Etest, manufactured by bioMérieux, is a manual in vitro diagnostic device used by laboratories to determine the MIC and whether or not a specific strain of bacterium or fungus is susceptible to the action of a specific antimicrobial. This type of test is most used in healthcare settings to help guiding physicians in treatment of patients by indicating what concentration of antimicrobial would treat an infection; the Etest strip was first described in 1988 and was introduced commercially in 1991 by AB BIODISK. BioMérieux acquired AB BIODISK in 2008 and continues to manufacture and market this product range under the mark Etest. During the 1950s, Hans Ericsson, the scientific founder of AB BIODISK, developed a method to standardize the disc diffusion method and to improve its reproducibility and reliability for clinical susceptibility predictions; the inhibition zone sizes from disc test results were compared to Minimum Inhibitory Concentration values based on the reference agar dilution procedure.
The correlation between zone sizes and MIC values was assessed using regression analysis and regression lines were used for extrapolating zone interpretive limits that corresponded to the MIC breakpoint values that defined susceptible and resistant categorical results. Etest was first presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Los Angeles in 1988 as a novel gradient concept for MIC determinations. In September 1991, Etest was launched globally as a MIC product after receiving the USA Food and Drug Administration clearance. Etest applications include many groups of fastidious organisms and mycobacteria as well as detecting various mechanisms of resistance and MIC testing of key antibiotics with critical specimens e.g. blood and cerebral spinal fluid. Etest is a quantitative technique for determining the antimicrobial susceptibility and MIC of Gram-negative and Gram-positive aerobic bacteria such as Enterobacteriaceae, Pseudomonas and Enterococcus species and fastidious bacteria, such as anaerobes, N. gonorrhoeae, S. pneumoniae and Haemophilius species.
Etest is a ‘ready-to-use’, inert and non poreus plastic reagent strip with a predefined gradient of antibiotic, covering a continuous concentration range, for the determination of precise MIC values of a wide range of antimicrobial agents against different organism groups. When Etest is applied to the surface of an agar plate inoculated with the test strain, there is an instantaneous release of the antimicrobial gradient from the plastic carrier to the agar to form a stable and continuous gradient beneath and in the immediate vicinity of the strip. Etest incubation and reading times have been determined based on the intrinsic growth characteristics of the organism, the specific incubation conditions. Therefore, for reliable and reproducible results, the stability of the gradient must be maintained for many hours; the predefined Etest gradient remains stable for at least 18 to 24 hours. When the Etest strip is placed on an agar surface, the antibiotic gradient on the strip is transferred to the agar matrix creating an imprint of the gradient on the strip in the agar.
The bacterial growth becomes visible after incubation and a symmetrical inhibition ellipse centered along the strip is seen. The MIC value is read from the scale in terms of µg/mL. Etest can be used with many different kinds of AST agar medium as long as the medium supports good growth of the test organism and does not interfere with the activity of the antimicrobial agent. However, to maximise reproducibility, the medium chosen should fulfil the basic requirements for a susceptibility test medium; the following AST mediums are recommended for use with Etest: Aerobes: Mueller Hinton agar such as MHE Anaerobes: Brucella blood agar with appropriate supplementsThese media may require supplemental nutrients to obtain enhanced growth of nutritionally fastidious organisms such as pneumococci, Abiotrophia, gonococci and Campylobacter. In general, media recommendations from the CLSI and the EUCAST are considered appropriate for Etest. After the required incubation period, only when an lawn of growth is distinctly visible, the MIC value can be read where the edge of the inhibition ellipse intersects the side of the strip.
The plate should not be read if the culture appears mixed or if the lawn of growth is too light or too heavy. Etest MIC endpoints are clear-cut although different growth/inhibition patterns may be seen. Etest products for more than 100 antimicrobial agents, including antibiotics, antifungal agents and antimycobacterial agents are available. In addition, specific Etest products are available for the detection of specific resistance mechanisms. Etest has been FDA cleared and CE marked for many organisms by comparing to conventional broth/agar dilution reference methods and shown to have excellent correlation; this is a partial list of organisms and antibiotics for which the test has been FDA cleared and CE marked. The Etest family of instruments is designed to simplify the daily use of Etest. Simplex C76, Nema C88, Retro C80 are easy to use, reducing operator fatigue, saving t
A microscope is an instrument used to see objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small structures using such an instrument. Microscopic means invisible to the eye. There are many types of microscopes, they may be grouped in different ways. One way is to describe the way the instruments interact with a sample to create images, either by sending a beam of light or electrons to a sample in its optical path, or by scanning across, a short distance from the surface of a sample using a probe; the most common microscope is the optical microscope, which uses light to pass through a sample to produce an image. Other major types of microscopes are the fluorescence microscope, the electron microscope and the various types of scanning probe microscopes. Although objects resembling lenses date back 4000 years and there are Greek accounts of the optical properties of water-filled spheres followed by many centuries of writings on optics, the earliest known use of simple microscopes dates back to the widespread use of lenses in eyeglasses in the 13th century.
The earliest known examples of compound microscopes, which combine an objective lens near the specimen with an eyepiece to view a real image, appeared in Europe around 1620. The inventor is unknown. Several revolve around the spectacle-making centers in the Netherlands including claims it was invented in 1590 by Zacharias Janssen and/or Zacharias' father, Hans Martens, claims it was invented by their neighbor and rival spectacle maker, Hans Lippershey, claims it was invented by expatriate Cornelis Drebbel, noted to have a version in London in 1619. Galileo Galilei seems to have found after 1610 that he could close focus his telescope to view small objects and, after seeing a compound microscope built by Drebbel exhibited in Rome in 1624, built his own improved version. Giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625; the first detailed account of the microscopic anatomy of organic tissue based on the use of a microscope did not appear until 1644, in Giambattista Odierna's L'occhio della mosca, or The Fly's Eye.
The microscope was still a novelty until the 1660s and 1670s when naturalists in Italy, the Netherlands and England began using them to study biology. Italian scientist Marcello Malpighi, called the father of histology by some historians of biology, began his analysis of biological structures with the lungs. Robert Hooke's Micrographia had a huge impact because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a simple single lens microscope, he sandwiched a small glass ball lens between the holes in two metal plates riveted together, with an adjustable-by-screws needle attached to mount the specimen. Van Leeuwenhoek re-discovered red blood cells and spermatozoa, helped popularise the use of microscopes to view biological ultrastructure. On 9 October 1676, van Leeuwenhoek reported the discovery of micro-organisms; the performance of a light microscope depends on the quality and correct use of the condensor lens system to focus light on the specimen and the objective lens to capture the light from the specimen and form an image.
Early instruments were limited until this principle was appreciated and developed from the late 19th to early 20th century, until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination, central to achieving the theoretical limits of resolution for the light microscope; this method of sample illumination produces lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. Further developments in sample illumination came from the discovery of phase contrast by Frits Zernike in 1953, differential interference contrast illumination by Georges Nomarski in 1955. In the early 20th century a significant alternative to the light microscope was developed, an instrument that uses a beam of electrons rather than light to generate an image; the German physicist, Ernst Ruska, working with electrical engineer Max Knoll, developed the first prototype electron microscope in 1931, a transmission electron microscope.
The transmission electron microscope works on similar principles to an optical microscope but uses electrons in the place of light and electromagnets in the place of glass lenses. Use of electrons, instead of light, allows for much higher resolution. Development of the transmission electron microscope was followed in 1935 by the development of the scanning electron microscope by Max Knoll. Although TEMs were being used for research before WWII, became popular afterwards, the SEM was not commercially available until 1965. Transmission electron microscopes became popular following the Second World War. Ernst Ruska, working at Siemens, developed the first commercial transmission electron microscope and, in the 1950s, major scientific conferences on electron microscopy started being held. In 1965, the first commercial scanning electron microscope was developed by Profess
In biology, a strain is a low-level taxonomic rank used at the intraspecific level. Strains are seen as inherently artificial concepts, characterized by a specific intent for genetic isolation; this is most observed in microbiology where strains are derived from a single cell colony and are quarantined by the physical constraints of a Petri dish. Strains are commonly referred to within virology and with rodents used in experimental studies. A strain is a genetic subtype of a microorganism. For example, a "flu strain" is a certain biological form of "flu" virus; these flu strains are characterized by their differing isoforms of surface proteins. New viral strains can be created due to mutation or swapping of genetic components when two or more viruses infect the same cell in nature; these phenomena are known as antigenic drift and antigenic shift. Microbial strains can be differentiated by their genetic makeup using metagenomic methods to maximize resolution within species; this has become a valuable tool to analyze the microbiome.
Scientists have engineered flu virus strains pandemic in humans. Funding for this research has been controversial as a result of safety concerns, has been halted at times. However, this research continues today. In biotechnology, microbial strains have been engineered to establish metabolic pathways suitable for treating a variety of applications. A major effort of metabolic research has been devoted to the field of biofuel production. Optimized strains of E. coli are are used for this application. E. coli are often used as a chassis for the expression of simple proteins. These strains, such as BL21, are engineered to minimize protease activity, hence enabling potential for high efficiency industrial scale protein expression. In the case of complex proteins including biologics, mammalian strains are used for expression. See Chinese hamster ovary cell. Yeasts are the most common subjects of eukaryotic strain engineering with respect to industrial fermentation. E. coli is most common species for prokaryotic strain engineering.
Scientists have succeeded in establishing viable minimal genomes from which new strains can be developed. These minimal strains provide a near guarantee that experiments on genes outside the minimal framework will not be effected by non-essential pathways; the term has no official ranking status in botany. A strain is a designated group of offspring that are either descended from a modified plant, or which result from genetic mutation; as an example, some rice strains are made by inserting new genetic material into a rice plant, all the descendants of the genetically modified rice plant are a strain with unique genetic information, passed on to generations. The rice plants in the strain can be bred to other rice strains or cultivars, if desirable plants are produced, these are further bred to stabilize the desirable traits. A laboratory mouse or rat strain is a group of animals, genetically uniform. Strains are used in laboratory experiments. Mouse strains can be inbred, mutated, or genetically engineered, while rat strains are inbred.
A given inbred rodent population is considered genetically identical after 20 generations of sibling-mating. Many rodent strains have been developed for a variety of disease models, they are often used to test drug toxicity; the common fruit fly was among the first organisms used for genetic analysis, has a simple genome, is well understood. It has remained a popular model organism for many other reasons, like the ease of its breeding and maintenance, the speed and volume of its reproduction. Various specific strains have been developed, including a flightless version with stunted wings. Genetic isolate Race Coli Genetic Stock Center EcoliWiki E. coli strain index International Mouse Strain Resource Rat strain index
Palatine tonsils called the tonsils and called the faucial tonsils, are tonsils located on the left and right sides at the back of the throat, which can be seen as flesh-colored, pinkish lumps. Tonsils only present as "white lumps" if they are inflamed or infected with symptoms of exudates and severe swelling. Tonsillitis is an inflammation of the tonsils and will but not cause a sore throat and fever. In chronic cases tonsillectomy may be indicated; the palatine tonsils are located in the isthmus of the fauces, between the palatoglossal arch and the palatopharyngeal arch of the soft palate. The palatine tonsil is one of the mucosa-associated lymphoid tissues, located at the entrance to the upper respiratory and gastrointestinal tracts to protect the body from the entry of exogenous material through mucosal sites. In consequence it is a site of, potential focus for, is one of the chief immunocompetent tissues in the oropharynx, it forms part of the Waldeyer's ring, which comprises the adenoid, the paired tubal tonsils, the paired palatine tonsils and the lingual tonsils.
From the pharyngeal side, they are covered with a stratified squamous epithelium, whereas a fibrous capsule links them to the wall of the pharynx. Through the capsule pass trabecules that contain small blood vessels and lymphatic vessels; these trabecules divide the tonsil into lobules. The nerves supplying the palatine tonsils come from the maxillary division of the trigeminal nerve via the lesser palatine nerves, from the tonsillar branches of the glossopharyngeal nerve; the glossopharyngeal nerve continues past the palatine tonsil and innervates the posterior 1/3 of the tongue to provide general and taste sensation. This nerve is most to be damaged during a tonsillectomy, which leads to reduced or lost general sensation and taste sensation to the posterior third of the tongue. Blood supply is provided by tonsillar branches of five arteries: the dorsal lingual artery, ascending palatine artery, tonsillar branch, ascending pharyngeal artery, the lesser palatine artery; the tonsils venous drainage is by the peritonsillar plexus, which drain into the lingual and pharyngeal veins, which in turn drain into the internal jugular vein.
Palatine tonsils consist of 15 crypts, which result in a large internal surface. The tonsils contain four lymphoid compartments that influence immune functions, namely the reticular crypt epithelium, the extrafollicular area, the mantle zones of lymphoid follicles, the follicular germinal centers. In human palatine tonsils, the first part exposed to the outside environment is tonsillar epithelium. Tonsillar B cells can mature to produce all the five major Immunoglobulin classes. Furthermore, when incubated in vitro with either mitogens or specific antigens, they produce specific antibodies against diphtheria toxoid, Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, the lipopolysaccharide of E. coli. Most Immunoglobulin A produced by tonsillar B cells in vitro appears to be 7S monomers, although a significant proportion may be l0S dimeric IgA. In addition to humoral immunity elicited by tonsillar and adenoidal B cells following antigenic stimulation, there is considerable T-cell response in palatine tonsils.
Thus, natural infection or intranasal immunization with live, attenuated rubella virus vaccine has been reported to prime tonsillar lymphocytes much better than subcutaneous vaccination. Natural infection with varicella zoster virus has been found to stimulate tonsillar lymphocytes better than lymphocytes from peripheral blood. Cytokines are humoral immunomodulatory proteins or glycoproteins which control or modulate the activities of target cells, resulting in gene activation, leading to mitotic division and differentiation, migration, or apoptosis, they are produced by wide range of cell types upon antigen-specific and non-antigen specific stimuli. It has been reported by many studies that the clinic outcome of many infectious, autoimmune, or malignant diseases appears to be influenced by the overall balance of production of pro-inflammatory and anti-inflammatory cytokines. Therefore, determination of cytokine profiles in tonsil study will provide key information for further in-depth analysis of the cause and underlying mechanisms of these disorders, as well as the role and possible interactions between the T- and B-lymphocytes and other immunocompetent cells.
The cytokine network represents a sophisticated and versatile regulatory system, essential to the immune system for overcoming the various defense strategies of microorganisms. Through several studies, the Th1 and Th2 cytokines and cytokine mRNA are both detectable in tonsillar hypertrophy and recurrent tonsillitis groups, it showed that human palatine tonsil is an active immunological organ containing a wide range of cytokine-producing cells. Both Th1 and Th2 cells are involved in the pathophysiology of RT conditions. Indeed, human tonsils persistently harbor microbial antigens when the subject is asymptomatic of ongoing infection, it could be an effect of ontogeny of the immune system. The pathogenesis of infectious/inflammatory disease in the tonsils most has its basis in their anatomic location and their inherent function as organ of immunity, processing infectious material, other antigens and becoming, paradoxically, a focus of infection/inflammation. No single theory of pathogenesis has yet been accepted, however.
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. A few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, are present in most of its habitats. Bacteria inhabit soil, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Bacteria live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, only about half of the bacterial phyla have species that can be grown in the laboratory; the study of bacteria is known as a branch of microbiology. There are 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere.
The nutrient cycle includes the decomposition of dead bodies. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Data reported by researchers in October 2012 and published in March 2013 suggested that bacteria thrive in the Mariana Trench, with a depth of up to 11 kilometres, is the deepest known part of the oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere—they're adaptable to conditions, survive wherever they are."The famous notion that bacterial cells in the human body outnumber human cells by a factor of 10:1 has been debunked. There are 39 trillion bacterial cells in the human microbiota as personified by a "reference" 70 kg male 170 cm tall, whereas there are 30 trillion human cells in the body.
This means that although they do have the upper hand in actual numbers, it is only by 30%, not 900%. The largest number exist in the gut flora, a large number on the skin; the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, though many are beneficial in the gut flora. However several species of bacteria are pathogenic and cause infectious diseases, including cholera, anthrax and bubonic plague; the most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, the recovery of gold, palladium and other metals in the mining sector, as well as in biotechnology, the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two different groups of organisms that evolved from an ancient common ancestor; these evolutionary domains are called Archaea. The word bacteria is the plural of the New Latin bacterium, the latinisation of the Greek βακτήριον, the diminutive of βακτηρία, meaning "staff, cane", because the first ones to be discovered were rod-shaped; the ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, bacteria and archaea were the dominant forms of life. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species.
However, gene sequences can be used to reconstruct the bacterial phylogeny, these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. The most recent common ancestor of bacteria and archaea was a hyperthermophile that lived about 2.5 billion–3.2 billion years ago. Bacteria were involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves related to the Archaea; this involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya. Some eukaryotes that contained mitochondria engulfed cyanobacteria-like organisms, leading to the formation of chloroplasts in algae and plants; this is known as primary endosymbiosis. Bacteria display a wide diversity of sizes, called morphologies.
Bacterial cells are about one-tenth the size of eukaryotic cells
Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, alpha-hemolytic or beta-hemolytic, facultative anaerobic member of the genus Streptococcus. They are found in pairs and do not form spores and are nonmotile; as a significant human pathogenic bacterium S. pneumoniae was recognized as a major cause of pneumonia in the late 19th century, is the subject of many humoral immunity studies. S. pneumoniae resides asymptomatically in healthy carriers colonizing the respiratory tract and nasal cavity. However, in susceptible individuals with weaker immune systems, such as the elderly and young children, the bacterium may become pathogenic and spread to other locations to cause disease, it spreads by direct person-to-person contact via respiratory droplets and by autoinoculation in persons carrying the bacteria in their upper respiratory tracts. It can be a cause of neonatal infections. S. Pneumoniae is the main cause of community acquired pneumonia and meningitis in children and the elderly, of septicemia in those infected with HIV.
The organism causes many types of pneumococcal infections other than pneumonia. These invasive pneumococcal diseases include bronchitis, acute sinusitis, otitis media, meningitis, osteomyelitis, septic arthritis, peritonitis, pericarditis and brain abscess. S. Pneumoniae can be differentiated from the viridans streptococci, some of which are alpha-hemolytic, using an optochin test, as S. pneumoniae is optochin-sensitive. S. pneumoniae can be distinguished based on its sensitivity to lysis by bile, the so-called "bile solubility test". The encapsulated, Gram-positive, coccoid bacteria have a distinctive morphology on Gram stain, lancet-shaped diplococci, they have a polysaccharide capsule. In 1881, the organism, known in 1886 as the pneumococcus for its role as a cause of pneumonia, was first isolated and independently by the U. S. Army physician the French chemist Louis Pasteur; the organism was termed Diplococcus pneumoniae from 1920 because of its characteristic appearance in Gram-stained sputum.
It was renamed Streptococcus pneumoniae in 1974 because it was similar to streptococci. S. Pneumoniae played a central role in demonstrating that genetic material consists of DNA. In 1928, Frederick Griffith demonstrated transformation of life turning harmless pneumococcus into a lethal form by co-inoculating the live pneumococci into a mouse along with heat-killed virulent pneumococci. In 1944, Oswald Avery, Colin MacLeod, Maclyn McCarty demonstrated that the transforming factor in Griffith's experiment was not protein, as was believed at the time, but DNA. Avery's work marked the birth of the molecular era of genetics; the genome of S. pneumoniae is a closed, circular DNA structure that contains between 2.0 and 2.1 million base pairs depending on the strain. It has a core set of 1553 genes, plus 154 genes in its virulome, which contribute to virulence and 176 genes that maintain a noninvasive phenotype. Genetic information can vary up to 10% between strains. Natural bacterial transformation involves the transfer of DNA from one bacterium to another through the surrounding medium.
Transformation is a complex developmental process requiring energy and is dependent on expression of numerous genes. In S. pneumoniae, at least 23 genes are required for transformation. For a bacterium to bind, take up, recombine exogenous DNA into its chromosome, it must enter a special physiological state called competence. Competence in S. pneumoniae is induced by DNA-damaging agents such as mitomycin C, fluoroquinolone antibiotics, topoisomerase inhibitors. Transformation protects S. pneumoniae against the bactericidal effect of mitomycin C. Michod et al. summarized evidence that induction of competence in S. pneumoniae is associated with increased resistance to oxidative stress and increased expression of the RecA protein, a key component of the recombinational repair machinery for removing DNA damages. On the basis of these findings, they suggested that transformation is an adaptation for repairing oxidative DNA damages. S. pneumoniae infection stimulates polymorphonuclear leukocytes to produce an oxidative burst, lethal to the bacteria.
The ability of S. pneumoniae to repair the oxidative DNA damages in its genome, caused by this host defense contributes to this pathogen’s virulence. Consistent with this premise, Li et al. reported that, among different transformable S. pneumoniae isolates, nasal colonization fitness and virulence depend on an intact competence system. S. pneumoniae is part of the normal upper respiratory tract flora. As with many natural flora, it can become pathogenic under the right conditions when the immune system of the host is suppressed. Invasins, such as pneumolysin, an antiphagocytic capsule, various adhesins, immunogenic cell wall components are all major virulence factors. After S. pneumoniae colonizes the air sacs of the lungs, the body responds by stimulating the inflammatory response, causing plasma and white blood cells to fill the alveoli. This condition is called pneumonia, it is susceptible to clindamycin. Pneumonia is the most common of the S. pneumoniae diseases which include symptoms such as fever and chills, rapid breathing, difficulty breathing, chest pain.
For the elderly, they may include confusion, low alertness, the former listed symptoms to a lesser degree. Pneumococcal me
A medical laboratory or clinical laboratory is a laboratory where clinical pathology tests are carried out on clinical specimens to obtain information about the health of a patient to aid in diagnosis and prevention of disease. Clinical Medical laboratories are an example of applied science, as opposed to research laboratories that focus on basic science, such as found in some academic institutions. Medical laboratories so offer a variety of testing services. More comprehensive services can be found in acute-care hospitals and medical centers, where 70% of clinical decisions are based on laboratory testing. Doctors offices and clinics, as well as skilled nursing and long-term care facilities, may have laboratories that provide more basic testing services. Commercial medical laboratories operate as independent businesses and provide testing, otherwise not provided in other settings due to low test volume or complexity. In hospitals and other patient-care settings, laboratory medicine is provided by the Department of Pathology, divided into two sections, each of which will be subdivided into multiple specialty areas.
The two sections are: Anatomic pathology: areas included here are histopathology and electron microscopy. Clinical pathology, which includes the following areas:Clinical Microbiology: This encompasses several different sciences, including bacteriology, parasitology and mycology. Clinical Chemistry: This area includes automated analysis of blood specimens, including tests related to enzymology and endocrinology. Hematology: This area includes manual analysis of blood cells, it often includes coagulation. Blood Bank involves the testing of blood specimens in order to provide blood transfusion and related services. Molecular diagnostics DNA testing may be done along with a subspecialty known as cytogenetics. Reproductive biology testing is available in some laboratories, including Semen analysis, Sperm bank and assisted reproductive technology. Layouts of clinical laboratories in health institutions vary from one facility to another. For instance, some health facilities have a single laboratory for the microbiology section, while others have a separate lab for each specialty area.
The following is an example of a typical breakdown of the responsibilities of each area: Microbiology includes culturing of clinical specimens, including feces, blood, cerebrospinal fluid, synovial fluid, as well as possible infected tissue. The work here is concerned with cultures, to look for suspected pathogens which, if found, are further identified based on biochemical tests. Sensitivity testing is carried out to determine whether the pathogen is sensitive or resistant to a suggested medicine. Results are reported with the identified organism and the type and amount of drug that should be prescribed for the patient. Parasitology is. For example, fecal samples may be examined for evidence of intestinal parasites such as tapeworms or hookworms. Virology is concerned with identification of viruses in specimens such as blood and cerebrospinal fluid. Hematology analyzes whole blood specimens to perform full blood counts, includes the examination of Blood films. Other specialized tests include cell counts on various bodily fluids.
Coagulation testing determines various blood clotting times, coagulation factors, platelet function. Clinical Biochemistry performs dozens of different tests on serum or plasma; these tests automated, includes quantitative testing for a wide array of substances, such as lipids, blood sugar and hormones. Toxicology is focused on testing for pharmaceutical and recreational drugs. Urine and blood samples are the common specimens. Immunology/Serology uses the process of antigen-antibody interaction as a diagnostic tool. Compatibility of transplanted organs may be determined with these methods. Immunohaematology, or Blood bank determines blood groups, performs compatibility testing on donor blood and recipients, it prepares blood components and products for transfusion. This area determines a patient's blood type and Rh status, checks for antibodies to common antigens found on red blood cells, cross matches units that are negative for the antigen. Urinalysis tests urine including microscopically. If more precise quantification of urine chemicals is required, the specimen is processed in the clinical biochemistry lab.
Histopathology processes solid tissue removed from the body for evaluation at the microscopic level. Cytopathology examines smears of cells from all over the body for evidence of inflammation and other conditions. Molecular diagnostics includes specialized tests involving DNA analysis. Cytogenetics involves using blood and other cells to produce a DNA karyotype; this can be helpful in cases of prenatal diagnosis as well as in some cancers which can be identified by the presence of abnormal chromosomes. Surgical pathology examines organs, tumors and other tissues biopsied in surgery such as breast mastectomies; the staff of clinical laboratories may include: Pathologist Clinical Biochemist Pathologists' Assistant Biomedical Scientist in the UK, Medical Laboratory Scientist in the US or Medical Laboratory Technologist in Canada Medical Laboratory Technician/Clinical Laboratory Technician Medical Laboratory Assistant Phlebotomist Histotechnologist/Histology Technician In the United States, there is a documented shortage of working laboratory professionals.
For example, in 2016 vacan