Search results
Results from the WOW.Com Content Network
Very few structures are acid-fast; this makes staining for acid-fastness particularly useful in diagnosis. The following are notable examples of structures which are acid-fast or modified acid-fast: All Mycobacteria – M. tuberculosis, M. leprae, M. smegmatis and atypical mycobacteria.
After the Ziehl-Neelsen staining procedure using carbol fuchsin, acid-fast bacteria are observable as vivid red or pink rods set against a blue or green background, depending on the specific counterstain used, such as methylene blue or malachite green, respectively. Non-acid-fast bacteria and other cellular structures will be colored by the ...
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.
Gram-positive, nonmotile and acid-fast rods (1-3 μm x 0.2-0.4 μm). Sometimes long rods with occasional beaded or swollen cells having non-acid-fast ovoid bodies at one end. Colony characteristics. Smooth hemispheric colonies, usually off-white or cream colored. May be butyrous, waxy, multilobate and even rosette clustered (dilute inocula).
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.
These bacteria cause Mycobacterium avium-intracellulare infections or Mycobacterium avium complex infections in humans. [2] These bacteria are common and are found in fresh and salt water, in household dust and in soil. [3] MAC bacteria usually cause infection in those who are immunocompromised or those with severe lung disease.
In some cases, the presence of acid-fast leprosy bacilli in skin smears is considered diagnostic; however, the diagnosis is typically made without laboratory tests, based on symptoms. [4] If a person has a new leprosy diagnosis and already has a visible disability caused by leprosy, the diagnosis is considered late. [31]
Other bacteria are commonly identified with a microscope by staining them with Gram stain. However, the mycolic acid in the cell wall of M. tuberculosis does not absorb the stain. Instead, acid-fast stains such as Ziehl–Neelsen stain, or fluorescent stains such as auramine are used. [4]