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Shigella Sonnei
''Shigella sonnei'' is a species of '' Shigella''. Together with '' Shigella flexneri'', it is responsible for 90% of shigellosis cases. ''Shigella sonnei'' is named for the Danish bacteriologist Carl Olaf Sonne. It is a Gram-negative, rod-shaped, nonmotile, non-spore-forming bacterium. Pathophysiology This species polymerizes host cell actin. Evolution This species is clonal and has spread worldwide. Analysis of 132 strains has shown that they originated from a common ancestor in Europe around 1500 AD. Causes "Group D" '' Shigella'' bacteria cause shigellosis. Those infected with the bacteria release it into their stool, thus causing possibility of spread through food or water, or from direct contact to a person orally. Having poorly sanitized living conditions or contaminated food or water contributes to contracting the disease. People at risk Infants and toddlers, the elderly, and people living with chronic health conditions are all susceptible to the most severe sympt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hektoen Enteric Agar
Hektoen enteric agar (HEK, HE or HEA) is a selective and differential agar primarily used to recover '' Salmonella'' and '' Shigella'' from patient specimens. HEA contains indicators of lactose fermentation and hydrogen sulfide production; as well as inhibitors to prevent the growth of Gram-positive bacteria. It is named after the Hektoen Institute in Chicago, where researchers developed the agar. Use The definitive use of HEA is to discriminate between ''Shigella'' and ''Salmonella'', although many other species may grow on these plates. However, while the other bacteria may be clinically relevant, the assay does not discriminate among them. Effectively, HEA uses a metabolic assay to divide colonies into "''Salmonella'' and ''Shigella''" and "everything else". Use of these plates assumes that the user is not interested in other enteric pathogens such as '' Klebsiella'' or '' Escherichia''. The plates contain various sugar sources ( lactose, sucrose, and salicin), none o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloodstream Infection
Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, which is characterized by severe inflammatory or immune responses of the host organism to pathogens. Bacteria can enter the bloodstream as a severe complication of infections (like pneumonia or meningitis), during surgery (especially when involving mucous membranes such as the gastrointestinal tract), or due to catheters and other foreign bodies entering the arteries or veins (including during intravenous drug abuse). Transient bacteremia can result after dental procedures or brushing of teeth. Bacteremia can have several important health consequences. Immune responses to the bacteria can cause sepsis and septic shock, which, particularly if severe sepsis and then septic shock occurs, have high mortality rates, especially if not treated q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catabolized
Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipids, nucleic acids, and proteins) into smaller units (such as monosaccharides, fatty acids, nucleotides, and amino acids, respectively). Catabolism is the breaking-down aspect of metabolism, whereas anabolism is the building-up aspect. Cells use the monomers released from breaking down polymers to either construct new polymer molecules or degrade the monomers further to simple waste products, releasing energy. Cellular wastes include lactic acid, acetic acid, carbon dioxide, ammonia, and urea. The formation of these wastes is usually an oxidation process involving a release of chemical free energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP). This molecule acts as a way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' may differ). This formula does not imply direct covalent bonding between hydrogen and oxygen atoms; for example, in , hydrogen is covalently bonded to carbon, not oxygen. While the 2:1 hydrogen-to-oxygen ratio is characteristic of many carbohydrates, exceptions exist. For instance, uronic acids and deoxy-sugars like fucose deviate from this precise stoichiometric definition. Conversely, some compounds conforming to this definition, such as formaldehyde and acetic acid, are not classified as carbohydrates. The term is predominantly used in biochemistry, functioning as a synonym for saccharide (), a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemoorganotroph
Primary nutritional groups are groups of organisms, divided in relation to the nutrition mode according to the sources of energy and carbon, needed for living, growth and reproduction. The sources of energy can be light or chemical compounds; the sources of carbon can be of organic or inorganic origin. The terms ''aerobic respiration'', '' anaerobic respiration'' and ''fermentation'' (''substrate-level phosphorylation'') do not refer to primary nutritional groups, but simply reflect the different use of possible electron acceptors in particular organisms, such as in aerobic respiration, or nitrate (), sulfate () or fumarate in anaerobic respiration, or various metabolic intermediates in fermentation. Primary sources of energy ''Phototrophs'' absorb light in photoreceptors and transform it into chemical energy. ''Chemotrophs'' release chemical energy. The freed energy is stored as potential energy in ATP, carbohydrates, or proteins. Eventually, the energy is used for life ... [...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] |
Trypticase Soy Agar
Trypticase soy agar or Tryptic soy agar (TSA) is a growth medium, growth media for the microbiological culture, culturing of moderately to non fastidious organism , fastidious bacteria. It is a general-purpose, non-selective media providing enough nutrients to allow for a wide variety of microorganisms to grow. It is used for a wide range of applications, including culture storage, enumeration of cells (counting), isolation of pure cultures, or simply general culture. TSA contains enzymatic digests of casein and soybean meal, which provide amino acids and other nitrogenous substances, making it a nutritious medium for a variety of organisms. Sodium chloride maintains the osmotic equilibrium, while dipotassium phosphate acts as buffering agent, buffer to maintain pH. Agar extracted from any number of organisms is used as a gelling agent. One liter of the agar contains: * 15 g tryptone, pancreatic digest of casein * 5 g soytone, peptic digest of soybean * 5 g sodium chloride * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacConkey Agar
MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate gram-negative and enteric (normally found in the intestinal tract) bacteria and differentiate them based on lactose fermentation. Lactose fermenters turn red or pink on MacConkey agar, and nonfermenters do not change color. The media inhibits growth of gram-positive organisms with crystal violet and bile salts, allowing for the selection and isolation of gram-negative bacteria. The media detects lactose fermentation by enteric bacteria with the pH indicator neutral red. Contents It contains bile salts (to inhibit most gram-positive bacteria), crystal violet dye (which also inhibits certain gram-positive bacteria), and neutral red dye (which turns pink if the microbes are fermenting lactose). Composition: * Peptone – 17 g * Proteose peptone – 3 g * Lactose – 10 g * Bile salts – 1.5 g * Sodium chloride – 5 g * Neutral red – 0.03 g * Crystal violet – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic Resistance
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resistance), viruses (antiviral resistance), parasites (antiparasitic resistance), and fungi (antifungal resistance). Together, these adaptations fall under the AMR umbrella, posing significant challenges to healthcare worldwide. Misuse and improper management of antimicrobials are primary drivers of this resistance, though it can also occur naturally through genetic mutations and the spread of resistant genes. Antibiotic resistance, a significant AMR subset, enables bacteria to survive antibiotic treatment, complicating infection management and treatment options. Resistance arises through spontaneous mutation, horizontal gene transfer, and increased selective pressure from antibiotic overuse, both in medicine and agriculture, which accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and recognize further and destroy any of the microorganisms associated with that agent that it may encounter in the future. Vaccines can be prophylaxis, prophylactic (to prevent or alleviate the effects of a future infection by a natural or "wild" pathogen), or therapeutic vaccines, therapeutic (to fight a disease that has already occurred, such as cancer vaccine, cancer). Some vaccines offer full sterilizing immunity, in which infection is prevented. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloody Diarrhea
Dysentery ( , ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications may include dehydration. The cause of dysentery is usually the bacteria from genus ''Shigella'', in which case it is known as shigellosis, or the amoeba ''Entamoeba histolytica''; then it is called amoebiasis. Other causes may include certain chemicals, other bacteria, other protozoa, or parasitic worms. It may spread between people. Risk factors include contamination of food and water with feces due to poor sanitation. The underlying mechanism involves inflammation of the intestine, especially of the colon. Efforts to prevent dysentery include hand washing and food safety measures while traveling in countries of high risk. While the condition generally resolves on its own within a week, drinking sufficient fluids such as oral rehydration solution is import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
