Fungi Ascomycota

Saccharomycetes Candida albicans

(1)

T. Walker, 10 Dec 03

kingdomphylum

class

genus species

Taxonomy, Ecology, Taxonomy, Ecology, EpidemiologyEpidemiology

• A common commensal, normally found in mouth, gastro-intestinal tract, vagina (B,

abstract)

– There is a bit of C. Albicans in the healthy intestine; bacteria that control yeast growth may by killed through overuse of:

• antibiotics• too much sugar consumption (feeding C. albicans,

which competes against the bacteria)• altering pH to suit fungal growth through minimal

vegetable consumption (9).

• Environmental presence due to human/animal contamination; b/c of this, found in food, soil, and fomites.

– NOT normally found in environs, except when in mold form for transfer between hosts.

– Infection by colonizing host’s organisms, e.g. the host’s hosts… (B)

• Closely related to C.krusei, a cause of fungemia (derivative of sepsis) (3)

Yeast form ofYeast form of C.albicans (10,000x)

Note the reproduction by budding

Taxonomy, Ecology, Epid., Taxonomy, Ecology, Epid., c’ond; Preventionc’ond; Prevention

• Medically-important fungi, dimorphic [having two forms; here yeast when in host, mold in environs – this is the YM shift]

• As yeast, in skin/mucous membranes; is type of opportunism (txt)

Infection symptoms; Infection symptoms; • Include fatigue, sweat, pain, sore throat, fever,

numbness, asthma susceptibility, sinusitis, allergies, irritabilty, abdomen pain, gas

• Notable are irregular menstrual cycles/pain, or yeast rashes– Possibly due to lack of estrogen or a menstrual cycle!– If these symptoms untreated while young, may delay

menarche, and menopause may come earlier (possibly early 20s).

Pathogenicity; DiseasePathogenicity; Disease

• Medical abstract suggests “substantial differences in mortality, organ colonization, and severity of tissue damage” after C. albicans inoculation (A)

• If lacking a certain compliment in the brain, one is more susceptible to disease caused by the fungus (A)

• Candida infections one-tenth of hospital bloodstream infections• 80% AIDS patients have Candida

• Move from bloodstream to organs (4)

• Candidisis is a mycosis [a disease caused by fungi, here C.albicans]; recognized since early 1800s under many names (txt)

Disease, con’dDisease, con’d

• The fungi normally found in body, as mentioned; growth usually limited by other organisms, but causes candidisis when uncontrolled

Disease: Disease: Paronychia/onychomycosisParonychia/onychomycosis

Disease: CandidisisDisease: Candidisis

• Again, may be induced by overuse of antibiotics (kills systemic bacteria that control C.albicans growth); also theraputic/surgical procedures (transplants and prosthetics) that allow it to contaminate body

• Also STD (txt)

Disease: CandidisisDisease: Candidisis

• Symptoms include arthritis, various inflammations (eye, heart, abdomen) (4, txt), meningitis, myositis [muscular pain]

• Vaginal form: yeast infection

• Candidisis affects all organs and tissues!

• Other types are oral candidisis (thrush) and diaper c’isis (when diapers moist and erratically changed) (txt)

Oral candidisis: ThrushOral candidisis: ThrushComprised of cellular debris, Comprised of cellular debris,

leukocytes, yeast cells leukocytes, yeast cells (txt(txt)

whassup!

Disease: Vulvovaginal Disease: Vulvovaginal C’isis (a reiteration, of C’isis (a reiteration, of sorts); also Preventionsorts); also Prevention• +50% of women over 25yrs develop it

• Again, recurrance (in less than 5% of cases) may b/c of:– Species similar to C. albicans acting “in place” of it)– Many antibiotics– Contraceptives (easier passage than dry skin)– Immunocompromization– Hyperglycemia (excess sugar) (9)

• One should avoid the above factors to repel c’isis, etc.

Treatment; MortalityTreatment; Mortality

• In vitro techniques in conjunction w/ antifungal agents may counter Candida

• A suggested cure is limiting internal adherance of the fungus; this concept is not understood, however (6, abstract)

• Very high mortality: 46% mean mortality from candidemia, with C.albicans involved in 70% of those deaths (5)

IdentificationIdentification• TefI gene from C. albicans and C.

dubliniensis amplified, compared to pure fungal genome (7)

• Another confirmation method:– After make inoculum, compare with densitometer

to known– Incubate, then use system like FungiFast to ID

(similar to E-II, for those in 202)– Based on colours produced by enzymes in rxns…

(8)

Identification: FungiFast table

Works CitedWorks Cited• http://www.candidapage.com/cccomp.shtml (1)• http://alces.med.umn.edu/candida/taxonomy.html (3)• http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?

cmd=Retrieve&db=PubMed&list_uids=10999981&dopt=Abstract (11)

• http://pathology5.pathology.jhmi.edu/micro/v16n05.htm (5)• http://www.unr.edu/mycology/ (6)• http://www.int-microbio.com/Fungifast_ITwin.htm (8)• http://www.excel.net/~jaguar/candida.html (9)• http://www.pubmedcentral.nih.gov/articlerender.fcgi?

rendertype=abstract&artid=174007 (A)• http://www.smartcycler.com/pdfs/candidas_poster.pdf (7)• http://www.intelihealth.com/IH/ihtIH/WSIHW000/9339/9935.html (E)• http://www.aafp.org/afp/20000601/3306.html (9)• Some definitions taken from www.m-w.com