Mycoses

12 Key excerpts on "Mycoses"

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  eBook - ePub

  Medical Microbiology

  • Anil K. Sharma, Girish Kumar Gupta, Mukesh Yadav, Anil K. Sharma, Girish Kumar Gupta, Mukesh Yadav(Authors)
  • 2022(Publication Date)
  • De Gruyter

    (Publisher)

  Chapter 5  Mycology

  Amit Kumar Singh

  Immunology and Microbial Diseases Laboratory , Albany Medical Center , Albany , United States of America

  Abstract

  Mycology is a very vast discipline of life science that deals with the study of fungi, their biochemical properties, environmental impact, pathogenesis and genetic analysis. Fungi are well known for their harmful as well as beneficial aspects in the area of microbiology. Fungi are responsible for a large number of diseases in humans and animals also. This chapter deals with the basics of mycology, classification of mycosis, diagnosis, microscopic examinations, advanced diagnosis and major fungi-mediated diseases.

  Keywords: fungi, mycology, mycosis, pathogenesis, fungal detection, mycotoxins, mycotoxicoses,

  5.1  Introduction

  Mycology is concerned with the discipline of life science that deals with the study of fungi, their biochemical properties, environmental impact, pathogenesis and genetic analysis. The term “mycology” is composed of two “Greek” words, where mukēs stands for “fungus” and logia means “study.” These microorganisms are considered under a separate kingdom “Fungi,” including filamentous fungi, molds, yeasts and mushrooms. Fungal strains are well known for their potential of producing commercial enzymes, food products, antibiotics, pigments and other valuable industrial products. Today, fungal strains are regularly used for various applications in different industries. Among the known fungal species, it is estimated that only 325 species are infectious to humans. The small subset of human pathogenic fungi is also plant pathogenic with the capability of cross-kingdom infection. These crossover pathogens include fungi, which belongs to phylum Ascomycota and subphylum Mucoromycotina. Most of ascomycetes crossover fungi are densely melanized, also called as dematiaceous fungi [1 ]. The fungal species with crossover pathogenesis are predominantly soil saprophytes with the abilities of causing infections in both plants and humans. Majority of fungi can establish nonfatal infection with limited but harmful effects on health, whereas they can cause serious and life-threatening infections in the immunocompromised individuals [2 , 3

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  Fungi

  Biology and Applications

  • Kevin Kavanagh(Author)
  • 2011(Publication Date)
  • Wiley

    (Publisher)

  The ubiquity of fungi in the environment has already been alluded to in earlier chapters of this book. Fungal species have evolved and adapted to live in a wide variety of environments and ecological niches and, consequently, constitute a very diverse group of organisms. There are fewer than 100 000 species of fungi that have been identified to date; however, this is likely to be just the tip of the iceberg and it has been conservatively estimated that there are probably at least 1.5 million fungal species inhabiting our planet. Given this vast number of species and their prevalence in the environment, it is hardly surprising that humans unwittingly come into contact with many different types of microscopic fungus every day and that humans offer a potential source of nutrients for some of these fungal species. For the most part, transient exposure to fungi or fungal colonization occurs without the knowledge of the affected individual. This is primarily due to the inherent low virulence of most fungi, especially when confronted with the full arsenal of the human immune system. However, some species of fungi are long-established members of the human microflora (i.e. commensals in the oral cavity and the gastrointestinal tract) and under certain conditions some fungi can cause disease and even death. As many as 200 fungal species have been associated with human infections (known as Mycoses); however, only a handful of these species are responsible for the vast majority of infections. Fortunately for us, fungi are far more important pathogens of plants (see Chapter 12) and insects.

  Some of the most common microbial infections in humans are caused by microscopic fungi (e.g. thrush, dandruff and ‘athlete's foot’). These are superficial and relatively innocuous; however, fungi can also cause far more devastating diseases, such as invasive aspergillosis and systemic candidosis, both of which have very high associated mortality rates. The incidence of these latter infections has been increasing in recent decades, and this has fuelled a heightened interest in Mycoses and the fungal species responsible for them amongst the clinical and scientific communities.

  The types of infection caused by fungi can be classified in a number of ways. One division is based on whether the infection occurs in an otherwise healthy host (i.e. primary Mycoses) or whether the host has an underlying medical condition causing impaired immune function (i.e. opportunistic Mycoses). These groups of diseases can be further subdivided depending on whether the infection is confined to the outer layers of the epithelia (i.e. superficial Mycoses) or whether the infecting organisms penetrate through this barrier into the bloodstream and disseminate throughout the body (i.e. systemic or disseminated Mycoses).

  10.2 Superficial Mycoses

  The human body is covered by skin, hair and nails which, given their location in the body, are continuously exposed to the environment and, consequently, a wide variety of environmental microbes. For the most part, the keratinised epithelia which comprise the outer layers of the skin constitute an effective barrier that excludes microorganisms from gaining entry to deeper tissues. In addition, the skin also produces secretions, including sweat, sebum, transferrin and antimicrobial peptides known as defensins, that have the ability to kill many bacterial and fungal species. The skin is also equipped with intra-epithelial T and B cells, as well as a range of phagocytes. However, a small number of fungal species have evolved mechanisms of overcoming these defensive mechanisms and can actively colonize the skin surface, becoming established as members of the normal skin microbial flora. From time to time (mainly for reasons that are still unclear) these fungi can cause disease (Table 10.1 ). Two examples of such infections are pityriasis versicolor and tinea nigra. The former is caused by a yeast-like organism known as Malassezia furfur . This species thrives on the fatty acids found in sebum secreted by the skin and affects pigment-producing cells, resulting in a pink rash on pale skin and hypopigmentation in darker skin. Interestingly, this species and the related species Malassezia globosa have also been associated with dandruff, a common ailment characterized by increased shedding of skin cells from the scalp. Tinea nigra, a rare dermatomycosis characterized by a rash caused by the mould species Hortaea werneckii , results from the production of melanin by the fungus that causes the formation of brown macular patches on the palms and soles of the feet. As well as infecting the skin, fungi can also infect hair and nails. For example, fungi belonging to the genus Trichosporon cause a disease in hair known as white piedra (from the Spanish for stone), while Trichophyton rubrum

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  Fungi

  Biology and Applications

  • Kevin Kavanagh(Author)
  • 2017(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  For the most part, transient exposure to fungi or fungal colonization occurs without the knowledge of the affected individual. This is primarily due to the inherent low virulence of most fungi, especially when confronted with the full arsenal of the human immune system. However, some species of fungi are long‐established members of the human microflora (i.e. commensals in the oral cavity and the gastrointestinal tract) and under certain conditions some fungi can cause disease and even death. As many as 200 fungal species have been associated with human infections (known as Mycoses); however, only a handful of these species are responsible for the majority of infections. Although, less well known than bacterial or viral pathogens, over a billion people are affected by fungal disease and approximately 1.5 million deaths are attributable to fungi annually. To put this in context, a similar number of people die from tuberculosis each year.

  Some of the most common microbial infections in humans are caused by microscopic fungi (e.g. thrush, dandruff, and “athlete’s foot”). These are superficial and relatively innocuous; however, fungi can also cause far more devastating diseases, such as invasive aspergillosis and systemic candidiasis, both of which have very high associated mortality rates. The incidence of these latter infections has been increasing in recent decades and this has fueled a heightened interest in Mycoses and the fungal species responsible for them among the clinical and scientific communities.

  The types of infections caused by fungi can be classified in a number of ways. One division is based on whether the infection occurs in an otherwise healthy host (i.e. primary Mycoses) or whether the host has an underlying medical condition causing impaired immune function (i.e. opportunistic Mycoses). These groups of diseases can be further subdivided depending on whether the infection is confined to the outer layers of the epithelia (i.e. superficial Mycoses) or whether the infecting organisms penetrate through this barrier into the bloodstream and disseminate throughout the body (i.e. systemic or disseminated Mycoses).

  One of the most exciting developments in the field of microbiology in recent years, made possible by the introduction of next‐generation sequencing, has been the ability to study the entire microbial populations present in specific parts of the body (i.e. the microbiome). These studies, which have largely been directed towards the bacterial component of the microbiome, have identified that fungi in general only represent approximately 0.1% of the total human microbiota. However, despite being present in comparatively small numbers, these studies have confirmed the diversity of fungi and have also shown that a significant proportion of the mycobiome (all of the fungal species) present in niches such as the oral cavity are noncultivatable and taxonomically unclassified. Studies are currently underway to investigate how the mycobiome evolves and varies in health and disease and to identify how fungi interact with other members of the microbiome.

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  Microbiology

  • Edward Bittar(Author)
  • 1998(Publication Date)
  • Elsevier Science

    (Publisher)

  Chapter 1 7 Fungal Diseases JUDITH E. DOMER Introduction Systemic Mycoses: Primary Pathogens Epidemiology and Ecology Risk Factors and Clinical Presentations Laboratory Considerations Immune Response Mechanisms of Resistance Systemic Mycoses: Opportunistic Pathogens Epidemiology and Ecology Risk Factors and Clinical Presentations Laboratory Considerations Immune Response Mechanisms of Resistance Subcutaneous Mycoses Sporotrichosis Chromomycosis and Phaeohyphomycosis Mycetoma 258 259 259 263 263 266 267 271 272 272 275 276 281 281 281 282 283 Principles of Medical Biology, Volume 9A Microbiology, pages 257-286. Copyright 9 1997 by JAI Press Inc. All rights of reproduction in any form reserved. ISBN: 1-55938-814-5 257 258 JUDITH E. DOMER Cutaneous Mycoses Etiologic Agents and Risk Factors Pathogenesis Diagnosis Mechanisms of Resistance Superficial Mycoses Antifungal Therapy 283 283 284 284 285 285 285 INTRODUCTION Fungal diseases are generally divided into categories representing the site at which the organism first enters the tissue to initiate disease. There are four such categories: the systemic fungal diseases, wherein the organism is inhaled and the primary lesion(s) develops in the lung; the subcutaneous Mycoses, characterized by the traumatic implantation of the fungus into the subcutaneous tissue; the cutaneous Mycoses which involve attack of the keratinized layers of the skin by fungi; and the Table 1. The Most Common Mycotic Diseases and their Etiologic Agents Primary Mycoses blastomycosis coccidioidomycosis histoplasmosis paracoccid ioidomycosis Opportunistic Mycoses: Blastomyces dermatitidis Coccidioides immitis Histoplasma capsulatum Paracoccidioides brasiliensis candidiasis cryptococcosis aspergillosis zygomycosis Subcutaneous Mycoses: Candida albicans, C tropicalis Cryptococcus neoformans* Aspergillus fumigatus, A.

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  Phytoconstituents and Antifungals

  • Awanish Kumar(Author)
  • 2022(Publication Date)
  • Academic Press

    (Publisher)

  The fungi are seen in the ecosystem as saprophytes because they acquire their nutrients from dead organic matter and living organisms also. However, fungi have a great impact on forestry, industry, agriculture, and medicine as they cause many infections in both plants and animals. An approximate of 1.5–5.0 million fungal species reside in this universe and only 5% are classified. Among them, several few species are responsible for systemic diseases in human beings. Of these several fungal species, only the genera belonging to Candida, Aspergillus, Cryptococcus, Histoplasma, and Pneumocystis affect the individuals to cause a wide variety of diseases. Globally the frequencies of endemic Mycoses in humans are significantly increasing [ 1 – 4 ]. Due to the increase of fungal infection, there is increase in the number of deaths related to fungal infections. The rate of deaths per year due to fungal infection accounts for 1.5 million, and it costs $12 billion to diagnose the disease. The incidence and prevalence of fungal infections have increased, particularly in the large population of immunocompromised patients and/or those hospitalized with serious underlying diseases, as a result of the rapid introduction of intravenous catheters, total parental nutrition, invasive procedures, and the increasing use of broad-spectrum antibiotics, cytotoxic chemotherapies, and transplantation. Fungi of medical importance may be characterized as primary or opportunistic. Mostly the human fungal infection caused by filamentous fungi is opportunistic and takes particular host condition. The exploitation of invasive disease with opportunistic organisms produces significant mortality and morbidity in immunocompromised patients [5]. The pathogenic fungi are single cellular or multicellular based on the modification of their cytoplasmic determinants and growth patterns. Commonly the maturation of fungi is of two basic types: either in yeast form or filamentous fungi (hyphae and pseudohyphae)

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  Fungal Allergy and Pathogenicity

  • M. Breitenbach, R. Crameri, S. B. Lehrer, T. A. E. Platts-Mills(Authors)
  • 2002(Publication Date)
  • S. Karger

    (Publisher)

  Breitenbach M, Crameri R, Lehrer SB (eds): Fungal Allergy and Pathogenicity. Chem Immunol. Basel, Karger, 2002, vol 81, pp 129–166 Cutaneous Mycology Thomas Hawranek Department of Dermatology, Landeskliniken Salzburg, Salzburg, Austria In 1839 it was shown for the first time that fungi can cause disease. Schoenlein and Gruby discovered what was later called Trichophyton schoen-leinii , the causative agent of scalp infection or favus [1]. But for many years, fungi somehow lived in the shadow of bacterial diseases: their importance grew during the last decades as a consequence of worldwide travel as well as the increased use of immunosuppressive drugs and the appearance of AIDS. Opportunistic infections caused by unknown fungi or fungi initially thought to be nonpathogenic were increasingly recognized. Dermatology is involved not only because the majority of fungal infections affect the skin or the subcuta-neous tissues, but also because systemic infections may present with cutaneous lesions and therefore lead to the diagnosis of systemic disease. Many of the subcutaneous and systemic Mycoses were first described by dermatologists. Excellent reference books [1–7], comprehensive reviews [8–12] and web sites are available on the theme. A good starting point for excursions into the world of mycology online is, for instance http://fungusweb.utmb.edu/mycology/. This short excursus on cutaneous mycology cannot and will not give an exten-sive overview on this vast field, but tries to expound some clinical aspects of fungal-induced dermatological diseases. Whether they display pleasant activi-ties, like the production of cheese or the fermentation of alcohol, or do harm by destroying crops or by attacking man, fungi are closely linked to our lives. Fungi may affect man in three ways: by causing allergy (cutaneous, respi-ratory and other forms), by their toxins (whether by ingestion of poisonous fungi or by production of mycotoxins) or by invasion.

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  The Fungi

  • Sarah C. Watkinson, Lynne Boddy, Nicholas Money(Authors)
  • 2015(Publication Date)
  • Academic Press

    (Publisher)

  Psilocybe species produce psilocybin, which is hallucinogenic for several hours (p. 162), and some people also experience nausea and panic attacks.

  Mycoses

  Fungal diseases can be categorised according to increasing severity as superficial, subcutaneous, or systemic. The latter can be further divided depending on whether the causative organism is a true pathogen able to invade tissues of an otherwise healthy host, or whether it is an opportunist able to invade tissues of a debilitated or immunocompromised host (Table 9.4 ). There are around half a dozen extremely unpleasant fungal diseases, including aspergillosis, candidiasis, histoplasmosis, coccidiomycosis, and blastomycosis. Ironically, with advances in some medical treatments there has been a rise in life-threatening fungal diseases, especially in the areas of transplant and chemotherapy, where the immune system is suppressed.

  Table 9.4 Categories of Fungal Infections of Humans Based on Severity of Effects

  Infection/mycosis	Definition and general description	Examples of disease	Causal fungus	Phylum
  Superficial	Superficial infection of skin or hair shaft; no invasion of living tissue	Seborrhoeic dermatitis, dandruff, folliculitis pityriasis	Malassezia furfur (lipophilic yeast)	Basidiomycota
  Cutaneous	Superficial infections of the hair, skin, or nails. No living tissue is invaded, but a variety of allergic or inflammatory response occurs in the host due to the fungus and its metabolic products

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  Medical Microbiology E-Book

  A Guide to Microbial Infections

  • Michael R. Barer, Will L Irving, Michael R. Barer, Will L Irving(Authors)
  • 2018(Publication Date)
  • Elsevier

    (Publisher)

  There are at least 100,000 named species of fungi. However, <1000 have been recognised to cause disease (mycosis) in humans or animals. Most are moulds, but there are a number of pathogenic yeasts, and some are dimorphic. Dimorphic fungi usually change from a multicellular mould form in the natural environment to a budding single-celled yeast form when causing infection. In the laboratory the tissue form can be induced by culture at 37°C on rich media such as blood agar, whereas the mould form develops when incubated at a lower temperature (25–30°C) on a less rich medium such as Sabouraud dextrose agar.

  Some fungi, such as the systemic pathogens Histoplasma capsulatum and Blastomyces dermatitidis , can establish an infection in all exposed individuals. Others, such as Candida and Aspergillus species, are opportunist pathogens that ordinarily cause disease only in a compromised host. In some Mycoses the form and severity of the infection depend on the degree of exposure to the fungus, the site and method of entry into the body and the level of immunocompetence of the host.

  Some fungi may cause serious, occasionally fatal, toxic effects in humans, following either ingestion of poisonous toadstools or consumption of mouldy food that contains toxic secondary metabolites (mycotoxins). Allergic disease of the airways may result from inhalation of fungal spores.

  Epidemiology

  Most human fungal infections are caused by fungi that grow as saprophytes in the environment. Infection is acquired by inhalation, ingestion or traumatic implantation. Some yeasts are human commensals and cause endogenous infections when there is some imbalance in the host. Only dermatophyte infections are truly contagious.

  Many fungal diseases have a worldwide distribution, but some are endemic to specific geographical regions, usually because the causal agents are saprophytes restricted in their distribution by soil and climatic conditions.

  Types of infection

  Superficial Mycoses

  Diseases of the skin, hair, nail and mucous membranes are the most common of all fungal infections and have a worldwide distribution.

  • • Dermatophytosis (ringworm) is a complex of diseases affecting the outermost keratinized tissues of hair, nail and the stratum corneum of the skin. it is caused by a group of closely related mould fungi called dermatophytes, which can digest keratin. Dermatophyte infections occur in both humans and animals.

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  Fungal Disease in Britain and the United States 1850–2000

  • Michael Worboys, Aya Homei(Authors)
  • 2013(Publication Date)
  • Springer Open

    (Publisher)

  3 We begin by discussing the new epidemiology of endemic fungal infections that emerged in the late 1940s and the attempts by medical mycologists and other interested clinicians to attract more resources for research, 98 Endemic Mycoses and Allergies: Diseases of Social Change 99 prevention and control. We discussed the increased incidence of acute, invasive candidiasis associated with new medical treatments in the last Chapter; here we examine in turn the three principal chronic, though occasionally epidemic, regional Mycoses prevalent in North America – coccidioidomycosis, blastomycosis and histoplasmosis. Our attention then switches to Britain and allergic fungal conditions, firstly, farmer’s lung and then allergic bronchopulmonary aspergillosis (ABPA). This class of fungal allergens was ‘discovered’ in Britain and seemingly absent from North America, until expertise was transferred back across the Atlantic. The new epidemiology of fungal diseases In the early 1950s, medical mycologists, along with cancer physicians and chest surgeons, began to draw attention to a new problem posed by invasive fungal infections. Writing in 1953, David Smith, a colleague of Norman Conant at Duke Medical School described the new situation as follows. Unlike most bacterial and viral infectious diseases, the systemic mycotic infections are not transmitted directly from patient to patient; consequently, one would not expect to see epidemics caused by fungi. In most instances the mycotic infections are endemic and sporadic but true epidemics of sporotrichosis, coccidioidomycosis and histoplasmosis do occur when groups of non-immune individ-uals are exposed to an environment containing large amounts of the saprophytic form of the fungus. More than a thousand cases of sporotrichosis developed in the gold mines of South Africa when the timbers in the mine became infected with Sporotrichum schenckii .

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  Systemic Mycoses

  • G. E. W. Wolstenholme, Ruth Porter, G. E. W. Wolstenholme, Ruth Porter(Authors)
  • 2009(Publication Date)
  • Wiley

    (Publisher)

  According to this definition the various fornis of tinea and other epidermophytoscs, and also such infections of mucosal surfaces as 6 6 * This note was compiled as a result of discussions at the time of the symposium (Professors Baker, Seeliger and Symmers, Drs. Emmons and Murray, Mr. Austwick and many others) and thanks to the considerable help of Dr. Murray and Mr. Austwick, and (especially) of Professor Symmers during the editing of the proceedings. The editors wish to thank all these contributors. We would like to emphasize that no one person agreed to everything in this note, the final responsibility for which rests with the editors. EDITORS’ N O T E O N T E R M I N O L O G Y candida vulvovaginitis and thrush, are classed as supcvjicial fungal infections (superficial Mycoses or surface inycoses). The group of deep (systemic) $ingal ilzfctions comprises the mycotic diseases of the dermis and deeper tissues, and includes such infections as sporotrichosis, cutaneous chromo- mycosis and the different forms of niycetoma, and the visceral and blood- stream infections, such as histoplasmosis, cryptococcosis and the various fungal septicaemias. T h e position of aerobic and anaerobic Actinomycetes and the diseases caused by thern. The problem of whether Actinomyces, Nocardia and Streptoniyces are fungi or not and, consequently, whether the diseases they cause are fungal diseases, caused mild controversy. It was decided that, although Actino- mycetes are filamentous bacteria, it was legitimate to discuss certain diseases attributcd to them by virtuc of the clinical similarity to some of the true mycoscs. This practice is in line with the conventions adopted by most medical and veterinary microbiologists.

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  Imported Skin Diseases

  • William R. Faber, Roderick J. Hay, Bernard Naafs, William R. Faber, Roderick J. Hay, Bernard Naafs(Authors)
  • 2012(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  All endemic systemic Mycoses can be seen as imported diseases. In Europe the most frequent is histoplasmosis Opportunistic Mycoses

  Systemic candidosis Aspergillosis Zygomycosis Cryptococcosis

  Others, for example, Fusarium , Trichosporon

  These can occur in any environment

  The pathogenic fungi usually exist as chains of cells, hyphae, or single cells that reproduce by budding, or yeasts, in human tissue. Fungi are said to be dimorphic if they exist in different morphological phases, for example, yeast or mould, at different stages of their life cycle. Some of the systemic Mycoses are dimorphic infections.

  Superficial Mycoses

  The superficial infections are common in all environments. Most are unlikely to be imported, although traveling conditions in hot and humid climates may lead to the development of tinea or dermatophytosis or Malassezia infections. Both are most likely to have originated from organisms already carried by the traveler but may still present clinically during or after exposure to hot climatic conditions. Tinea cruris (dermatophytosis of the groin) presenting in someone returning from the tropics would be an example. Likewise tinea pedis can be exacerbated by moist and humid conditions on the foot and can become secondarily infected with Gram-negative bacteria as well. There are however a few less common Mycoses that can only be acquired in tropical areas.

  Tinea imbricata is a form of tinea corporis that occurs in the West Pacific, Indonesia, and some remote areas of Brazil and Central America. It is caused by Trichophyton concentricum and is occasionally acquired by individuals working in an endemic area. It is seldom seen in short-term visitors. It is clinically characteristic, presenting with concentric and often extensive concentric rings of scales on the trunk or limbs. The diagnosis is confirmed by cultural identification of the organism.

  Tinea capitis, due to organisms that are nonendemic in Europe, can be imported into a city with visiting children or with immigrants. These are usually due to anthropophilic organisms transmitted from child to child and they present with scaling and hair loss [2]. The organisms range from Trichophyton violaceum (East Africa and Indian subcontinent) to Microsporum audouinii (West Africa). Trichophyton tonsurans

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  Cell Biology Physiology and Mycology

  • Emea, A(Authors)
  • 2018(Publication Date)
  • Agri Horti Press

    (Publisher)

  There are four types of mycotic diseases : 1. Hypersensitivity: An allergic reaction to molds and spores. 2. Mycotoxicoses: Poisoning of man and animals by feeds and food products contaminated by fungi which produce toxins from the grain substrate. 3. Mycetismus: The ingestion of preformed toxin (mushroom poisoning). 4. Infection: In this section, we shall be concerned only with the last type. Fungi can appear microscopically as either rounded, budding forms (yeastlike organisms) or hyphae . Yeastlike colonies are smooth, while mold colonies are fuzzy; fungi that grow as yeasts include species of Candida and Cryptococcus , while fungi that grow as molds include species of Aspergillus , Rhizopus , and dermatophytes (ringworm fungi). The fungi that cause histoplasmosis, blastomycosis, sporotrichosis, coccidioidomycosis, and paracocci-dioidomycosis are called dimorphic (“having two forms”) because they are spherical in tissue but grow like molds when cultured at room temperature. Candida species other than Candida glabrata appear in tissue as both budding yeasts and tubular elements called pseudohyphae . Pneumocystis carinii is closer to fungi than to parasites by ribosomal sequences . Because the drugs used to treat Pneumocystis pneumonia are also used to treat parasitic or bacterial infections. Many fungi can form two different types of spores and are given different names, depending on the spore-bearing structures. When the spores are produced by mitosis, the fungus is said to be an anamorph , or to be in the imperfect state. Many fungi can have different sporulating structures in which genetic recombination occurs, often as a result of coculture with a strain of the opposite mating type. A fungus producing those distinctive spores is said to be a teleomorph , or to be in the perfect state. Diagnostic laboratories usually use the name of the anamorph because they do not use culture conditions that would produce the teleomorph.

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