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Coccus
Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea). Generally, the basic morphologies are spheres (coccus) and round-ended cylinders or rod shaped (bacillus). But, there are also other morphologies such as helically twisted cylinders (example '' Spirochetes''), cylinders curved in one plane (selenomonads) and unusual morphologies (the square, flat box-shaped cells of the Archaean genus '' Haloquadratum)''. Other arrangements include pairs, tetrads, clusters, chains and palisades. Types Coccus A coccus (plural ''cocci'', from the Latin ''coccinus'' (scarlet) and derived from the Greek ''kokkos'' (berry)), is any microorganism (usually bacteria) whose overall shape is spherical or nearly spherical. Coccus refers to the shape of the bacteria and can contain multiple genera, such as st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococci
''Streptococcus'' is a genus of gram-positive spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, thus when growing they tend to form pairs or chains, which may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera '' Enterococcus'' and '' Lactococcus''. Currently, over 50 species are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe, meaning that it can grow without oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococci
''Staphylococcus'', from Ancient Greek σταφυλή (''staphulḗ''), meaning "bunch of grapes", and (''kókkos''), meaning "kernel" or " Kermes", is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical ( cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultative anaerobic organisms (capable of growth both aerobically and anaerobically). The name was coined in 1880 by Scottish surgeon and bacteriologist Alexander Ogston (1844–1929), following the pattern established five years earlier with the naming of '' Streptococcus''. It combines the prefix "staphylo-" (from ), and suffixed by the (from ). Staphylococcus was one of the leading infections in hospitals and many strains of this bacterium have become antibiotic resistant. Despite strong attempts to get rid of them, staphylococcus bacteria stay present in hospitals, where they can infect people who are most at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus Pyogenes
''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus '' Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They are clinically important for humans, as they are an infrequent, but usually pathogenic, part of the skin microbiota that can cause group A streptococcal infection. ''S. pyogenes'' is the predominant species harboring the Lancefield group A antigen, and is often called group A ''Streptococcus'' (GAS). However, both '' Streptococcus dysgalactiae'' and the '' Streptococcus anginosus'' group can possess group A antigen as well. Group A streptococci, when grown on blood agar, typically produce small (2–3 mm) zones of beta-hemolysis, a complete destruction of red blood cells. The name group A (beta-hemolytic) ''Streptococcus'' is thus also used. The species name is derived from Greek words meaning 'a chain' () of berries ( atiniz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrococcus
''Micrococcus'', from Ancient Greek μικρός (''mikrós''), meaning "small", and κόκκος (''kókkos''), meaning "sphere", is a genus of bacteria in the Micrococcaceae family (biology), family. ''Micrococcus'' occurs in a wide range of environments, including water, dust, and soil. Micrococci have Gram-positive spherical cells ranging from about 0.5 to 3 micrometers in diameter and typically appear in tetrads. They are catalase positive, oxidase positive, indole negative and citrate test, citrate negative. ''Micrococcus'' has a substantial cell wall, which may comprise as much as 50% of the cell mass. The genome of ''Micrococcus'' is rich in guanine and cytosine (GC), typically exhibiting 65 to 75% GC-content. Micrococci often carry plasmids (ranging from 1 to 100 MDa in size) that provide the organism with useful traits. Some species of ''Micrococcus'', such as ''M. luteus'' (yellow) and ''M. roseus'' (red) produce yellow or pink colonies when grown on mannitol salt agar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplococci
Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea). Generally, the basic morphologies are spheres (coccus) and round-ended cylinders or rod shaped (bacillus). But, there are also other morphologies such as helically twisted cylinders (example '' Spirochetes''), cylinders curved in one plane (selenomonads) and unusual morphologies (the square, flat box-shaped cells of the Archaean genus '' Haloquadratum)''. Other arrangements include pairs, tetrads, clusters, chains and palisades. Types Coccus A coccus (plural ''cocci'', from the Latin ''coccinus'' (scarlet) and derived from the Greek ''kokkos'' (berry)), is any microorganism (usually bacteria) whose overall shape is spherical or nearly spherical. Coccus refers to the shape of the bacteria and can contain multiple genera, such as sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pneumonia
Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, chest pain, fever, and Shortness of breath, difficulty breathing. The severity of the condition is variable. Pneumonia is usually caused by infection with viruses or bacteria, and less commonly by other microorganisms. Identifying the responsible pathogen can be difficult. Diagnosis is often based on symptoms and physical examination. Chest X-rays, blood tests, and Microbiological culture, culture of the sputum may help confirm the diagnosis. The disease may be classified by where it was acquired, such as community- or hospital-acquired or healthcare-associated pneumonia. Risk factors for pneumonia include cystic fibrosis, chronic obstructive pulmonary disease (COPD), sickle cell disease, asthma, diabetes, heart failure, a history of smoking, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meningitis
Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasionally photophobia. Other symptoms include confusion or altered consciousness, nausea, and an inability to tolerate loud noises. Young children often exhibit only nonspecific symptoms, such as irritability, drowsiness, or poor feeding. A non-blanching rash (a rash that does not fade when a glass is rolled over it) may also be present. The inflammation may be caused by infection with viruses, bacteria, fungi or parasites. Non-infectious causes include malignancy (cancer), subarachnoid hemorrhage, chronic inflammatory disease ( sarcoidosis) and certain drugs. Meningitis can be life-threatening because of the inflammation's proximity to the brain and spinal cord; therefore, the condition is classified as a medical emergency. A lumba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
