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 Scanning electron micrograph of Actinomyces israelii. The scanning electron microscope ( SEM) is a type of Electron microscope that images the sample surface by scanning it with a high-energy beam of Electrons
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A. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Actinobacteria or actinomycetes are a group of Gram-positive bacteria with high G+C ratio. Actinomycetales is an order of Actinobacteria. They are very diverse and contain a variety of subdivisions as well as yet unclassified isolates Actinomycetaceae is a family of bacteria in the order Actinomycetales that contains the medically important genus Actinomyces. bovis |
Actinomyces is a genus of the actinobacteria class of bacteria. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Actinobacteria or actinomycetes are a group of Gram-positive bacteria with high G+C ratio. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have They are all Gram-positive and can be either anaerobic or facultatively anaerobic . Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. An anaerobic organism is any Organism that does not require Oxygen for growth and may even die in its presence A facultative anaerobic organism is an Organism, usually a Bacterium, that makes ATP by Aerobic respiration if Oxygen is present Actinomyces species do not form endospores, and, while individual bacteria are rod-shaped, morphologically Actinomyces colonies form fungus-like branched networks of hyphae. An endospore is a dormant, tough and non-reproductive structure produced by a small number of Bacteria from the Firmicute phylum A fungus (ˈfʌŋgəs is a eukaryotic Organism that is a member of the kingdom Fungi (ˈfʌndʒaɪ A hypha (plural hyphae) is a long branching filamentous cell of a Fungus, and also of unrelated Actinobacteria. [1]
Actinomyces are known for causing disease in humans, and for the important role they play in soil ecology. Soil ecology is the study of the interactions among soil organisms and between biotic and abiotic aspects of the soil environment They produce a number of enzymes that help degrade organic plant material, lignin and chitin. Organic matter (or organic material) is Matter that has come from a once-living Organism; is capable of Lignin or lignen is a complex Chemical compound most commonly derived from Wood and an integral part of the secondary Cell walls of Plants Chitin ( C 8 H 13 O 5 N)n (ˈkaɪtən is a long-chain Polymer of a N-acetylglucosamine As such, their presence is important in the formation of compost. Compost (ˈkɒmpɒst or US /ˈkɒmpoʊst/ also known as brown manure is the aerobically decomposed remnants of Organic matter.
Many Actinomyces species are opportunistic pathogens of humans and other mammals, particularly in the oral cavity. The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up [2] In rare cases, these bacteria can cause actinomycosis, a disease characterized by the formation of abscesses in the mouth, lungs, or the gastrointestinal tract. Actinomycosis (ak-tuh-nuh-my-KOH-sihs, is a rare infectious Bacterial disease of humans generally caused by Actinomyces israelii, An abscess (abscessus is a collection of Pus (dead Neutrophils) that has accumulated in a cavity formed by the tissue on the basis of an infectious process [3]
Some species are responsible for the smell of topsoil, which is often particularly noticeable after rain. [4] The main chemical responsible from this smell is geosmin. Geosmin, which literally translates to " earth smell " is an organic compound with a distinct earthy flavour and aroma and is responsible [5]
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Disease
Actinomycosis is most frequently caused by Actinomyces israelii and is sometimes known as the "most misdiagnosed disease," as it is frequently confused with neoplasms. A. israelii is a normal colonizer of the vagina, colon, and mouth. Infection is established first by a breach of the mucosal barrier during various procedures (dental, GI), aspiration, or pathologies such as diverticulitis. The chronic phase of this disease is also known the "classic phase" because the acute, early phase is often missed by health care providers. This is characterized by slow contiguous growth that ignores tissue planes and forms a sinus tract that can spontaneously heal and recur, leading to a densely fibrotic lesion. This lesion is often characterized as "wooden. " Sulfur granules form in a central purulence surrounded by neutrophils. This conglomeration of organisms is virtually diagnostic of Actinomyces israelii. Oral-cervicofacial disease is the most common form of actinomycosis. It is characterized by a painless "lumpy jaw. " Lymphadenopathy is uncommon in this form of the disease. Another form of actinomycosis is thoracic disease, which is often misdiagnosed as a neoplasm, as it forms a mass that extends to the chest wall. It arises from aspiration of organisms from the oropharynx. Symptoms include chest pain, fever, and weight loss. Abdominal disease is another manifestation of actinomycosis. This can lead to a sinus tract that drains to the abdominal wall or the perianal area. Pelvic actinomycosis is often caused by intrauterine devices (IUD). An intrauterine device ( intra meaning within, and uterine meaning of the Uterus) is a Birth control device placed An intrauterine device ( intra meaning within, and uterine meaning of the Uterus) is a Birth control device placed Symptoms include fever, abdominal pain, and weight loss. [6] Actinomyces sp. have also been shown to infect the central nervous system in a dog "without history or evidence of previous trauma or other organ involvement. " [1]
Treatment
Treatment for actinomycosis consists of antibiotics such as penicillin or amoxicillin for six to twelve months, as well as surgery if the disease is extensive. [6]
Diagnosis
Consider actinomycosis when the patient has chronic progression of disease across tissue planes that is mass-like at times, sinus tract development that may heal and recur, and refractory infection after a typical course of antibiotics. [6]
References
- ^ Holt JG (editor) (1994). Bergey's Manual of Determinative Bacteriology, 9th ed. , Williams & Wilkins. ISBN 0-683-00603-7.
- ^ Madigan M; Martinko J (editors). (2005). Brock Biology of Microorganisms, 11th ed. , Prentice Hall. ISBN 0-13-144329-1.
- ^ Bowden GHW (1996). Actinomycosis in: Baron's Medical Microbiology (Baron S et al, eds. ), 4th ed. , Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
- ^ The Sweet Smell of Rain
- ^ The Role of Actinomycetes in Coffee Plantation Ecology. Retrieved on 2008-01-16. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 27 BC - The title Augustus is bestowed upon Gaius Julius Caesar Octavian by the Roman Senate.
- ^ a b c El Sahli, MD, MS. "Anaerobic Pathogens. " Infectious Disease Module 2007. Baylor College of Medicine, 2007.
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