Bacterial Infection

3D medical illustration example of bacteria

Bacterial infection and diseases occur when pathogenic bacteria get into the body and begin to reproduce and crowd out healthy bacteria, or to grow in tissues that are normally sterile. Harmful bacteria may also emit toxins that damage the body.

Bacterial diseases are contagious and can result in many serious or life-threatening complications, such as blood poisoning, kidney failure, and toxic shock syndrome.

Common pathogenic bacteria and the types of bacterial diseases they cause include:

Salmonella

A group of bacteria that commonly cause a foodborne illness called salmonellosis. According to Medical Microbiology (University of Texas Medical Branch at Galveston), humans and animals typically have some Salmonella bacteria in their stomach and intestines, but stomach acid and intestinal bacteria generally kill the Salmonella before it has the opportunity to invade cells and replicate. Or, the Salmonella simply exit the digestive tract before it causes problems.

Escherichia coli (E.coli)

A non-spore-forming, Gram-negative bacterium, usually motile by peritrichous flagella. E.coli is the most common cause of acute urinary tract infections as well as urinary tract sepsis. It may also cause acute enteritis in humans as well as animals and is a general cause of 'traveller's diarrhoea', a dysentery-like disease affecting humans, and haemorrhagic colitis often referred to as 'bloody diarrhoea'.

Helicobacter pylori (H. pylori)

A spiral-shaped bacterium that grows in the mucus layer that coats the inside of the human stomach.

Neisseria meningitidis (N. meningitidis)

A gram-negative diplococcus, which can cause a disseminated infection known as acute meningococcemia. In this condition, the small vessels of the skin are involved causing a hemorrhagic or vesicular skin rash.

Neisseria gonorrhoeae

N. gonorrhoeae is spread by sexual contact or through transmission during childbirth.

Staphylococcus aureus

A commensal organism that resides in skin and mucosa. It stains Gram positive and is non-moving small round shaped or non-motile cocci. It is found in grape-like (staphylo-) clusters.

Streptococcal bacteria (strep)

A genus of bacteria characterized by being coccus, Gram-positive, and occurring in chains of varying length, and includes bacterial strains responsible for numerous infections such as scarlet fever, tonsillitis, erysipelas, endocarditis, rheumatic fever, glomerulonephritis, impetigo, pneumonia, meningitis, pharyngitis, lymphadenitis and wound infections.