Various bacteria
tsmith | January 26, 2007 Speaking of microbiology basics, along comes an article in the San Diego Union-Tribune about the petri dish, a staple of microbiology labs everywhere:
Before 1877, scientists exploring the nature and mechanics of microscopic life had a real problem. Bacteria used for study were typically cultured or grown in bottles or bowls of broth. Koch greatly improved the situation by developing ways to grow microbes in gel, which allowed researchers to separate and investigate individual types of bacteria.
But practical problems remained. It was hard to manipulate bacterial colonies through the small…
tsmith | January 25, 2007Like most fields, microbiology is one filled with jargon. Many laymen don't even realize the differences between a bacterium and a virus, much less the smaller differences between, for example, a pathogenic versus a commensal organism. So, while I haven't decided yet exactly what I might write about in future posts, I thought I'd begin with a very general microbiology primer to get everyone up to speed on the basics of the microbial word.
To begin with, in the "well, duh" category, microbiology is the study of very tiny life. Initially, those studied were mainly disease-causing organisms;…
tsmith | January 24, 2007I've previously mentioned a bacterial pathogen called Acinetobacter baumannii (a bit more information here), and Mike has discussed it rather frequently. A. baumannii is ordinarilly a commensal bacterium--one that may live on the skin of healthy people for many years without ever causing disease. It becomes a problem when one is immunocompromised in some manner, and unable to keep growth of the bacterium in check. Once this happens, it's difficult to reverse, as the bacterium brings new meaning to the term "antibiotic resistant." As Mike blogged previously, a genomic analysis revealed…
tsmith | January 23, 2007 As I described previously in this post, war and disease are inextricably intertwined:
War and its concomitant devastation and social upheaval leaves its victims at an increased risk of disease transmission to begin with due to poor sanitation, collapse of public health and medical facilities and support personnel, crowding in refugee camps, breaks in supply chains of food, medicine, and other necessary items, malnutrition and depression, and other factors.
This social upheaval frequently lasts much longer than the actual fighting. Additionally, in some cases where areas have been…
tsmith | January 22, 2007An essential piece of trivia: what bacterium was named after a George Lucas invention?
An investigator discovers a new bacterium that lives in the mitochondria in tick ova. Can you guess what Star Wars organisms they're named after?
Soon, Lo and his colleagues began looking for a name for their new genus, which proved easier said than done. The morphology of the organism didn't present any immediate clues, and there weren't any eminent tick bacterium researchers in whose honor it could be named.
So Lo started surfing the Web, looking for ideas and finding nothing until one link took him to…
tsmith | December 21, 2006Ho ho ho, and welcome to the early Christmas edition of Animalcules. Sit back, grab some hot cocoa, and click below to open your Christmas gift of some of the most interesting microbiology-themed blog posts over the past month.
To start us off with, in a new blog to me (the Cornell Mushroom blog), we learn how a fungus assists in the transmission of a nematode from the environment to the host--in this case, cattle. It's a fascinating example of commensalism.
From the same blog comes another post on Batrachochytrium dendrobatidis (or Bd), a fungus which is a cause of skin infections in…
tsmith | December 12, 2006 I've written previously about how it's a bad idea to import exotic pets, after "exotic" African species of small animals were imported into the United States and housed alongside prairie dogs that were also to be sold as pets. The African animals brought along with them their own diseases, including monkeypox, which then spread to the prairie dogs and onto humans, causing at least 80 cases of monkeypox in the U.S.
Think this is a rare event, unlikely to re-occur? Think again. The Baltimore Sun has a story on how "exotic" pets like these African rodents enter the U.S. by the millions…
tsmith | December 1, 2006Revere over at Effect Measure has an excellent post linking together the current bird flu situation with John Snow's investigations of 19th century cholera outbreaks. It's an interesting take on the situation--check it out.
tsmith | November 30, 2006Esther Lederberg dies at 83
Stanford University microbiologist Esther Miriam Zimmer Lederberg, a trailblazer for female scientists and the developer of laboratory techniques that helped a generation of researchers understand how genes function, has died at Stanford Hospital.
Professor Lederberg, who lived at Stanford, was 83 when she died Nov. 11 of pneumonia and congestive heart failure.
She discovered the lambda phage, a parasite of bacteria that became a key tool for the laboratory study of viruses and genetics, and was the co-developer with her husband [Nobel prize winner Joshua…
tsmith | November 16, 2006 I was just lecturing yesterday on streptococci, and discussing how the diseases caused by the group A streptococcus (Streptococcus pyogenes). This is the bacterium that causes diseases as varied as "strep throat," streptococcal toxic shock syndrome, and necrotizing fasciitis (aka the "flesh-eating disease.") It's also caused historical epidemics of scarlet fever, a major scourge in many countries from the mid-1800s or so until around the turn of the century, when it started to wane for no apparent reason. (The worry over this illness was captured in Margery Williams' 1923 book, "The…
tsmith | October 24, 2006Orac has an excellent post discussing the rise in pertussis ("whooping cough") in many areas, and its correlation with easier exemption from mandatory vaccination (using a "personal belief" exemption in addition to a religious exemption, for example). I've written about pertussis previously, and a problem is that the vaccine effectiveness quickly wanes, so that adults frequently lack significant immunity. While we rarely get sick, we can be carriers of the bacterium and infect children around us. As such, new recommendations suggest that adults also should get a pertussis booster. I worry…
tsmith | October 23, 2006Apologies for the radio silence, so to speak. October has been a killer month for me and November won't be that much better, but I'll work on getting back to posting on a regular basis, including a new post for tomorrow. In the meantime, a few things to check out:
Mike on treating strep throat (which he's correct is near and dear to my heart--though not literally, thankfully, since they can cause heart disease!).
A belated Friday the 13th Tangled Bank
Last week's Grand Rounds.
tsmith | October 6, 2006Toddler's death blamed on E. coli, officials say
Heartbreaking.
As federal agents launched a criminal investigation into two produce companies involved in the contaminated spinach outbreak, Idaho health officials confirmed the death of a 2-year-old boy Sept. 20 was caused by tainted spinach.
Kyle Allgood was the second confirmed death in the E. coli outbreak, which also killed a Wisconsin woman.
The boy, who would have turned 3 in December, died in Salt Lake City after developing a type of kidney failure caused by E. coli. Health officials had to wait for the results of genetic testing on the…
tsmith | October 3, 2006I write on a somewhat regular basis on here about vaccines: new research, new shots, addressing skepticism about how well they work or if they're related to autism, etc. Recently, several vaccine stories have been in the news that I've not gotten to yet, so consider this a vaccine meta-post. More after the jump.
The first story is timely in that it discusses the influenza vaccination (and we're heading into that season). Allow me to share an anecdote first. When I was pregnant with my daughter in 1999, I was in graduate school and the lab I worked in was affiliated with a hospital. So…
tsmith | September 29, 2006Nina Plank, the author of the NY Times article I commented on in this post, stopped by to comment. Rather than just having this lost in the comments to a week-old post, I wanted to take a moment and quickly address two of her points (with potentially a follow-up post next week when I have a bit more free time).
First, to Nina, thanks for stopping by. I'll just say that I very much disagree with your stance on raw milk and dairy. Indeed, contamination can also happen after pasteurization and nothing replaces vigilance, but having seemingly healthy cows is no guarantee of healthy milk.…
tsmith | September 26, 2006I was travelling over the weekend and I'm incredibly busy up through Wednesday, so new material from me will have to wait until later in the week. In the meantime, I'll point you to a stellar post I wanted to highlight last week, from Revere on H5N1 and the evolution ov virulence, and another excellent one from Mike regarding the importance of surveillance when it comes to detecting and containing outbreaks (such as the recent O157 outbreak). He also describes a timeline for how long many of the common procedures take; quite a bit different from what you get watching CSI or similar shows…
tsmith | September 21, 2006 That's certainly the claim in a new New York Times editorial (via The Frontal Cortex). The author, Nina Planck (author of Real Foods: What to Eat and Why), claims that it's as easy as just feeding cattle grass, and poof!--E. coli O157 will vanish.
More on this and why organic farming won't necessarily stop such outbreaks after the jump.
Planck writes:
Where does this particularly virulent strain come from? It's not found in the intestinal tracts of cattle raised on their natural diet of grass, hay and other fibrous forage. No, O157 thrives in a new -- that is, recent in the history of…
tsmith | September 20, 2006David over at Orcinus has an excellent post reminding about the anniversary of the that passed largely without mention, and its stark contrast to the anniversary of 9/11.
...today also marks the fifth anniversary of the terrorist attacks that followed -- the anthrax letters mailed to a variety of media figures and liberal senators, killing five people and convulsing the nation with fear of similar attacks elsewhere for several weeks afterward.
But there are no network specials planned. No wreath-laying by the president. No ABC docudramas blaming the Clinton administration with made-up…
tsmith | September 19, 2006From the New York Times:
The last of the anthrax-laced letters was still making its way through the mail in late 2001 when top Bush administration officials reached an obvious conclusion: the nation desperately needed to expand its medical stockpile to prepare for another biological attack.
The result was Project BioShield, a $5.6 billion effort to exploit the country's top medical and scientific brains and fill an emergency medical cabinet with new drugs and vaccines for a host of threats. "We will rally the great promise of American science and innovation to confront the greatest danger of…
tsmith | September 18, 2006And who said spinach was boring?
If the ongoing E. coli outbreak due to spinach has done one thing, it's highlight the mystery that revolves around Salinas, California:
The sunny Salinas Valley holds a dark mystery: Why, in the past decade, have nine Escherichia coli outbreaks been linked to produce grown here?
It's still unknown why this fertile land has been hit by what an FDA official calls "significant" crop contamination.
Throughout the picturesque terrain here, questions swirl.
Has cattle waste contaminated irrigation water? Does contaminated soil blow in the wind? Do birds feeding on…