Britannica Sources used in this answer

Which illnesses can be caused by pathogenic bacteria such as E. coli, Staphylococcus aureus, and Streptococcus?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Diagram showing the West Nile virus transmission cycle: a mosquito bites an infected bird (the primary reservoir host), then transmits the virus to humans or horses (incidental hosts) through subsequent bites. — infectious disease Birds are the primary reservoirs of West Nile virus. The virus is transmitted to humans and horses by mosquitoes that have bitten infected birds.

Pathogenic bacteria such as E. coli, Staphylococcus aureus, and Streptococcus are responsible for a wide range of human illnesses. While many of these bacteria exist as harmless commensals in healthy individuals, they can cause serious disease when they invade tissues or the bloodstream.1234

Escherichia coli (E. coli)

While most strains are harmless, pathogenic E. coli can cause:
* Gastrointestinal illness: Including gastroenteritis and foodborne illness characterized by abdominal cramps and bloody diarrhea.24
* Systemic and other infections: Such as urinary tract infections, bacteremia, sepsis, and neonatal meningitis.24
* Hemolytic uremic syndrome: A serious condition involving kidney injury and blood cell destruction.4

Staphylococcus aureus

This bacterium is a major human pathogen capable of causing:
* Skin and soft tissue infections: Including boils, carbuncles, cellulitis, and impetigo.52
* Systemic conditions: Such as septicemia, endocarditis, osteomyelitis, pneumonia, and meningitis.15
* Toxin-mediated diseases: Including food poisoning, toxic shock syndrome, and staphylococcal scalded skin syndrome.15

Streptococcus

Various species cause diverse conditions:
* Respiratory and throat infections: Including strep throat, tonsillitis, scarlet fever, and pneumonia.13
* Skin and invasive diseases: Such as impetigo, erysipelas, and necrotizing fasciitis (flesh-eating disease).13
* Systemic and inflammatory conditions: Including rheumatic fever, puerperal fever, meningitis, and toxic shock syndrome.13