Various bacteria
tsmith | April 24, 2006So, I've had this research article on multiple drug-resistant Salmonella in the drafts section for about a week now, waiting for me to do a bit of background research before commenting on it. (Anything involving Salmonella always makes me a bit hesitant--one almost needs a PhD on the bacterium just to keep up with the nomenclature). This morning I'm doing my quick glance-through of my blogroll, and lo and behold, what do I find but these posts by Mike the Mad Biologist, who just happens to have been quoted in the New York Times write-up of the research.
Michael Feldgarden, who helps…
tsmith | April 21, 2006California woman hospitalized with plague
Health officials in Los Angeles have confirmed the city's first human case of bubonic plague in more than two decades.
They say a woman, who was not identified, was admitted April 13 with a fever, swollen lymph nodes and other symptoms. A blood test confirmed she had contracted the bacterial disease. Officials said she was placed on antibiotics and is in stable condition.
Though this case is notable because it's the first one reported in Los Angeles in decades, plague is endemic in many areas of the United States, though it's infrequently transmitted…
tsmith | April 13, 2006 Okay, so I lied. I was planning to wrap up the emerging diseases and zoonoses series with the post on monkeypox, but I think I'll just continue it as a sporadic event, since a new paper fits into the series perfectly.
I talk a lot here about streptococcus. As regular readers know, there's a good reason for that. Though my main research right now is on Streptococcus agalactiae (group B streptococcus, GBS), I also have a project working on a related organism, Streptococcus suis. As the "suis" name suggests, this is mainly a pathogen of swine. Indeed, it's kind of the pig equivalent of…
tsmith | April 12, 2006 A new study in the journal Pediatrics suggests this common procedure may improve the condition of kids diagnosed with attention defecit/hyperactivity disorder (ADHD). I think it's an excellent case of some true "alternative explanations" for the data.
Creationists often try to validate their position by saying that both they and mainstream scientists start from the same data, but that creationists use their "Bible glasses" to interpret it, while scientists view it through their "evolution glasses." In other words, they're not wrong--it's just a different interpretation of the same data,…
tsmith | April 10, 2006I wrote previously about a recent study that found all sorts of bacterial diversity in a place once thought to be rather barren--the human stomach. One of the species they discovered appeared to be related to an extremophile--microbes that live in extreme environments (in this case, a relative of one that could withstand incredibly high doses of radiation). A new story from the BBC reports the discovery of another extremophile in a place one may not expect it (or at least, may not expect the one they found):
Researchers have found traces of a heat-loving bacterium that may live beneath a…
tsmith | April 6, 2006 Last week's Nature had an article on yet another example of poor design: mitochondrial diseases. Mitochondria are the organelles within eukaryotic cells that provide the energy for the cells. Once free-living bacteria, the precursors of mitochondria were engulfed by larger cells billions of years ago. Since that time, mitochondria have lost much of their genome--only 37 genes remain in human mitochondria. Many have ended up in the host nucleus, leaving the mitochondria dependent on the host cell for much of their processes.
Mutation rates of mitochondrial genes are 10-20 times higher…
tsmith | April 5, 2006...but just haven't had the time to do more extensive write-ups. So, a mini carnival of good stuff:
First, as other Sciencebloggers have noted, Seed is sponsoring a writing contest. $1000 dollar top prize and publication in Seed to the winner.
Cervantes at Stayin' Alive writes about the cost of pandemic preparedness--you might be surprised that it's, well, nothing so far. You get what you pay for?
Joseph has a post on Ebola examining the claims made by Eric Pianka that have received so much attention lately.
Some Ohio infectious disease news: tuberculosis found in illegally-transported…
tsmith | April 2, 2006 Joseph over at Immunoblogging has two posts on Mycobacterium bovis and gives a potential answer to Dave S.'s question here. In post one, Joseph notes (after the fold):
It's interesting to note that Mycobacterium bovis, which infects farmed animals dates back roughly to the time we domesticated animals proving that for a change, we gave one of our pathogens to an animal and not the other way around.
In part two, Joseph discusses mycobacteria in general, and why M. bovis is a threat to farm economies.
Part three discusses the role badgers play (or don't) in the transmission of M. bovis to…
tsmith | March 27, 2006Part One: Introduction to Emerging Diseases and Zoonoses
Part Two: Introduction to Emerging Diseases and Zoonoses continued
Part Three: Bushmeat
Part Four: War and Disease
Part Five: Chikungunya
Part Six: Avian influenza
Part Seven: Reporting on emerging diseases
Part Eight: Disease and Domesticated Animals
Part Nine: The Emergence of Nipah Virus
Part Ten: Monkeypox
Part Eleven: Streptococcus suis
Part Twelve: Salmonella and fish
Part Thirteen: new swine influenza virus detected
Part Fourteen: dog flu strikes Wyoming.
Part Fifteen: Clostridium species.
Part Sixteen:…
tsmith | March 17, 2006 Is Crohn's disease caused by Mycobacterium avium pseudotuberculosis (MAP)?
In an article out yesterday, Australian Dr. Thomas Borody claims yes, and that the medical community is simply too "stuck in their ways" to admit it. I explain below why I think this is incorrect--or at least, premature.
I mentioned several times in the various AIDS threads and in the prostate cancer/virus thread that it's often difficult to determine an infectious cause of a so-called "chronic" disease. Not only is there generally a time lag between infection and disease development, but it may be that only…
tsmith | March 15, 2006Tim Lambert over at Deltoid notes Dunk malaria day is coming up this Sunday, and has offered to match donations (up to $300 total) readers make to The Global Fund to fight AIDS, TB, and malaria. Very cool--I'm kicking in a few bucks for a good cause--if you do the same, drop a line at Tim's blog.
tsmith | March 6, 2006I meant to plug this last week: RPM at Evolgen has a post on microbial diversity in the gut, referencing a new Cell paper.
I was going to write up this paper on MRSA within amoebae, but haven't had time. I still might do a more extensive commentary, but Joseph has a few words on it.
tsmith | March 6, 2006Okay, my morning meeting went a bit faster than expected so I can sneak in a quick post before my first lecture. We were discussing infectious causes of cancer here. I received an email stating how "inconsistent" I was by asserting that a disease could be infectious but not contagious. So, rather than keep giving more examples of other chronic diseases that develop due to an infectious agent, I thought I'd take a different approach (after the jump...)
Y'see, as I've mentioned before, one of my interests is planning for any kind of major infectious disease outbreak--which includes…
tsmith | March 3, 2006The Infectious Disease Society of America (IDSA) has released a list of the six drug-resistant pathogens scientists should be most concerned about.
The AATF (Antimicrobial Availability Task Force) created a list of high-priority bacterial and fungal pathogens on the basis of ⩾1 of the following characteristics: current clinical and/or public health concern in the United States because of a high incidence of infection and substantial morbidity; infection with high attributable mortality rates, even if the population-based incidence is low (e.g., the majority of infections occur in…
tsmith | February 27, 2006I'm swamped today, so alas, nothing new from me. However, since many of you are newer readers, I thought I'd totally cheat and dig up one from the archives on antimicrobial resistance. This one I cross-posted to Panda's Thumb where it received some decent discussion; it was also mentioned in a write-up of Panda's Thumb featured in Science magazine. I also find it very fitting since we have a number of commenters discussing a number of things microbes "can't" do, as the post tells the story of one scientist who made a similar comment, was taken up on that, and proven wrong.
Resistance…
tsmith | February 26, 2006Necrotizing fasciitis (the so-called "flesh-eating disease") is a rare manifestation of infection with the group A streptococcus (Streptococcus pyogenes, though occasionally other bacteria cause it as well). Apparently, it's been a banner year for the infection in Boulder, Colorado. The Daily Camera (registration required) has the story:
Sixteen months after University of Colorado physicist Eric Cornell lost his left arm and shoulder to a rare, invasive form of strep A, at least three more otherwise healthy Boulder residents have been stricken by the same disease in the past four months.…
tsmith | February 12, 2006As PZ mentioned, today would be Charles Darwin's 197th birthday. To celebrate, Mike over at The Questionable Authority is putting together a mini-carnival of posts on evolution. Specifically, he asked how those of us who are scientists use evolutionary theory in our work.
Personally, I'm a bit of a hybrid. I'm a microbiologist by training (my PhD is in microbial pathogenesis and gene regulation), but I loved epidemiology as an undergrad, and so did post-doctoral work in that area--and now am officially titled and "infectious disease epidemiologist". But, I'm still a lab rat rather than…
tsmith | January 30, 2006Okay, not to overwhelm with Streptococcus biology, but I mentioned this new paper in the comments to this post, and had to share a bit of the results, because 1) it's just cool, and 2) it directly stems from some of the research I did for my dissertation. (Always a bonus when someone else can actually *use* stuff you slaved over).
A bit of background: I noted that Streptococcus pyogenes is a tough pathogen to study. Strains of the bacterium may vary in the presence or expression of virulence genes, and even when one insight into the regulation of these genes is uncovered in one strain,…
tsmith | January 5, 2006Microbial ecology, and its relation to the development of infectious disease, is an ever-growing field of study. Of course, there are a vast number of bacterial species living amongst us, most of which do not cause us any harm. Others may infect us only when, so to speak, the stars align in a certain manner: when a number of factors collide that result in the development of a diseased state. For instance, we may already be immunocompromised due to the presence of another infection--something minor, such as a rhinovirus, or something more serious, such as HIV--and this chink in our armor…
tsmith | December 24, 2005NHANES is an abbreviation that's quite familiar to epidemiologists of all stripes: the National Health and Nutrition Examination Survey. This survey dates back to 1956 with the passage of the National Health Survey Act, providing legislative authorization for "a continuing survey to provide current statistical data on the amount, distribution, and effects of illness and disability in the United States." Generally, information from these surveys has been used to look at the effect of nutrition, particularly micronutrients, on the health status of the population, or subgroups within the…