Biological Sciences
Candidiasis
Candidiasis is a fungal infection caused by the overgrowth of Candida, a type of yeast. It commonly affects the skin, mouth, throat, and genital areas. Symptoms may include redness, itching, and discomfort, and treatment typically involves antifungal medications. In severe cases, candidiasis can lead to systemic infections, especially in individuals with weakened immune systems.
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12 Key excerpts on "Candidiasis"
eBook - PDF- Dilip K. Arora(Author)
- 2003(Publication Date)
- CRC Press(Publisher)
37 Candidiasis A.G.Palma-Carlos/M.Laura Palma-Carlos I Clinica Médica Universitária e Centro de Hematologia e Imunologia, Faculdade de Medicina, Lisboa, Portugal 1 INTRODUCTION The term Candidiasis is used to refer to the diseases caused by fungi of the genus Candida, a common saprophyte in the human gastrointestinal tract and elsewhere (Benett 2001; Ellis 1994). Until recently, Candida infection was thought to be caused mainly by Candida albicans, however, in the last few years other Candida species, such as C. parapsilosis, C. tropicalis and C. krusei, have been found to be important causes of disease. These species can be important pathogens in immunodepressed patients. Candida glabrata (syn. Torulopsis glabrata) causes the same spectrum of diseases (Benett 2001). Candida species, particularly C. albicans, colonize the human gastrointestinal, respiratory and reproductive tracts, skin, and nails. C. albicans is a constituent of the normal oral and gut flora of most healthy people although the carriage rate varies substantially in relation to the methods used to detect it. Carriage is highest in immunodepressed, diabetic or hospitalized patients. Since Candida comprises a highly heterogeneous group of yeasts and some species such as C. parapsilosis are a mixture of genetically different organisms; different immunopathogenic mechanisms can be involved in infections by different species (Ashman 1998; Ellis 1994; Lehman 1993; Shoham and Levitz 2000). 2 CANDIDA SPECIES 2.1 Candida Versus Torulopsis The inclusion of species of Torulopsis in the genus Candida has been proposed. Originally the genus Torulopsis was separated from Candida by the absence of pseudomycelium and the lack of hyphae in vivo (Ellis 1994; Shoham 2000). Yarrow and Meyer (1998) have however suggested that all Torulopsis species should be included in the genus Candida.
eBook - PDF- Moselio Schaechter(Author)
- 2011(Publication Date)
- Academic Press(Publisher)
(a) (b) (c) FIGURE 5 Candida albicans can grow as budding yeast (a), yeast cells with elongated buds called pseudohyphae (b), or as true hyphae (c). Short hyphal cells shown in (c) are also known as germ tubes. Chapter 11 Fungal Infections, Systemic 157 Epidemiology The epidemiology of Candidiasis differs from the epidemi-ology of most other fungal diseases because normal people are colonized by Candida . Thus, Candidiasis is acquired from endogenous sources rather than by exposure to fungi in the environment. Among the major Candida species, C. albicans , C. tropicalis , and C. glabrata populate the gas-trointestinal tract and vagina of normal individuals, and C. parapsilosis is often found on the skin. Consequently, symptomatic infections generally develop when these fungi overgrow at sites of colonization (often as a consequence of suppression of the competing bacterial flora because of an-timicrobial therapy) and when the host’s defenses against infection are diminished. Pathogenesis and clinical features There are two general patterns of Candidiasis. In people in whom overgrowth of Candida occurs because of suppression of competing bacterial flora by antibiotics or defects in cell-mediated immunity (e.g., corticosteroid recipients and patients with advanced HIV infection), the predominant form of disease is mucosal or cutaneous Candidiasis. Typical muco-sal lesions consist of white plaques that overlie shallow ulcers on an erythematous base. The ulcers are often filled with in-flammatory cells and a mixture of Candida yeast cells and pseudohyphae, and the base may bleed if the white plaque is scraped off. Mucosal Candidiasis of the mouth and pharynx is referred to as thrush, and similar lesions can occur anywhere in the gastrointestinal tract.
eBook - PDF- David Schlossberg(Author)
- 2015(Publication Date)
- Cambridge University Press(Publisher)
PART XXII Specific organisms: fungi 172. Candidiasis 1104 Christopher F. Carpenter and Nicholas Gilpin 173. Aspergillosis 1113 Sanjay Ram and Stuart M. Levitz 174. Mucormycosis (and entomophthoramycosis) 1119 Scott F. Davies 175. Sporotrichum 1124 Ronald A. Greenfield 176. Cryptococcus 1128 William G. Powderly 177. Histoplasmosis 1134 Mitchell Goldman and Alvaro Lapitz 178. Blastomycosis 1138 Peter G. Pappas 179. Coccidioidomycosis 1141 Laurence F. Mirels and Stan Deresinski 180. Pneumocystis jirovecii (carinii) 1151 Shelley A. Gilroy and Nicholas J. Bennett 181. Miscellaneous fungi and algae 1156 Cheryll N. Cash and George A. Pankey 172. Candidiasis Christopher F. Carpenter and Nicholas Gilpin Candida species are small unicellular yeasts that are found in a number of environments, includ- ing soil, hospital surroundings, food, and other inanimate objects. Most species are commensal organisms, colonizing the skin, gastrointestinal tract, and vagina. They become opportunistic pathogens when the host has compromised immunologic or mechanical defenses or when there are changes in the host’s normal flora, such as those triggered by broad-spectrum antibiotic use and chemotherapy. Candida species are common causes of disease ranging from superfi- cial cutaneous and mucocutaneous infections to invasive infections such as candidemia and dis- seminated Candidiasis. There are more than 150 species of Candida, with Candida albicans (Figure 172.1) being the most frequently impli- cated in human disease processes. Over the past two decades, however, there has been a notice- able increase in disease due to non-albicans species. Important non-albicans pathogens include Candida tropicalis (Figure 172.2), Candida parapsilosis, Candida glabrata (Figure 172.3), Can- dida krusei (Figure 172.4), Candida kefyr, Candida lusitaniae, Candida dubliniensis, and Candida gulli- ermondii.
- Richard L. Guerrant, David H. Walker, Peter F. Weller(Authors)
- 2011(Publication Date)
- Saunders(Publisher)
Candida albicans , are frequent human commensals, but a diverse range of infections can occur when host defenses break down or are breached. Mucocutaneous infections are common in all climates. In hot, humid tropical regions macerated skin often becomes infected, resulting in cutaneous Candidiasis. Mucosal Candidiasis can involve the lower genital tract, oropharynx, or the esophagus. Vulvovaginal Candidiasis is one of the most common genital problems of women in both industrialized and developing countries. Extensive use of antibiotics, diabetes mellitus, local genital immune factors, and human immunodeficiency virus (HIV) all contribute to the widespread prevalence of vulvovaginal Candidiasis. Oropharyngeal and esophageal Candidiasis are typically encountered in association with local mucosal injury, or as a result of defects in cell-mediated immunity, particularly HIV. With globalization, illnesses previously associated with wealthier societies are assuming an increasingly important role in developing nations. In that regard, in newly industrialized countries, deeply invasive Candidiasis occurring in the setting of, or as a consequence of, medical progress have emerged as new challenges. Examples include oropharyngeal and esophageal Candidiasis among recipients of cytotoxic therapies, bloodstream infection in persons with indwelling vascular devices, and disseminated Candidiasis in highly immunocompromised hosts such as neonates and transplant recipients. Expansion of populations at risk, changes in distribution of colonizing and infecting species, and the impact of widespread use of antifungal agents upon the evolution of resistant organisms are now experienced in an increasing number of regions worldwide. Studies designed to optimize use of existing antifungals and to aid in the development of novel agents continue to be crucial. Perhaps even more important is expansion of our knowledge of regional and global epidemiological patterns, candidal pathogenesis, and host defenses, and the translation of this information into a better understanding of the fungus as it relates to patients in a diversity of environments.The Agents
The genus Candida encompasses over 150 species, but only a small number are human pathogens. In nature, Candida species are principally associated with plants and rotting vegetation. Most are unable to grow at temperatures of 37°C and require vitamins produced mainly in plant materials.1, 2 Of the species known to cause human disease, C. albicans , C. glabrata , C. parapsilosis , C. tropicalis , C. krusei , C. lusitaniae , C. guilliermondii , and C. dubliniensis are the most commonly encountered.3 - 8 Because C. dubliniensis shares many characteristics with C. albicans , it may be misidentified in clinical specimens.9Laboratory identification relies on morphological and biochemical features of the fungus. Candida species grow as ovoid budding yeasts (blastoconidia), typically 4–6 µm in diameter. Most species also produce pseudohyphae. Microscopic examination is facilitated by 10% potassium hydroxide (KOH), which digests epithelial cells. Fluorescence microscopy of specimens stained with calcofluor white and Gram staining (Candida
eBook - ePubOral and Maxillofacial Medicine
The Basis of Diagnosis and Treatment
- Crispian Scully(Author)
- 2012(Publication Date)
- Churchill Livingstone(Publisher)
The opportunistic pathogen grows either as yeasts or hyphae (i.e. it is a dimorphic fungus). Actual infection with Candida (usually Candida albicans) is common mainly in people who are otherwise unwell; candidosis is thus called a ‘disease of the diseased’. The importance of Candida has increased greatly, particularly as the HIV pandemic extends since, when host defences are compromised, Candida typically colonizes mucocutaneous surfaces and causes only superficial infections but in immunocompromised people candidosis is commonly oro-pharyngeal and can be a portal for entry into deeper tissues and invasive candidosis (see Chs 53 and 54). AETIOLOGY Host defences against Candida species include the following: Oral epithelium: a physical barrier. Microbial interactions: competition and inhibition by the oral flora. Salivary non-immune defences: mechanical cleansing plays a major role but other factors include salivary antimicrobial proteins (AMPs): lysozyme (muramidase): can damage Candida, stimulate phagocytosis and agglutinate Candida lactoferrin: is antifungal and antibacterial due to binding of iron or altering yeast cell wall permeability lactoperoxidase: is anticandidal via multiple factors (H 2 O 2 and halides) glycoproteins antigenically similar to blood group antigens – affect adherence to mucosa histatins antileukoprotease (secretory leukocyte protease; SLIP1) histidine-rich polypeptides calprotectin β-defensin 2. Oral immune defences, which include. mainly cell-mediated responses: T cells and phagocytes. The full expression of phagocyte effectiveness is dependent on augmentation by cytokines synthesized or induced by T cells, such as lymphokines and IFN-γ
- Michael Worboys, Aya Homei(Authors)
- 2013(Publication Date)
- Springer Open(Publisher)
7 At this time the causal organism was known as Monilia albicans ( M. albicans ) and the infection monilia-sis, but this changed to Candidiasis or candidosis with the renaming of the pathogen. 8 In this chapter we keep to the terms used by doctors and others in context; but be warned there were no sudden changes, thus, old and new terms coexisted for many years. We begin the chapter with a discussion of thrush in the nineteenth and early twentieth centuries and its transition from an oral infection of weak children to a genital infection of women. In both cases, doctors framed the disease in terms of the metaphor of ‘seed and soil’; namely, that to spread and develop pathogenic fungi required vulnerable human tissue, weakened by poor nutrition or other diseases. We then discuss the ‘Antibiotic Era’ and the inter-connected development of fungi as sources of antibiotics, including antifungals, and the claims that the use of antibiotics precipitated a general increase in fungal infections and new types of systemic fungal disease. The iatrogenic consequences of antibiotics have been discussed by doctors and historians in relation to the development of bacterial resistance, but hardly at all with regard to fungal infections. 9 The most prevalent of the new infections was sys-temic or invasive Candidiasis, which was present in new patient groups; firstly, patients with leukaemia and those being treated for other can-cers with steroids; later, transplant patients, and finally in the 1980s, people with HIV/AIDS. The common factor was that all were immuno-compromised or -suppressed, showing once again the importance of the relationship between bodily ‘soil’ and fungal ‘seeds’. We end the chap-ter with a discussion of one of the great popular health crazes of the last Candida: A Disease of Antibiotics 69 quarter of the twentieth century – ‘The Yeast Connection’ – whose advo-cates argued that many of the new chronic and debilitating ailments of modernity were due to C.
eBook - ePub- Kathleen E. Sullivan, E. Richard Stiehm(Authors)
- 2014(Publication Date)
- Academic Press(Publisher)
albicans, C. parapsilosis, C. krusei, C. glabrata, C. tropicalis, C. guillermondii, and C. kefyr. Invasive (deep-seated or disseminated) Candidiasis occurring in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), hematologic malignancies, and cancer may involve almost any internal organ or anatomic site. 6 Granulocytes play a key role in host defense against invasive Candidiasis, by rapidly ingesting and killing opsonized Candida yeasts. 7 – 9 Therefore, Candida species pose a particular threat to patients with primary immunodeficiencies such as congenital neutropenia and impaired innate immunity due to a functional defect of phagocytic cells. 10, 11 Mucocutaneous Candidiasis (MC) refers to clinically well-defined diseases characterized by candidal infection of the skin, nail, and mucous membranes. 4, 5, 8, 12, 13 Overview of Common Clinical Features of Mucocutaneous Candidiasis A considerable proportion of healthy individuals carry detectable numbers of colonizing Candida on the skin and the oral, gastrointestinal, and genitourinary mucosae, but only a few suffer from overt Candidiasis. Carriage of oral Candida yeasts was reported to range from 25% to 75% in the healthy population but in the absence of musosal lesions and manifest Candidiasis. 12, 14 The existence of the huge gastrointestinal reservoir of Candida ensures regular seeding of the oral cavity. Candida yeasts colonize surfaces of the oral cavity and most frequently are found on the dorsum of the tongue. Longitudinal studies showed that oral carriage was continuous and regular re-seeding was not required to maintain the oral candida population. 15 Among the factors involved in the adherence of Candida to the mucosal epithelium are integrin-like molecules such as INT1p expressed by C
eBook - PDF- Doblin Sandai(Author)
- 2019(Publication Date)
- IntechOpen(Publisher)
This alarming increase in nosocomial fungal infections has alerted clinicians and scientist that yeasts, previously thought innocuous and relegated to plant pathology or industrial use were capable of caus-ing serious illness. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. While infections caused by Candida species are typically superficial and restricted to the uro -genital or mucosal oral cavities, they are also capable of entering the bloodstream leading to deep-tissue infections [2]. The predominant yeasts in bloodstream infection remain restricted to the genus Candida [3] most of which, belong to the CTG clade, where the CTG codon is translated as Serine rather than Leucine [4]. Although the recent rise in the number of these infections [5] is mainly associated to C. albicans , non-albicans candida (or NAC) related diseases are also increasingly reported in different parts of the world [ 6]. The relative rates of infection among all Candida infections are shown in Figure 1 . There are at least a dozen Candida species that can be patho-genic for humans, but more than 90% of reported invasive infections are associated with C. albicans , C. glabrata , C. parapsilosis , C. krusei , and C. tropicalis [7] . The definition of a new or “emerging” pathogen is subjective at best. For example, how many independent isolations are required before an emerging pathogen is established as an infec-tious agent? Indications of emerging infections typically consist of case reports.
eBook - PDF- S. M. Abu Sayen(Author)
- 2014(Publication Date)
- Apple Academic Press(Publisher)
This chapter was originally published under the Creative Commons Attribution License. Tournu H and Van Dijck P. Candida Biofilms and the Host: Models and New Concepts for Eradication. International Journal of Microbiology 2012 (2012), http://dx.doi.org/10.1155/2012/845352. CHAPTER 14 CANDIDA BIOFILMS AND THE HOST: MODELS AND NEW CONCEPTS FOR ERADICATION H É L È NE TOURNU and PATRICK VAN DIJCK 14.1 INTRODUCTION Biofilms, adherent microbial communities embedded in a polymer matrix, are common in nature. However, they are also a persistent cause of hy-giene problems in the food industry and in the medical field [1]. Biofilms result from a natural tendency of microbes to attach to biotic or abiotic surfaces, which can vary from mineral surfaces and mammalian tissues to synthetic polymers and indwelling medical devices, and to further grow on these substrates [2–4]. Candidiasis, caused most frequently by Candida albicans , and to a lesser extent by C. glabrata , C. tropicalis , or C. parap-silosis , is often associated with the formation of biofilms on the surface of medical devices and tissues [5]. Candida albicans is a dimorphic fungus and is part of the commensal human micoflora. It is also an opportunistic pathogen of the human body when its proliferation is not controlled by the host immune system. It is one of the most often identified agents in 302 Biofilm Control and Antimicrobial Agents nosocomial infections and is capable of invading virtually any site of the human host, from deep tissues and organs, to superficial sites such as skin and nails, to medical implants and catheters [6]. C. albicans biofilm de-velopment has been characterized in various model systems both in vitro and in vivo [7–9] and consists of distinct phases. The initial step consists of the adhesion of fungal cells of the yeast form to the substrate.
eBook - PDFIllustrated Manual of Pediatric Dermatology
Diagnosis and Management
- Susan Mallory, Alanna F. Bree, Peggy Chern(Authors)
- 2005(Publication Date)
- CRC Press(Publisher)
Most common immune defect is a specific inability to respond to antigens of C. albicans • Systemic Candidiasis 1. Candidal infection in the blood, urine or cerebrospinal fluid (CSF) 9 FUNGAL DISEASES Figure 9.1 Candida – thrush on the lips and tongue 2. Affects 2–4% of very-low-birth-weight infants 3. Associated with long-term hospitalization, invasive instrumentation, immunosuppression 4. Cutaneous findings: erythematous macules, papules and plaques • Other manifestations of candida infection: folliculitis, candidal intertrigo, vaginitis and vulvovaginitis, esophagitis and laryngitis, intravenous line sepsis, candiduria • Risk factors for invasive infection: 1. High risk: HIV, extreme prematurity, neutropenia, diabetes, chemotherapy, corticosteroid therapy 2.
eBook - PDF- Maria de Lourdes Ribeiro de Souza da Cunha(Author)
- 2012(Publication Date)
- IntechOpen(Publisher)
Section 1 Epidemiology of Dermatomycoses and Candida spp. Infections 1 Microsatellite Typing of Catheter-Associated Candida albicans Strains Astrid Helga Paulitsch-Fuchs 1,2 , Bettina Heiling 1 , Birgit Willinger 3 and Walter Buzina 1 1 Institute of Hygiene, Microbiology and Environmental Medicine Medical University of Graz, Graz 2 Wetsus Centre of Excellence for Sustainable Water Technology, Leeuwarden 3 Division of Hygiene and Medical Microbiology, Medical University of Vienna, Vienna 1,3 Austria 2 The Netherlands 1. Introduction Candida albicans is the most common pathogenic fungus and occurs frequently in the digestive tract (Bernhardt, 1998; Doskey, 2004). Vaginal Candidiasis (Mohanty et al. 2007; Paulitsch et al., 2006; Sobel, 2007) is also a wide spread problem. This species can become invasive, causing infections on many different sites in patients with severe underlying diseases (Marol & Yükesoy, 2008; Odds et al., 2007). Catheter or shunt related infections caused by C. albicans (Pierce 2005) were reported e.g. by Sánchez-Portocarrero et al. (1994), David et al. (2005) and Tumbarello et al. (2007). The classical picture of yeast cells as unicellular life forms is based on the pure-culture model of growth. In their natural habitat microorganisms including yeasts are mostly organized in biofilm ecosystems which are often ´multicultural´, made not only of yeasts but also of bacteria (El-Aziz et al., 2004; López-Ribot, 2005; Ramage et al., 2005; Nobile et al., 2006). The possibility to adhere to a surface is a very important factor for the development of fungal (Hogan, 2006; Verstrepen & Klis, 2006) and bacterial biofilms (Dolan, 2001). Microsatellites, which are also known as short tandem repeats, are repeated nucleotide sequences with a length from 2 up to 7 base pairs. These polymorphic DNA loci are variable within a population and in this way multiple alleles are created for a single microsatellite locus.
- Dongyou Liu(Author)
- 2011(Publication Date)
- CRC Press(Publisher)
.Genital.candidosis.usually.presents.with.itching,. redness,. and. burning. with. occasional. discharge,. fissuring,. and.the.presence.of.plaques . Invasive.disease.can.cause.a.variety.of.clinical.manifesta-tions. with. translocation. from. the. GI. tract. or. skin. resulting. in.candidemia.and.hematogenous.dissemination.to.a.variety. of.organs.in.the.critically.ill.population . .Symptoms.are.non-specific.including.a.refractory.fever.and.macronodular.rash . . Symptoms. representative. of. specific. manifestations. (e .g., . peritonitis,.endocarditis,.meningitis).are.no.different.to.bac-terial.disease . .For.a.concise.but.informative.review.of.all.the. clinical.presentations.of.both.superficial.and.invasive.candi-dal.diseases,.see.the.book. Fungal Infection; Diagnosis and Management . 30 The. pathogenicity. of. Candida . varies. between. species . . C. albicans . is. the. most. potent. followed. by. C. tropicalis . 31 . Sixty-four. gene. families. have. been. positively. identified. in. highly.pathogenic. Candida .species.and.are.associated.with. the.cell.wall.and.cell.morphology,.including.hyphal.and.bio-film.functions . 32 .To.become.a.human.pathogen,.an.organism. must.be.able.to.grow.at.37°C.and.the.ability.to.grow.at.higher. temperatures.(40°C).may.contribute.to.virulence,.particularly. as.invasive.candidal.infections.result.in.fever . 12 . C. albicans ,. C. dubliniensis ,. C. famata ,. C. glabrata ,. C. inconspicua ,. C. kefyr ,. C. krusei ,. C. lusitaniae ,.and. C. tropicalis .all.have. the.capacity.to.grow.at.40°C . 6 Following. infection,. it. is. paramount. that. the. interaction. with.the.host.is.maintained.and.this.is.achieved.through.the. production.of.adhesins.(Als1p,.Hwp1p,.Int1p,.and.Mnt1p) . 16 . Adherence.to.human.buccal.cells.appears.to.be.greater.for. C. albicans . than. C. parapsilosis . 33 . C. albicans . possesses. eight. ALS .family.genes.coding.for.cell.well.glycoprpoteins. (adhesins).that.are.adhesive.and/or.promote.flocculation.and.
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