Which condition occurs when there is an infection in a group of tissues often due to bacterial multiplication?

The condition described, involving an infection in a group of tissues often due to bacterial multiplication, aligns with the definition of an infection. Infections occur when pathogens, such as bacteria, invade tissues and begin to multiply, leading to a response from the body which can cause a variety of symptoms. This response typically involves the immune system trying to eliminate the invading organisms, hence leading to localized or systemic effects depending on the severity and type of infection.

Contamination refers to the presence of pathogens on a surface or tissue without causing an infection. Inflammation is actually part of the body's response to infection, marked by redness, heat, swelling, and pain in the affected area, but does not denote the presence of the pathogens themselves. Colonization refers to the growth of microorganisms on a host without causing disease; in this case, the pathogens may exist without eliciting symptoms of infection. Therefore, the term that accurately represents an infection resulting from bacterial multiplication is indeed infection.