Red Alert

What am I looking at?

This is an image of salmonella bacteria on the lining of a human intestine. The bacteria are red (1) and the intestinal tissue around them is yellow (2).

Click on the right arrow to see another view of salmonella (which are orange in this image).

Biology in the background

Food poisoning is a general term for any illness caused by food or drink that’s been contaminated with a pathogen. One of the main forms of food poisoning is through food contaminated with salmonella bacteria. This is why salmonella infections are often simply referred to as food poisoning.

Salmonella bacteria invade and destroy the cells that line the intestine, known as the intestinal epithelium. This makes it harder for your intestine to absorb water and digest food properly. As a result, water and undigested food can accumulate in the intestine and cause diarrhea and abdominal pain. In addition, the immune system’s reaction to the infection can cause secondary symptoms, such as fever, fatigue, and body aches.

A salmonella bacterium can grow up to 5 micrometers long, or roughly 15 times smaller than the width of a human hair.

Technique

This image was created using colored scanning electron microscopy.