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Neisseria Lactamica
''Neisseria lactamica'' is a gram-negative diplococcus bacterium. It is strictly a commensal species of the nasopharynx. Uniquely among the ''Neisseria'' they are able to produce β-D-galactosidase and ferment lactose. This species is most commonly carried by young children. There is an inverse relationship between colonisation by ''N. lactamica'' and ''Neisseria meningitidis''. Carriage of ''N. lactamica'' has been associated with decreased incidence of invasive meningococcal disease. However, resistance to penicillin and other beta-lactams may be transmitted from commensal neisseriae such as ''Neisseria lactamica'' to disease causing ''Neisseria meningitidis'' by the process of genetic transformation. References External links * tp://ftp.sanger.ac.uk/pub/pathogens/Neisseria/lactamica/ Genome sequence of ''Neisseria lactamica'' (an ST640 strain).Published on the Wellcome Trust Sanger Institute The Wellcome Sanger Institute, previously known as The Sanger Centre and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplococcus
A diplococcus (plural diplococci) is a round bacterium (a coccus) that typically occurs in the form of two joined cells. Types Examples of gram-negative diplococci are '' Neisseria spp.'' and ''Moraxella catarrhalis.'' Examples of gram-positive diplococci are ''Streptococcus pneumoniae'' and ''Enterococcus'' spp. Presumably, diplococcus has been implicated in encephalitis lethargica Encephalitis lethargica is an atypical form of encephalitis. Also known as "sleeping sickness" or "sleepy sickness" (distinct from tsetse fly-transmitted sleeping sickness), it was first described in 1917 by neurologist Constantin von Economo a .... Taxonomy Gram-negative diplococci ''Neisseria'' spp. Phylum: Proteobacteria Class: Betaproteobacteria Order: Neisseriales Family: Neisseriaceae Genus: ''Neisseria'' The genus ''Neisseria'' belongs to the family Neisseriaceae. This genus, ''Neisseria,'' is divided into more than ten different species, but most of them are gram negat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commensalism
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit from each other; amensalism, where one is harmed while the other is unaffected; parasitism, where one is harmed and the other benefits, and parasitoidism, which is similar to parasitism but the parasitoid has a free-living state and instead of just harming its host, it eventually ends up killing it. The commensal (the species that benefits from the association) may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the remoras that ride attached to sharks and other fishes. Remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasopharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food and air to the esophagus and larynx respectively. The flap of cartilage called the epiglottis stops food from entering the larynx. In humans, the pharynx is part of the digestive system and the conducting zone of the respiratory system. (The conducting zone—which also includes the nostrils of the nose, the larynx, trachea, bronchi, and bronchioles—filters, warms and moistens air and conducts it into the lungs). The human pharynx is conventionally divided into three sections: the nasopharynx, oropharynx, and laryngopharynx. It is also important in vocalization. In humans, two sets of pharyngeal muscles form the pharynx and determine the shape of its lumen. They are arranged as an in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neisseria
''Neisseria'' is a large genus of bacteria that colonize the mucosal surfaces of many animals. Of the 11 species that colonize humans, only two are pathogens, '' N. meningitidis'' and ''N. gonorrhoeae''. ''Neisseria'' species are Gram-negative bacteria included among the Pseudomonadota, a large group of Gram-negative forms. ''Neisseria'' diplococci resemble coffee beans when viewed microscopically. Pathogenesis and classification Pathogens Species of this genus (family Neisseriaceae) of parasitic bacteria grow in pairs and occasionally tetrads, and thrive best at 98.6 °F (37 °C) in the animal body or serum media. The genus includes: * ''N. gonorrhoeae'' (also called the gonococcus) causes gonorrhea. * '' N. meningitidis'' (also called the meningococcus) is one of the most common causes of bacterial meningitis and the causative agent of meningococcal septicaemia. These two species have the ability of 'breaching' the barrier. Local cytokines of the area become secr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-galactosidase
β-Galactosidase (EC 3.2.1.23, lactase, beta-gal or β-gal; systematic name β-D-galactoside galactohydrolase), is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides. β-Galactosides include carbohydrates containing galactose where the glycosidic bond lies above the galactose molecule. Substrates of different β-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins. Function β-Galactosidase is an exoglycosidase which hydrolyzes the β-glycosidic bond formed between a galactose and its organic moiety. It may also cleave fucosides and arabinosides but with much lower efficiency. It is an essential enzyme in the human body. Deficiencies in the protein can result in galactosialidosis or Morquio B syndrome. In '' E. coli'', the ''lacZ'' gene is the structural gene for β-galactosidase; which is present as part of the inducible system ''lac'' operon which is activ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neisseria Meningitidis
''Neisseria meningitidis'', often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a coccus because it is round, and more specifically a diplococcus because of its tendency to form pairs. About 10% of adults are carriers of the bacteria in their nasopharynx. As an exclusively human pathogen, it is the main cause of bacterial meningitis in children and young adults, causing developmental impairment and death in about 10% of cases. It causes the only form of bacterial meningitis known to occur epidemically, mainly in Africa and Asia. It occurs worldwide in both epidemic and endemic form. ''N. meningitidis'' is spread through saliva and respiratory secretions during coughing, sneezing, kissing, chewing on toys and through sharing a source of fresh water. It has also been reported to be transmitted through oral sex and cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformation (genetics)
In molecular biology and genetics, transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). For transformation to take place, the recipient bacterium must be in a state of competence, which might occur in nature as a time-limited response to environmental conditions such as starvation and cell density, and may also be induced in a laboratory. Transformation is one of three processes that lead to horizontal gene transfer, in which exogenous genetic material passes from one bacterium to another, the other two being conjugation (transfer of genetic material between two bacterial cells in direct contact) and transduction (injection of foreign DNA by a bacteriophage virus into the host bacterium). In transformation, the genetic material passes through the intervening medium, and uptake is completely dependent on the recipient bacterium. As of 2014 about 8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanger Institute
The Wellcome Sanger Institute, previously known as The Sanger Centre and Wellcome Trust Sanger Institute, is a non-profit organisation, non-profit British genomics and genetics research institute, primarily funded by the Wellcome Trust. It is located on the Wellcome Genome Campus by the village of Hinxton, outside Cambridge. It shares this location with the European Bioinformatics Institute. It was established in 1992 and named after double Nobel Laureate Frederick Sanger. It was conceived as a large scale DNA sequencing centre to participate in the Human Genome Project, and went on to make the largest single contribution to the gold standard sequence of the human genome. From its inception the institute established and has maintained a policy of data sharing, and does much of its research in collaboration. Since 2000, the institute expanded its mission to understand "the role of genetics in health and disease". The institute now employs around 900 people and engages in five mai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
