Tuesday, October 16, 2007

Robert Koch's ironic discovery

Robert Koch's Original photos!

The reason I say IRONIC is because we all know about Robert Koch (or should) and his discovery of Koch's Postulates, but what we don’t know is that he was using some of the most virulent bacteria that live still today. You may remember Anthrax from the "Amerithrax" phase in September 2001, following the terrorist attack on the twin towers. Robert Koch was the first to isolate this capsule-forming and spore-forming gram-positive bacteria named Bacillus anthracis. If you remember the formation of Koch's postulates, you will recognize the process by witch he discovered the relationship between a causative bacteria and a disease. The first causative bacteria to prove this association therefore, was Bacillus anthracis! Also interesting is that Robert Koch discovered Bacillus anthracis's ability to form endospores in 1877, however, the severe toxic properties of the bacteria were not recognized until 1954. Do you think Koch knew the phenomenon of the bacteria he selected at the time? The part that I find fascinating is that they believed that, because of the potency of anthrax bacilli observed in the deceased animals, the cause of death was actually the effect of a suggested "log-jam" theory (referring to a block in the capillaries). The fascinating part is not the theory (although intriguing), the fascinating part is that Koch survived, because the dead body of a bacillus anthracis infected mammal is considered a very dangerous source of anthrax spores. At this point, Lister’s idea of Phenol was evident, however, we know that this period of experimentation had not allowed for the safety procedures of today’s standards to mature in light of sanitation. It seems amazing that Koch, or anyone working with him, did not develop any obvious symptoms of the deadly disease cause by the bacteria. This is why:

The "log-jam" theory failed upon proof that cells extracted from animals dying of anthrax infection were toxin-filled and that was the real cause of symptoms and death due to the anthrax disease. Upon observation of this consistently appearing toxin, it was confirmed that a diffusible exotoxin made the bacillus anthracis highly pathogenic! But that’s not it!!!! ..... Bacillus Anthracis also has the ability to form a clycocalyx made of poly-D-glutamate polypeptide. The capsule is a strong survival mechanism, protecting its self from phagocytosis as well as aiding in the initial stages of infection. The bacteria form a spore as well, making it resistant to heat (of up to 80 degrees), cold, and desiccation. The spore has been known to survive for decades, sprouting consequential growth at an opportune change of environment any ware across the globe. Bacillus anthracis is contacted in humans in three ways: Ingestion, by skin contact, or by inhalation. Skin contact infection gives rise to the Greek origin on the name “anthrax”, meaning coal, due to the distinctive black lesion an infection produces. Inhalation is the most fatal, often causing death if not treated promptly. Seeing as the most common way to contract the disease is by direct contact with infected animals or their carcasses, Koch must have been either very careful in his experiments or very lucky. In fact, Koch lived to be 66 years old, and died from a heart attack that seems to be unrelated to his study of disease.

Another notable fact that made Bacillus anthracis's "claim to fame" for previously oblivious microbiology students and people alike, was the anthrax panic in the United States in 2001. The strain of bacteria used in the letters was originally a warfare weapon for World War II (sick hey?) but is now being controlled within an estimated 15 labs throughout the United States. Two forms of anthrax were synthesized from the same bacterial Ames strain. The anthrax letters, addressed to different media stations in New York as well as to the senator, were contaminated with the cutaneous anthrax (the skin contact infection) and the more serious inhalation form of anthrax. Five people died of anthrax infections, 11 were in critical condition, and 22 people showed sever symptoms, but were treated efficiently.

Overall, I thought this was a pretty interesting bacteria. Let me know what you all think!
Sorry about my horrid spelling- I spell checked but I know Im not the best speller.



sabrina said...

the text did not appear - the photos at the top are koch's ORIGIONAL photos. I thought that was cool too!

Dominic B. said...

TWO very important thing need to come to mind when considering spores and their potency as a pathogenic vector

1) Inoculum size. How many spores can we tolerate in an inhalation? The answer seems to be many and;

2) Spore size. Spores are be definition very small but they are nevertheless filtered by the constant beating of cilia and mucus on the mucosa.

I bet that Koch was exposed to many spores in his lifetime but the inoculum was probably very small.

Interesting blog....