Alligator Blood May Be Source of New Antibiotics

esocid writes "Biochemists from McNeese State University have described how proteins in gator blood may provide a source of powerful new antibiotics to help fight infections associated with diabetic ulcers and severe burns. This new class of drug could also crack so-called 'superbugs' that are resistant to conventional medication. Previous studies have showed alligators have an unusually strong immune system; unlike humans, alligator immune systems can defend against microorganisms such as fungi, viruses, and bacteria without having prior exposure to them. Scientists believe that this is an evolutionary adaptation to promote quick wound healing, as alligators are often injured during fierce territorial battles."

Why evolution?

[AutopsyReport]

Scientists believe that this is an evolutionary adaptation to promote quick wound healing, as alligators are often injured during fierce territorial battles.

Or conversely, alligators as a species have always had these antibiotics. Why is it that every interesting or perplexing feature about a species must be somehow attributed to, or be a product of, evolution?

I'm as much a believer in evolution as the next, but I've grown a bit tired of every amazing discovery being associated with evolution.

I guess what's old is new again.

[b4dc0d3r]

http://news.bbc.co.uk/1/hi/health/4155522.stm [bbc.co.uk]

About three and a half years ago he tested alligator blood and pinpointed why these animals were so resistant to infection. Alligators and crocodiles, like humans, have a natural defence system against invading bacteria, viruses and fungi, which involves a group of proteins called the complement system. When Dr Merchant exposed the alligator blood to pathogens such as HIV, West Nile Virus and E Coli, it started to kill them. "It turns out that this complement system is much more effective than ours.

and that was already 3 years old.

Maybe because you have read about it before:

[Maddog Batty]

Crocodile's Immune System Kills HIV - story from 2005 [slashdot.org]

Komodo dragons too

[cats-paw]

Turns out Komodo dragons have a fairly lethal cocktail of bacteria in their saliva.
Kills prey that manages to escape their immediate grasp, then they use smell to track it down.
Naturally they need protection from this goo too.

Couldn't find a better link than this:

http://www.ncbi.nlm.nih.gov/pubmed/12238371/ [nih.gov]

Humans can respond w/out prior exposure

[Anonymous Coward]

The authors must never have heard of the innate immune system. Unlike the adaptive arm, the innate system responds very quickly to non-self and can combat infection or at least control the spread of pathogens until the adaptive system can respond effectively. Defensins and other bacteriacidal proteins are as old as insects and have been purified from haemolymph (the insect functional equivalent of blood) for almost two decades. Humans also boast a large repertoire of Toll-Like Receptors, analogues to Drosophila Toll, which recognize molecular patterns never expressed by the host, but always associated with pathogens. Another way humans respond to viruses, bacteria and fungi is the complement system, which also does not need prior exposure. This seems like grandstanding on the part of the authors, if you can even call them that, since this isn't published peer-reviewed work yet. I'll stick to eating gumbo for my alligator-derived health benefits.

Re:Have you seen where these things live?

[Mordac]

And for those of you who are making all of the croc meat jokes, keep in mind that croc meat is tough, stringy, and lacking in flavor compared to other meats.

Alligator meat from Louisana is darn good eats.

Their legs can be treated like Buffalo Wings, very tasty.

The tail is the most popular part, as thats used much like chicken tenders. Most people enjoy fried gator tail. You can go back further up on its back, for the tenderloin, but not as good.

Last part I've tried is the ribs. Very similar to baby back ribs, its a white meat, no question about it when eating the ribs. Yes, the amount of meat to bone isn't all that good, but its good enough to enjoy a slow smoking.

Alligator really is the other other white meat, and one of my favourites.

Not the only species

[PCM2]

It could also be that the changes required to end up with an immune system like that are incredibly complex and may involve steps along the way that are not evolutionarily advantageous in most species, so the necessary sequence of evolutionary steps was not completed in most species.

The alligator does not seem to be entirely unique in this.

In my Emerging Infectious Diseases class, we learned that the tiny ticks that spread the Lyme disease bacterium are known to bite and feed on the blood of the western fence lizard. An interesting side effect of this behavior is that the blood of the lizard apparently clears the ticks' guts of Lyme bacteria. [sfgate.com] So this immune adaptation is apparently present in a number of lizard species.

Think, also, of the Komodo dragon, which walks around with a poisonous soup of microbes in its mouth at all times -- in fact, it actually uses this disease cocktail as an offensive weapon.

Re:Maybe because you have read about it before:

[cpricejones]

And of course several species are going extinct. Will this finding change anything? Probably not once the blood has been well studied such that the components can be synthesized.

Here is a good link for you (http://www.flmnh.ufl.edu/cnhc/csl.html) if you're interested in all the different species. I imagine that the differences in their immune systems would also be of some benefit.

Re:superbugs

[Punko]

Steady on.

There are many antibiotics that are not used in agriculture. They have been set aside to fight the superbugs. Unfortunately, we are finding strains of bacteria resistant to even these "reserved" antibiotics. If it turns out that an antibiotic can kill these bugs, then we can use it just on the superbugs.

Yes, in time, a bacteria will adapt to this antibiotic. Potentially this bacteria may find its way into the crocodile ecosystem. But look at it this way, if crocodiles have had this antibody in their bodies for (perhaps) millions of years, is it not possible that a resistant bacteria already exists?

As a note, the reason doctors throw "everything" at a superbug, is because you want to ensure the vast majority of the population is dead, to reduce the possibility of adaptation. In addition, several antibiotics work really well in combination, doing a better job than if utilitized one at a time.

and lastly, just because a bacteria is resistant to antibodies in your system, doesn't make it fatal. Humans lived through smallpox outbreaks. Many don't. Same thing for your phantom crocolisk superbug. Maybe it invades their systems and give them cold sores.

Re:Cue TMNTs

[Impy the Impiuos Imp]

I think it causes the blood vessels to expand, hence the drunk's bulbous nose. And if you're still out in the cold, expanding the capillaries on your skin is the last thing you want to do.

Re:Cue TMNTs

[John Newman]

Really? I thought that once you had them in a warm environment, alcohol would help increase circulation and even out body temperature. Or perhaps it will cause a sudden rush to the heart of cold blood that was near the skin. I've not got any training in cold weather rescue, so excuse my ignorance.

Alcohol is a mild vasodilator, so it would reverse your body's major defense against cold, restricting blood flow to the extremities/surface and keeping a pool of warm blood in the core. Even after the person is in a warm environment, vasodilation is dangerous because the extremities/skin are cold, the blood there is cold, and suddenly moving a bunch of warm core blood through the cold extremities and back will lower the core temperature further. The teaching is that this could kill a patient by pushing their core temperature down suddenly, past the critical value. When resuscitating a severely hypothermic patient, you always warm from the inside out, and you never give vasodilators.

Re:Maybe because you have read about it before:

[krayzkrok]

Yes, that's the research I was involved in. We actually first discovered this way back in 1999! We tested serum activity (and lysed leucocytes) in Australian saltwater crocodiles and later in 2002 in Australian freshwater crocodiles. We called this antimicrobial peptide "crocodillin". The work from 2005 comes from a project I did with Mark Merchant on saltwater crocs where we tried to learn more about the antimicrobial and antiviral activity. This latest media release is essential the same as the previous work, except this time with American alligators because Mark has more of them in the backyard than he does saltwater crocs. Adam

Re:Have you seen where these things live?

[krayzkrok]

The goal is to sequence the peptides involved, ultimately to synthesize them. It's not going to affect wild alligator populations, not that there's a dearth of them! Adam

Re:I guess what's old is new again.

[krayzkrok]

I made the initial discovery with saltwater crocodiles back in 1999, and my colleague Dr Gill Diamond named the peptide "crocodillin". So this is really a decade old now!

http://news.bbc.co.uk/2/hi/science/nature/680840.stm [bbc.co.uk]

Adam Britton