Antibiotic resistance
sporte | April 17, 2008In the class that I'm teaching, we found that several PCR products, amplified from the 16S ribosomal RNA genes from bacterial isolates, contain a mixed base in one or more positions.
We picked samples where the mixed bases were located in high quality regions of the sequence (Q >40), and determined that the mixed bases mostly likely come from different ribosomal RNA genes. Many species of bacteria have multiple copies of 16S ribosomal RNA genes and the copies can differ from each other within a single genome and between genomes.
Now, in one of our last projects we are determining where…
tsmith | April 14, 2008This is the first of 6 guest posts on infectious causes of chronic disease.
By David Massaquoi
Is this the Beginning of the end of antibiotic resistant problem or just another scientific false hope of eradicating microorganisms that have co-existed with humans for millions of years? In the days before antibiotics, some researchers saw bacteriophages, viruses that can seek out and destroy bacteria, as a promising candidate for fighting infections. Now, as more organisms develop resistance to existing antibiotics, phage research is finding new favor.
(More after the jump...)
At the Society…
tsmith | April 3, 2008Early this week, grant application; yesterday and today, IRB and IACUC for another project. But once again, fellow Sbers are keeping me busy reading about stories I'd like to be writing on; see yet again Mike on E. coli O157:H7--everything old is new again; Ed on a new study showing yet again how amazing bacteria are; and DrugMonkey discussing heroin addiction as a family legacy, and notes that this sad story again shows that Narcan saves lives.
tsmith | January 16, 2008 Methicillin-resistant Staphylococcus aureus (MRSA) has taken up residence in sport teams, prisons, schools, the military, and even swine. A new article in the Annals of Internal Medicine shows that, at least in Boston and San Francisco, it's also causing a lot of infections in men who have sex with men; more after the jump.
To examine this, the authors looked at MRSA infections from a variety of health care settings: medical centers, community health clinics, HIV clinics, and emergency rooms. These were examined in separate analyses. For example, for the medical centers they looked at…
tsmith | January 15, 2008Over at Evolgen, RPM notes an interesting study in PNAS, looking at antibiotic use and how it serves to drive the emergence and maintenance of antibiotic-resistant strains. The current paradigm for antibiotic use is to prescribe relatively high doses of drugs for a few days to a few weeks (or months, in the case of tuberculosis), and patients are cautioned to stay on them until all the doses are finished. However, the new study RPM describes suggests this may be doing more harm than good, looking at what happens with Plasmodium species treated with antimalarials in a mouse model.
Do…
tsmith | December 17, 2007 In my field, many things that cause the average man-on-the-street to get a bit squeamish or squicked are rather commonplace. My own studies include two types of bacteria that are carried rectally in humans (and other animals), so I spend an absurd amount of time thinking about, well, shit, and the lifeforms that inhabit it and collectively make up our normal gut flora. The vast majority of these species don't harm us at all, and many are even beneficial: priming our immune system; assisting in digestion; and filling niches that could be colonized by their nastier bacterial brethren.
It…
tsmith | November 8, 2007 Both Mike and Revere have new posts up documenting swine as a new threat to human health (beyond the pork chops and bacon), via carriage of methicillin-resistant Staphylococcus aureus in these animals. Several papers have been published recently documenting high rates of MRSA carriage in swine in the Netherlands, and also have documented transmission of this bacterium from swine to humans. However, even more worrisome to me than the Dutch publications is a new one out in Veterinary Microbiology, showing high rates of MRSA in Canadian swine--and guess where we import about 9 million hogs…
tsmith | November 4, 2007Welcome to this month's edition of Pediatric Grand Rounds! Sit back with a cup of mulled cider and enjoy the best of the past month:
Revere at Effect Measure tells the tale of Streptococcus pneumoniae serotype 19A--a serotype that's not included in the current vaccine, but has increasingly found as a cause of ear aches in children.
Of course, in addition to ear infection, 'tis the season for influenza. As such, it's timely that Highlight Health, Walter emphasizes the importance of influenza vaccination.
My own addition to this month's carnival touches on similar themes: how kids'…
tsmith | October 18, 2007 A few news stories hit my inbox all at once yesterday--and the combination of them doesn't bode well for childrens' health; more after the jump.
First, despite several years now of banging the drum for having kids vaccinated against influenza, they're still being overlooked when it comes to pandemic planning:
Children would likely be both prime spreaders and targets of a flu pandemic, but they're being overlooked in the nation's preparations for the next super-flu, pediatricians and public health advocates reported Wednesday.
The report urges the government to improve planned child…
tsmith | October 16, 2007Busy day here, but I do have a brief post up on MRSA over at Correlations if you're looking for some reading material.
[Edited to add: Mike has a lot more new MRSA stuff here; well worth reading!]
tsmith | September 18, 2007...They make be spreading disease.
British hospitals are working on keeping that in check by implementing a new dress code:
British hospitals are banning neckties, long sleeves and jewelry for doctors -- and their traditional white coats -- in an effort to stop the spread of deadly hospital-borne infections, according to new rules published Monday.
Hospital dress codes typically urge doctors to look professional, which, for male practitioners, has usually meant wearing a tie. But as concern over hospital-born infections has intensified, doctors are taking a closer look at their clothing.
"…
tsmith | September 13, 2007Clostridium difficile is an emergent bacterium. A close relative of the bacteria that cause tetanus and botulilsm (Clostridium tetani and Clostridium botulinum, respectively), C. difficile is an intestinal bacterium that can cause colitis. C. difficile has until recently been a fairly rare cause of disease, and then only typically within a hospital setting. However, the emergence of a new, highly virulent strain of the bacterium a few years ago, coinciding with an increase in the rate of serious infections it caused, put this pathogen on the map. And like methicillin-resistant…
tsmith | July 27, 2007XDR-TB has been in the news quite a bit lately, largely thanks to Andrew Speaker's notoriety. Even though his TB was later re-classified as "just" multi-drug resistant (MDR-TB) instead of the initial extremely drug resistant (XDR) type, it did serve to raise awareness about the issues public health authorities face when dealing with something like tuberculosis--and where the gaps are in the control of its spread. (Indeed, a breaking story out of Taiwan shows how difficult it can be to enforce a travel ban).
However, while XDR-TB is rather new on the radar of the general public (and even…
tsmith | May 31, 2007Just popping in quickly after I saw Klearchos' comment on the updated tuberculosis post. He notes on his website that the CDC has released additional travel information about the XDR-TB infected patient, including shorter flights made within Europe in addition to the intercontinental flights. However, Klearchos notes:
...there is a big "hole" in the information provided by the CDC since, nobody has answered yet the question about how he moved from Santorini to Mykonos. CDC doesn't say anything about that in its report!!
There is no direct flight between the two Greek islands so he must have…
tsmith | May 30, 2007I blogged earlier about the Georgia man who globe-trotted while infected with XDR-TB. I wrote that post late Tuesday evening, and since then, a number of other details about his case have come to light--and they're not encouraging. In fact, this serves as a nice example of a convergence of a number of areas I've written about before--obviously, the evolution of antibiotic resistance and the terrible position it leaves us in, the politics and policies of quarantine/isolation (and how they'd be enforced), and the global spread of infectious disease, so I figured this would warrant another…
tsmith | May 30, 2007 I blogged back in March about World TB day, the theme of which was "TB anywhere is TB everywhere." We know that someone can simply hop on a plane halfway across the world, and be practically anywhere else on the globe in the span of about a day--and their bacteria and viruses are just along for the ride. This is particularly disconcerting when it comes to respiratory diseases, where fellow airline passengers may be coughing and sneezing all over you, or touching shared objects without washing their hands. This is also a scenario that's known to have spread SARS, and may spread a future…
tsmith | March 30, 2007I don't know if you've seen any of the posts here at Scienceblogs or Panda's Thumb about the Discovery Institute's newest protégé, Dr. Michael Egnor. A professor of neurosurgery at SUNY-Stony Brook, Dr. Egnor has been pontificating on how "Darwinism" has nothing to offer to medicine; and indeed, that evolutionary biology has "hijacked" other fields of study. Mike has already aptly pointed out many of Egnor's strawmen and intellectual dishonesties, so I won't review them all. I've stayed out of the fray until now because I've had limited time and others have been handling it quite ably,…
tsmith | March 15, 2007 When we think of the spread of antibiotic resistance between animals and humans, we tend to think of it going from Them to Us. For example, much of the research over the past 20 years on the sub-clinical use of antibiotics in animal feed has looked how this use of antibiotics as a growth promotant breeds resistant organisms in animals, which can then enter the human population via the food we eat. Along a similar line, I just mentioned Burt's post post on cephalosporin use in cattle and the evolution of antibiotic resistance, where the worry is that use of these broad-spectrum antibiotics…
tsmith | March 14, 2007The most recent edition of Tangled Bank, your one-stop science blogging carnival, is up over at Living the Scientific Life.
In addition, there are a few other posts I've been meaning to plug:
Nick on Texas House overturning mandatory HPV vaccination.
Burt at Panda's Thumb on Why you should care if cattle get fourth-generation cephalosporins and why doctors need to know about evolution (a takedown of this Discovery Institute essay).
And a nice follow-up to those: Mike on why antibiotic resistance matters.
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…