antibiotics

I think I was a little too optimistic about MRSA (methicillin resistant Staphylococcus aureus) in pigs staying in pigs and not spreading to humans. A recent study in the Netherlands found that people exposed to pigs were 1000 times (yes, one thousand) more likely to be MRSA carriers than the general population, and the MRSA strain was usually the 'pig' strain. What does this mean? The authors conclude: After introduction of the new MRSA risk category in a hospital [Mad Biologist: screening those in contact with farm animals], which is located in a region with a relatively high density of…
Yesterday, I posted about how feral pigs might be responsible for the spinach-associated E. coli O157:H7 outbreak. A while back, I described the epidemic spread of a new strain of MRSA throughout pigs in Europe. What was puzzling to me was why this MRSA strain, found at forty to sixty-fold greater frequency than all commensal MRSA in humans hadn't entered the human population. A recent paper in Emerging and Infectious Diseases lays out one possible reason--this strain of MRSA does not grow well on retail meat (which is thought to be a major conduit of strains from the farm to humans): A…
The NY Times has an article about the MRSA (methicillin resistant Staphylococcus aureus) strain that is spreading rapidly among gay men. One factor is that a subset of the gay population is immunocompromised due to HIV, and consequently, is more likely to acquire MRSA skin infections. This strain is very drug resistant, unlike most community-acquired MRSA ('CA-MRSA'). Most CA-MRSA, while resistant to methicillin, is sensitive to clindamycin. However, this strain has acquired a plasmid (a transferable 'mini-chromosome') that confer resistance to commonly-used drugs to treat MRSA: "This…
You would think after the sound thrashing Michael Egnor received due to his mangling of the basics of evolutionary biology, the Discovery Institute might want to find someone else to quote in a guide for students. Nope: "Microbiology tells us that bacterial populations are heterogeneous. Individual bacteria differ from one another. Molecular biology tells us that some bacteria have molecular mechanisms by which they can survive antibiotics. Molecular genetics tells us how these resistance mechanisms are passed to other bacteria and through generations of bacteria. Pharmacology helps us…
Beta-lactam antibiotics, penicillin and all of its subsequent derivatives, are critical, life saving drugs. One way bacteria protect themselves from these antibiotics is by producing enzymes known as beta-lactamases that cleave the beta-lactam, rendering the beta-lactam antibiotic harmless. There are many different kinds of beta-lactams (such as CTX-M), and they differ in how common or rare they are. A recent study examined looked at the role fitness might have in making TEM class beta-lactamases very frequent and found in many different species, and keeping SME class beta-lactamases rare…
...and scuttle one of the best efforts going to reduce the problem of antibiotic resistance. I discussed before how the antibiotic resistance problem is, in the context of hospital infections, an infection control problem: One of the hidden stories in the rise in the frequency of antibiotic resistant bacterial strains is that this has also been accompanied by an absolute increase in the number of infections. In other words, it's not the case that you used to have 90 sensitive infections and 10 resistant infections per year in your hospital, and now, you have 50 sensitive and 50 resistant…
By way of Amanda, I came across this NY Times op-ed by Michael Pollan that discusses the role of agribusiness' misuse of antibiotics in the rise community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA). I've talked about the MRSA 'pig epidemic' before, and, Intelligent Designer knows I've talked about the misuse of antibiotics in agriculture, such as the attempt to get cefquinome approved for use in agriculture (Sack, met Mr. Stupid and Ms. Hammers). But I'm not sure that Pollan is correct about this. The strain of CA-MRSA found in pigs is nothing like those found in healthy…
While the most recent misrepresentation of antibiotic resistance at Answers in Genesis by Georgia Purdom is not of the two usual varieties (either resistance evolves through gene transfer, and therefore mutation does not cause antibiotic resistance, or resistance arises through mutations only, and so mutations can't lead to novel 'kinds'--yes, creationists are that stupid), it's still pretty bad, and it shows a profound ignorance of recent work in the field of antibiotic resistance. Purdom writes: The mechanisms of mutation and natural selection aid bacteria populations in becoming resistant…
Suppose US agribusiness food animals were being fed a poison that killed a few tens of thousands of Americans a year. Would we want them to stop? Maybe we weren't sure but had more than ample grounds for suspicion. Would we want scientists and the government to be looking into it and maybe even halting it until we had a clear answer? I would hope so. But that seems to be the situation with antibiotics and factory farming. Yesterday we posted about the discovery by Dutch scientists that methicillin resistant Stophylococcus aureus (MRSA) had a home and probably an origin in pigs and cattle in…
The Charge of the Light MRSA Brigade A few months ago, I discussed an article that demonstrated that pigs had ridiculously high frequencies of MRSA. ScienceBlogling Revere discusses another paper about pigs and MRSA. Like the previous study (published by some of the same authors), several of the same conclusions can be drawn: These are astronomical rates of MRSA, relative to anything outside of a clinical setting--and the Netherlands' MRSA frequency is an order of magnitude lower than the U.S. One piece of evidence argues for the hypothesis that the use of antibiotics in agriculture, either…
In commenting on a post by SA Smith that rebuts (quite well) Behe's latest ID creationist idiocy, tristero writes (bold original; italics mine): But reading Smith's post on HIV evolution, I have to confess I can't for the life of me understand it. Ms Smith, I promise I'll spend some more time on it later and try to puzzle it out; I like that kind of a challenge (and please don't bother rewriting it for civilians, you've got better things to do!). But the tactic Behe is employing worries me, because it is so cynical, and dangerously effective. Essentially, id creationists are slowly trying to…
If don't already know, the world's frog (and other amphibian) populations are facing a massive decline. One cause is an infection by chytridiomycosis, a fungal disease. Scientists in New Zealand have announced that treatment with chloramphenicol, an antibacterial agent can cure chytridiomycosis: Fearful that chytridiomycosis might wipe out New Zealand's critically endangered Archey's frog (Leiopelma archeyi), the researchers have been hunting for a compound that would kill off the disease's trigger, the fungus Batrachochytrium dendrobatidis. They tested the chloramphenicol candidate on two…
I have a week off, so I've been going to the gym in the morning later than usual. I'm still recovering from the near-lobotomization of morning radio, so I wasn't prepared for a report on the "superbug" on Fox's The Morning Show with Mike and Juliet--think of it as a cheap knockoff of Regis and Kelly. Since the sound wasn't turned on for the television, I should have just left it alone, but no, I had to check out the video on the interwubs when I came home. First, anyone who says that evolutionary biologists suck at communicating should watch this bozo. It's a classic example of how not to…
Because this week is really hectic, I just want to follow up on this post I wrote about MRSA. One of the hidden stories in the rise in the frequency of antibiotic resistant bacterial strains is that this has also been accompanied by an absolute increase in the number of infections. In other words, it's not the case that you used to have 90 sensitive infections and 10 resistant infections per year in your hospital, and now, you have 50 sensitive and 50 resistant infections (which would be bad enough). Instead, you have the same 90 sensitive infections and 90 resistant infections (for a…
If you have or have had small children you may be all too familiar with earaches. When our kids were small we felt as if we were single-handedly supporting the amoxicillin makers. A major cause of middle ear infection is the organism Streptococcus pneumoniae (S. pneumoniae), which sometimes it invades other tissues and causes bacterial meningitis (not the kind that you read about killing healthy teenagers, but bad enough) and sometimes other body sites. It is also a cause of pneumonia in adults and was a common cause of secondary bacterial pneumonia in the 1918 flu. That was then. Now there…
Atrios identifies the problem with the Republican choice-based 'vision' of healthcare: Well, really, the Republican vision, as slobbered over by cenrtist [sic] David Broder. In this case, he is visualizing a radically different kind of medical marketplace, in which families armed with specific information about the treatment success and prices of hospitals and doctors can shop at will for the best quality and most affordable care. We pay doctors to make these decisions for us because most of us haven't been to medical school. I know this point is simple and obvious and everyone makes it, but…
According to the Boston Globe, a new study indicates that deaths from the bacterium Staphylococcus aureus ('staph infections') have exceeded AIDS/HIV deaths in the U.S (italics mine): Deaths tied to these infections may exceed those caused by AIDS, said one public health expert commenting on the new study. The report shows just how far one form of the staph germ has spread beyond its traditional hospital setting. The overall incidence rate was about 32 invasive infections per 100,000 people. That's an "astounding" figure, said an editorial in Wednesday's Journal of the American Medical…
We're getting worse at washing our hands according to the Baltimore Sun. One thing I've said many times before, but it bears repeating: the best way to avoid getting sick is to limit contact with someone else who is sick. While that sounds obvious, one very good way to do that is handwashing. Handwashing breaks the 'transmission network' and essentially isolates the sick person. If you view preventing infectious disease as a question of how can I protect myself from disease, then we've already lost. The best measures (vaccination and handwashing) aren't just about protecting yourself,…
During the past few Fridays (or least here and here), we've been looking at a paper that was published from China with some Β-lactamase sequences that were supposedly from Streptococcus pneumoniae. The amazing thing about these particular sequences is that Β-lactamase has never been seen in S. pneumoniae before, making this a rather significant (and possibly scary) discovery. If it's correct. tags: DNA sequence analysis, antiobiotic resistance , microbiology, blastn The way this sequence was identified as Β-lactamase was through a blastn search at the NCBI. And in fact, it was correct to…
...then please take this survey (it's anonymous). The survey designers are trying to understand more about about the concerns of people affected by MRSA. The survey should take about 25 minutes to complete. You can take the survey here. If you know someone who has had a MRSA infection, please forward this link to him or her. Also, if your blog can handle it, please think about posting the link.