antibiotics
lborkowski | April 13, 2012Yesterday, the FDA announced a new program that has the potential to slash the routine use of antibiotics by livestock producers. The routine administration of antibiotics to livestock with no signs of sickness helps animals grow more quickly, but it's also a significant contributor to the rise of antibiotic-resistant bacteria. An estimated 70% of the antibiotics sold in the US are given to non-human animals, and most of them are the same drugs that humans rely on to treat our illnesses.
Gardiner Harris's New York Times article about FDA's announcement bears the exciting (to me, anyway)…
jtoney | February 19, 2012
Ice 9 by toastforbrekkie.
The idea of Ice-9, although fictional, has always fascinated me. Its properties are so powerful, so influential, that one "seed crystal" can direct its entire surroundings, freezing oceans. A recent discovery of one component of the cell wall of bacterium reminded me of this effect. Let me explain.
First:
Ice-nine is a fictional material appearing in Kurt Vonnegut's novel Cat's Cradle. It is supposed to be a more stable polymorph of water than common ice (Ice Ih) which instead of melting at 0 degrees Celsius (32 degrees Fahrenheit), melts at 45.8 °C (114.4 °F…
tsmith | January 19, 2012Back in November, I blogged about one of our studies, examining methicillin-resistant Staphylococcus aureus (MRSA) in Iowa meat products. In that post, I mentioned that it was one of two studies we'd finished on the subject. Well, today the second study is out in PLoS ONE (freely available to all). In this study, we focused only on pork products, and included 395 samples from Iowa, Minnesota, and New Jersey. We also looked at not only conventional meats, but also "alternative" meat products. Most of the latter were products labeled "raised without antibiotics" or "raised without antibiotic…
jtoney | January 12, 2012
The are many reasons not to use recreational drugs and this story is likely one of the scariest.
So called "bath salts," which have nothing to do with bathing, are widely available and legal to acquire. A study that was just published in the journal Orthopedics reveals for the first time a link between use of these salts and the flesh-eating bacteria or necrotizing fasciitis. It is caused by a variety of bacteria including Group A streptococcus (Streptococcus pyogenes), Staphylococcus aureus, Vibrio vulnificus, Clostridium perfringens and Bacteroides fragilis). While these bacteria can…
lborkowski | January 10, 2012At her Superbug blog, Maryn McKenna reports on a disturbing, but not unexpected development: over the past three months, 12 cases of tuberculosis at a single Mumbai hospital have been found to be resistant to all the drugs used to treat the disease.
This is not the first time totally drug-resistant tuberculosis (TDR-TB) has been reported; in 2009, McKenna notes, the disease was identified in 15 patients in Iran. This was only three years after extremely drug-resistant tuberculosis (XDR-TB) was first identified. The drivers of such rapidly evolving drug resistance include inadequate…
mikethemadbiologist | August 19, 2011In this story about the use of rapid genomic sequencing to monitor a hospital outbreak of multi-drug resistant Klebsiella pneumoniae (more details here), this end bit is interesting (italics mine):
"In the E. coli outbreak, we had enough E. coli reference strains and knew enough about E. coli biology to quickly identify a set of genes for specific diagnostics before we had the whole genome sequence," says Dag Harmsen, a microbiologist at the University of Münster who was involved in sequencing efforts during both outbreaks. "But we don't have as much experience with Klebsiella, so this time…
mikethemadbiologist | June 24, 2011Recently, ScienceBlogling Jeff Toney responded to Chief Veterinarian of the National Pork Producers Council Liz Wagstrom's argument that widespread antibiotic use in agriculture has little effect on the antibiotic resistance problem. He concludes:
However, the scientific facts support this idea [of agricultural misuse being a problem] - imagine the effect on our population of literally thousands of tons of antibiotics used in agriculture and animal husbandry, not intended in any way to support public health. Any microbiologist knows that if you grow bacteria in low levels of antibiotics, you…
jtoney | June 20, 2011Source: Sheep purple Flickr Photostream.
Big Ag and antibiotics are becoming a lightning rod for a culture war of facts. Does agricultural use of antibiotics contribute to their diminishing effectiveness in people?
Liz Wagstrom, Chief Veterinarian of the National Pork Producers Council says no. In in a Letter to the Editor in The New York Times, she writes:
In fact, numerous peer-reviewed risk assessments show virtually no risk to humans from antibiotic use in animals.
...
The risk to public health from overuse or misuse of antibiotics comes overwhelmingly from human medicine, not…
lborkowski | April 7, 2011Today is World Health Day, and the World Health Organization is using the occasion to draw attention to a serious global health problem: the rapid spread of bacteria resistant to antibiotics. The development and widespread use of antibiotics counts as a public health triumph, as infections that once routinely killed large numbers of people became much easier to treat. That triumph can be undone, though. WHO Director-General Margaret Chan warns, "In the absence of urgent corrective and protective actions, the world is heading towards a post-antibiotic era, in which many common infections will…
mikethemadbiologist | March 4, 2011I haven't gone after creationists in quite a while, because it just starts to feel like picking on the slow kid. Both PZ Myers and Kele Cable attended a seminar by Answers in Genesis High Wackaloon Terry Mortenson. I don't think you could pay me enough to wade through that morass of unadulterated bullshit, but they've filed some reports (there's a Twitter feed here). But what burned me up was seeing this come across the Twitter transom:
Antibiotic resistance always evolves from a loss of information. [PZ:] Not true!
Sweet Baby Intelligent Designer, Mortenson is stupid.
Let's leave aside…
mikethemadbiologist | January 13, 2011Microbiologist Julian Davies once said that the world is bathed in a dilute solution of tetracycline (an antibiotic). Between human use and production in the environment by naturally-occurring bacteria, there's a lot of tetracycline out there. In spite of all of this tetracycline, most soil bacteria, and even a fair number of clinical bacteria are sensitive to tetracycline. This led researchers to examine in a 2010 paper (pdf) if tetracycline resistance is disadvantageous in certain habitats.
Before getting to the paper, it's worth reviewing some elementary basics of antibiotic resistance…
mikethemadbiologist | January 5, 2011...or it won't be much of a revolution. Yesterday, I discussed the difference between a DNA sequencing revolution and a genomics revolution, and how we have a long way to go before there's a genome sequencer in every pot (or something). But let's say, for argument's sake, these problems are overcome--and I think they will be.
Then the real trouble begins.
The big issue is standardization--without it we will have a genomic Towel of Babel:
"There is a growing gap between the generation of massively parallel sequencing output and the ability to process and analyze the resulting data," says…
mikethemadbiologist | November 24, 2010When biologists refer to the 'wild type', we mean that there is a dominant phenotype or trait that most organisms in a species possess. For example, most Drosophila melangaster (the fly commonly used in genetics) have red eyes--red eyes are the wild type, while white eyes are often referred to as the 'mutant' phenotype.
If there's any good news about antibiotic resistance, it's that the wild type regarding resistance among commensal bacteria (those that live on and in us and that don't typically cause disease) is still sensitivity to antibiotics, not resistance. Only 1.6% of Staphylococcus…
mikethemadbiologist | November 9, 2010If you haven't heard, there's a new antibiotic resistance gene, NDM-1, which stands for New Delhi metallo-beta-lactamase-1. This gene has been found in Gram-negative Enterobacteriaceae (E. coli and Klebsiella), and confers resistance to every penicillin derivative. Like the KPC genes, this gene is found on miniature chromosomes that also carry other resistance genes, making this organism resistant to just about everything we can throw at it.
By way of Maryn McKenna, we find this nice ATCC chart which shows just how bad one of these bacteria can be:
All those "R"s mean that drug doesn't…
mikethemadbiologist | October 28, 2010Maryn McKenna has a good article about a new strain of methicillin resistant of Staphylococcus aureus, ST239, aka The Brazilian Clone (as far as I know, no bikini wax is involved...). ST239 is troubling since it's not only resistant to methicillin, but also resistant to other antibiotics, including clindamycin, tetracycline, cotrimoxazole (also known as Bactrim), moxifloxacin, and gentamicin. While cotrimoxazole and tetracycline are old drugs, they have proven to be reasonably effective against many MRSA. So spread of a multidrug resistant MRSA means that we really only have one drug that…
mikethemadbiologist | September 8, 2010One of the constant assumptions in the field of antibiotic resistance is that the massive exposure of bacteria to antibiotics, and the evolution of resistance to these antibiotics, didn't occur until after the widespread introduction of penicillin and other antibiotics less than a century ago. But ScienceDaily reports that we might have to rethink this:
A chemical analysis of the bones of ancient Nubians shows that they were regularly consuming tetracycline, most likely in their beer....
In 1980, he discovered what appeared to be traces of tetracycline in human bones from Nubia dated between…
mikethemadbiologist | July 27, 2010So, in some quarters, there's been wailing and gnashing of teeth over the Congressional hearings about the direct-to-customer ('DTC') genetic testing industry. I've discussed why I don't think regulation is a disaster before, but I'll add one more issue to the mix: maintaining subject confidentiality in NIH genomic studies. If someone related to a person in a study publicly releases his or her genome, it could be possible to identify a 'deidentified' anonymous subject. I'm curious to see how that issue shakes out.
But that's not what this post is about. Instead, I propose that the DTC…
mikethemadbiologist | July 13, 2010
No, MR-CoNS isn't some kind of crazy new conservative, it stands for methicillin resistant coagulase-negative staphylococci. CoNS are relatives of the bacterium Staphylococcus aureus (the 'SA' in MRSA), and are common human commensals--they typically live on us and in us without causing disease.
One of the important things, from a health perspective, about CoNS is that many are resistant to methicillin (methicillin resistance is the "MR" in MRSA). In fact, the resistance mechanism, known as the SCCmec gene cassette, is similar to those found in MRSA (SCCmec is a class of similar, yet…
mpendergrast | June 21, 2010Mark Pendergrast writes: To kick off this book club discussion of Inside the Outbreaks, I thought I would explain briefly how I came to write the book and then suggest some possible topics for discussion.
The origin of the book goes back to an email I got in 2004 from my old high school and college friend, Andy Vernon, who wrote that I should consider writing the history of the EIS. I emailed back to say that I was honored, but what was the EIS? I had never heard of it. I knew Andy worked on tuberculosis at the CDC, but I didn't know that he had been a state-based EIS officer from 1978…
mikethemadbiologist | June 1, 2010So I was at the ASM meeting last week, and one of the talks I heard was by Kim Ware about Clostridium difficile infection control: how one hospital learned to contain and prevent outbreaks (Note: these are from my notes; I haven't downloaded the presentation yet). C. difficile is a bacterium that causes diarrhea and more serious intestinal conditions such as colitis. It is often associated with antibiotic therapy and stays in healthcare environments: this is primarily a 'hospital disease.' While most cases result in diarrhea (which isn't trivial if you're already very sick), eleven…