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Marler Blog Providing Commentary on Food Poisoning Outbreaks & Litigation

Salmonella – The Movie

With two recalls of Salmonella-tainted product in the last two days, I have received a few emails asking for an explanation on how this nasty bug attacks the human body and complications, like Reiter’s Syndrome.  Click on camera for a nice video clip. The explanation of the clip is as follows:

1.Salmonella has a dramatic way of invading the host cell.

2.The surface of intestinal cells is covered with microvilli.

3.Like the enteropathogenic E. coli, Salmonella uses a specialized syringelike mechanism to inject proteins through the host membrane surface and into the cytoplasm.

4.The injected proteins trigger the epithelial cell membrane to extend outward (ruffle), and as a result, the bacterium is engulfed and dragged inside the host cell.

5.Once many bacteria have adhered to the intestinal lining, symptoms of the infection (diarrhea and cramping) commence.

6.The process of engulfing the bacterium ends up with the bacterium completely encased in a vacuole made up of the host cell membrane. The vacuole is dragged inside the cell by actin filaments.

7.Under normal circumstances, the host cell has the bacterium exactly where it wants it. The normal mechanism for dealing with a foreign body invading a cell involves lysosomes of the cell fusing with the vacuole surrounding the invader and showering it with a concentrated mix of digestive enzymes, which degrade the intracellular pathogen. So, unless the Salmonella can do something fast, it is doomed.

8.However, the Salmonella has injector system to inject other bacterial proteins into the surrounding vacuole and adjacent area. This second injection alters the vacuole structure (shown as a white-blue glow in the animation). The vacuole is now blocked from fusion with toxic lysosomes (shown as red balls).

9.Now safe and sound, Salmonella begins to divide inside the vacuole. The bacteria continue to divide while the vacuole grows.

10.The Salmonella infection may now spread from the intestines to the blood stream, and then to other body sites.

In the last few days Mexican actress, Jacqueline Bracamontes, is reported to have come down with Salmonella according to our friends at Barfblog.  Perhaps she would be interested in the movie?