Streptococcus pyogenes is a species of Gram-positive, aerotolerant bacterium in the genus Streptococcus. These bacteria are extracellular, made up of non-motile and non-sporing cocci, it is clinically important for humans. It is an infrequent, but pathogenic, part of the skin microbiota, it is the predominant species harboring the Lancefield group A antigen, is called group A Streptococcus. However, both Streptococcus dysgalactiae and the Streptococcus anginosus group can possess group A antigen. Group A streptococci when grown on blood agar produces small zones of beta-hemolysis, a complete destruction of red blood cells, it is thus called group A Streptococcus, it can make colonies greater than 5 mm in size. Like other cocci, streptococci are round bacteria; the species name is derived from Greek words meaning'a chain' of berries and pus -forming, because streptococcal cells tend to link in chains of round cells and a number of infections caused by the bacterium produce pus. The main criterion for differentiation between Staphylococcus spp. and Streptococcus spp. is the catalase test.
Staphylococci are catalase positive. S. pyogenes can be cultured on fresh blood agar plates. Under ideal conditions, it has an incubation period of 1 to 3 days. An estimated 700 million GAS. While the overall mortality rate for these infections is 0.1%, over 650,000 of the cases are severe and invasive, have a mortality rate of 25%. Early recognition and treatment are critical. S. pyogenes colonizes the throat, genital mucosa and skin. Of healthy individuals, 1 % to 5 % have vaginal, or rectal carriage. In healthy children, such carriage rate varies from 2% to 17%. There are four methods for the transmission of this bacterium: inhalation of respiratory droplets, skin contact, contact with objects, surface, or dust, contaminated with bacteria or, less transmission through food; such bacteria can cause a variety of diseases such as streptococcal pharyngitis, rheumatic fever, rheumatic heart disease, scarlet fever. Although pharyngitis is viral in origin, about 15 to 30% of all pharyngitis cases in children are caused by GAS.
The number of pharyngitis cases is higher in children when compared with adults due to exposures in schools, as a consequence of lower host immunity. Such cases Streptococcal pharyngitis occurs more from December to April in seasonal countries due to changing climate, behavioural changes or predisposing viral infection. Disease cases are the lowest during autumn. MT1 clone is associated with invasive Streptococcus pyogenes infections among developed countries; the incidence and mortality of S. pyognes was high during the pre-penicillin era, but had started to fall prior to the widespread availability of penicillin. Therefore, environmental factors do play a role in the S. pyogenes infection. Incidence of S. pyogenes is 2 to 4 per 100,000 population in developed countries and 12 to 83 per 100,000 population in developing countries. S. pyogenes infection is more found in men than women, with highest rates in the elderly, followed by infants. In people with risk factors such as heart disease, malignancy, blunt trauma, surgical incision, virus respiratory infection, including influenza, S. pyogenes infection happens in 17 to 25% of all cases.
GAS secondary infection happens within one week of the diagnosis of influenza infection. In 14 to 16% of childhood S. pyogenes infections, there is a prior chickenpox infection. Such S. pyogenes infection in children manifests as severe soft tissue infection with onset 4 to 12 days from the chickenpox diagnosis. There is 40 to 60 times increase in risk of S. pyogenes infection within the first two weeks of chickenpox infection in children. However, 20 to 30% of S. pyogenes infection does occur in adults with no identifiable risk factors. The incidence is higher in children with no known risk factors; the rates of scarlet fever in UK was 4 in 100,000 population, however, in 2014, the rates had risen to 49 per 100,000 population. Rheumatic fever and rheumatic heart disease occurs at 2 to 3 weeks after the throat infection, more common among the impoverished people in developing countries. From 1967 to 1996, the global mean incidence of rheumatic fever and RHD was 19 per 100,000 with the highest incidence at 51 per 100,000.
Maternal S. pyogenes infection happens in late pregnancy. This represents 20 to 100 times increase in risk for S. pyogenes infections. Clinical manifestations are: pneumonia, septic arthritis, necrotizing fasciitis, genital tract sepsis. According to a study done by Queen Charlotte's hospital in London during the 1930s, the vagina was not the common source of such infection. On the contrary, maternal throat infection and close contacts with carriers were the more common sites for maternal S. pyogenes infection. In 1928, Rebecca Lancefield published a method for serotyping S. pyogenes based on its cell-wall polysaccharide, a virulence factor displayed on its surface. In 1946, Lancefield described the serologic classification of S. pyogenes isolates based on their surface T-antigen. Four of the 20 T-antigens have been revealed to be pili, which are used by
The Interarmy Special Vehicles Test Centre was France's first space launch and ballistic missile testing facility. Outside France, the facility is referred to by the name of the nearest town, Hammaguir, it was established on 24 April 1947, by ministerial decree as the Special Weapons Test Center for use by the French Army. In 1948, it was turned over to the French Air Force, who renamed it CIEES, its remote location in the middle of the Saharan Desert and its relative closeness to the Equator made it an attractive launch site for missiles and orbital rockets. The origins of CIEES and the French missile and space program date to the end of the Second World War. On 12 June 1945, less than a month after V-E Day, the War Department ordered the study of self-propelled projectiles. On 13 August, the Directorate of Studies and Manufactures of Armaments proposed the creation of a Rocket Studies Center to continue studying and developing ballistic missiles; the Center aimed to attempt to reconstruct the V-2 rocket based on blueprints captured from V-2 launch sites in France.
In November 1946, a mission arrived at Colomb-Béchar, French Algeria, to study the site's suitability as a missile range and launch facility. CIEES began operations at Colomb-Béchar six months on 24 April 1947; the Air Force built two launch pads at Colomb-Béchar: the small B0 pad for sounding rockets, B1, completed in December 1949, for larger missiles. However, both of these launch sites were suitable only for smaller missiles, so a larger launch pad – dubbed CIEES B2 – was built at Hammaguir, 120 kilometres southwest of Colomb-Béchar, in May 1952. CIEES B2 expanded to include five launch pads: Bacchus, for solid fueled sounding rockets, for liquid fueled sounding rockets, for testing the Hawk surface-to-air missile and the Cora and Europa rockets, Brigette/A, for the "precious stones" series of rockets, CB, for the Monica sounding rocket. CIEES remained in use until 1 July 1967, when it was turned over to the government of newly-independent Algeria. French withdrawal from the CIEES facility and other military bases in Algeria was stipulated by the 1962 Évian Accords that ended the Algerian War of Independence.
Following CIEES's closure, French space launches were moved to the Kourou Space Center in French Guiana, while missile tests were moved to DGA Essais de missiles in the department of Landes in metropolitan France. The Director of CIEES was directly appointed by the Minister of the Armed Forces, they were required to be the Commander of the Colomb-Béchar Airbase and Commander of military installations in the Sahara. The Director was required to be from the Air Force, the Deputy Director was required to be from the Army. In order, CIEES was commanded by: Colonel Robert Aubinière Colonel Hériard Colonel Charbonneau General Millet General Y. Hautière As France's main launch site from 1947-1967, CIEES was responsible for all early milestones of the French space program. France's first successful rocket launch, of the Véronique sounding rocket, was from CIEES on 22 May 1952. France's first satellite, the Astérix-1, was launched from CIEES on a Diamant rocket on 26 November 1965. CIEES was the launch site for France's first animal in space: a cat named Félicette, launched to an altitude of 157 kilometres on a Véronique rocket.
She survived the flight. Due to CIEES's long period of operation, it launched a wide variety of missiles. With regard to space launches, CIEES was most notable for launching the "precious stones" series of rockets, which included the Diamant, the first French rocket to put a satellite into orbit, the first non-US or Soviet rocket to deliver a satellite to orbit; the "precious stones" rockets included the Emeraude, Rubis and Topaze. Other notable spacecraft included the first tests of the Europa rocket, the first rocket of the European Launcher Development Organisation and France's first three geodetic satellites, the Diadem. With regard to missiles, CIEES was the launch site for 1960s-era tests associated with the development of France's land-based medium-range ballistic missiles – the SBSS missile program – and submarine-launched ballistic missiles – the MSBS missile program, it served as the launch site for testing a myriad of other sounding rockets and anti-aircraft missiles. CIEES was the initial launch site for the CT 10 drone, a target drone copy of the V-1 flying bomb, used by the French and British militaries during the early days of the Cold War, as well as the 1950s-era R.511 air-to-air missile.
Dinophysis acuta is a species of flagellated planktons belonging to the genus Dinophysis. It is one of the few unusual photosynthetic protists that acquire plastids from algae by endosymbiosis. By forming massive blooms in late summer and spring, it causes red tides, it produces toxic substances and the red tides cause widespread infection of seafood crabs and mussels. When infected animals are consumed, severe diarrhoea occurs; the clinical symptom is called diarrhetic shellfish poisoning. The main chemical toxins were identified in 2006 as okadaic acid and pectenotoxins, they can produce non-fatal or fatal amounts of toxins in their predators, which can become toxic to humans. Dinophysis acuta is a marine unicellular protist, is the largest among Dinophysis, it is an armoured species with a distinct body covering called theca or test. The body is laterally compressed with a much larger hypotheca, it has the double collars around the top of the cell, a further wing running vertically down the cell.
It is oblong in shape with entirely rounded posterior end, but the tip of the end is pointed. The size ranges from 54 to 94 µm in length and 43 to 60 µm in dorso-ventral width, with the widest region below the middle; the small epitheca is composed of four plates. It is low, flat or weakly convex, is invisible in lateral view, a good identifying feature; the sulcus consists of several irregularly-shaped plates, it contains the flagellar pore. The hypotheca has four large plates; the anterior two-thirds of the hypotheca has convex margins, while the posterior third forms a broad asymmetrical triangle with a straight dorsal edge, a concave ventral edge. Reproduction is by simple binary fission; the most unusual cellular structure is the presence of numerous reddish-yellow chloroplasts, which are derived from its prey, which in turn had acquired from algae. The first cases of diarrhetic shellfish poisoning due to D. acuta were recorded in 1972 in Peru, but were reported to the scientific community only in 1991.
It is a mildest form of seafood poisoning, indicated by severe diarrhoea. The first toxins isolated from the species were pectenotoxins in 2003 from specimens collected from the west coast of South Island, New Zealand, PTX-12 independently at Skjer, Sognefjorden in Norway. In 2004, the presence of okadaic acid esters was reported. Further identification and the importance of these compounds as causal factors of DSP were discovered in 2006. Taxonomy at ITIS report Profile at marine Species Identification Portal WorMS SAHFOS Marine Animal Encyclopedia Phyto'Pedia Enclopedia of Life