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Exogenous Bacteria
Exogenous bacteria are microorganisms introduced to closed biological systems from the external world. They exist in aquatic and terrestrial environments, as well as the atmosphere. Microorganisms in the external environment have existed on Earth for 3.5 billion years. Exogenous bacteria can be either benign or pathogenic. Pathogenic exogenous bacteria can enter a closed biological system and cause disease such as ''Cholera,'' which is induced by a waterborne microbe that infects the human intestine. Exogenous bacteria can be introduced into a closed ecosystem as well, and have mutualistic benefits for both the microbe and the host. A prominent example of this concept is ''bacterial flora,'' which consists of exogenous bacteria ingested and endogenously colonized during the early stages of life. Bacteria that are part of normal internal ecosystems, also known as bacterial flora, are called ''Endogenous Bacteria''. A significant amount of prominent diseases are induced by ''exogenous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Systems
A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. On the micro to the nanoscopic scale, examples of biological systems are cells, organelles, macromolecular complexes and regulatory pathways. A biological system is not to be confused with a living system, such as a living organism. Organ and tissue systems These specific systems are widely studied in human anatomy and are also present in many other animals. * Respiratory system: the organs used for breathing, the pharynx, larynx, bronchi, lungs and diaphragm. * Digestive system: digestion and processing food with salivary gland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Flora
Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found to be crucial for immunologic, hormonal, and metabolic homeostasis of their host. The term ''microbiome'' describes either the collective genomes of the microbes that reside in an ecological niche or within the microbes themselves. The microbiome and host emerged during evolution as a synergistic unit from epigenetics and genetic characteristics, sometimes collectively referred to as a holobiont. The presence of microbiota in human and other metazoan guts has been critical for understanding the co-evolution between metazoans and bacteria. Microbiota play key roles in the intestinal immune and metabolic responses via their fermentation product (short-chain fatty acid), acetate. Introduction All plants and animals, from simple life fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella
''Salmonella'' is a genus of rod-shaped (bacillus) Gram-negative bacteria of the family Enterobacteriaceae. The two species of ''Salmonella'' are ''Salmonella enterica'' and '' Salmonella bongori''. ''S. enterica'' is the type species and is further divided into six subspecies that include over 2,600 serotypes. ''Salmonella'' was named after Daniel Elmer Salmon (1850–1914), an American veterinary surgeon. ''Salmonella'' species are non-spore-forming, predominantly motile enterobacteria with cell diameters between about 0.7 and 1.5 μm, lengths from 2 to 5 μm, and peritrichous flagella (all around the cell body, allowing them to move). They are chemotrophs, obtaining their energy from oxidation and reduction reactions, using organic sources. They are also facultative anaerobes, capable of generating ATP with oxygen ("aerobically") when it is available, or using other electron acceptors or fermentation ("anaerobically") when oxygen is not available. ''Salmonella'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholera
Cholera is an infection of the small intestine by some strains of the bacterium '' Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and muscle cramps may also occur. Diarrhea can be so severe that it leads within hours to severe dehydration and electrolyte imbalance. This may result in sunken eyes, cold skin, decreased skin elasticity, and wrinkling of the hands and feet. Dehydration can cause the skin to turn bluish. Symptoms start two hours to five days after exposure. Cholera is caused by a number of types of ''Vibrio cholerae'', with some types producing more severe disease than others. It is spread mostly by unsafe water and unsafe food that has been contaminated with human feces containing the bacteria. Undercooked shellfish is a common source. Humans are the only known host for the bacteria. Risk factors for the disease include poor sanitation, not enou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campylobacter
''Campylobacter'' (meaning "curved bacteria") is a genus of Gram-negative bacteria. ''Campylobacter'' typically appear comma- or s-shaped, and are motile. Some ''Campylobacter'' species can infect humans, sometimes causing campylobacteriosis, a diarrhoeal disease in humans. Campylobacteriosis is usually self-limiting and antimicrobial treatment is often not required, except in severe cases or immunocompromised patients. The most known source for ''Campylobacter'' is poultry, but due to their diverse natural reservoir, ''Campylobacter'' spp. can also be transmitted ''via'' water. Other known sources of ''Campylobacter'' infections include food products, such as unpasteurised milk and contaminated fresh produce. Sometimes the source of infection can be direct contact with infected animals, which often carry ''Campylobacter'' asymptomatically. At least a dozen species of ''Campylobacter'' have been implicated in human disease, with ''C. jejuni'' (80–90%) and '' C. coli'' (5-10%) b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthrax
Anthrax is an infection caused by the bacterium '' Bacillus anthracis''. It can occur in four forms: skin, lungs, intestinal, and injection. Symptom onset occurs between one day and more than two months after the infection is contracted. The skin form presents with a small blister with surrounding swelling that often turns into a painless ulcer with a black center. The inhalation form presents with fever, chest pain and shortness of breath. The intestinal form presents with diarrhea (which may contain blood), abdominal pains, nausea and vomiting. The injection form presents with fever and an abscess at the site of drug injection. According to the USA's Centers for Disease Control and Prevention, the first clinical descriptions of cutaneous anthrax were given by Maret in 1752 and Fournier in 1769. Before that anthrax had been described only through historical accounts. The Prussian scientist Robert Koch (1843–1910) was the first to identify ''Bacillus anthracis'' as the bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botulism
Botulism is a rare and potentially fatal illness caused by a toxin produced by the bacterium '' Clostridium botulinum''. The disease begins with weakness, blurred vision, feeling tired, and trouble speaking. This may then be followed by weakness of the arms, chest muscles, and legs. Vomiting, swelling of the abdomen, and diarrhea may also occur. The disease does not usually affect consciousness or cause a fever. Botulism can be spread in several ways. The bacterial spores which cause it are common in both soil and water. They produce the botulinum toxin when exposed to low oxygen levels and certain temperatures. Foodborne botulism happens when food containing the toxin is eaten. Infant botulism happens when the bacteria develops in the intestines and releases the toxin. This typically only occurs in children less than six months old, as protective mechanisms develop after that time. Wound botulism is found most often among those who inject street drugs. In this situation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Flora
Microbiota are the range of microorganisms that may be commensal, symbiotic, or pathogenic found in and on all multicellular organisms, including plants. Microbiota include bacteria, archaea, protists, fungi, and viruses, and have been found to be crucial for immunologic, hormonal, and metabolic homeostasis of their host. The term ''microbiome'' describes either the collective genomes of the microbes that reside in an ecological niche or within the microbes themselves. The microbiome and host emerged during evolution as a synergistic unit from epigenetics and genetic characteristics, sometimes collectively referred to as a holobiont. The presence of microbiota in human and other metazoan guts has been critical for understanding the co-evolution between metazoans and bacteria. Microbiota play key roles in the intestinal immune and metabolic responses via their fermentation product (short-chain fatty acid), acetate. Introduction All plants and animals, from simple life fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterborne Diseases
Waterborne diseases are conditions (meaning adverse effects on human health, such as death, disability, illness or disorders) caused by pathogenic micro-organisms that are transmitted in water. These diseases can be spread while bathing, washing, drinking water, or by eating food exposed to contaminated water. They are a pressing issue in rural areas amongst developing countries all over the world. While diarrhea and vomiting are the most commonly reported symptoms of waterborne illness, other symptoms can include skin, ear, respiratory, or eye problems. Lack of clean water supply, sanitation and hygiene (WASH) are major causes for the spread of waterborne diseases in a community. Therefore, reliable access to clean drinking water and sanitation is the main method to prevent waterborne diseases. Microorganisms causing diseases that characteristically are waterborne prominently include protozoa and bacteria, many of which are intestinal parasites, or invade the tissues or circ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbial Growth And Nutrition
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in older texts. The informal synonym ''microbe'' () comes from μικρός, mikrós, "small" and βίος, bíos, "life". is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India. The scientific study of microorganisms began with their observation under the microscope in the 1670s by Anton van Leeuwenhoek. In the 1850s, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In the 1880s, Robert Koch discovered that microorganisms cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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