What fluid is commonly associated with a bacterial infection in the body?

Pus is commonly associated with bacterial infections in the body because it is a thick fluid that forms as a result of the body's immune response to infection. When bacteria invade body tissues, the immune system responds by sending white blood cells, particularly neutrophils, to the site of infection. These white blood cells attack the bacteria and, during this process, they can die off and accumulate, forming pus. Pus contains dead cells, bacteria, and tissue debris, which is why its presence is a clear indicator of an ongoing infection.

On the other hand, serum is the clear fluid that remains after blood coagulates, and while it plays a role in the immune system, it is not specifically an indicator of bacterial infection. Sweat is primarily involved in thermoregulation and doesn't directly indicate infection. Mucus does play a role in trapping pathogens and can be associated with infections of the respiratory tract, but it is not as specifically tied to bacterial infections as pus is.