Civil Rights
Movements, leaders, victories and the continuing fight for equality.
q2K BHP
Black History Portal
THE BHP WIRE —
HIDDEN TRUTHS
What's New!
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
Mansa Musa was the ruler of the Mali Empire in West Africa. Details recorded here should be sourced; unknown information is left blank.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
| Nocardia | |
|---|---|
| |
| Close-up image of a Nocardia species culture on sheep blood agar | |
Scientific classification 
| |
| Domain: | Bacteria |
| Kingdom: | Bacillati |
| Phylum: | Actinomycetota |
| Class: | Actinomycetes |
| Order: | Mycobacteriales |
| Family: | Nocardiaceae |
| Genus: | Nocardia Trevisan 1889 (Approved Lists 1980) |
| Type species | |
| Nocardia asteroides (Eppinger 1891) Blanchard 1896 (Approved Lists 1980)
| |
| Species | |
|
See text. | |
| Synonyms[1] | |
| |
Nocardia is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. Species from this genus form partially acid-fast beaded branching filaments (appearing similar to fungi, but being truly bacteria). It contains a total of 85 species. Some species are nonpathogenic, while others are responsible for nocardiosis.[3] Nocardia species are found worldwide in soil rich in organic matter. In addition, they are oral microflora found in healthy human gingiva, as well as periodontal pockets.[4] Most Nocardia infections are acquired by inhalation of the bacteria or through traumatic introduction through openings in epithelial barriers.
Nocardia colonies have a variable appearance, but most species appear to have aerial hyphae when viewed with a dissecting microscope, particularly when they have been grown on nutritionally limiting media. Nocardia grow slowly on nonselective culture media, and are strict aerobes with the ability to grow in a wide temperature range. Some species are partially acid-fast (meaning a less concentrated solution of sulfuric or hydrochloric acid should be used during the staining procedure) due to the presence of intermediate-length mycolic acids in their cell wall. Majority of strains possess the cord factor (trehalose 6-6' dimycolate), an important virulence factor.
They are catalase positive and can grow easily on the most commonly used media with colonies becoming evident in 3–5 days. However, prolonged incubation periods (2–3 weeks) are sometimes needed.
The various species of Nocardia are pathogenic bacteria with low virulence; therefore clinically significant disease most frequently occurs as an opportunistic infection in those with a weak immune system, such as small children, the elderly, and the immunocompromised (most typically, HIV). Nocardial virulence factors are the enzymes catalase and superoxide dismutase (which inactivate reactive oxygen species that would otherwise prove toxic to the bacteria), as well as a "cord factor" (which interferes with phagocytosis by macrophages by preventing the fusion of the phagosome with the lysosome).[citation needed]
An important virulence factor in many pathogenic strains of Nocardia is trehalose dimycolate, which is also found in the bacterial genus Mycobacterium. This toxin can cause cachexia, a form of muscle wasting.[5]
 | This article needs more citations. (July 2009) |
The most commonly encountered species are Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, and Nocardia nova. Nocardia asteroides is most frequently found species causing noncutaneous invasive disease. Most cases occur as an opportunistic infection in immunocompromised patients. N. brasiliensis is the most common species causing cutaneous nocardiosis. N. caviae is another species of medical interest. The genus is acid-fast to some degree, it stains only weakly Gram positive.
The most common form of human nocardial disease is a slowly progressive pneumonia, the common symptoms of which include cough, dyspnea (shortness of breath), and fever. It is not uncommon for this infection to spread to the pleura or chest wall. Pre-existing pulmonary disease, especially pulmonary alveolar proteinosis, increases the risk of contracting a Nocardia pneumonia. Every organ can be affected if a systemic spread takes place.
Nocardia species are deeply involved in the process of encephalitis as one of its main pathogenic effects. In about 25–33% of people Nocardia infection takes the form of encephalitis and/or brain abscess formation. Nocardia may also cause a variety of cutaneous infections such as actinomycetoma (especially N. brasiliensis), lymphocutaneous disease, cellulitis, and subcutaneous abscesses.[6]
Nocardia isolation from biological specimens can be performed using an agar medium enriched with yeast extract and activated charcoal (BCYE), the same used for Legionella species. Selective media for mycobacteria or fungi can also be inoculated. The most suitable specimens are the sputum, or when clinically necessary, bronchoalveolar lavage or biopsy. Further biochemical tests for species identification are not routinely performed. Serological or cutaneous tests are not available.
In most patients with Nocardia infection, the combination of antibiotics is needed.[7] Antibiotic therapy with a sulfonamide, most commonly trimethoprim-sulfamethoxazole, is the treatment of choice.[8] People who take trimethoprim-sulfamethoxazole for other reasons, such as prevention of Pneumocystis jirovecii infection, appear to have fewer Nocardia infections,[9] although this protective effect has been considered unreliable,[10] and some studies have disputed it altogether.[11] Minocycline is usually substituted when a sulfa cannot be given; high-dose imipenem and amikacin have also been used in severe or refractory cases.[8] Linezolid appears to be highly effective against Nocardia, but it is very expensive and may cause severe adverse effects.[12]
Antibiotic therapy is continued for six months (in immunocompetent people) to a year (in immunosuppression), and may need to be continued indefinitely.[8] Proper wound care is also critical.
Although Nocardia has interesting and important features such as production of antibiotics and aromatic compound-degrading or -converting enzymes, the genetic study of this organism has been hampered by the lack of genetic tools. However, practical Nocardia–E. coli shuttle vectors have been developed recently.[13]
The genera Nocardia and Rhodococcus have been found to be closely related, supported by two conserved signature indels consisting of a one-amino-acid deletion in the alpha subunit of acetyl coenzyme A carboxylase (ACC), and a three-amino-acid insertion in a conserved region of an ATP-binding protein that are specifically shared by species from these two genera. In addition, 14 hypothetical conserved signature proteins have been identified which are unique to the genera Nocardia and Rhodococcus.[14]
Nocardia comprises the following species:[1]
The genus was named for Edmond Nocard (1850–1903), a French veterinarian and biologist.[15]
The genus was circumscribed in 1888 by Vittore Benedetto Antonio Trevisan di Saint-Léon in Annales de l'Institut Pasteur volume 2 (Issue 6) on page 295.[2]
| Authority control databases: National |
|---|
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
Nocardia is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. Species from this genus form partially acid-fast beaded branching filaments (appearing similar to fungi, but being truly bacteria). It contains a total of 85 species. Some species are nonpathogenic, while others are responsible for nocardiosis. Nocardia species are found worldwide in soil rich in organic matter. In addition, they are oral microflora found in healthy human gingiva, as well as periodontal pockets. Most Nocardia infections are acquired by inhalation of the bacteria or through traumatic introduction through openings in epithelial barriers.
In microbiology, collective bacteria and other microorganisms in a host are historically known as flora. Although microflora is commonly used, the term microbiota is becoming more common as microflora is a misnomer. Flora pertains to the Kingdom Plantae. Microbiota includes Archaea, Bacteria, Fungi and Protists. Microbiota with animal-like characteristics can be classified as microfauna.
A lawn aerator is a garden tool designed to create holes in the soil in order to help lawn grasses grow. In compacted lawns, aeration improves soil drainage and encourages worms, microfauna and microflora which require oxygen.
A fermentation starter (called simply starter within the corresponding context, sometimes called a mother) is a preparation to assist the beginning of the fermentation process in preparation of various foods and alcoholic drinks. Food groups where they are used include breads, especially sourdough bread, and cheese. A starter culture is a microbiological culture which actually performs fermentation. These starters usually consist of a cultivation medium, such as grains, seeds, or nutrient liquids that have been well colonized by the microorganisms used for the fermentation. These starters are formed using a specific cultivation medium and a specific mix of fungal and bacterial strains. Typical microorganisms used in starters include various bacteria and fungi (yeasts and molds): Rhizopus, Aspergillus, Mucor, Amylomyces, Endomycopsis, Saccharomyces, Hansenula anomala, Lactobacillus, Acetobacter, etc. Various national cultures have various active ingredients in starters, and often involve mixed microflora. Industrial starters include various enzymes, in addition to microflora.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Shirley Chisholm, elected in 1968.
