07/01/2013 10:35 EDT | Updated 08/31/2013 05:12 EDT

Germs That Could Save Your Sight


It's summertime and movie companies are once again betting on the draw of the classic fight between good and evil manifested in our love for the superhero and our hatred for the supervillain. From the iconic Superman and his battle with the evil General Zod to Iron Man and his struggles against The Mandarin, epic clashes are packing theatres.

Closer to home, our bodies are being subjected to similar conflicts in which germs are constantly fighting to take over a more important prize: our health.

The supervillains are few, but they are well known and can bring fear to anyone who is aware of them, or worse, has suffered from their evil deeds. While perhaps the worst of them all are the ever dreaded Ebola virus, SARS, and avian influenza, cases of these are few and far between. The real archnemesis is without a doubt Norovirus, which can halt a cruise ship in its tracks and close down hospital wards.

This week, another major enemy of the human state was given the spotlight in the microbiological world. A group led by Dr. Joshua Adkins at the Pacific Northwest National Laboratory in Richland, Washington, took a closer look at Salmonella, the fourth leading cause of foodborne illness. They wanted to see just how infection progressed in the gut. What they found would make even Dr. Doom proud.

As Salmonella enters the gastrointestinal tract, it finds a happy environment that is going about its business in a comfortable manner. But soon, Salmonella starts to make trouble, stealing away valuable nutrients from the happy microbial citizens and vandalizing the lining of the intestines. As the immune system reacts, the normal microbes start to disappear either through the inability to thrive, or worse, from the overreaction of the immune system. As the disruption continues, Salmonella continues to multiply and soon simply outnumbers all the other cells in the area. At the height of the attack, the entire area is worse than a Bane-destroyed Gotham City.

Eventually, as the destruction takes its toll, the evil bacteria start to decrease in number -- their job is over and they have moved on to seek other victims. Much like Gotham, the intestinal city, which could be called "Gutham," will eventually recuperate, but life there may never be the same.

Thankfully, there are a group of superheroes who can help ward off the Salmonella attack. Probiotics, specifically Lactobacillus, have been shown to fight Salmonella at every stage of its attack. They can prevent the bacterium from getting anywhere near the intestinal lining; help to control the immune system's reaction to infection to ensure that the intruder is killed; and they even have the ability to kill the invaders with their own superpowered weapons known as antimicrobial compounds. While probiotics, much like superheroes, cannot stop these invaders entirely, they can help to protect our "Gutham" and even help to fight off the enemies when they come.

This week also saw the unveiling of another supreme battle between the forces of good and evil with a globe at stake. Although in this case, the spherical object isn't the Earth; it's your eye.

Researchers from the University of Pittsburgh and the University of Medicine and Dentistry of New Jersey collaborated on a project that focused on how using two microbial superheroes named Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus can help to protect the eye from the threat of a duo of supervillains.

Infection of the eye, in this case, bacterial keratitis, is an inflammation of the front of the eye causing itching, redness, and pain. If it is untreated, the damage can be severe and even cost a person his or her vision. There are several sight-scaring supervillains but the two examined in this study were Pseudomonas aeruginosa and Serratia marcescens.

The researchers engaged a battle in a petri dish, putting the four bacterial species together. Sure enough, over 48 hours, B. bacteriovorus and M. aeruginosavorus, lived up to the meanings of their names: bacteria and aeruginosa devouring. The predatory nature of these two bacteria was sufficient to reduce the level of both P. aeruginosa and S. marcescens by anywhere from 99 to 99.99%. The superheroes were hungry and they feasted. But while that worked in a petri dish, the researchers also wanted to see if this could be used in the eye itself. Rather than using humans, they had a surrogate, the larvae of the wax moth .

The results were just as impressive; almost all the worms' eyes were saved. There was even an added bonus. The two heroes did not trigger an immune response and as such, the crawlers were able to live naturally without any concern for their sight. The good bacteria were worthy of their heroic title in the lab as well as the insect model.

The battle for the body is a continuous one and there will never be a time when we are not threatened by one of the long list of microbial threats. However, as we realize that we as humans are not alone, we are learning how to work with good germs, such as Lactobacillus, Bdellovibrio, and Micavibrio, as allies in the fight. Although their actions may not be as appealing as what we might see on the big screen, the work of these small defenders deserves our attention and respect. Moreover, while we may know of many at the moment, there is little doubt that with continued research in microbes and their interaction with us, we'll continue to find even more superheroes.

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