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Corynebacterium
''Corynebacterium'' () is a genus of Gram-positive bacteria and most are aerobic. They are bacilli (rod-shaped), and in some phases of life they are, more specifically, club-shaped, which inspired the genus name ('' coryneform'' means "club-shaped"). They are widely distributed in nature in the microbiota of animals (including the human microbiota) and are mostly innocuous, most commonly existing in commensal relationships with their hosts. Some, such as '' C. glutamicum'', are commercially useful. Others can cause human disease, including, most notably, diphtheria, which is caused by '' C. diphtheriae''. As with various species of amicrobiota (including their relatives in the genera '' Arcanobacterium'' and ''Trueperella''), they usually are not pathogenic, but can occasionally opportunistically capitalize on atypical access to tissues (via wounds) or weakened host defenses. Taxonomy The genus ''Corynebacterium'' was created by Lehmann and Neumann in 1896 as a tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corynebacterium Diphtheriae
''Corynebacterium diphtheriae'' is the pathogenic bacterium that causes diphtheria. It is also known as the Klebs–Löffler bacillus, because it was discovered in 1884 by German bacteriologists Edwin Klebs (1834–1912) and Friedrich Löffler (1852–1915). The bacteria are usually harmless unless they are infected by a bacteriophage that carries a gene that gives rise to a toxin. This toxin causes the disease. Diphtheria is caused by the adhesion and infiltration of the bacteria into the mucosal layers of the body, primarily affecting the respiratory tract and the subsequent release of an endotoxin. The toxin has a localized effect on skin lesions, as well as a metastatic, proteolytic effects on other organ systems in severe infections. Originally a major cause of childhood mortality, diphtheria has been almost entirely eradicated due to the vigorous administration of the diphtheria vaccination in the 1910s. Diphtheria is no longer transmitted as frequently due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corynebacterium Ulcerans
''Corynebacterium ulcerans'' is a rod-shaped, aerobic, and Gram-positive bacterium. Most ''Corynebacterium'' species are harmless, but some cause serious illness in humans, especially in immunocompromised humans. ''C. ulcerans'' has been known to cause diphtheria and diphtheria-like infections in patients. Previously thought to simply be contaminants recovered from diphtheria patients, “coryneform” or “diphtheroids” are now believed to be the ''cause'' of such infections. Disease Increasingly over the past few decades, ''C. ulcerans'' has been recognized as an emerging pathogen in over six countries across the globe including the United States, the United Kingdom, and Japan. '' C. diphtheriae'' is the causative agent of classical diphtheria, and ''C. ulcerans'' has been found to carry the same gene that codes for the diphtheria toxin. After swabbing lesions on a 53-year-old woman in Germany who experienced swelling of her pharynx and who developed a whitish pseudomembran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corynebacterium Glutamicum
''Corynebacterium glutamicum'' is a Gram-positive, rod-shaped bacterium that is used industrially for large-scale production of amino acids. While originally identified in a screen for organisms secreting L-glutamate, mutants of ''C. glutamicum'' have also been identified that produce various other amino acids. Due to its industrial importance, several clones of ''C. glutamicum'' have been sequenced by both industry and academic groups. Furthermore, small RNA data was obtained by RNA-Seq in ''C. glutamicum'' ATCC 13032. The metabolism of this strain has been reconstructed and is available in the form of a genome-scale metabolic model. See also * List of sequenced bacterial genomes References External links Genome sequence for ''C. glutamicum''from NCBI The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the gover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphtheria
Diphtheria is an infection caused by the bacterium '' Corynebacterium diphtheriae''. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks more than 10% of those diagnosed with the disease may die. Signs and symptoms may vary from mild to severe and usually start two to five days after exposure. Symptoms often come on fairly gradually, beginning with a sore throat and fever. In severe cases, a grey or white patch develops in the throat. This can block the airway and create a barking cough as in croup. The neck may swell in part due to enlarged lymph nodes. A form of diphtheria which involves the skin, eyes or genitals also exists. Complications may include myocarditis, inflammation of nerves, kidney problems, and bleeding problems due to low levels of platelets. Myocarditis may result in an abnormal heart rate and inflammation of the nerves may result in paralysis. Diphtheria is usually spread between people by direct contact or throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Microbiota
This article lists some of the species recognized as belonging to the human microbiome. Whole-body distributed *''Acinetobacter calcoaceticus'' *''Burkholderia cepacia'' *''Pseudomonas pseudoalcaligenes'' *''Peptostreptococcus spp'' Natural cavities *''Fusobacterium necrophorum'' *''Eubacterium spp'' *'' Microbacterium spp'' Skin *''Acinetobacter spp'' *''Bacillus spp'' *''Candida albicans'' *''Candida parapsilosis'' *''Corynebacterium spp'' *''Corynebacterium parvum'' *''Cutibacterium acnes'' *''Demodex folliculorum'' *''Enterobacter cloacae'' *'' Epidermophyton floccosum'' *''Micrococcus spp'' *'' Micrococcus luteus'' *''Mycobacterium spp'' *''Neisseria spp'' *''Peptostreptococcus spp'' *'' Malassezia ovale'' *''Propionibacterium spp'' *''Pseudomonas aeruginosa'' *'' Sarcina spp'' *''Staphylococcus aureus'' *''Staphylococcus epidermidis'' *'' Staphylococcus haemolyticus'' *''Streptococcus viridans'' *''Trichophyton spp'' Hair follicles *''Staphylococcus aureus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcanobacterium
''Arcanobacterium'' () is a genus of bacteria. They are gram-positive, non– acid fast, nonmotile, facultatively anaerobic, and non–endospore forming. They are widely distributed in nature in the microbiota of animals (including the human microbiota) and are mostly innocuous. Some can cause disease in humans and other animals (for example, ''Arcanobacterium haemolyticum'' infections). As with various species of a microbiota (including their cousins in the genera ''Corynebacterium'' and ''Trueperella''), they usually are not pathogenic but can occasionally opportunistically capitalize on atypical access to tissues (via wounds) or weakened host defenses. Taxonomy As explained by Yassin ''et al''., the genus ''Arcanobacterium'' was first described by Collins ''et al''. in 1982 to accommodate bacterial strains previously assigned to the genus ''Corynebacterium'' variously (and controversially) as ''C. pyogenes hominis'' and then ''C. haemolyticum'', thenceforth to be known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Agar
An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate will grow into individual colonies, each a clone genetically identical to the individual ancestor organism (except for the low, unavoidable rate of mutation). Thus, the plate can be used either to estimate the concentration of organisms in a liquid culture or a suitable dilution of that culture using a colony counter, or to generate genetically pure cultures from a mixed culture of genetically different organisms. Several methods are available to plate out cells. One technique is known as "streaking". In this technique, a drop of the culture on the end of a thin, sterile loop of wire, sometimes known as an inoculator, is streaked across the surface of the agar leaving organisms behind, a higher number at the beginning of the streak and a low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthrobacter
''Arthrobacter'' (from the Greek, "jointed small stick”) is a genus of bacteria that is commonly found in soil. All species in this genus are Gram-positive obligate aerobes that are rods during exponential growth and cocci in their stationary phase. ''Arthrobacter'' have a distinctive method of cell division called "snapping division" or reversion in which the outer bacterial cell wall ruptures at a joint. Description ''Arthrobacter'' can be grown on mineral salts pyridone broth, where colonies have a greenish metallic center on incubated at . Under the microscope, ''Arthrobacter'' appear as rods when rapidly dividing, and cocci when in stationary phase. Dividing cells may also appear as chevrons ("V" shapes). Other notable characteristics are that it can use pyridone as its sole carbon source, and that its cocci are resistant to desiccation and starvation. Use in industry ''Arthrobacter'', like other bacterial genera including ''Brevibacterium'', '' Microbacterium'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocardia
''Nocardia'' is a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments (acting as 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 gingiva, as well as periodontal pockets. Most ''Nocardia'' infections are acquired by inhalation of the bacteria or through traumatic introduction. Culture and staining ''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-f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus (shape)
A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name ''Bacillus'', capitalized and italicized, refers to a specific genus of bacteria. The name Bacilli, capitalized but not italicized, can also refer to a less specific taxonomic group of bacteria that includes two orders, one of which contains the genus ''Bacillus''. When the word is formatted with lowercase and not italicized, 'bacillus', it will most likely be referring to shape and not to the genus at all. Bacilliform bacteria are also often simply called rods when the bacteriologic context is clear. Bacilli usually divide in the same plane and are solitary, but can combine to form diplobacilli, streptobacilli, and palisades. * Diplobacilli: Two bacilli arranged side by side with each other. * Streptobacilli: Bacilli arranged in chains. * Coccoba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosomal RNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal DNA (rDNA) and then bound to ribosomal proteins to form small and large ribosome subunits. rRNA is the physical and mechanical factor of the ribosome that forces transfer RNA (tRNA) and messenger RNA (mRNA) to process and translate the latter into proteins. Ribosomal RNA is the predominant form of RNA found in most cells; it makes up about 80% of cellular RNA despite never being translated into proteins itself. Ribosomes are composed of approximately 60% rRNA and 40% ribosomal proteins by mass. Structure Although the primary structure of rRNA sequences can vary across organisms, base-pairing within these sequences commonly forms stem-loop configurations. The length and position of these rRNA stem-loops allow them to create thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
