2. OPPORTUNISTIC MYCOSES
True Pathogenic Fungi Opportunistic Fungi
Diseases Histoplasmosis Aspergillosis
Blastomycosis Candidiasis
Paracoccidioidomycosis Mucormycosis
Coccidioidomycosis Cryptococcosis
Host Normal Abrogated/
Compromised
Portal of Primary infection is Various
Entry pulmonary
Monday, January 16, 2012
3. OPPORTUNISTIC MYCOSES
True Pathogenic Fungi Opportunistic Fungi
Prognosis 99% spontaneous resolution Recovery depends on the
severity of impairment of
host defenses
Immunity Resolution results to strong No specific resistance to
specific immunity infection
Host Response Tuberculoid granuloma, Depends on degree of
mixed pyogenic impairment necrosis to
pyogenic to
granulomatous
Morphology in All agents showed No change in morphology
Tissue dimorphism to a tissue
form
Distribution Geographically restricted Ubiquitous
Monday, January 16, 2012
4. CANDIDIASIS
C. albicans is the most common (4-6 um;
budding)
Multiplication: blastospore formation
producing either pseudohyphae or
septate hyphae
Identification: assimilation and
fermentation of CHOs; physiologic and
morphologic responses they exhibit
when grown under controlled
nutritional conditions “germ tubes”
Monday, January 16, 2012
5. CANDIDIASIS
“chlamydoconidia”
Monday, January 16, 2012
6. FACTORS THAT AFFECT CANDIDA
NORMAL POPULATION
poor oral hygiene
use of antibiotics
use of oral contraceptives
diet
presence of antagonistic inhibitory bacteria
Monday, January 16, 2012
7. Candida albicans is a resident flora of the
skin, mouth, vagina and stool!
Imbalance will lead to infection....HOW?
Changes in the Physiology: e.g.
pregnancy, use of steroids and diabetes
Prolonged administration of antibiotics
Immunocompromised patients
Monday, January 16, 2012
8. MUCOCUTANEOUS CANDIDIASIS
(MC)
a condition caused by a fungus from
the candida family (lives on the
surface of skin) that develops a
diffuse and persistent type of
infection of the mouth, nails, skin, and
at times other organs
affects infants (starts before age 3) and
young adults, is rarely seen in adults
with other diseases
including chronic mucocutaneous
candidaisis or CMCC
Monday, January 16, 2012
13. CANDIDIASIS IN DIAPER RASH
“Candida may come from fecal origin”
Monday, January 16, 2012
14. SYSTEMIC INVOLVEMENT
Urinary tract
Endocarditis
Meningitis
Septicemia
Latrogenic candidemia
Dissemination to other organ systems
Monday, January 16, 2012
15. DISSEMINATED CANDIDIASIS
originate at a gastrointestinal site
CA enters epithelial microvilli through persorption of yeast cells
or by germination (a,c)
In both cases, organisms enter the vasculature (b,d) for
dissemination into tissues such as the kidney (e)
localizes in the cortex (f) where it grows as hyphae/
pseudohyphae
A vigorous host response occurs at this site consisting of both
mononuclear and polymorphonuclear leukocytes
Virulence factors (adhesins, morphogenesis, switch phenotypes,
antioxidant proteins and invasive enzymes) promote the invasion
of the organism
Monday, January 16, 2012
17. LABORATORY DIAGNOSIS:
CADIDIASIS
Direct microscopic
examination
Specimen for examination can
be sputum, skin scrapings,
vaginal swabs, biopsy material,
from any types of organs or
even in blood.
The specimen is treated with
1-2 drops of 10-20% KOH.
Monday, January 16, 2012
18. LABORATORY DIAGNOSIS:
CADIDIASIS
The presence of the capsule
and budding yeast cells are
considered as the positive
results.
Aside from KOH, other
stains can be used such as
India ink and Papanicolaou
stain.
Monday, January 16, 2012
19. GERM TUBE TEST
Most isolates of
C. albicans produce a
hyphal growth from
blastospores when
they are suspended in
serum at 37°C for 2-3
hours.
Monday, January 16, 2012
20. IN CULTURE...
SDA at either room temperature or at 37°C
Colonies: usually develop in 2-3 days as
white, typical yeast colonies
In vitro: monomorphic, growing as non
encapsulated yeast cells at any temperature
Monday, January 16, 2012
23. TREATMENT OF CANDIDIASIS
Most localized, cutaneous, candidiasis infections may
be treated with any number of topical antifungal
agents (eg, clotrimazole, econazole, ciclopirox,
miconazole, ketoconazole, nystatin).
For Candida onychomycosis, oral itraconazole
(Sporanox)
For Genitourinary tract candidiasis, VVC can be
managed with either topical antifungal agents or
Monday, January 16, 2012
24. TREATMENT OF CANDIDIASIS
Caspofungin acetate (Cancidas) as a 70-mg
loading dose is followed by 50 mg/d IV for a
minimum of 2 weeks after improvement or
after blood cultures have cleared.
Chronic mucocutaneous candidiasis is treated
with oral azoles, either fluconazole (Diflucan)
Monday, January 16, 2012
25. ASPERGILLOSIS
One of the largest of the fungal genera
Hundred of species have been recorded
The most important species:
A. fumigatus
A. flavus
A. niger
Monday, January 16, 2012
26. ASPERGILLUS FUMIGATUS
Aspergillus fumigatus
identified according to
the pattern of
conidiophore
development,
morphologic features
and color of the
conidia
Monday, January 16, 2012
28. SPECTRA OF ASPERGILLOSIS
Toxicity due to ingestion of contaminated foods
Allergy and sequelae to the presence of conidia or transient
growth of the organism in body orifices
Colonization without extension in preformed cavities and
debilitated tissues
Invasive, inflammatory, granulomatous, necrotizing disease of
lungs and other organs
Systemic and fatal disseminated disease
Monday, January 16, 2012
29. ALLERGIC ASPERILLOSIS
Allergic aspergillosis maybe benign early on and
severe as the patient grows older
In secondary colonization, a chronic clinical
situation may exist with little distress except
occasional bout of hemoptysis and some
pathological changes in the lungs that may lead to
the formation of fungus ball.
Monday, January 16, 2012
31. SYSTEMIC ASPERGILLOSIS
An extreme serious disorder that is usually
rapidly fatal unless diagnosed early and treated
aggressively
The status of the host’s immune system
contributes to the prognosis of the patient
Monday, January 16, 2012
33. Disease Etiologic Factors
Mycotoxicoses Ingestion of contaminated food
products
Hypersensitivity Allergic bronchopulmonary
peumonitis disease
Secondary Colonization of preexisting
colonization cavity (pulmonary abscess)
without invasion into
contiguous tissue
Systemic disease Invasive disease involving
multiple organs
Monday, January 16, 2012
34. DISSEMINATED ASPERGILLOSIS
Aerosols of Aspergillus fumigatus conidia are inhaled and
travel to the alveoli
In the healthy host, alveolar macrophages (AM) phagocytose
and kill the organism after swelling of the conidium, an
essential pre-germination stage
The production of reactive oxygen intermediates by AM is
required to eliminate the organism, but
polymorphonuclear cells (PMNs) also contribute
In the immunosuppressed patient, reduced numbers of PMNs
and inefficient AM allow growth of the fungus
Consequently, the conidia germinate and escape from the AM
Monday, January 16, 2012
35. LABORATORY DIAGNOSIS
Aspergillosis is easy to isolate and identify....BUT!
also important to distinguish a true pathogen
from a contaminant
If sputum sample is to be collected, it is expected
to be thick and gelatinous
In invasive sampling, lung aspirates or tissue
biopsy is used
Monday, January 16, 2012
36. LABORATORY DIAGNOSIS
Direct microscopic examination will show
hyaline, dichotomously branched and septate
hyphae
Occasionally in sputum, in cases of pulmonary
aspergillosis, one may also sees very small, rough
walled spores (3-4 um in diameter).
Monday, January 16, 2012
38. TREATMENT
Amphotericin B was used
for many years BUT!!! with
disappointing results
In 1990 itraconazole was
introduced as a new broad
spectrum anti-fungal agent.
Monday, January 16, 2012
39. ZYGOMYCOSIS/PHYCOMYSIS
Class Phycomycetes
Rhizopus
Absidia
Mucor
They formed coenocytic hyphae and reproduce
asexually by producing sporangiosphores within
which develops sporangiospores
Monday, January 16, 2012
40. ZYGOMYCOSIS/PHYCOMYSIS
Repeated isolation of the
organisms from consecutive
specimens provides strong
evidence that the organisms
may be relevant, even though
coenocytic hyphal elements
are not seen in
histopathologic examination
of tissue.
Monday, January 16, 2012
42. CATEGORIES COMMENTS
Rhinocerebral It is the most frequent presentation overall and classically affects diabetics with
ketoacidosis.
Usually presents with facial and/or eye pain, proptosis and progressive signs of
involvement of orbital structures (muscles, nerves and vessels).
Common complications include cavernous sinus and internal carotid artery
thrombosis.
Pulmonary It occurs most frequently among neutropenic patients.
It presents with nonspecific symptoms such as fever, cough and dyspnea;
hemoptysis may occur with vascular invasion.
Radiological presentation includes segmental consolidation that progresses to
contiguous areas of the lung, with occasional cavitation.
Gastrointestinal Usually affects patients with severe malnutrition
May involve the stomach, ileum, and colon
Clinical picture mimics intra-abdominal abscess. The diagnosis is often made at
autopsy.
Cutaneous It has been reported with minor trauma, insect bites, no sterile dressing, wounds, and
burns.
The necrotic lesions progressively evolve from the epidermis into dermis and even
muscle.
Others Heart, bone, kidneys, bladder, trachea, and mediastinum
Monday, January 16, 2012
43. DIRECT EXAMINATION: ZYGOMYCOSIS
A rapid diagnosis is critical
Fungal elements are usually not numerous in discharges
Scrapings from the upper turbinates, aspirated material
from sinuses, sputum in pulmonary disease, and biopsy
material mounted in 10% KOH typically contain thick-
walled, refractile hyphae 6-15 um in diameter
Swollen cells (up to 50 um) and distorted hyphae may be
present
Monday, January 16, 2012
44. IN CULTURE...
Sabouraud dextrose agar:
Incubate at 30°C
DON’T: cycloheximide =
sensitive
Sterile bread:
for recovery of Zygomycetes
when other media fail
WHY bread???
Monday, January 16, 2012
45. TREATMENT
Control of the diabetes
Aggressive surgical
debridement of involved tissue
High doses of amphotericin B
are recommended
Monday, January 16, 2012
