Clostridium tetani and rusty metals

[jhirlo]

"Rusty metal is a favourite place for C. tetani to hang out, and in fact puncture wounds with rusty nails are a common cause of tetanus." We all know this, but why is that, why C. tetani has this affection fot rusty metals ?

C. tetani is anaerobe, and I wonder does this living in iron oxide environment has something to do with their potential ability (if they have it) to use iron oxides as electron acceptors in non oxygen breathing process?

What do you think?

 

[Moonbear]

There isn't anything special about rust or rusty nails when it comes to tetanus, other than an old nail that is rusting has probably been around long enough to have gathered a lot of dirt on it, and hence a lot of germs. Because tetanus comes from an anaerobic bacterial infection, you are at greatest risk if you have a puncture wound, so the bacteria are deposited deep inside the wound, away from the aerobic environment near the surface. The old, dirty, rusty nail does a good job of creating a puncture wound and depositing a lot of bacteria inside of it, but anything that creates a puncture wound can deposit bacteria inside the wound unless it is completely sterile. You'll notice that even when the doctor or nurse gives you a shot using a sterile needle, they clean your arm with alcohol first. This is to kill the bacteria living on your skin before giving you the injection in that spot. There are a lot of bacteria just sitting out on your skin or on all surfaces that are harmless if they are kept outside your body, but if a needle passes through them and drags them inside your body as it punctures your skin, then you can get an infection from it. This is not necessarily C. tetani, but bacteria in general.