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H. Ducreyi
''Haemophilus ducreyi'' is a fastidious gram-negative coccobacillus bacteria. It causes the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Chancroid starts as an erythematous papular lesion that breaks down into a painful bleeding ulcer with a necrotic base and ragged edge. More recently, it has also been found to cause chronic skin ulceration away from the genitalia, infect children and adults, and behave in a manner that mimics yaws. These strains seem to have diverged quite recently. ''H. ducreyi'' can be cultured on chocolate agar. It is best treated with a macrolide, e.g. azithromycin, and a third-generation cephalosporin, e.g. ceftriaxone. ''H. ducreyi'' gram stain resembles a "school of fish." Pathogenesis ''H. ducreyi'' is an opportunistic microorganism that infects its host by way of breaks in the skin or epidermis. Inflammation then takes place as the area of infec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maurice Neveu-Lemaire
Maurice Neveu-Lemaire (24 September 1872 in Montbéliard – 4 May 1951 in Paris) was a French physician and parasitologist. After receiving his degree in natural sciences (1895), he spent several years as an intern in marine laboratories at Banyuls-sur-Mer, Roscoff and Tatihou, as well as performing duties as ''préparateur'' at the laboratory of parasitology in Paris. After receiving his medical doctorate, he participated as a physician and naturalist aboard the yacht ''Princesse Alice'' to the Canary Islands, Madeira, Cape Verde and the Azores (1901-02). During the following year, he performed similar roles as part of the ''Créqui Montfort et Sénéchal de la Grange'' mission in South America.Service des Archives de l'Institut Pasteur (chronological biography) From 1904 to 1920, he was an associate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Hendricks Bergey
David Hendricks Bergey was an American bacteriologist, born December 27, 1860, in Skippack, Pennsylvania, Skippack, Pennsylvania, died September 5, 1937, in Philadelphia, Pennsylvania. He studied at University of Pennsylvania, where he obtained his Bachelor of Science and Doctor of Medicine degrees in 1884. He practiced medicine in North Wales, Pennsylvania until 1893. He then joined the university's hygiene laboratory, where he taught hygiene and bacteriology. He led the laboratory from 1929 until his retirement in 1932. During WW I he was on academic leave of absence from 1917 to 1919, when he served in the United States Army Medical Reserve Corps as chief of the laboratory staff at Fort Oglethorpe (Fort Oglethorpe, Georgia), Fort Oglethorpe. His ''Principles of Hygiene'' was first published in 1901 and went through seven editions. He was chairman of the Editorial Board for the first edition of Bergey's Manual of Determinative Bacteriology, published in 1923. The Determinative Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fastidious
A fastidious organism is any organism that has complex or particular nutritional requirements. In other words, a fastidious organism will only grow when specific nutrients are included in its medium. The more restrictive term fastidious microorganism is used in microbiology to describe microorganisms that will grow only if special nutrients are present in their culture medium. Thus fastidiousness is often practically defined as being difficult to culture, by any method yet tried. Examples An example of a fastidious bacterium is ''Neisseria gonorrhoeae'', which requires blood or hemoglobin and several amino acids and vitamins to grow.Todar, Kenneth''Neisseria gonorrhoeae'', the Gonococcus, and Gonorrhea. Lectures in Microbiology. 2009. Retrieved 2013-03-05. Other examples include ''Campylobacter'' spp. and ''Helicobacter'' spp., which are capnophilic – require elevated CO2 – among other requirements. Fastidious organisms are not inherently "weak"—they can flourish and t ... [...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] |
Sexually Transmitted Disease
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are spread by sexual activity, especially vaginal intercourse, anal sex, and oral sex. STIs often do not initially cause symptoms, which results in a risk of passing the infection on to others. Symptoms and signs of STIs may include vaginal discharge, penile discharge, ulcers on or around the genitals, and pelvic pain. Some STIs can cause infertility. Bacterial STIs include chlamydia, gonorrhea, and syphilis. Viral STIs include genital herpes, HIV/AIDS, and genital warts. Parasitic STIs include trichomoniasis. STI diagnostic tests are usually easily available in the developed world, but they are often unavailable in the developing world. Some vaccinations may also decrease the risk of certain infections including hepatitis B and some types of HPV. Safe sex practices, such as use of condoms, having a smaller n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chancroid
Chancroid ( ) is a bacterial sexually transmitted infection characterized by painful sores on the genitalia. Chancroid is known to spread from one individual to another solely through sexual contact. However, there have been reports of accidental infection through another route which is by the hand. While uncommon in the western world, it is the most common cause of genital ulceration worldwide. Signs and symptoms These are only local and no systemic manifestations are present. The ulcer characteristically: * Ranges in size dramatically from 3 to 50 mm (1/8 inch to 2 inches) across * Is painful * Has sharply defined, undermined borders * Has irregular or ragged borders, ''described as saucer-shaped''. * Has a base that is covered with a gray or yellowish-gray material * Has a base that bleeds easily if traumatized or scraped * Painful swollen lymph nodes occur in 30–60% of patients. * Dysuria (pain with urination) and dyspareunia (pain with intercourse) in females A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yaws
Yaws is a tropical infection of the skin, bones, and joints caused by the spirochete bacterium ''Treponema pallidum pertenue''. The disease begins with a round, hard swelling of the skin, in diameter. The center may break open and form an ulcer. This initial skin lesion typically heals after 3–6 months. After weeks to years, joints and bones may become painful, fatigue may develop, and new skin lesions may appear. The skin of the palms of the hands and the soles of the feet may become thick and break open. The bones (especially those of the nose) may become misshapen. After 5 years or more, large areas of skin may die, leaving scars. Yaws is spread by direct contact with the fluid from a lesion of an infected person. The contact is usually of a nonsexual nature. The disease is most common among children, who spread it by playing together. Other related treponemal diseases are bejel (''T. pallidum endemicum''), pinta (''T. carateum''), and syphilis (''T. p. pallidum''). Ya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chocolate Agar
Chocolate agar (CHOC) or chocolate blood agar (CBA), is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80°C. Chocolate agar is used for growing fastidious respiratory bacteria, such as ''Haemophilus influenzae'' and ''Neisseria meningitidis''. In addition, some of these bacteria, most notably ''H. influenzae'', need growth factors such as nicotinamide adenine dinucleotide (factor V or NAD) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is the presence of red blood cell lysates. The heat also inactivates enzymes which could otherwise degrade NAD. The agar is named for its color and contains no chocolate products. Variants Chocolate agar with the addition of bacitracin becomes selective for the genus ''Haemophilus''. Another variant of chocolate agar called Thayer–Martin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrolide
The Macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Macrolides belong to the polyketide class of natural products. Some macrolides have antibiotic or antifungal activity and are used as pharmaceutical drugs. Rapamycin is also a macrolide and was originally developed as an antifungal, but is now used as an immunosuppressant drug and is being investigated as a potential longevity therapeutic. Macrolides are bacteriostatic in that they suppress or inhibit bacterial growth rather than killing bacteria completely. Definition In general, any macrocyclic lactone having greater than 8-membered rings are candidates for this class. The macrocycle may contain amino nitrogen, amide nitrogen (but should be differentiated from cyclopeptides), an oxazole ring, or a thiazole ring. Benzene rings are exclude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalosporin
The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotics called cephems. Cephalosporins were discovered in 1945, and first sold in 1964. Discovery The aerobic mold which yielded cephalosporin C was found in the sea near a sewage outfall in Su Siccu, by Cagliari harbour in Sardinia, by the Italian pharmacologist Giuseppe Brotzu in July 1945. Structure Cephalosporin contains a 6-membered dihydrothiazine ring. Substitutions at position 3 generally affect pharmacology; substitutions at position 7 affect antibacterial activity, but these cases are not always true. Medical uses Cephalosporins can be indicated for the prophylaxis and treatment of infections caused by bacteria susceptible to this particular form of antibiotic. First-generation cephalosporins are active predominantly against Gram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensitivity And Specificity
''Sensitivity'' and ''specificity'' mathematically describe the accuracy of a test which reports the presence or absence of a condition. Individuals for which the condition is satisfied are considered "positive" and those for which it is not are considered "negative". *Sensitivity (true positive rate) refers to the probability of a positive test, conditioned on truly being positive. *Specificity (true negative rate) refers to the probability of a negative test, conditioned on truly being negative. If the true condition can not be known, a " gold standard test" is assumed to be correct. In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. If the goal is to return the ratio at w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Standard (test)
In medicine and statistics, a gold standard test is usually the diagnostic test or benchmark that is the best available under reasonable conditions. In other words, a gold standard is the most accurate test possible without restrictions. Both meanings are different because for example, in medicine, dealing with conditions that would require an autopsy to have a perfect diagnosis, the gold standard test would be the best one that keeps the patient alive instead of the autopsy. In medicine "Gold standard" can refer to the criteria by which scientific evidence is evaluated. For example, in resuscitation research, the "gold standard" test of a medication or procedure is whether or not it leads to an increase in the number of neurologically intact survivors that walk out of the hospital.''ACLS: Principles and Practice''. p. 62. Dallas: American Heart Association, 2003. . Other types of medical research might regard a significant decrease in 30-day mortality as the gold standard. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
