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Yersinia Pestis
''Yersinia pestis'' (''Y. pestis''; formerly ''Pasteurella pestis'') is a Gram-negative bacteria, gram-negative, non-motile bacteria, non-motile, coccobacillus Bacteria, bacterium without Endospore, spores. It is related to pathogens ''Yersinia enterocolitica'', and ''Yersinia pseudotuberculosis'', from which it evolved. ''Yersinia pestis'' is responsible for the disease plague (disease), plague, which caused the Plague of Justinian and the Black Death, one of the deadliest pandemics in recorded history. Plague takes three main forms: Pneumonic plague, pneumonic, Septicemic plague, septicemic, and bubonic plague, bubonic. ''Y. pestis'' is a facultative anaerobic organism, facultative anaerobic Parasitism, parasitic bacterium that can infect humans primarily via its host the Oriental rat flea (''Xenopsylla cheopis''), but also through airborne transmission , aerosols and airborne droplets for its pneumonic form. As a parasite of its host, the rat flea, which is also a parasit ...
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Plague (disease)
Plague is an infectious disease caused by the bacterium '' Yersinia pestis''. Symptoms include fever, weakness and headache. Usually this begins one to seven days after exposure. There are three forms of plague, each affecting a different part of the body and causing associated symptoms. Pneumonic plague infects the lungs, causing shortness of breath, coughing and chest pain; bubonic plague affects the lymph nodes, making them swell; and septicemic plague infects the blood and can cause tissues to turn black and die. The bubonic and septicemic forms are generally spread by flea bites or handling an infected animal, whereas pneumonic plague is generally spread between people through the air via infectious droplets. Diagnosis is typically by finding the bacterium in fluid from a lymph node, blood or sputum. Those at high risk may be vaccinated. Those exposed to a case of pneumonic plague may be treated with preventive medication. If infected, treatment is with antibiotics a ...
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Scanning Electron Microscope
A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition. The electron beam is scanned in a raster scan pattern, and the position of the beam is combined with the intensity of the detected signal to produce an image. In the most common SEM mode, secondary electrons emitted by atoms excited by the electron beam are detected using a secondary electron detector ( Everhart–Thornley detector). The number of secondary electrons that can be detected, and thus the signal intensity, depends, among other things, on specimen topography. Some SEMs can achieve resolutions better than 1 nanometer. Specimens are observed in high vacuum in a conventional SEM, or in low vacuum or wet conditions in a variable pressure or environmental SEM, an ...
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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 ...
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Louis Pasteur
Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist, pharmacist, and microbiologist renowned for his discoveries of the principles of vaccination, Fermentation, microbial fermentation, and pasteurization, the last of which was named after him. His research in chemistry led to remarkable breakthroughs in the understanding of the causes and preventions of diseases, which laid down the foundations of hygiene, public health and much of modern medicine. Pasteur's works are credited with saving millions of lives through the developments of vaccines for rabies vaccine, rabies and anthrax vaccine, anthrax. He is regarded as one of the founders of modern bacteriology and has been honored as the "father of bacteriology" and the "father of microbiology" (together with Robert Koch; the latter epithet also attributed to Antonie van Leeuwenhoek). Pasteur was responsible for disproving the doctrine of spontaneous generation. Under the auspices of the French Aca ...
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Hong Kong
Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the world. Hong Kong was established as a colony of the British Empire after the Qing dynasty ceded Hong Kong Island in 1841–1842 as a consequence of losing the First Opium War. The colony expanded to the Kowloon Peninsula in 1860 and was further extended when the United Kingdom obtained a 99-year lease of the New Territories in 1898. Hong Kong was occupied by Japan from 1941 to 1945 during World War II. The territory was handed over from the United Kingdom to China in 1997. Hong Kong maintains separate governing and economic systems from that of mainland China under the principle of one country, two systems. Originally a sparsely populated area of farming and fishing villages,. the territory is now one of the world's most signific ...
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1894 Hong Kong Plague
The 1894 Hong Kong plague, part of the third plague pandemic, was a major outbreak of the bubonic plague in British Hong Kong, Hong Kong. While the plague was harshest in 1894, it returned annually between 1895 and 1929, and killed over 20,000 in total, with a fatality rate of more than 93%. The plague was a major turning point in the history of colonial Hong Kong, as it forced the colonial government to reexamine its policy towards the Chinese community, and invest in the wellbeing of the Chinese. Origins It is thought that the pandemic originated from Yunnan, China, which saw an outbreak as early as 1792, in 1855 and again in 1866–7. An outbreak in neighboring city of Guangzhou from January 1894 onwards killed 80,000. From March 1894, British scientists and doctors in Hong Kong became aware of the outbreak in China. By the end of April, the government in Hong Kong requested Dr. Alexander Rennie, the consular surgeon for Canton, to report on the disease. Rennie identified it a ...
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Pasteur Institute
The Pasteur Institute (, ) is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccines for anthrax and rabies. The institute was founded on 4 June 1887 and inaugurated on 14 November 1888. For over a century, the Institut Pasteur has researched infectious diseases. This worldwide biomedical research organization based in Paris was the first to isolate HIV, the virus that causes AIDS, in 1983. It has also been responsible for discoveries that have enabled medical science to control diseases such as diphtheria, tetanus, tuberculosis, poliomyelitis, influenza, yellow fever, and Plague (disease), plague. Since 1908, ten Institut Pasteur scientists have been awarded the Nobel Prize for medicine and physiology—the 2008 Nobel Prize in Physiology or Medicine was shared between two Pasteur scientists. History The Institut Pasteur was founded in 1887 by ...
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Bacteriologist
A bacteriologist is a microbiologist, or similarly trained professional, in bacteriology— a subdivision of microbiology that studies bacteria, typically Pathogenic bacteria, pathogenic ones. Bacteriologists are interested in studying and learning about bacteria, as well as using their skills in clinical settings. This includes investigating properties of bacteria such as Morphology (biology), morphology, ecology, genetics and biochemistry, phylogenetics, genomics and many other areas related to bacteria like Medical diagnosis, disease diagnostic testing. Alongside human and animal health care, healthcare providers, they may carry out various functions as Biomedical scientist, medical scientists, veterinary scientists, Pathology, pathologists, or Medical laboratory scientist, diagnostic technicians in locations like Clinic, clinics, blood banks, hospitals, laboratories and Veterinary medicine, animal hospitals. Bacteriologists working in public health or biomedical research help de ...
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Physician
A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Medical diagnosis, diagnosis, prognosis and therapy, treatment of disease, injury, and other physical and mental impairments. Physicians may focus their practice on certain disease categories, types of patients, and methods of treatment—known as Specialty (medicine), specialities—or they may assume responsibility for the provision of continuing and comprehensive medical care to individuals, families, and communities—known as general practitioner, general practice. Medical practice properly requires both a detailed knowledge of the Discipline (academia), academic disciplines, such as anatomy and physiology, pathophysiology, underlying diseases, and their treatment, which is the science of medicine, and a decent Competence (human resources ...
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Alexandre Yersin
Alexandre Émile John Yersin (22 September 1863 – 1 March 1943) was a Swiss- French physician and bacteriologist. He is remembered as the co-discoverer (1894) of the bacillus responsible for the bubonic plague or pest, which was later named in his honour: ''Yersinia pestis''. Another bacteriologist, the Japanese physician Kitasato Shibasaburō, is often credited with independently identifying the bacterium a few days earlier. Yersin also demonstrated for the first time that the same bacillus was present in the rodent as well as in the human disease, thus underlining the possible means of transmission. Early life and education Yersin was born in 1863 in Aubonne, in the canton of Vaud, Switzerland, as the posthumous son of Jean-Alexandre-Marc Yersin from his wife Fanny-Isaline-Emilie Moschell. From 1883 to 1884 he studied medicine at Lausanne, followed by Marburg, and Paris (1884–1886). Career In 1886, Yersin entered Louis Pasteur's research laboratory at the École Normal ...
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Hyperparasite
A hyperparasite, also known as a metaparasite, is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two other insect orders, the Diptera (true flies) and Coleoptera (beetles). Seventeen families in Hymenoptera and a few species of Diptera and Coleoptera are hyperparasitic. Hyperparasitism developed from primary parasitism, which evolved in the Jurassic period in the Hymenoptera. Hyperparasitism intrigues entomologists because of its multidisciplinary relationship to evolution, ecology, behavior, biological control, taxonomy, and mathematical models. Examples The most common examples are insects that lay their eggs inside or near parasitoid larvae, which are themselves parasitizing the tissues of a host, again usually an insect larva. A well-studied case is that of the small white butterfly ('' Pieris rapae''), a serious horticultural pest ...
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Rat Flea
A rat flea is a parasite of rats. There are at least four species: * Oriental rat flea (''Xenopsylla cheopis''), also known as the tropical rat flea, the primary vector for bubonic plague * Northern rat flea (''Nosopsyllus fasciatus''). According to Prince, "... it too is an efficient vector of plague. It was found to be even more widely distributed than X. cheopis, occurring in 12 of the 13 States surveyed". * '' Xenopsylla brasiliensis'', a vector of bubonic plague Bubonic plague is one of three types of Plague (disease), plague caused by the Bacteria, bacterium ''Yersinia pestis''. One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and ..., found in South America, Africa, and India * Leptopsylla segnis References {{Animal common name Insect common names Former disambiguation pages converted to set index articles ...
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