Candidosis

Question 1

Candidiasis morphology 2

Answer 1

C.tropicalis - severe infection
C.parapsilosis- HAI
C.glabrata- vaginal candidosis, no psuedohyphae

Question 2

Pathogenesis

Answer 2

1) host immune system ( cellular immune system + risk factors)
2) tropism of glycogen containing tissues
a) adherence to mucosal cells ( surface glucomannan receptors on yeast–> may bind to fibronectin covering the epithelial cells)
b) invasiveness ( shift from yeast to hyphae form)
c) pseudohyphae ( proteolytic &lipolytic activity )
d) endotoxins ( low activity)
e) true hyphae ( providing deep invasion)
f) corticosteroids binding receptor ( surface of C.albicans)

Question 3

Optimal growth

Answer 3

Ph: less than 5.5
T: more than 33
C.albicans (18 strains) phenotypic changes
1) resistant to changed growth factor (ph,t)
2) AG changes
3) Resistant to antifungals

Question 4

Resistance

Answer 4

1) Environment 10-15days

2) hands ( medical staff) -15 minutes to 2 hours

Question 5

Epidemiology

Answer 5

1) Endogenous flora ( intestinal, genital, oral)

2) on vegetables

Question 6

Risk factors

Answer 6

1) Antibacterial therapy
2) corticosteroid therapy
3) local and invasive infection
4) diabetes mellitus
5) AIDS ( immunosuppression)
6) invasive procedures
7) macerated, wet skin ( dishwashers)

Question 7

Clinical manifestation

Answer 7

1) superficial invasion of mucous membrane ( oral cavity, vagina) –> white cheesy plaque (loosely adherent to the mucosal surface)
- -oral lesions ( thrush) in tongue , palate
- - vagina : thick, curd like discharge, itching of the vulva
2) skin candidosis –> skin folds (wet macerated skin), recurrent immersion in water (dish washers) —- eritrematous Papules, fissures of the skin
3) Onychomycosis - 40% hand nails
4) dissemination - immunosuppressive patients ( hematogenous dissemination–> visceral organs ( kidneys, brain, heart and eye ))

Question 8

Candidiasis morphology 1

Answer 8

• oval budding yeast cell
• 4-6 micrometer
• normal flora
• pseudo hyphae - elongated budding in cells in chains

Question 9

Onychomycosis - candida

Answer 9

• hand nails (40%)
• agents : C.albicans, C.tropicalis,C.guilliermomdii
• clinical finding: hyperkeratosis , colour: brown

Question 10

Diagnosis

Answer 10

KOH 10% (dark field examination)

Question 11

Cultivation

Answer 11

• Sabouraud medium
• Mycoline
• CHROM-agar ( candida cultivation and differentiation )

Question 12

Transportation

Answer 12

• no special transport media

- mould =long life

Question 13

Germ test

Answer 13

Young cultures from germ tubes placed in serum for 3 hours at 37•C

Question 14

Diagnosis of vulvovaginal candidosis

Answer 14

Vvc: acute vvc , recurrent - >*4 a year

Diagnosis:

1) clinical ( I thing, burning, curd like discharge, swelling)
2) ph 4.0-4.5
3) smear : - wet mount 0.9% nacl, 10% KOH - from post arch of Vagina and vulva
- gram staining
- methylene blue
- yeast like forms , pseudohyphae, specificity - 22-25%
4) cultivation in Sabouraud medium- specificity 65% ( species are identified in cases of recurrent vvc)