The Egnor Challenge: Tooth Decay and Human Origins (afarensis)
Pigheaded Egnorance, Antibiotic Resistance, and Tautologies (MarkCC)
The Egnor challenge, day 2 (Orac)
Michael Egnor, Paleyist surgeon (PZ)
There are others, farther back. The gist of it is that there is this dude at the Discorevy Institute who is trying to argue that doctors do not need to understand evolution.
I just want to take on a small piece of this.
As Mark quoted in the post linked above:
Our battle against bacterial resistance to antibiotics depends on the study of the intricate molecular strategies bacteria use to fight antibiotics, and our development of new antibiotics is a process of designing drugs to counter the bacterial strategies. We use molecular biology, microbiology, and pharmacology. We understand that bacteria aren't killed by antibiotics that they're resistant to. We understand tautologies. Darwin isn't a big help here.
The part I want to add is this: Egnor misses a big point. He does not understand drug discovery and development. Does he not remember the Bactrim story? Bactrim is a combination of two antibiotics. The combination was chosen specifically to make it harder for bacteria to evolve resistance. It seemed to work for a while, although it could not, and did not, last forever.
Perhaps he should actually read up on the discovery of new antibiotics before he goes off making unfounded statements. A full understanding of the basic science underlying antibiotics is indeed necessary; that would include an understanding of evolution.
If it were otherwise, this paper would never have been written, much less published in a top-tier journal:
Synergy and contingency as driving forces for the evolution of multiple secondary metabolite production by Streptomyces species
Then there is this:
For any new antibiotic, resistant bacteria typically show up in four years, or less. Penicillin resistance was reported clinically even before large-scale use of the antibiotic began in 1942. The battle against antibiotic-resistant bacteria demands new drugs and smarter, more responsible ways to use existing ones. Some researchers, however, are pursuing another type of weapon: drugs that sidestep natural selection. Less virulent bacteria would decrease the need for antibiotics, some reason, and drugs that drastically slow mutation rates might cut off evolution's power source...
A drug that blocks MarA's activity, Levy reasons, would keep bacteria in a free-floating state, both less dangerous and easier prey for the immune system. Ideally, infections could be prevented in susceptible patients without resorting to antibiotics that select for resistance. Because the drug wouldn't actually kill the bacteria, mutations blocking its function wouldn't be highly selected for...
And this:
The emergence of drug-resistant bacteria poses a serious threat to human health. In the case of several antibiotics, including those of the quinolone and rifamycin classes, bacteria rapidly acquire resistance through mutation of chromosomal genes during therapy. In this work, we show that preventing induction of the SOS response by interfering with the activity of the protease LexA renders pathogenic Escherichia coli unable to evolve resistance in vivo to ciprofloxacin or rifampicin, important quinolone and rifamycin antibiotics. We show in vitro that LexA cleavage is induced during RecBC-mediated repair of ciprofloxacin-mediated DNA damage and that this results in the derepression of the SOS-regulated polymerases Pol II, Pol IV and Pol V, which collaborate to induce resistance-conferring mutations. Our findings indicate that the inhibition of mutation could serve as a novel therapeutic strategy to combat the evolution of antibiotic resistance.
Of course this could go on all day. The fact is, an understanding of evolution is essential to process of discovering new antibiotics.
Comments
"The fact is, an understanding of evolution is essential to process of discovering new antibiotics."
.... The above doesn't begin to get into the specialized training/experience IN the area of microbial genetics required to develop new modalities.
And this is why the Pharma companies hire PhD and PharmD scientists to develop new antimicrobials, and not neurologists.
Just as I would not want to comment on the intricate workings of dorsal root ganglia, I would hope that a neurologist would keep out of interpreting resistance genotypes, no matter what level of avocational interest s/he might have........
Posted by: Chromosome Crawl | March 19, 2007 3:24 PM
Yes. And within the last few days there have been reports of the spreading of extensively resistent TB as well as the discovery of a resistent strain of the plague.
These new antibiotics are much needed.
Posted by: Kristjan Wager | March 21, 2007 10:37 AM