GENERAL PROPERTIES OF THE FUNGUSES.
THE REALM OF THE FUNGUSES.
The funguses are an extraordinarily diverse group of eucariontes that differ a lot by his structural characteristics and his ways of reproduction. Have very little in common, except the nutrition heterotrófa forced, by the absence of chlorophyl. His cells are included in cellular walls at least in some stage of his vital cycle, and produce some type of spore, generally in big number, during the process reproductor. There are two groups of funguses: Myxomycota, or molds of the légamo, and Eumycota or true funguses. They can consider like separate divisions in the vegetal realm, or both can join constituting the realm of the funguses, as it proposed Whittaker. Myxomycota Includes the cellular molds of the légamo, and the molds plasmodiales of the légamo that differ netamente by his structure and by his means of reproduction. The molds of the légamo cellular (class Acrasiomycetes) are resembled the protozoarios and remedan amibas during the greater part of his vital stages. They do not have cells flageladas in any moment of his vital cycle, and the spores do not produce by divisions citoplásmicas, as in other funguses, but by training of walls to the rededor of cells amiboides individual.
Ordinariamente, these cells reproduce asexualmente, by fission, but one of the most curious biological phenomena is the aggregation and fusion of molds of individual earth, similar to amibas, to form a body of producing fruit of spores(figure 8-18).
When a spore arrives to a humid surface, absorbs water, opens his wall and the subsequent division gives place to cells amiboides. Finally some of these cells amiboides work like gametes that join to form a zygote, that afterwards divides giving place to the gelatinous mass multinucleada(the plasmodium), with which completes the vital cycle.
The plasmodiums of molds of the légamo are microorganicos peculiar, present like gelatinous masses on the leaves or the wood in decomposition; they displace by means of seudópodos, the same that the amibas. In successive stages of his vital cycle present like flagelados unicellular, amibas unicellular, masses multinucleadas of cytoplasm (the mass that forms a colony calls plasmodium), and, finally, similar organisms to plants with cut and producing body of fruits. The plasmodium does not have clear-cut form, can present brilliant colours and drags slowly by trip of his cytoplasm, feeding of small organic particles microorganisms in his distance. The movements plasmodiales accompany of rhythmical and reversible currents of the cytoplasm. The plasmodium grows by synthesis of his components citoplásmicos, accompanied of mitotic divisions of the cores. They know some 450 species of mixomicetos that can distinguish by the volume, colour and texture of the plasmodium, and by the types of sporangiums and spores produced.
Division Eumycota: true funguses.
There is some 80 000 species of true funguses; they coincide in a lot of properties with the seaweeds. The true funguses comprise plants like yeasts, some molds, mildeu, royas, tizones and mushrooms. Some true funguses are unicellular, but the mayoria are multicellular formed of filaments ramificados called hyphas. The external wall of the body of the funguses can be composed of cellulose, chitin or a combination of both. Also it can contain lignin and the carbohydrate callosa. In some species, the hyphas are divided by transversal walls that separate the successive cores, the plant is, then , multicellular; in other species there are not such transversal septums and the fungus is multinuclear. All the mass of hypha ramificada that forms an alone fungus calls micelio. The presence of micelio is one of the characteristics of Eumycophyta. In the common mold of the bread this micelio presents in shape of a mass of strands interwoven on the surface, those that penetrate in the interior of the bread. In other funguses, for example the mushrooms, big part of the micelio finds under the earth. The "hat" of the fungus that eat is the body esporífero, a structure reproductora skilled that desarrola of the micelo, underground. The funguses are saprophytes or parasites; they find dondequiera that exist available organic substance; they develop better in places obscuros and humid. Some funguses can grow even under conditions when seeming very desfavorables; they resist considerably the plasmólisis; as they can develop in solutions concentrated of salt or sugar, for example, on jam. However , many of these funguses produce grave illnesses in the man, domestic animals and in the harvests. They are largely I motivate that they spoil the wood, leather, cloth and other substances. The reproduction can revestir distinct forms: asexual, by division, gemmation or spores, and sexual by characteristic means of each subgroup. The spores of the aquatic funguses have flagelos typical, and the ones of the terrestrial funguses are motionless cells that disperse by the action of the wind or of the animals. The classes of Eumycota (Chytridiomycetes, Oomycetes, Zygomycetes, Ascomycetes, and Basidiomycetes) distinguish by his means of sexual reproduction. They have established other two classes of Mycota- the Deuteromycetes or imperfect funguses, and the Líquenes. These classes are agrupamientos taxonómicos artificial of bad organisms known, or are symbiotic associations (líquenes) of two different organisms. The imperfect funguses include a very heterogeneous group of organisms; it does not comprise completely his relative position and desconoce the form of sexual reproduction.
The funguses algales
The three first classes of Eumycota in the past had grouped boards in an alone class, the Ficomicetos, names that can translate like "funguses algales". Many of the 1 100 species, roughly, in these three classes resemble some of the seaweeds filamentosas simpler by his organisation citoplásmica, the structure of his sexual organs, spores and gametes, and by his aquatic way of life. These similarities with the seaweeds and between them, can be resulted of the convergent evolution rather that of a relacion evolucionaria narrow.
Chytridiomycetes. The members of the class Chytridiomycetes include forms of type protozoario, as well as types miceliales, all which reproduce by means of zoosporas uniflageladas and gametes. There is Allomyces, an isolated microscopic fungus of the floor in diverse parts of the world, that can grow in crop of seeds of hemp boiled. The fungus develops like a growth of filaments of hyphas that grow on the seeds. The hyphas are coenocíticas, and ramifican developing gametangios masculine and feminine. The gametangios masculine free masculine gametes flagelados, that are attracted by a substance designated sirenina produced by the feminine gametes flagelados bulkier. These organisms develop mitosporangias and produce mitosporas mobile (zoospora). These give place to more plants esporofilas, but when the crop ages the esporangias begin to develop brownish thick walls, that will resist the desiccation. When the esporangias resistant plant in a humid environment suffer meiosis and form meiosporas flageladas, that give place to the following generation of gametophytes.
Oomicetos. The oomicetos are forms miceliales, many of them aquatic and of type of seaweeds. These funguses have sexual reproduction oogámica and spores flageladas. Any of these funguses, are saprobas and parasitic of fish, larvae of insects and seeds, and attack animal and vegetal rests. The mold of the fish Saprolegnia, can parasitar to the fish; it is a frequent infection in aquariums excessively populated. The oomicetos form eggs and reproduce sexually by conjugacón between small motionless masculine cells and eggs a lot greater. His spores are biflageladas and mobile.
Zygomycetes. The cigomicetos are probably the funguses algales better known. A common form is the black mold of the bread Rhizopus nigricans. The bread "rusts " when it falls on him a spore of the black mold. The spore germinates and develops until forming a mass interwoven of filaments, the micelio. Some of the hyphas, designated rizoides, penetrate in the bread of the that obtain his sustento; others, calls estolones spread horizontally with remarkable speed. Afterwards, some hyphas grow upwards and give place in an extreme to a sporangium or sack of spores. Inside this sack develop pendants of spherical black spores that free when it breaks the thin sack of spores. It takes place the sexual reproduction when they find attach two hyphas of different individuals. The mold of the bread is heterotálico.
Class ascomicetos: the funguses of sacks
The ascomicetos, or funguses of sacks, form the widest class of the funguses (near of 35 000 species); his name is due to that the spores produce in sacks called disgusts. Each disgust produces of two to eight ascosporas. The molds ascomicetos that present on the food can give him bad taste, but are not poisonous. The special flavour of cheese like the Roquefort and Camembert is due to the action of ascomicetos. The ascomiceto Penicillium produces the famous antibiotic penicillin. They result to be ascomicetos founding in his structure of hyphas and his conidios, but the sexual phase still is not known, therefore, classify like Fungi Imperfecti. The bodies of the ascomicetos can be unicellular as in the yeasts; they can consist of micelios filamentosos multicellular, like the mildeu pulverulento, or be thick and fleshy, as in the truffle. The reproduction is asexual by gemmation (yeasts) or by spores called conidios that develop in series successive in the extremes of some hyphas, and sexual by a process of fertilisation that has to place in two stages. In the first stage, plasmogamia, there is a mix of resultant cytoplasm of the transfer of one or more cores and something of cytoplasm from an anteridio masculine to the interior of a gametangio feminine, called an ascogonio. The cells of the hyphas that form before the plasmogamia are uninucleadas; those that develop from the ascogonia after the plasmogamia are binucleadas. The second stage in the fertilisation is the fusion of cores, or cariogamia, that takes place in the terminal cells of the hifasbinucleadas. The resultant disgust has a core 2N, and the meiosis, generally followed of a mitotic division, results in the training of eight ascosporas, each one 1N in the number of chromosomes, inside the disgust. The asexual reproduction between the ascomicetos takes place with production of conidios, spores that form protrusions seriadas in the tips of some hyphas, in place of which form inside the esporangias. The conidios, called sometimes "spores of grain", are half for the fast propagation of micelios new. They present in forms, volumes and diverse colours according to the species; it is the colour of the conidio the one who gives the characteristic dye black, blue, green, rose or another to many of these molds. The capacity of the yeasts to produce alcohol étilico from glucose in absence of oxygen is of big economic importance. The present yeasts in the preparation of the wine are used to to be the found spontaneously on the skin of the grape; part of the difference of flavour of the distinct wines has to to the type of yeast of the region. The yeasts of the panificación and manufacture of beer are cultivated and conserve carefully like pure strains to avoid the pollution. The ascomiceto Neurospora crassa is a saprophyte that presents on cakes and cakes, under form of a white lint algodonosa at the beginning, that afterwards goes back rose when appearing spores asexuadas of this colour; it uses a lot in genetics and biochemical.
Another ascomiceto, Claviceps purpurea, produces the illness of the cornezuelo in diverse vegetables and other cereals, that originates poisoning of the man and of the livestock, the called ergotismo (dance of saint vito). The acid lisérgico is one of the constituents of the cornezuelo, and intermediate product in the syntheses of the dietilamida of the acid lisérgico (LSD). In some aspesctos the ascomicetos resemble the oomicetos. However, unlike the oomicetos, any ascomiceto produce cells flageladas. In any other appearances, and in particular by his way of reproduction, the ascomicetos resemble the red seaweeds, by what other researchers think that the ascomicetos proceeded of said seaweeds when being saprófitas and perder his pigments of photosynthesis
Class basidiomicetos: the mushrooms
The 25 000 or more species of basidiomecitos comprise the mushrooms, amanitas, royas, tizones and mushrooms. The vegetative body of the cultured fungus Agarius campestris, is formed by a mass of white hyphas ramificadas filiformes that in his greater part are subterranean. The hyphas are tabicadas, but the septums are not drilled as in the ascomicetos. After some time appear at intervals on the micelio compact masses of hyphas called "yolks" (fig. 8-22). The yolk gives place to the training that we are used to to call mushroom, formed by cut and socket. In the inferior face of the socket finds a lot of perpendicular plates calls laminillas, that extend radialmente from the cut until the edge of the socket. The basidios develop on the surface of these plates (fig. 8-23). Each basidio contains two cores that join to form a diploid core. To his time, this suffers division by meiosis, to give origin to four basidiosporas haploid. These hyphas grow a lot and finish developing basidiocarpos, the structure that know like "funguses or mushrooms", formed by hyphas entreveradas gathered together. In some regions of the basidiocarpo, groove them of the mushroom, the cells in the tips of the hyphas suffer cariogamia (nuclear fusion), followed of meiotic division to attain basidiosporas haploid. The words "mushroom" or "fungus" does not designate any particular species of basidiomicetos, but so only the body of distinct varieties. There is some 200 edible and some 25 poisonous. The mortal fungus called "angel exterminador" in English, Amanita verna is very toxic, and the "holy funguses" of the Aztecs, Conocybe and Psilocybe contain dangerous hallucinogens. The evolutionary origin of the basidiomicetos is a complete mystery. It does not have relation with some seaweed and, in general, thinks that they proceed of other funguses, maybe of the ascomicetos.
Líquenes
Although the líquenes seem individual plants are in reality an intimate combination of a seaweed and a fungus, the seaweed can be green or verdeazul and the fungus is generally an ascomiceto; in some líquenes tropical the fungus is a basidiomiceto. The components fungoso and algálico can separate and do grow isolatedly in means of suitable crop. The líquenes resist extreme conditions of temperature and humidity, and find dondequiera can have life. The seaweed, by means of phenomena of photosynthesis, produce the food for both components; the fungus portege to the seaweed with his micelio resistant and gelatinous and supplies him water and mineral salts. The líquenes have an important paper in the training of the earth, as gradually they dissolve and disintegrate the rocks on which fix . The funguses of some líquenes produce pigments coloreados. There is some 10 000 species of líquenes, true problem of classification, as it is necessary to decide if it classifies them of agreement to the component of seaweed, to the of fungus, or of another way.
Economic importance of the funguses.
They are few the funguses that the man uses like food, also are few the parasites of the man. The only harmful funguses for the man are a few poisonous mushrooms and the ascomiceto Clariceps that produces in the rye an illness called cornezuelo. If the man ingiere bread of ready flour of ill plants, suffers the intoxication of the cornezuelo, that characterises by hallucinations, madness and death. A derivative of the cornezuelo, the acid lisérgico, and the affine compound LSD (dietilamida of the acid lisérgico), produces similar hallucinations to the ones of the schizophrenia and can lesionar the chromosomes and produce mental and emotional disorders. The ficomicetos produce the illness of the putrefacción in retoños of corn, tobacco, peas, beans.
caracteristicas Of the funguses
The funguses an been considered traditionally like similar wings plant. The myoria of the especiescrece by the continuous extencion and bifurcion of structures like the branch of a to´rbol the funguses grow like celulas unicas,yeasts,or like colonies multicelulares filamentosas,molds and mushrooms. The forms multicelulares do not possess leaves, tallos neither raices and estan poe ellomucho less differentiated that the upper plants but enough but that the bacteria. However, the hongosno possess pigments fotosinteticos, by what limitaa an existence saprofita or paracita. A celula uninuleada can generate strands filamentosas multinucleares, yeasts bodies with diverse spores and celulas that differentiate sexually(in a lot of species).ademas, some species form remarkable sepos and cheats to capture to diverse creatures microscopicas.
The funguses abound in the floor, in the vegetacion and in the water, where live mainly on the leaves or wood in descomposcicion. His ubicuas spores airlifted are with annoying frequency contaminantes of crops bacterianos and of celulas of mamiferos. In fact, simply one of these contaminantes codujo to the discovery of the penicillin
Metabolism
The majority of the funguses are aerobic forced, but the forms of yeasts,able to grow in the depth of liquid means , are frequently facultativos. To exception of the absence of estróficos or of anaerobios forced, the funguses exhibit like group a diversity of possibilities metabolicas almost so big like the bacteria
reproduccion
In addition to growing by extinction apícola and bifurcacion, the funguses reproduce by means of sexual and asexual cycles, as well as by some processes for sexual .
ASEXUAL REPRODUCTION: the vegetative growth of a micelio senocitico comports nuclear resignation without cellular resignation ensuring the classical process of mitosis, the transmission of a complete group of chromosomes to the core and each cell hija.el additional step of the cellular resignation drives wing asexual reproduction (vegetative); this is, wing formacion of a new clone without participacion of gametes neither nuclear function.
SEXUAL REPRODUCTION: the funguses that effect sexual reproduction: first,a nucleo aploide of a cell of the donor penetrates in the cytoplasm of a celula receptor. Second,the nucles of the donor and of the receptor merge to form a nucleo cigotico diploid.
Third,the nucleo diploid gives origin, by meiosis, to 4 nucleos aploides, some of which can be recombinantes geneticos. In the mayoria of the species, the face aploide is the one who goes asocida to the prolonged vegetative growth and elo diploid state is transitory, but in other species, as in the upper animals, sucede the contrary.
CYCLE FOR SEXUAL: some funguses effect a cycle that contribute them some of the advantages biologies of the sexuality(for example, recombinacion of the DNA of the progenitors) without that esten ibolucradas gametes or algun type of organo skilled in the mating.
taxonomia
The deuteromicetos(imperfect funguses) include the majority of human pathogens. As it has observed face sexual in them, designate frequently imperfect funguses. The hyphas are septadas and his forms conidiles very resembled the ones of the ascomicetos; for this reason it has suspected during long that they could be escomisteis special whose face sexual serious extremely infrequent or opened disappeared during the return.
Classification
In accordance with the Dictionary of Funguses (Hawksworth et al, 1995), this realm has roughly 103 orders, 484 families, 4.979 genders and some 80.000 species described. It divides in four groups or edges: Ascomycota, Basidiomycota, Chytridiomycota and Zygomycota
Ascomycota
Is the biggest group. These funguses possess forms very varied: of glass, button, disk, beehive and fingers, between others. It groups a big quantity of pathogenic funguses of plants and animal and those that grow on foods, besides some that can find on leather, cloth, paper, glass, lens of cameras, walls, etc. The main characteristic, in addition to his form, is the presence of structures reproductoras microscopic calls ascas, that give origin to the spores. The ascas are formed by a skilled cell with form of sack in whose interior form the spores. To the spores produced by the disgusts also calls them ascosporas. The líquenes belong to the realm of the Funguses because have the same type of reproduction and 99% of the species known belong to the Edge Ascomycota (Ascolíquenes) and only 1% to the Edge Basidiomycota.
Basidiomycota
Includes those funguses with form of sombrilla, of choral, the ears of stick, the gelatinous, globosos and some yeasts, among others. Also it includes those that have appearance polvoriento or like stains and grow on diverse structures of the plants (flowers, fruits, leaves, cut or roots). Some have economic importance, like the royas and the coals. To microscopic level his main characteristic is the presence of structures reproductoras skilled or basididos, which give origin to the spores but in shape external, generally in groups of four, although in some species can find two and six spores by basidio. The spores know like basidiósporas.
Chytridiomycota
Group formed mainly by microscopic aquatic funguses, although some can grow also on organic matter in decomposition or alive organisms like worms, insects, plants and other funguses. In this case, the spores, calls "zoosporas", possess flagelos that allow them move in liquid means. This group has not been taken in account until the moment in the present Inventory of Funguses of Costa Rica.
Zygomycota
Composed by microscopic funguses that they can develop on organic matter in decomposition, although also they can find in the digestive tract of some species of arthropods, like the insects. This group has not been taken in account until the moment in the present Inventory of Funguses of Costa Rica.
Morphology.
They are anatomical units and of growth: the hypha, in multicellular funguses (Fig. 1), and the yeast, in unicellular funguses
(Fig. 2).
- The hyphas are cylindrical structures, cenocíticas (aseptadas) or tabicadas (with septos), generally multinucleadas. They grow by the apex (elongación) and can do it in any direction, even inside the sustrato (Fig. 3). A group of hyphas designates micelio and when they reach some size says that it forms colonies (Fig. 4).
- The yeasts (Fig. 2) they present diverse forms, spherical, ovoid, elipsoidal and cylindrical; they grow of form isodiamétrica (by all sides) constituting the vegetative part and in little time reproduce asexualmente by gemmation, binary fission or fragmentation. Some yeasts form chains, structures to which designates seudohifas (by what the aggregation of several of them knows like seudomicelio). (Fig. 3). The colonies generally are little high and of soft consistency, cremosa, and his colour oscillates, in general, between the white - yellow, although some contain pigments carotenoides(Fig. 4).
In the Medical Mycology consider the funguses dimórficos. Usually, in these cases, identifies a form infectiva, and a parasitic form, the first present in the nature, the second in the hospedero.
Reproduction.
The funguses, during the vegetative phase (of nutrition and growth), are haploid (n) in the greater part of his cycle of life. The micelio vegetative grows inside or on the sustrato and absorbs the nutrients; it develops aerial hyphas, which generally constitute the most visible portion of the colony, and in which they differentiate fertile hyphas, that are reproductive and formadoras of spores.
The cycle of life initiates with the germination of one of the spores, continues with the growth in a sustrato, increases the biomass, and finishes again with the esporulación and the dissemination of the propágulos.
The reproduction can be asexual (mitosis) or sexual (meiosis), and can present simultaneously. The sexual reproduction initiates with the plasmogamia (fusion of membranes) of two haploid gametes; they approach the cores and later occurs the cariogamia, forming the diploid zygote (2n) and finally occurs the meiosis for reestablecer the haploid condition; so 2 haploid cores will give place to 4 new cores recombinados haploid. This genetic recombination provides big advantages to invade or resist in environments desfavorables. Some species can “retardar” the process of meiosis and remain in a condition dicariótica (n+n), a form to resist conditions desfavorables.
Of schematic form could write: haploid vegetative Phase --- plasmogamia --- cariogamia --- meiosis --- haploid spores --- haploid vegetative phase. Depending of the phylum of the fungus, the sexual spores are produced in skilled structures like ascas or basidios and are designated: Cigosporas, ascosporas or basidiosporas.
On the other hand, the asexual reproduction only includes: vegetative phase heteroploide (n, 2n, 4n) --- mitosis—spores heteroploides --- vegetative phase heteroploide. The advantage of this type of reproduction is the big number of spores that form , as well as the rapidity with that carries out the process. The funguses filamentosos can reproduce by the simple fragmentation of the hyphas or by means of the training of skilled structures (cells conidiógenas or sporangiums), whereas the yeasts reproduce by gemmation, binary fission or fragmentation. The spores of asexual origin group in: Conidios and esporangiosporas.
Factors of virulence of the funguses.
The course of the illnesses micóticas, determines it the interaction of the agent with the different mechanisms of natural and specific defence of the guest.
The spores or fragments of micelio of a pathogenic fungus, can remain latent or germinate on the surface of the guest or if they are inhaled, in the alveolos of the lungs, the resultant hyphas can penetrate the fabrics, colonise them, reproduce and disperse, altering the physiology of the guest and causing illness.
In the human, the systems of defence generally are effective, since the majority of the funguses that are in the environment, do not cause illness. The immune system of the mammals involves factors so much innate (complement, fagocitosis, processes inflamatorios, quimiotaxis) as adaptative (cells and specific antibodies), whose main function is to keep us clean of agents infecciosos; however, they exist situations that weaken these natural defences or purchased, doing susceptible to the guest.
The factors of virulence will be those “properties”, generally molecules, that allow to the fungus cause damage or illness in the one who lodges it.
The development or expression of such factors, begins by external stimuli to the cell fúngica. These stimuli activate cracked of signaling that cause compound protective (p. ej: Enzymes, determinants antigénicos, receptors), causantes to his time of the development of the patogénesis. It exists a complex network of interactions that include the participation of a lot of molecules, so much by part of the guest as of the fungus, that allow the expression of diverse roads; the result of this interaction, will be evaluated (illness or no) according to the level of damage caused in the guest.
Some examples of factors of virulence studied in funguses, are enlistados in the following picture:
Agent Illness Factor of virulence Effect
Aspergillus sp. Aspergilosis “rodlets” (hidrofobinas) Inhibition of the fagocitosis
Aspergillus sp. Aspergilosis Pulmonary Gliotoxina Alentan The ciliary movement and lesionan the epithelium of high respiratory tracts.
Dermatofitos You dye Queratinasas Destruction of the stratum córneo
Dermatofitos Ides Toxins Hipersensibilidad
Cryptococcus Criptococosis Capsule Inhibition of immune answer (prevents migration of cells of the immunity and properties antifagocíticas)
Cryptococcus Criptococosis Production of melanin Anti-Oxidant, resistance to anfotericina B
Sporothrix spp. Esporotricosis linfangítica Production of melanin It inhibits the fagocitosis by macrófagos.
Mucorales Mucormicosis Ceto-reductasa They degrade the bodies cetónicos presents in blood, favouring the growth and dissemination of the fungus.
Malassezia spp. Pitiriasis versicolor hipocrómica Acids dicarboxílicos Inhibition of the tirosinasa and of the production of melanin comporting a lower protection against the rays UV and the establishment of harmful microbial agents.
Malassezia spp. Dermatitis seborréica Fosfolipasas Destruction of the acids grasos essential in the skin causing dryness
Coccidioides spp. Coccidioidiomicosis Elastasas They destroy the elastic fibres of the fabrics.
THE WELL And THE BAD
The funguses produce secondary metabolites and the man processes them for different industries eat: bakery, brewery, quesería, in the production of antibiotics (penicillins, cefalosporinas), inmunodepresores (ciclosporina), hormones and steroids, organic acids (sour láctico and the citrus acid employee in the preparation of a soda of big consumption), enzymes (celulasa, catalase, amylase, renina). Saccharomyces cerevisiae Is a valuable yeast no only by his commercial value but like system model in studies of eukaryotic genetics.
The funguses simbiontes have beneficial relations with other organisms. Examples of ésto are the líquenes, associations of funguses with seaweeds or cianobacterias whose intimate relation allows them colonise different sustratos, even rocks, that of independent way are unable to degrade and the micorrizas, associations of funguses and roots of plants whose interaction favore the growth of the plant and the obtaining of nutrients by part of the fungus in floors that are them desfavorables. Also they present symbiotic relations with insects, like the ants and termites.
The funguses have an essential paper in the decomposition of the cellulose, with the production of bióxido of carbon and water; on the other hand, they represent economic losses when degrading paper, cloths, leather, hydrocarbons and other products; the useful appearance is his responsibility in the recycling of the wood in the forests and his employment for the bioremediación of floors contaminated by toxic materials. They degrade almost everything, with exception of some plastics and pesticidas.
On the other hand, they are cause of economic losses in the agricultural production and grazier because of the illnesses that cause to animals and plants.
IMPORTANCE IN THE MEDICINE
The funguses can cause in the human: Hipersensibilidad (allergies), infections (micosis) and intoxications (micotoxicosis and micetismos).
The allergies by funguses are padecimientos caused by a reaction of hipersensiblidad of the human to spores or fragments of hyphas (alérgenos fúngicos). The clinical pictures presented are cutaneous or gastric, but the most common are of respiratory origin.
In general, the micotoxicosis purchase for consuming foods of vegetal origin (especially seeds and grains of leguminosas and oleaginosas), on which funguses filamentosos grew, contaminating to the vegetable with toxic metabolites or micotoxinas (product of the natural growth on the sustrato). The identification of micotoxinas in grains stored for human consumption or for animals involves his waste.
The micetismos or ingestion of some macromicetos by recreation, mistake or so as to have a "mystic experience" is origin of severe intoxications (micetismo).
The infections of origin fúngico designate micosis (superficial, cutaneous, subcutáneas, sistémicas, turncoats).
The acquisition of a micosis, depends often of factors predisponentes, such like age, occupation, pregnancy, burns, inmunodepresión, chemotherapy, radiation, use of catéteres, malignant processes or metabolic illnesses in the people. The forms infectantes purchase usually of the environment, already was by direct contact (dermatofitos) by inhalation (p. Ej: Coccidioides) Or injuries of continuity (Sporothrix). Others, can contract or come from of the microbiota normal, like sucede in the micosis opportunist ocasionada by Candida.
CLINICAL CLASSIFICATION OF THE MICOSIS
Types Illness Fungus (Gender)
Superficial: (Photography 1)
external Layers of skin (epidermis), hair, nails, mucosas Pitiriasis versicolor
Dye black
Dermatofitosis Malassezia
Hortaea
Trichophyton
Microsporum
Epidermophyton
Subcutáneo: (Photography 2)
Dermis, fabric subcutáneo and muscle Eumicetoma
Esporotricosis
Cromoblastomicosis Madurella
Sporothrix
Fonsecaea
Sistémico Or deep: (Photography 3)
One or more organs / knitted deep Histoplasmosis
Paracoccidiodomicosis
Coccidiodomicosis Histoplasma
Paracoccidioides
Coccidioides
Turncoat: (Photography 4)
Diverse organs. Topográficamente Can be superficial, subcutáneas or sistémicas, but are caused by innocuous funguses
In a subject susceptible, any fungus can be a turncoat Candidosis
Criptococosis
Zigomicosis Candida
Cryptococcus
Rhizopus
The answers tisulares more frequent that induce the funguses, when they cause a micosis are:
- acute Inflammation supurativa
- chronic Inflammation
- Inflammation granulomatosa
The micosis are the infections caused by funguses. Can classify in:
Micosis Superficial: they Are superficial infections by funguses of the skin or of the hair. It does not invade the alive fabric and there is not cellular answer of the guest. There are not pathological changes. These infections are often so innocuous that the patients are not conscious of them. Example:
• pitiriasis versicolor, dermatitis seborréica and the dandruff, including follicular pink: Malassezia furfur (a yeast lipofílica)
Micosis Cutaneous: they Are superficial infections by funguses of the skin, hair or nails. They do not invade the alive fabrics, however, a variety of pathological changes produce in the hospedador because of the presence of the agent infeccioso and his metabolic products.
Examples
• Dermatofitosis(Dye of the scalp): Dermatofitos (Microsporum,Trichophyton, Epidermophyton)
• Candidiasis Of the skin, membranes mucosas and nails: Candida albicans and affine species.
Micosis subcutáneas: They are chronic infections located of the skin and the fabric subcutáneo after a traumatic implantation of the agent etiológico. The funguses causantes are saprophytes of the floor whose capacity to adapt to the surroundings cause pathology extremely variable.
Examples:
• Esporotricosis: Sporothrix schenckii
Micosis sistémicas Or deep: they Are infections in the organs or internal fabrics,caused by pathogenic funguses dimórficos that can combat to the defences of the normal human guest changing his morphological form. They are geographically limited and the main place of infection is generally pulmonary, produced by the inhalation of the conidias .
Examples:
• Histoplasmosis: Histoplasma capsulatum
• Blastomicosis: Blastomyces dermatitidis
Micosis Opportunist: S
on infections that produce almost exclusively in
p acientes with the immunity altered.
The organisms involved are funguses with a very low virulence.
Examples
* Candidiasis: Candida albicans and species related
• Criptococosis:Cryptococcus neoformans
* Aspergilosis: Aspergullus fumigatus
Pathology caused by micotoxinas: The micotoxinas are compound toxic produced by the funguses, that accumulate in foods contaminated.
• Amatoxinas, Aflatoxinas
DESINFECCION And ESTERILIZACION
CONTROL OF THE MICROBIAL POPULATIONS: ESTERILIZACIONY DESINFECCIONI.- DEFINITIONS And CONCEPTS
Sterilisation: process to destroy the agents infecciosos or microorganismosincluyendo his forms of resistance, by means of agents fisicos oquimicos.
It is the process to destroy all the forms of microbial life. Therefore,it generates a situation in which the probability that the object tratadocontenga at least a survivor is infinitely small.Like this, an object esterilizado, in microbiological sense, is free demicroorganismos alive. The only valid criterion of death in the case of unmicroorganismo is the irreversible loss of the capacity to reproduce .Eiminación Of all form of life, incluídas the spores.
Disinfection: process to destroy the agents infecciosos or microorganismospero no his forms of resistance, by means of agents fisicos or quimicos
Sanitizacion: Process whereby destroy the microorganisms to nivelestales that are innocuous for the industrial process in that relacionano for the human beings that alli operate.
A generally chemical compound that kills or interferes with elcrecimiento and activity of the microoganismos. It classifies of agreement asu application and to as it acts
Agent antimicrobial: it is a generally chemical compound that kills or interferes with elcrecimiento and activity of the microoganismos. It classifies of agreement asu application and to as it acts.
Germicida: It is a chemical agent that kills the microorganisms but nonecesariamente the spores (ej. The bactericidas kill bacteria, losfungicidas kill funguses, the viricidas kill virus).
Agent microbiostático: it is one that inhibits the growth of the microoganismos but no losmata (ej. bacteriostático Inhibits the growth bacterial).
Antisepsia:Operations or technical directed to create an environment that impidael development of the microorganisms and even can kill them.
Asepsis:technical employees to prevent the access of microorganisms alcampo of work.
Antibiosis:Biological phenomenon in which it exists an arrest or destruction delcrecimiento microbial because of substances produced by another living being.
Microbicidas
:Substances that kill the vegetative forms, but nonecesariamente the spores of a microorganism (bactericida, fungicida,etc.).
Microbiostáticos:Substances that inhibit the growth of microorganisms(bacteriostáticos, fungistáticos, etc.).
Antisépticos: It refers to substances that apply on the body.
Desinfectantes:It refers to substances employed on objects inanimados.
Therapeutic agents:antimicrobic employees in the treatment of infections.
Agents quimioterapéuticos:chemicals employed in the treatment of enfermedadesinfecciosas or illnesses caused by the proliferation of célulasmalignas.
Antibiotics:substances produced by a living being that oponen to the life deotro living being.
BIBLIOGRAFIAS
Joseph Lister (1827-1912)
Along the 19th century the surgery found solutions for the three big problems that had still posed: the pain, the infection and the bleeding. The superación of these three barriers is what know like "surgical revolution". The contributions of Joseph Lister were decisive to solve the fearsome infection.
Lister Was born in Upton (Essex) on 5 April 1827. It proceeded of a family of cuáqueros. His father was trader of wines and possessed good knowledges of physics and mathematical. Also it devoted time to the realisation of microscopic works and to the optics; it was one of the first constructors of achromatic lens. It studied in London and in 1854 formed like surgeon in Edinburgh, beside Jarnes Syme, with whose daughter married . In this city devoted to several works of anatomical type, physiological and pathological. In 1860 it left to Glasgow, where replaced to Syme and developed his more child-bearing work. Later, in 1877, in London, was appointed professor of the King´s College.
When it did charge of the surgical clinic of Glasgow, Lister had to confront to what was one of the main problems: of a 30 to 50% of the patients ingresados sucumbían victims of the hospitable gangrene, the erisipela, the piemia or the edema purulento. Like other surgeons in the past, wanted to rebel against the doctrine of the pus loable, but did it of distinct way. It thought that the infection of the wounds and the training of pus were equiparables to the putrefacción.
Lister Was abreast of the ideas of Pasteur. By a part, knew that this had showed that the putrefacciones were due to the arrival of alive germs until the matter putrefascible, and by another, that this conserved unalterable if it kept out of the contact of the air or if this arrived filtered. It moved these notions to the terrain of the surgery, especially to the cases of open fractures. It had observed that the simple fractures cured without too many problems whereas those that were opened or with wounds finish usually with a supuración or infection. It thought that the atmospheric air was the manager because it contributed the germs. Therefore, it was necessary «to filter it» somehow. It tested the chloride of cinc and the sulfitos, but thought that it could employ the acid fénico, substance that obtained facilmente of the tar of hulla and that, from 1859, came employing to avoid putrefacciones. A Parisian chemist called Lemaire, that studied thoroughly this substance between 1860 and 1863, showed also that the microorganisms did not develop in his presence.
Although Lister was not to the so much of this last, yes knew that in his country this substance used to avoid the fetidez of the albañales and that in the fields by where discurrían the waters fenicadas disappeared the entozoos that parasitaban to the livestock.
In 1857 it published the work titled New treatment of the open fractures and of the abcesos; observations on the causes of the supuración, that hardly had resonance between the scientists. In 1867 it presented the results of a new study on the subject in front of the British medical Association. A year later did it in the Medical Society-surgical of Glasgow, and in 1869, used it for the opening lesson of course of his University. This material published it in shape of book in 1867 with the title On the Antiseptic Principle in the Practice of the Surgery.
Between the first publication and the second debugged the technician. First it applied compressed of water fenicada and afterwards powdered the environment and the objects that could go in in contact with the wound completing it with the use of ointments fenicadas. Little by little it was accumulating a series of cases fruit of an experience continued. In 1867, for example, it decided to operate to a patient with a fracture of tibia that had consolidated defectuosamente, using his method antiséptico. Usually in these situations the denouement was funesto. However, the patient cured without any problem.
Soon the "listerismo" began to have follower in the continent (Thiersch, von Volkmann, Lucas-Championnière, Mikulicz, etc.); nevertheless, it did not convince to all the surgeons. R. Lawson Tait, of Birmingham, described to the antisepsia of «useless complication», although afterwards it finish surrendering in front of the evidence. In other European countries sucedió something alike. In Vienna, for example, where the surgery was very developed, some surgeons did not accept it. Even Billroth refused it in a principle. Sir James Paget and James Young Simpson went also opponents.
Knowing the value of the statistics, Lister accumulated data and figures. In 1870 it presented relative results to amputations. Before the use of the antisepsia the mortality was of the 45 % and afterwards descended to the 15 %. From 1871 the tendency to apply the method of Lister generalised with rapidity in all the countries. It accepts usually in the manuals of history of the medicine that Bottini used it by first time in Italy; Richard von Volkmann (1830-1889), Hagedorn, Bardelebar and Karl Thiersch (1822-1895) in Germany; and that in 1869, Justo Lucas Champinnière (1843-1913), that had been personally in Glasgow with Lister learning the technician, entered it in France. In Spain relates with Salvador Cardinal, Antonio Moral Pérez, Miguel Fargas, Nicolás Ferrer and Juan Aguilar and Lara.
Lister Died on 10 February 1912 having received all class of honours, homages and recognitions. It celebrated the funeral in the Abbey of Westminster, where recorded his effigy beside the one of Hunter and Willis. The name of Lister has remained registered to designate to a gender of microorganisms of the family Corynebacteriaceae, order Eubacteriales: Listeria. It is constituted by grampositivos cocoides or bacilares that are used to find in the inferior animals in which it produces an illness septicémica or encefalomielítica in shape sporadic or epizoótica. It can infect to the man to the that produces him an illness of high respiratory tracts with linfadenitis and conjunctivitis, or an illness septicémica, and even can take a form encefalítica. Sometimes it accompanies of monocitosis. Only there is a species: the Listeria monocytogenes.
William Steward Halsted (1852-1922)
William Steward Halsted belongs to the glorious period of the surgery, period that designate “surgical revolution” in which they surpassed the three barriers: pain, bleeding and infection. To finals of the 19th century there was a renaissance of the surgery hunteriana or physiological. Halsted Made investigation of laboratory in physiology and pathology that applied to the surgery. It is considered like one of the parents of the modern surgery and, in concrete, of the North American surgery.
William Steward Halsted was born on 23 September 1852 in the breast of a distinguished family of New York. It made his first studies in a strict religious school of Massachussets of which finish escaping. Afterwards ingresó in the School Phillips Andover. It graduated in 1869. During a year studied Greek and Latin, and afterwards ingresó in the University of Yale. Apart from studying showed an extraordinary interest in several sports like the baseball, oar, fight, boxing, etc.
It studied medicine and went assistant of John Dalton. It obtained the title To.B. In 1874 and the one of M.D. By the School of Doctors and Surgeons of the University of Columbia, in 1877. It was like internal in the Bellevue Hospital (1876-1877) and like doctor in the New York Hospital (1877-1878). There it arrived to create a system of register of the temperature, the pulse and the breath, by means of points and of curves of several colours.
It completed studies in Europe between 1878 and 1880 in Vienna, Leipzig and Würzburg beside the most prestigious names of the moment like the surgeon Theodor Billroth, the pathologist Hans Chiari, the dermatologist Moritz Kaposi, the ophthalmologist Ernst Fuchs, and the embriólogo Albrecht von Kolliquer.
To his return to New York established a private query and formed part of the staff of six hospitals. Also it gave classes of surgery the Sundays. Soon it won a big reputation like surgeon and like enthusiast of the methods antiséptico and aseptic. It was the author of one of the first colelitomías that made in the United States.
It used the cocaine like anaesthetic. As it affirms habituó personally to his consumption that afterwards substituted by the morphine. It had to make a cure of detoxication in Providence, in 1886, that went back to repeat shortly after.
It was invited by William H. Welch Of Baltimore this same year to investigate in the recently created laboratory of pathology. It worked with Franklin P. Mall And perfected the technicians of intestinal suture (suture of Halsted) and investigated the healing of wounds in dogs. Also it made surgical studies on the thyroid in these animals.
In 1890 it was appointed first surgeon boss of the recently inaugurated hospital of John Hopkins University, and in 1892 was appointed first professor of surgery of the school of medicine.
His assistant in the operating theatre was the aristocratic Carolina Hampton, that suffered a dermatitis that saw accused by the antisépticos that used then. Halsted Asked to the signature Good Year that manufactured him some gloves of rubber. East was the beginning of the use of the gloves in the operating theatres. To protect to somebody that suffered an illness, happened afterwards to protect the barren field of the hands of the surgeon and of the ones of the assistants. It married with Carolina Hampton in 1890.
In John Hopkins Halsted and his team made investigation of laboratory, reglaban with minuciosidad the interventions, applied the best technical of asepsis and hemostasia and used good materials and instruments. It was an innovative regarding the technicians to take part the thyroid gland and the parathyroid (effected the first transplantes of gland parathyroid), cancer of breast, hernia and vascular system. It considered that the suspicious fabrics had to be extirpados in an alone piece and with a big exéresis of skin, that forced with frequency to make injertos; it was contrary to an escisión fragmentada.
Precisely it knows like operation of Halsted to the wide amputation of the breast with ablation of the pectoral muscles and cleaning ganglionar local and axillary in the mammary carcinoma. The syndrome of Halsted is the edema postoperatorio of the upper member after a wide amputation of the breast.
The suture of Halsted is a variety of similar intestinal suture to the one of colchonero. It entered also the use of the fabric of gutapercha in the drainage (1880), the dressings of leaves of silver (1896) and the transfixión of the fabrics sangrantes.
In John Hopkins created the departments of orthopaedics, otorhinolaryngology, urology and radiology. In this centre formed a lot of surgeons that afterwards would extend the technicians of Halsted by all the country. Between these found Harvey Cushing.
In 1919 it was taken part and practised him a colecistectomía after suffering several colics biliares by litiasis.
In 1921, in autumn, suffered an enterocolitis grave with colangitis acute. It aggravated him in January of the following year and decided operate. During the posoperatorio suffered a pneumonia that drove him to the death on 7 September 1922.
José L. Fresquet. Institute of History of the Science and Documentation (Universitat of València-CSIC), February of 2004
