E. coli
mikethemadbiologist | May 4, 2007No, KPC isn't a new fast food restaurant. It's short for Klebsiella pneumoniae carbapenemase. The bad news: it's very hard to treat. The good news: it's very rare...for now.
Actually, the correct term is KPC-possessing K. pneumoniae*, but we'll just use the slang 'KPC'--it's what all the cool microbiologists use (I'll refer to the carbapenemase gene as the 'KPC gene'). KPC causes pneumonia, urinary tract infections, and sepsis; the mortality rate from these infections is extremely high.
The KPC gene confers resistance to all cephalosporins and Ã-lactam antibiotics: basically,…
mikethemadbiologist | May 2, 2007Yesterday, the NY Times had an article about using vaccination to eliminate or greatly reduce E. coli O157:H7 infections. Strategies differ: some would vaccinate the cows, while others would vaccinate people. The new threat due to E. coli O157:H7 isn't from contaminated meat, but from contaminated vegetables, such as the spinach outbreak. Unfortunately, I don't think vaccination is going to work.
We'll ignore the notion that if we were to institute a mass vaccination campaign of either cattle or people, we might want to target something that kills more than 61 people per year, and, in…
mikethemadbiologist | April 19, 2007'E. coli conservatives' is Rick Perlstein's phrase, not mine. After all, the Mad Biologist is quite partial to E. coli; I suppose that makes me an E. coli liberal. Most E. coli, including those isolated from retail meats, are not harmful, so I've always thought the bug gets a bad rap. Only a minority of strains cause intestinal disease (e.g., Shigella), unless they wind up in a place they're not supposed to be, such as the bloodstream or urinary tract. These strains, known as 'ExPEC', which is short for 'extra-intestinal pathogenic E. coli', are only a small, albeit nasty, percentage of…
mikethemadbiologist | April 13, 2007While I'm not as bothered by the Pope's statement about evolution as PZ is, what's troubling is the scientific misunderstanding shown by his statements.
I agree with one sentiment, which is that biology doesn't tell us much about meaning, since I think meaning is something we ascribe to physical reality (and events). Many biologists have made much philosophical and ethical hay of the common ancestry of humankind, so it's certainly reasonable for the Pope (or anyone else) to do so. What is really disturbing is how ignorant he is of modern biology and science. According to the Pope:
"The…
mikethemadbiologist | April 10, 2007I've mentioned the National Antimicrobial Resistance Monitoring System (NARMS) before. Today, I'll be attending the NARMS public hearing which is going to discuss four questions:
1) Why, on this night
1) Are there inherent biases in the sampling strategies employed in NARMS? If so, how can they be improved to ensure that the data and interpretation are scientifically sound given current resources?
2) Are there epidemiological and/or microbiological research studies that would better serve the goals of NARMS and the regulatory work of FDA?
3) Are current plans for data harmonization and…
mikethemadbiologist | March 19, 2007There's an interesting news story about antibiotic resistance in wild chimpanzee populations that claims to have found transfer of resistant Escherichia coli from humans to wild animals.
According to the article:
To do the study, the UI researchers, working with colleagues from Makerere University in Uganda and McGill University in Canada , examined 2 of the communities of chimpanzees living in the Kibale park. One of them has been under study by scientists for more than 2 decades. The other is visited regularly by ranger guides who shepherd tourists in the park. The researchers collected…
mikethemadbiologist | March 14, 2007You might not know this, but your body produces a whole bunch of antibacterial compounds, one of which is lactoferrin. It's found in breast milk and mucosal substances such as tears and saliva. Lactoferrin hasn't really been investigated as a medical antibiotic because many disease-causing bacteria (e.g., E. coli) also live on (and in) people as harmless commensals, and consequently, have evolved resistance to lactoferrin. However, a new paper suggests that some lactoferrin might kill these pathogens.
The authors found that people with a single amino acid change in lactoferrin "were more…
mikethemadbiologist | March 9, 2007There's something very interesting about the unfolding story of the possible FDA cefquinome approval (I've covered it here). After doing a Technorati search, virtually all of the blogs that discuss this issue are either non-partisan or progressive/liberal (I say 'virtually' because I might have missed one, but I actually didn't see any). The rightwing bloggysphere is nowhere to be found. Any thoughts on why that might be? Maybe they are just slow off the mark on this one? Infections don't check political affiliation....
mikethemadbiologist | March 1, 2007It sure looks that way. Last night, I was talking to a colleague and he told me that several groups, including his, are seeing a very interesting pattern in commensal Escherichia coli (those E. coli that live in everyone's gut and aren't making us sick).
In humans, it appears that roughly 20% of all commensal E. coli belong to one of three clones that have a global distribution (in bacteriology, a clone is a group of very closely related strains). (an aside: In animals, there doesn't appear to be this skewed pattern. In animals, the distribution of clones appears to be more evenly…
mikethemadbiologist | February 15, 2007I've blogged before about how, for children under five, it's not the 'sexy' microbes that kill, but instead, the run of the mill ones: the bacteria that cause diarrhea and pneumonia are the culprits. One of the things I have heard a lot of recently regarding antibiotic development (and related therapies) is that we need to focus on 'non-paradigm' and non-model organisms. There's a problem with that approach:
The non-standard microbes aren't the ones causing the bulk of bacterial disease.
Oh dear.
In roaming around the International Society for Microbial Resistance website, I came across…
mikethemadbiologist | January 18, 2007In the developed world, shigellosis, a diahrreal disease caused by the bacterial species Shigella, typically isn't considered dangerous, even though it makes about 450,000 ill in the U.S. To shorten the length of illness and to reduce potential infection of other people, antibiotics are typically prescribed, usually cotrmoxazole or ampicillin. However, recent shigellosis outbreaks are cause for concern (italics mine):
Surveillance data for antimicrobial resistance among all S. sonnei isolates received by NARMS during 1999--2003 indicated that 80% of the isolates were resistant to ampicillin…
mikethemadbiologist | December 1, 2006One of the constant refrains I always hear is that diarrheal diseases, such as shigellosis, cholera, and other bacterial dysenteries, could be easily solved if there were adequate potable water and sanitation. That's completely correct. It's also completely unrealistic, as a recent editorial by Lorenz von Seidlein in Tropical Medicine & International Health argues.
The problem is that this 'ultimate' solution of massive infrastructure investment often means that foreign governments and NGOs are discouraged from effective, short-term solutions. One such solution is the oral cholera…
mikethemadbiologist | November 16, 2006A few weeks ago, an FDA expert panel by a vote of 6-4 decided against the approval of the use of the antibiotic cefquinome in cattle. Unfortunately, I've heard through the grapevine that the political appointees at the FDA plan to overrule the expert panel and approve the use of cefquinome. The chairman of the panel is under pressure to alter the panel's findings, and the FDA has not posted the minutes of the meeting, which is apparently required by law.
About the post title: cefepime, like cefquinome, is what is known as a fourth-generation cephalosporin antibiotic. While cefquinome is…
mikethemadbiologist | September 20, 2006A CDC website lays out how we actually identify an outbreak of O157:H7. Guess what? It doesn't happen like it does in the movies or on TV. This is why keeping these networks fully functional (i.e., adequately funded) matters: time is critical and delays in processing due to inadequate resources or personnel can be deadly. For kicks, imagine if this were something far more contagious than a food-borne pathogen.
Here's the timeline:
1. Incubation time: The time from eating the contaminated food to the beginning of symptoms. For E. coli O157, this is typically 3-4 days.
2. Time to…
mikethemadbiologist | September 18, 2006Over at Viva la Evolucion!, there's a new edition of Animalcules, the Carnival o'the Wee Beasties. I have a post there. There's also a really good post about Vibrio cholerae--the critter that causes cholera.
mikethemadbiologist | September 15, 2006
(from here)
There's been an outbreak of E. coli food poisoning due to contaminated lettuce. This gives me an opportunity to briefly talk about one of my favorite organisms, Escherichia coli. But first, from the AP:
Consumers nationwide should not eat fresh bagged spinach, say health officials probing a multistate outbreak of E. coli that killed at least one person and made dozens of others sick.
Food and Drug Administration and state officials don't know the cause of the outbreak, although raw, packaged spinach appears likely. "We're advising people not to eat it," said Dr. David Acheson…
mikethemadbiologist | August 4, 2006One of the lesser known microbiology facts is that the pathogen Shigella is actually E. coli. From the archives, here's an explanation (with a little modification).
As I mentioned in a previous post, Orac has two very good posts on MDs and creationism. In one of the posts, he links to a creationist medical student who writes the following:
Has anyone ever documented a plateful of Strep pneumo mutating into E coli? Or even into Strep pyogenes? I didn't think so. They mutate, and they exchange information. But they remain separate species, with their own unique characteristics. Staph aureus…