Aspergillosis is caused by fungi of the genus Aspergillus and can cause a variety of diseases in humans depending on the immune status of the host. These include allergic reactions, colonization of pre-existing lung cavities, and invasive infections. Aspergillus fumigatus is the most common cause of invasive pulmonary aspergillosis. Diagnosis involves culture, histopathology of tissues showing characteristic hyphal growth patterns, and serological detection of antibodies.

1. INSTITUTE OF HEALTH TECHNOLOGY, DHAKA
Department of Laboratory Medicine
BSc in Health Technology (Laboratory)- 1st Year
MYCOLOGY
Lecture No. 7.3 (Opportunistic Mycoses -Aspergillosis)
By
Sk. MIZANUR RAHMAN
Lecturer, Mycology
MS in Biotechnology & Genetic Engineering (UODA)
MS in Microbiology (SU)

2. Aspergillosis
Aspergillosis is a spectrum of diseases of humans and animals
caused by members of the genus Aspergillus. These include
(1) mycotoxicosis due to ingestion of contaminated foods;
(2) allergy and sequelae to the presence of conidia or transient
growth of the organism in body orifices;
(3) colonization without extension in preformed cavities and
debilitated tissues;
(4) invasive, inflammatory, granulomatous, necrotizing disease of
lungs, and other organs; and rarely
(5) systemic and fatal disseminated disease. The type of disease
and severity depends upon the physiologic state of the host and
the species of Aspergillus involved.
Distribution: World-wide.
Aetiological Agents: Aspergillus fumigatus, A. flavus, A. niger, A.
nidulans and A. terreus.

3. CLASSIFICATION OF ASPERGILLOSIS
Persistence
without disease -
colonisation of the
airways or
nose/sinuses
Airways/nasal
exposure to
airborne Aspergillus
Invasive aspergillosis
• Acute (<1 month course)
• Subacute/chronic necrotising (1-3 months)
Chronic aspergillosis (>3 months)
• Chronic cavitary pulmonary
• Aspergilloma of lung
• Chronic fibrosing pulmonary
• Chronic invasive sinusitis
• Maxillary (sinus) aspergilloma
Allergic
• Allergic bronchopulmonary (ABPA)
• Extrinsic allergic (broncho)alveolitis (EAA)
• Asthma with fungal sensitisation
• Allergic Aspergillus sinusitis (eosinophilic
fungal rhinosinusitis)

4. Aspergillosis infection
1. Allergic aspergillosis
Asthma
Allergic bronchopulmonary aspergillosis (ABPA)
IgE antibodies present. In ABPA also 1gG
2. Colonizing aspergillosis (ASpergilloma=Aspergillus fungus ball)
Pulmonary aspergilloma
diagnoses include: cough , hemoptysis, variable fever
CXR will show coin-like mass in the lung

5. 3. Invasive aspergillosis-pulmonary
Sings: cough, hemoptysis, fever, Penomonia, leukocytosis
Lab investigation (direct microscopy and culture) may be
negative especially if specimen is noninvasive like sputum
4. Aspergillus sinusitis
Nasal polyps-sinusitis-eye-cranium (rhinocerebral)
The most common cause is Aspergillus flavas (also other
fungi can cause sinusitis)
Aspergillosis infection

6. 5. Eye infection,, corneal ulcer-endopthalamitis
6. Ear infection,,otitis externa-otitis media
7. Nail and skin infection
8. Toxicosis due to ingestion of aflatoxin
9. Disseminated form-rare, in debilitated patients
Fungus ball or Pulmonary Aspergilloma which is characteristically
seen in the old cavities of TB patients. This is easily recognized by
x-ray, because the lesion (actually a colony of mold growing in the
cavity) is shaped like a half-moon (semi-lunar growth). The patients
may cough up the fungus elements because the organism
frequently invades the bronchus. Chains of conidia can sometimes
be seen in the sputum.
Aspergillosis infection

7. Aspergillus
Conidiophore
Swollen apex of conidiophore (vesicle)
Conidia
Supporting cell (branch or metulae)
Conidiogenous cells (phialides)
Basal part of conidiophore (foot cell)

14. Culture:
•Aspergilli require 1-3 weeks for growth.
•The colony begins as a dense white mycelium which
later assumes a variety of colors, according to species,
based on the color of the conidia.
•The hyphae are branching and septate.
• Species differentiation is based on the formation of
spores as well as their color, shape and texture.
Histopathology:
•The septate hyphae are wide and form dichotomous
branching, i.e., a single hypha branches into two even
hyphae, and then the mycelium continues
branching in this fashion
Diagnosis

15. Serology:
•There is an excellent serological test for
aspergillosis which is an Immunodiffusion test
( ELISA).
•There may be 1 to 5 precipitin bands. Three or
more bands usually indicate increasingly severity
of the disease. i.e., tissue invasion.( detection of
IgG and IgE)
Diagnosis

17. 033
Grocott’s methenamine silver (GMS) stained tissue section of
lung showing fungal balls of hyphae of Aspergillus fumigatus.

18. 034
Grocott’s methenamine silver (GMS) stained tissue section of lung
showing dichotomously branched, septate hyphae of Aspergillus
fumigatus.

19. 035
Grocott’s methenamine silver (GMS) stained tissue sections
showing Aspergillus fumigatus in lung tissue, note conidial heads
forming in an alveolus.

20. 036
Grocott’s methenamine silver (GMS) stained tissue sections
showing Aspergillus fumigatus in lung tissue, note conidial heads
forming in an alveolus.

21. 037
Aspergillus fumigatus on Czapek dox agar showing typical blue-green
surface pigmentation with a suede-like surface consisting of a dense
felt of conidiophores.

22. 040
Aspergillus niger on Czapek dox agar. Colonies consist of a
compact white or yellow basal felt covered by a dense layer of
dark-brown to black conidial heads.

23. 042
Aspergillus flavus on Czapek dox agar. Colonies are granular, flat,
often with radial grooves, yellow at first but quickly becoming
bright to dark yellow-green with age.

24. 048
Immunodiffusion test showing precipitins against
Aspergillus.