Cutibacterium acnes is the relatively slow-growing, typically aerotolerant anaerobic, gram-positive bacterium (rod) linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. Its genome has been sequenced and a study has shown several genes can generate enzymes for degrading skin and proteins that may be immunogenic.
Obligate anaerobes are microorganisms killed by normal atmospheric concentrations of oxygen (20.95% O2). Oxygen tolerance varies between species, with some species capable of surviving in up to 8% oxygen, while others lose viability in environments with an oxygen concentration greater than 0.5%.
Actinomyces naeslundii is a Gram-positive, rod-shaped bacterium found in the mouth of humans. The species has been implicated in periodontal disease, as well as various tooth cavities. In other cases, A. naeslundii is associated with good oral health. It is one of the first bacteria to occupy the oral cavity and colonize the tooth's surface. It has also been isolated from women with bacterial vaginosis.
Endodontics is the dental specialty concerned with the study and treatment of the dental pulp.
Actinomyces is a genus of the Actinomycetia class of bacteria. They all are gram-positive. Actinomyces species are facultatively anaerobic, 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. The aspect of these colonies initially led to the incorrect assumption that the organism was a fungus and to the name Actinomyces, "ray fungus".
Actinomycosis is a rare infectious bacterial disease caused by Actinomyces species. The name refers to ray-like appearance of the organisms in the granules. About 70% of infections are due to either Actinomyces israelii or A. gerencseriae. Infection can also be caused by Streptomyces somaliensis and Propionibacterium propionicus. The condition is likely to be a polymicrobial anaerobic infection.
Focal infection theory is the historical concept that many chronic diseases, including systemic and common ones, are caused by focal infections. In present medical consensus, a focal infection is a localized infection, often asymptomatic, that causes disease elsewhere in the host, but focal infections are fairly infrequent and limited to fairly uncommon diseases. Focal infection theory, rather, so explained virtually all diseases, including arthritis, atherosclerosis, cancer, and mental illnesses.
Thauera is a genus of Gram-negative bacteria in the family Zoogloeaceae of the order Rhodocyclales of the Betaproteobacteria. The genus is named for the German microbiologist Rudolf Thauer. Most species of this genus are motile by flagella and are mostly rod-shaped. The species occur in wet soil and polluted freshwater.
Aggregatibacter actinomycetemcomitans is a Gram-negative, facultative anaerobe, nonmotile bacterium that is often found in association with localized aggressive periodontitis, a severe infection of the periodontium. It is also suspected to be involved in chronic periodontitis. Less frequently, A. actinomycetemcomitans is associated with nonoral infections such as endocarditis. Its role in aggressive periodontitis was first discovered by Danish-born periodontist Jørgen Slots, a professor of dentistry and microbiology at the University of Southern California School of Dentistry.
Root canal treatment is a treatment sequence for the infected pulp of a tooth which is intended to result in the elimination of infection and the protection of the decontaminated tooth from future microbial invasion. Root canals, and their associated pulp chamber, are the physical hollows within a tooth that are naturally inhabited by nerve tissue, blood vessels and other cellular entities. Together, these items constitute the dental pulp.
Oral microbiology is the study of the microorganisms (microbiota) of the oral cavity and their interactions between oral microorganisms or with the host. The environment present in the human mouth is suited to the growth of characteristic microorganisms found there. It provides a source of water and nutrients, as well as a moderate temperature. Resident microbes of the mouth adhere to the teeth and gums to resist mechanical flushing from the mouth to stomach where acid-sensitive microbes are destroyed by hydrochloric acid.
Actinomyces israelii is a species of Gram-positive, rod-shaped bacteria within the genus Actinomyces. Known to live commensally on and within humans, A. israelii is an opportunistic pathogen and a cause of actinomycosis. Many physiologically diverse strains of the species are known to exist, though not all are strict anaerobes. It was named after the German surgeon James Adolf Israel (1848–1926), who studied the organism for the first time in 1878.
Rothia dentocariosa is a species of Gram-positive, round- to rod-shaped bacteria that is part of the normal community of microbes residing in the mouth and respiratory tract.
Actinomyces gerencseriae is a species in the genus Actinomyces once known as Actinomyces israelii serovar II.
A phoenix abscess is an acute exacerbation of a chronic periapical lesion. It is a dental abscess that can occur immediately following root canal treatment. Another cause is due to untreated necrotic pulp. It is also the result of inadequate debridement during the endodontic procedure. Risk of occurrence of a phoenix abscess is minimised by correct identification and instrumentation of the entire root canal, ensuring no missed anatomy.
Pulp stones are nodular, calcified masses appearing in either or both the coronal and root portion of the pulp organ in teeth. Pulp stones are not painful unless they impinge on nerves.
Lactobacillus crispatus is a common, rod-shaped species of genus Lactobacillus and is a hydrogen peroxide (H2O2) producing beneficial microbiota species located in both the vagina, through vaginal discharge, and the vertebrate gastrointestinal tract. The strain CTV-05 is used as a probiotic that can be used by premenopausal and postmenopausal women that experience recurrent urinary tract infections. It is being evaluated specifically for the prevention and treatment of bacterial vaginosis, which is characterized by the absence of Lactobacillus flora necessary to protect the host from infection.
Actinomyces radicidentis is a species in the genus Actinomyces, first isolated from infected root canals of teeth. Once characterized, it has since been found to be present in failed root canal treatments. Its pathogenicity has been suggested to be due to an ability to form cell aggregates, held together by embedding in an extracellular matrix in host tissues. Like other pathogenic Actinomyces, by collectively finding itself in a protected biofilm environment can evade elimination by host defenses, including phagocytosis.
Actinomyces bovis is a branching, Gram-positive, rod-shaped bacterium of the genus Actinomyces. It is the causative agent of lumpy jaw (actinomycosis) in cattle, and occasionally causes infections in humans. A. bovis normally populates the gastrointestinal tract of healthy ruminants, but is opportunistic in nature and will move into tissues through ulcerations or abrasions of the mucosa to cause disease. Disease occurs when there is physical damage to the tissue of the mouth, allowing the bacteria to colonize the deep tissue and bone, typically affecting the mandible and maxilla. Actinomycosis is pathognomonic for abscesses containing "sulfur" granules, and appears as basophilic colonies with club-shaped reaction products on a histological preparation. Lumpy jaw is commonly treated with broad-spectrum antibiotics with varying success, and can be a major economic loss for producers in countries where it is endemic. Because this organism is zoonotic, it is a human health concern and can cause granulomas, abscesses, skin lesions, and bronchopneumonia.
Actinomyces viscosus is a human and animal pathogen/pathobiont which colonises the mouths of 70% of adult humans. A. viscosus has a low level of virulence and is often mistaken with other actinomycetes.
