Bacterial Diseases

Definition Cellulitis is a bacterial infection that affects the skin as well as the soft tissues under the surface of the skin. This kind of an infection usually occurs when bacteria enter normal or broken skin and start spreading under the skin into the soft tissues. This causes inflammation and …

Definition Lyme disease is caused by a bacteria, Borrelia burgdorferi, that’s transmitted to humans through a bite from an infected black-legged or deer tick. Symptoms can occur anywhere from 3 to 30 days after the bite, and symptoms can be wide-ranging, depending on the stage of the infection. Lyme disease …

Definition Trachoma is a contagious bacterial infection which affects the conjunctival covering of the eye, the cornea, and the eyelids. It is often associated with poverty and lack of proper hygiene. Trachoma is caused by the Chlamydia trachomatis bacteria and is essentially totally preventable and curable. It is the leading …

Definition Amoebiasis is a condition in which your gut (intestines) becomes infected with the parasite E. histolytica. Entamoebae are a group of single-celled parasites (living things that live in, or on, other living organisms) that can infect both humans and some animals. There are at least six species of entamoeba …

Definition Brucellosis is an infectious disease caused by a type of bacteria called Brucella. The bacteria can spread from animals to humans. There are several different strains of Brucella bacteria. Some types are seen in cows. Others occur in dogs, pigs, sheep, goats, and camels. Recently, scientists have seen new …

Definition Plague is an infectious disease caused by bacteria called Yersinia pestis. These bacteria are found mainly in rodents, particularly rats, and in the fleas that feed on them. Other animals and humans usually contract the bacteria from rodent or flea bites. SEM image of Yersinia pestis History Historically, it …

Definition Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract. Salmonella bacteria typically live in animal and human intestines and are shed through feces. Humans become infected most frequently through contaminated water or food.   Types Salmonella is divided into two groups: Typhoidal Salmonella, which is …

Definition Pneumonia is an infection in one or both lungs. It can be caused by bacteria, viruses, or fungi. Bacterial pneumonia is the most common type in adults. Pneumonia causes inflammation in the air sacs in your lungs, which are called alveoli. The alveoli fill with fluid or pus, making …