoose, stretching your donation farther. Finally, donors–don’t forget to register for prizes!

The Scienceblogs DonorsChoose challenge is wrapping up–the contest officially ends at the end of the month. So far readers here have donated $1,590 to help out teachers and students, largely in districts with high poverty levels. I want to first send out a hearty thank you to those of you who’ve donated, whether it was a few dollars or a much larger chunk of change. We’ve already exceeded the amount raised here last year, but we’re not quite finished yet. If we make it to the $2000 mark (just another $410 to go), DonorsChoose will donate an extra 10% to fund additional projects as a completion bonus.

5 of the projects I selected are already fully funded, but 2 of the original ones still need help. These are “The Human Body: Learning by Heart!”, requesting stethoscopes and blood pressure cuffs (only needs $68 to be fully funded), and “Putting the “Why?” in Science”, which needs an additional $318 to purchase basic science supplies–graduated cylinders, petri dishes, beakers, etc. Since these together don’t quite equal my fundraising goal, I added one additional project as well:

“Scope It Out!”

Needs: $347 (50% funded)
Asking for: Microscope and slide collection (district is 50% low income)

Science is very popular among this eager group…always exploring and asking questions. A dependable, high quality microscope would be the perfect companion for most of our scientific inquiries. We would like to see the world up close and magnified. Prepared slides would enable us to look at different Kingdoms in the classification system, flora and fauna. We look forward to preparing our own slides too! This will be an integral part of all of our life science studies in biology and botany.

I know many of you read multiple blogs here and may have donated elsewhere, but for those of you who’ve not kicked in a few dollars yet, any amount you can give will make an impact. As I mentioned, the one project only needs $68 to be fully funded, and if we raise the $490 to meet the original challenge goal, we can fund additional projects with the extra $200 from DonorsChoose. Plus, I already mentioned I have copies of Arthur Allen’s “Vaccine” to give away to donors, and Seed is kicking in some loot as well, including T-shirts, mugs, and an iPod Nano.

Thanks again for your generosity so far, and look for the final donations tally later in the week! More science coming up tomorrow…

BBC apologizes for promotion of misleading HIV denial film, “Guinea Pig Kids”

For those of you who might not brave the comments threads on any HIV post, you may have missed this tidbit of information. I’ve written about “investigative journalist” Liam Scheff previously; he’s an HIV “dissident” and author of a story from a few years back titled “The House that AIDS Built”. In this, he claimed that HIV+ children had been removed from their parents’ homes and force-fed “toxic” drugs to treat their condition (which of course, he claims is based on “inaccurate” HIV testing in the first place):

The drugs being given to the children are toxic – they’re known to cause genetic mutation, organ failure, bone marrow death, bodily deformations, brain damage and fatal skin disorders. If the children refuse the drugs, they’re held down and have them force fed. If the children continue to resist, they’re taken to Columbia Presbyterian hospital where a surgeon puts a plastic tube through their abdominal wall into their stomachs. From then on, the drugs are injected directly into their intestines.

This story was picked up as the basis for the 2004 documentary “Guinea Pig Kids,” an independent movie which was aired by the BBC–a move they now are apologizing for after an intense investigation into the claims made by the movie, and the people involved in creating it. More after the jump…
Continue reading “BBC apologizes for promotion of misleading HIV denial film, “Guinea Pig Kids””

Newly discovered Ebola viruses: filling in gaps in viral ecology

It’s only taken 30 years, but information about Ebola in nature is finally starting to snowball. First, after almost 15 years of disappearing from the human population, Ebola returned with a vengeance in the mid 1990s, causing illness in 6 separate outbreaks in Gabon, Ivory Coast, Democratic Republic of Congo (DRC), and South Africa (imported case) between 1994 and 1996. As doctors and scientists rushed in to contain the outbreaks, they were also able to collect viral samples, and trap animals and insects in the area, searching for a reservoir for the virus. In this decade, there have been almost yearly outbreaks of Ebola and/or the closely related Marburg virus in Africa, resulting in the discovery of both Ebola and Marburg infection in species of fruit bats–suggesting these animals may be a reservoir species for filoviruses (though more work remains to be done to confirm this).

As I blogged about previously, prior work has suggested that the most deadly Ebola subtype, known as Ebola-Zaire (EBO-Z) after its initial site of isolation, has been spreading steadily eastward across the central African continent. This was tracked by examining isolates of the virus obtained during human epidemics, which introduces a bias into the sample. However, viral isolates from other sources have been quite difficult to obtain, despite many years of searching. A new paper examines viral isolates collected from dead gorillas and reconstructs their phylogeny in an effort to fill in some of these gaps; more after the jump.
Continue reading “Newly discovered Ebola viruses: filling in gaps in viral ecology”

DonorsChoose: over the halfway mark

The DonorsChoose drive here at ScienceBlogs is just over halfway finished. My challenge is almost 50% funded, with $952 raised so far as I write this and donations from 10 of you out there (and thank you very much for that). There’s still quite a ways to go, however, and many incentives to get there. For one, DonorsChoose will kick in additional money for anyone who meets their challenge goal, so that’s great for the kids; and second, Seed is offering a number of prizes for donors (and especially for donors to my challenge, copies of “Vaccine” by Arthur Allen). If you’ve donated already and haven’t registered for any prizes, send along your receipt to for the Seed prizes, or to for a copy of “Vaccine.”

I’ve highlighted several of the projects I’m supporting here already (and 3 of them are now fully funded!), so I’ll take today to describe the last two.

Putting the “Why?” in Science

Needs: $341 (27% funded)
Asking for: Basic supplies for an 8th grade class: graduated cylinders, beakers, filter paper, eye droppers, proto-slo solution, petri dishes, markers, and paper.

The curriculum we study is so exciting and includes geologic history, the hydrosphere, chemistry and microbiology, however, I need the resources to help me teach these subjects and I’m missing the basics right now. I’ve done my best to buy what I can afford for my classroom, but would love to have some real science equipment for my students to use.

The Human Body: Learning by Heart!

Needs: $165 (0% funded)
Asking for: stethoscopes and blood pressure cuffs for middle school class

As part of a unit on the circulatory system, I would love to have my students be able to listen to their heartbeat and determine their blood pressure under different conditions. Students learn science best when it is hands-on and personal, and what could be more personal than actually hearing their own circulatory system in action?

Funding these projects would impact 340 students this year, and more in years to come. There are also additional projects still in need of funding at my challenge if those don’t interest you; again, no amount is too small, and they all add up.

Mail harmless bacteria, go to jail

Being a microbiologist can be a dangerous business. Some of us work out in the field, exposed to weather, animals, and pathogens of all different forms. Some do research in countries with unstable governments, collecting samples and tracking down infected individuals in the midst of strife, poverty, and warfare. Some remain in the lab, but share it with agents that can be handled only under high levels of containment, and may need special labs and permits just to do their research. We all realize our job contains some level of risk, and do what we can to minimize that.

However, as much as we try to protect ourselves against biological dangers, we can’t wall ourselves off from every form of risk, especially if it comes at us from unexpected places–like those who are supposed to keep the public safe. Since 9/11, the government has invested a huge amount of resources into research on pathogens that have the potential to be biological weapons (at the expense of basic research into other, more “mundane” pathogens), and scrutiny of all things microbiological has increased dramatically. This has caused scientists to get caught in the crosshairs, such as Thomas Butler, a microbiologist at Texas Tech who worked on Yersinia pestis (the bacterium that causes bubonic plague) among other organisms.

After initially being investigated for charges including bioterrorism (later dropped) following his report of missing bacterial vials, he was sentenced to 2 years in prison for a collection of other charges unrelated the original incident, producing a chilling effect upon the microbiology community: no one is safe from prosecution, and even a simple mistake can land you behind bars, stripped of your job and defending yourself with your retirement savings.

This isn’t the only case like this, either. Just last week, a University of Pittsburgh geneticist, Robert Ferrell, plead guilty to charges of failing to follow proper procedures in mailing samples, after being investigated initially for charges related to bioterrorism that were dropped (similar to the Butler case), and another professor awaits trial; more after the jump.
Continue reading “Mail harmless bacteria, go to jail”