is a gram-positive organism that grows
slowly with branching filaments. It is a commensal
but becomes invasive. Macroscopically it appears as
yellow (sulfur) granules less than 1 mm in diameter.
Microscopically, they are gram-positive mycelial filaments
surrounded by a sheath of eosinophilic matter, which
imparts a club-shaped appearance to the ends of these
These are like A. israelii but lack the clubbed ends. The
filaments are gram-positive, bacilliform in shape and in
some stains are partially acid fast. It may, however, be a
saprophyte in the upper respiratory tract. Its repeated
presence is diagnostic of pulmonary nocardiosis.
Direct examination with India ink is advocated. The
organism appears as a single budding blastospore, 2 to 20 µ
in diameter and is surrounded by a capsule from 3 to 5 µ in
Sputum staining with Wright’s/Giemsa’s stain reveals
macrophages with characteristic intracellular small yeast
Examine sputum by wet direct mounts. The organism
appears as a spherule, 5–200 µ in diameter and is filled
with endospores. In the chronic cavity, hyphae may be
Infection beginning from lungs may spread hematogenously. In direct wet mounts, the organisms appear
as 8–15 µ diameter spherules without a capsule. Budding
may be seen with a characteristic sputum. No mycelium
It is a throat commensal but overgrows with excessive use
of antibiotics and immunosuppressants and becomes
pathogenic (keep in mind that they can grow very well
on sputum in vitro also). The report should indicate the
number of organisms seen per field. On direct mount,
they appear as 4µ diameter, thin-walled organisms
singly, in pairs, or in small clusters. Budding forms and
pseudomycelia may be seen. The organisms stain intensely
These are like C. albicans, the organism appears often as a
Mucormycosis rarely causes pulmonory lesions and occur
more commonly in diabetics. Direct wet mount may show
huge (15 µ diameter) aseptate hyphae. Isolation on culture
The sputum is usually white and mucoid and contains no
blood or pus unless an underlying infection is present.
1. Eosinophilia: Sputum has eosinophilic staining
properties (attributed to increased accumulation of
serum proteins), not seen in chronic bronchitis.
2. Bronchial epithelial cells: These often occur singly and
show hydropic change with poorly defined original
morphology. During acute phases, these cells gather
in larger clusters, display a vacuolated cytoplasm with
ciliated border—known as Creola bodies. In addition,
one may see hypersecretory goblet cells singly/
3. Charcot-Leyden crystals: Seen almost only in the
sputum of bronchial asthma cases. The crystals are
colorless, pointed hexagons and variable in size
(may look needle shaped). These are derived from
disintegration of eosinophils, hence they stain strongly
4. Blood cells: Mostly eosinophils are seen, infection
brings with it a neutrophilic response. Monocytes and
histiocytes appear in significant numbers during the
5. Creola bodies: Almost exclusively seen in sputum of
bronchial asthma cases. Their appearance is a poor
6. Curschmann’s spirals: These are characteristic of
bronchial asthma sputum but may be seen in other
respiratory disorders. Macroscopically, they can
sometimes be recognized by the naked eye and appear
as yellow-white, mucoid, wavy threads frequently
coiled into little balls. Their length may exceed
1.5 cm. Microscopically, they show a central thread
around which mucus is wrapped, supported by a fibril
The production of mucopurulent sputum is one of
the cardinal signs of bronchiectasis and the amount
expectorated varies with the posture. Morning cough is
typical. Characteristically, the sputum is putrid, gray green
in color (50–250 mL/day), at times blood tinged. On sitting,
the sputum separates into three layers: (i) upper frothy
layer, which later subsides, (ii) a middle turbid mucous
layer and (iii) a bottom layer of pus cells and various
organisms. The microscopic examination of bottom layer
discloses bronchial epithelial cells, fatty crystals, bacteria
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