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Mannheimia Succiniciproducens
''Mannheimia'' is a genus of Gram-negative bacteria in the family ''Pasteurellaceae''. Members of this genus are typically facultatively anaerobic, non-spore-forming, and non-motile coccobacilli. Species of ''Mannheimia'' are primarily associated with mucosal surfaces of domestic and wild animals, especially ruminants. The most well-known species, ''Mannheimia haemolytica'', is an important pathogen in veterinary medicine and is a leading cause of bovine respiratory disease complex (BRDC). History The genus ''Mannheimia'' was proposed in 1999 by Danish microbiologist Ole Angen and colleagues. It was created to resolve taxonomic confusion within the former '' Pasteurella haemolytica'' complex based on results from DNA–DNA hybridization and 16S rRNA 16S ribosomal RNA (or 16Svedberg, S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannheimia Haemolytica
''Mannheimia haemolytica'' is a species of Gram-negative bacteria belonging to the family Pasteurellaceae. It is a facultatively anaerobic, non-spore-forming, and non-motile coccobacillus. ''M. haemolytica'' is a primary bacterial pathogen implicated in the bovine respiratory disease complex (BRDC), also commonly known as "shipping fever," particularly affecting cattle, sheep, and goats. History ''Mannheimia haemolytica'' was originally described as ''Pasteurella haemolytica'' by Newsom and Cross in 1932, based on bipolar organisms isolated from cases of pneumonia in sheep and cattle. For decades, it was classified within the genus ''Pasteurella''. However, advances in molecular taxonomy led to a reassessment of the '' asteurellahaemolytica'' complex. In 1999, Angen and colleagues conducted a comprehensive study using DNA–DNA hybridization and 16S rRNA gene sequencing, which demonstrated sufficient genetic divergence to warrant creation of a new genus, ''Mannheimia''. Pathogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasteurellaceae
The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notable group of facultative anaerobes. Their biochemical characteristics can be distinguished from the related Enterobacteriaceae by the presence of oxidase, and from most other similar bacteria by the absence of flagella. Bacteria in the family Pasteurellaceae have been classified into a number of genera based on metabolic properties, but these classifications are not generally accurate reflections of the evolutionary relationships between different species. ''Haemophilus influenzae'' was the first organism to have its genome sequenced and has been studied intensively by genetic and molecular methodologies. The genus '' Haemophilus'' is a notorious human pathogen associated with bacteremia, pneumonia, meningitis and chancroid. Other pathogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16S Ribosomal RNA
16S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S rRNA genes and are used in reconstructing phylogenies, due to the slow rates of evolution of this region of the gene. Carl Woese and George E. Fox were two of the people who pioneered the use of 16S rRNA in phylogenetics in 1977. Multiple sequences of the 16S rRNA gene can exist within a single bacterium. Terminology The descriptor ''16S'' refers to the size of these ribosomal subunits as reflected indirectly by the speed at which they sediment when samples are centrifuged. Thus ''16S'' means 16 Svedburg units. Functions * Like the large (23S) ribosomal RNA, it has a structural role, acting as a scaffold defining the positions of the ribosomal proteins. * The 3-end contains the anti- Shine-Dalgarno sequence, which binds upstream ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA–DNA Hybridization
In genomics, DNA–DNA hybridization is a molecular biology technique that measures the degree of genetic similarity between DNA sequences. It is used to determine the genetic distance between two organisms and has been used extensively in phylogeny and taxonomy. Method The DNA of one organism is labelled, then mixed with the unlabelled DNA to be compared against. The mixture is incubated to allow DNA strands to dissociate and then cooled to form renewed hybrid double-stranded DNA. Hybridized sequences with a high degree of similarity will bind more firmly, and require more energy to separate them. An example is they separate when heated at a higher temperature than dissimilar sequences, a process known as " DNA melting". To assess the melting profile of the hybridized DNA, the double-stranded DNA is bound to a column or filter and the mixture is heated in small steps. At each step, the column or filter is washed; then sequences that melt become single-stranded and wash off. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasteurella Haemolytica
__NOTOC__ ''Pasteurella'' is a genus of Gram-negative, facultatively anaerobic bacteria. ''Pasteurella'' species are nonmotile and pleomorphic, and often exhibit bipolar staining ("safety pin" appearance). Most species are catalase- and oxidase-positive. The genus is named after the French chemist and microbiologist, Louis Pasteur, who first identified the bacteria now known as ''Pasteurella multocida'' as the agent of chicken cholera. Pathogenesis Many ''Pasteurella'' species are zoonotic pathogens, and humans can acquire an infection from domestic animal bites. In cattle, sheep, and birds, ''Pasteurella'' species can cause a life-threatening pneumonia; in cats and dogs, however, ''Pasteurella'' is not a cause of disease, and constitutes part of the normal flora of the nose and mouth. ''Pasteurella haemolytica'' is a species that infects mainly cattle and horses: '' P. multocida'' is the most frequent causative agent in human ''Pasteurella'' infection. Common symptoms of pasteu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bovine Respiratory Disease Complex
Bovine respiratory disease (BRD) is the most common and economically devastating infectious disease affecting beef cattle in the world. It is a complex, bacterial or viral infection that causes pneumonia in calves which can be fatal. It also affects many other species of feedlot animals like sheep and pigs, but is most prominent in calves. The infection is usually a sum of three codependent factors: stress, an underlying viral infection, and a new bacterial infection. The diagnosis of the disease is complex since there are multiple possible causes and cattle are reluctant to display any indications of pain. The disease manifests itself most often in calves within four weeks of weaning, when calves are sorted into groups of roughly 10–15 in number, and sold to different feedlots via train, tractor trailer, and truck. Because of this, BRD is most commonly referred to as "shipping fever". It is not known whether the stress itself, co-mingling, or travel conditions are at most to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccobacillus
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-motile Bacteria
Non-motile bacteria are bacteria species that lack the ability and structures that would allow them to propel themselves, under their own power, through their environment. When non-motile bacteria are cultured in a stab tube, they only grow along the stab line. If the bacteria are mobile, the line will appear diffuse and extend into the medium. The cell structures that provide the ability for locomotion are the cilia and flagella. Coliform and Streptococci are examples of non-motile bacteria as are ''Klebsiella pneumoniae'', and ''Yersinia pestis''. Motility is one characteristic used in the identification of bacteria and evidence of possessing structures: peritrichous flagella, polar flagella and/or a combination of both. Though the lack of motility might be regarded a disadvantage, some non-motile bacteria possess structures that allow their attachment to eukaryotic cells The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the Biological life cycle, life cycles of many plants, algae, fungus, fungi and protozoa. They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. In some rare cases, a diploid spore is also p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facultative Anaerobic Organism
A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are '' Staphylococcus'' spp., ''Escherichia coli'', ''Salmonella'', '' Listeria'' spp., '' Shewanella oneidensis'' and '' Yersinia pestis''. Certain eukaryotes are also facultative anaerobes, including pupfish, fungi such as ''Saccharomyces cerevisiae'' and many aquatic invertebrates such as nereid polychaetes. It has been observed that in mutants of '' Salmonella typhimurium'' that underwent mutations to be either obligate aerobes or anaerobes, there were varying levels of chromatin-remodeling proteins. The obligate aerobes were later found to have a defective DNA gyrase subunit A gene ('' gyrA''), while obligate anaerobes were defective in topoisomerase I (''topI''). This indicates that topoisomerase I and its associated relaxation of chromosomal DNA is r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacteria
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists of a thin peptidoglycan gram-negative cell wall, cell wall sandwiched between an inner (Cytoplasm, cytoplasmic) Cell membrane, membrane and an Bacterial outer membrane, outer membrane. These bacteria are found in all environments that support life on Earth. Within this category, notable species include the model organism ''Escherichia coli'', along with various pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They pose significant challenges in the medical field due to their outer membrane, which acts as a protective barrier against numerous Antibiotic, antibiotics (including penicillin), Detergent, detergents that would normally damage the inner cell membrane, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name (zoology), specific name or the specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
