Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity of the condition is variable.
Pontiac fever is an acute, nonfatal respiratory disease caused by various species of Gram-negative bacteria in the genus Legionella. It causes a mild upper respiratory infection that resembles acute influenza. Pontiac fever resolves spontaneously and often goes undiagnosed. Both Pontiac fever and the more severe Legionnaire's disease are caused by the same bacteria, but Pontiac fever does not include pneumonia.
Legionella is a genus of pathogenic Gram-negative bacteria that includes the species L. pneumophila, causing legionellosis including a pneumonia-type illness called Legionnaires' disease and a mild flu-like illness called Pontiac fever.
Atypical pneumonia, also known as walking pneumonia, is any type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of "typical" pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease, it is called primary atypical pneumonia (PAP).
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection.
Legionella pneumophila is a thin, aerobic, pleomorphic, flagellated, non-spore-forming, Gram-negative bacterium of the genus Legionella. L. pneumophila is the primary human pathogenic bacterium in this group and is the causative agent of Legionnaires' disease, also known as legionellosis.
The Legionellales are an order of Proteobacteria. Like all Proteobacteria, they are Gram-negative. They comprise two families, typified by Legionella and Coxiella, both of which include notable pathogens. For example, Q fever is caused by Coxiella burnetii and Legionella pneumophila causes Legionnaires' disease and Pontiac fever.
Legionella longbeachae is one species of the family Legionellaceae. It was first isolated from a patient in Long Beach, California. It is found predominantly in potting soil and compost. In humans, the infection is sometimes called Pontiac fever. Human infection from L. longbeachae is particularly common in Australia, but cases have been documented in other countries including the United States, Japan, Greece and the UK.
An opportunistic infection is an infection caused by pathogens that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune system, an altered microbiome, or breached integumentary barriers. Many of these pathogens do not cause disease in a healthy host that has a non-compromised immune system, and can, in some cases, act as commensals until the balance of the immune system is disrupted. Opportunistic infections can also be attributed to pathogens that cause mild illness in healthy individuals but lead to more serious illness when given the opportunity to take advantage of an immunocompromised host.
Grepafloxacin was an oral broad-spectrum fluoroquinolone antibacterial agent used to treat bacterial infections. Grepafloxacin was withdrawn worldwide from markets in 1999, due to its side effect of lengthening the QT interval on the electrocardiogram, leading to cardiac events and sudden death.
The 1976 Legionnaires disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, United States was the first occasion in which a cluster of a particular type of pneumonia cases were determined to be caused by the Legionella pneumophila bacteria.
Legionella anisa is a Gram-negative bacterium, one of more than 40 species in the family Legionellaceae. After Legionella pneumophila, this species has been isolated most frequently from water samples. This species is also one of the several pathogenic forms of Legionella having been associated with rare clinical cases of illness including Pontiac fever and Legionnaires' disease.
Legionella bozemanae is a Gram-negative bacterium in the family Legionellaceae. Its type strain is WIGA. It is associated with human pneumonia.
Legionella cherrii is an aerobic, flagellated, Gram-negative bacterium from the genus Legionella. It was isolated from a heated water sample in Minnesota. L. cherrii is similar to another Legionella species, L. pneumophila, and is believed to cause major respiratory problems.
Legionella gormanii is a Gram-negative bacterium from the genus Legionella which was isolated from soil samples from a creek bank in Atlanta and from the bronchial brush specimen of a patient who suffered from pneumonia. L. gormanii can cause atypical pneumonia together with L. pneumophila.
Legionella jordanis is a Gram-negative bacterium from the genus Legionella which was isolated from the Jordan River in Bloomington, Indiana and from the sewage in DeKalb County, Georgia. L. jordanis is a rare human pathogen and can cause respiratory tract infections.
Legionella londiniensis is a Gram-negative bacterium from the genus Legionella which was isolated from hot spring water in Shizuoka in Japan.
Legionella steelei is a Gram-negative bacterium from the genus Legionella which was isolated from specimens of the respiratory tract of patients with bronchitis in California and South Australia.
Legionnaires' disease is a form of atypical pneumonia caused by any species of Legionella bacteria, quite often Legionella pneumophila. Signs and symptoms include cough, shortness of breath, high fever, muscle pains, and headaches. Nausea, vomiting, and diarrhea may also occur. This often begins 2–10 days after exposure.
Mycoplasma amphoriforme is a species of bacteria in the genus Mycoplasma. This genus of bacteria lacks a cell wall around their cell membrane. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam antibiotics that target cell wall synthesis. Mycoplasma are the smallest bacterial cells yet discovered, can survive without oxygen and are typically about 0.1 µm in diameter.
