How do you classify actinomycetes?

How do you classify actinomycetes?

Order: The Actinomycetes belong to the order Actinomycetales, these are diverse and can be found in terrestrial and aquatic environments in nature. These are aerobic organisms and Gram-positive organisms.

What are characteristics of actinomycetes?

Actinomycetes usually have 1-2 µm diameter. They generally possess a rod shape with a filamentous or branched structure. The filaments contain mumaric acid. Most of the species are aerobic, while a few are anaerobes to facultative aerobes. Cell wall and internal structures are similar to bacteria.

How can you distinguish between actinomycetes and fungi?

Actinomycetes grow as colonies which resemble mycelia of fungi. The key difference between actinomycetes and fungi is that Actinomycetes are prokaryotic organisms while fungi are eukaryotic organisms.

What does actinomycetes look like?

Actinomycetes. The Actinomycetes are a group of unicellular filamentous bacteria that form a branching network of filaments and produce spores. They have long been recognized as sources of severe earthy-musty tastes and odours in drinking water (Mallevialle and Suffet, 1987).

What are Actinomyces species?

Actinomyces species are slow-growing, microaerophilic to facultative anaerobic, gram-positive, filamentous branching bacilli that are known to cause infection in three distinct anatomic sites: cervicofacial, thoracic, and abdominal. 26. They belong to the order Actinomycetales, along with Mycobacteria and Nocardia.

Is Actinomyces aerobic or anaerobic?

Actinomycetes are a group of aerobic and anaerobic bacteria in the order Actinomycetales. These organisms are phylogenetically diverse but morphologically similar, exhibiting characteristic filamentous branching structures which then fragment into bacillary or coccoid forms (1) (Figure 1).

How do actinomycetes appear under a microscope?

Under the light microscope , Actinomyces appear fungus-like. They are thin and joined together to form branching networks. Bacteria of this genus retain the primary stain in the Gram stain reaction, and so are classified as being Gram positive. Actinomycetes are not able to form the dormant form known as a spore.

What is the cell wall composition of actinomycetes?

The cell walls of the actinomycetes were made up of sugars, amino sugars and amino acids (the latter few in number). The general pattern of components was thus identical with that previously found for Gram-positive bacteria. In the fungi, however, the mycelial walls were composed entirely of carbohydrate.

How would you distinguish between bacteria and actinomycetes colony?

Actinomycetes form powdery colonies that stick firmly to agar while bacterial colonies are slimy and distinct. Further, Actinomycetes colonies grow slowly while bacterial colonies grow faster.

How can you tell the difference between Actinomyces and Nocardia?

Actinomyces are part of the normal flora of the mouth and gastrointestinal tract and are generally low virulence. In contrast, Nocardia are saprophytic organisms with a worldwide distribution in soil. Human infections result from direct inoculation of the skin or soft tissue or by inhalation of contaminated soil.

How do actinomycetes appear under microscope?

Is actinomycetes aerobic or anaerobic?

Actinomyces species are facultatively anaerobic (except A. meyeri and A. israelii are obligate anaerobe), and they grow best under anaerobic conditions. Actinomyces species may form endospores, and while individual bacteria are rod-shaped, Actinomyces colonies form fungus-like branched networks of hyphae.

Are actinomycetes fungi or bacteria?

In this section, we shall discuss three genera of actinomycetes: Actinomyces, Nocardia, and Streptomyces. These organisms have been shown to be higher bacteria, but they were thought to be fungi for many years because they have filamentous forms, 0.5 to 0.8 microns in diameter, which appear to branch (figure 1).

How do you identify actinomycete hyphae?

Morphologically, actinomycetes resemble fungi because of their elongated cells that branch into filaments or hyphae. These hyphae can be distinguished from fungal hyphae on the basis of size with actinomycete hyphae much smaller than fungal hyphae ( Figure 4.22 ).

How do you identify aerobic filamentous actinomycetes?

The traditional methods used for the identification of the aerobic filamentous actinomycetes are laborious, time consuming and oftenrequire a series of specialized tests (Steingrubeet al., 1995; Wilson et al., 1998; Harvey et al., 2001).

What is actinomycotic mycetomatous granule?

Actinomycotic mycetomatous granule due to the bacteria Streptomyces somaliensis. Streptomyces spp.are Gram-positive aerobic actinomycetes known for their production of antimicrobial substances. Though they seldom cause human disease, infections can manifest as localized, chronic suppurative lesions of the skin.