MYCOTIC BRAIN ABSCESS DUE TO CLADOSPORIUM
A NEW SPECIES
TRICHOIDES,
REPORT OF A CASE*
C H A P M A N H . B I N F O R D , M.D.,f R. K. T H O M P S O N , M . D . . J AND
M A R Y E . G O R H A M , A.B.
Pathology and Surgical Services, USPHS Hospital, Baltimore,
of Infectious Diseases, National Microbiological Institute,
Maryland,
Bethesda,
and Laboratory
Maryland
WITH MYCOLOGIC REPORT BY C. W. EMMONS, P H . D .
National
Microbiological
Institute,
Bethesda,
Maryland
From a brain abscess, removed surgically, we encountered a species of fungus
that we had not seen previously in human or animal tissues and that apparently
has not been reported as a cause of disease in man or animals.
R E P O R T OF CASE
J. W. H . , a colored man, age 22, a truck driver, was hospitalized August 2, 1949. H e
complained of frontal headaches b u t was so sleepy and drowsy t h a t he could not give an
adequate history. T h e accompanying relatives were unable to give a detailed account of
his symptoms, but stated t h a t for approximately 2 weeks he had complained of headache
and had become progressively more drowsy.
Physical examination. H e was well developed and well nourished. Only with difficult}'
was he aroused sufficiently to answer simple questions. T h e oral temperature was 99 F . ,
the pulse rate 60 per minute, and the blood pressure 112/70. H e resisted forcible effort to
bend his neck, b u t it was observed t h a t he could flex it voluntarily without a p p a r e n t discomfort. The pupils were of equal size and reacted to light. T h e axillary nodes were slightly
enlarged. There was a soft blowing systolic murmur. With the exception of slight facial
weakness on the left, no cranial nerve changes were observed. All of the superficial reflexes were physiologically active. No abnormal reflexes were observed. No sensory changes
were detected. Ophthalmoscopic examination demonstrated \ to \ diopters of disk clouding
bilaterally and moderate distention of retinal veins.
Laboratory data. On admission the total white-cell count was 14,S50 with 7S per cent
neutrophils, 14 per cent lymphocytes, 6 per cent monocytes and 2 per cent eosinophils.
T h e hemoglobin value was 15 grams per 100 ml. of blood. A serologic test for syphilis was
negative. T h e blood urea nitrogen was 18 mg., blood sugar SS mg. and serum bilirubin
0.35 mg. On urinalysis the specific gravity was 1.024, the albumin 800 mg. per 100 ml. of
urine and there were a few coarsely granular casts.
A lumbar puncture was performed on the day of admission. T h e pressure was 370 mm. of
cerebrospinal fluid. T h e fluid was clear, with a cell count of 2. T h e total protein was 70 mg.,
the sugar 70 mg. and the chloride (as.NaCl) 700 mg. A Kolmer Wassermann test was negative. A routine culture for bacteria was reported negative after 4 d a y s ' observation. Culture for acid-fast bacilli was reported negative after observing for 7 weeks. Three blood
cultures were reported negative after observation periods of 1 week. Roentgenographic
examination of the paranasal sinuses and skull was negative. T h e chest appeared normal
* Received for publication, F e b r u a r y 1, 1952.
f Present address: Armed Forces I n s t i t u t e of Pathology, Washington', D . C.
| Consultant in Neurosurgery, Baltimore, Maryland.
535
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BINFORD ET
AL.
except t h a t there were a few calcified nodules about the lung roots and one in the left midlung field.
On August 5, 1949, a ventriculogram was performed under local anesthesia. T h e lateral
ventricles were injected with 15 to 20 ml. of air. Roentgenogram demonstrated blunting
of the anterior horn of the left lateral ventricle, with slight deviation toward t h e right.
Immediately following this examination under endotracheal ether-oxygen anesthesia a left
frontal craniotomy was performed. On exploratory aspiration purulent material was obtained. An abscess wall was encountered about 3 cm. below the cortical surface of the left
frontal lobe. This wall was gently shelled out by finger dissection. T h e dura was closed,
and the bone flap replaced. Immediately following the aspiration the p a t i e n t was placed
on a regimen of 100,000 units of penicillin intramuscularly every 3 hours and 4 grams of
sulfadiazine intravenously daily. This medication was continued for 21 days.
On the night of operation purulent material obtained from the abscess was inoculated
into broth (aerobic and anaerobic) and on blood agar. No bacteria were observed on smear,
and after 2 d a y s ' incubation no growth was observed.
Pathologic report. T h e specimen was examined after formalin fixation. I t was an oval
mass 3 by 3 by 3.5 cm. consisting of an outer wall 0.5 cm. thick and a central p a r t of soft
grayish, homogeneous material: Microscopically the central part of the specimen revealed
degenerating purulent exudate in which were found numerous filamentous s t r u c t u r e s . T h e
hyphae measured 1 to 2 microns in diameter, exhibited branching, numerous septate divisions and irregularly distributed bulbous swellings. With hematoxylin and eosin stains
and in unstained preparations the hyphae were light brown. Accompanying this fungus
was a severe granulomatous reaction characterized by the presence of numerous multinucleated giant cells, many of which contained varying numbers of fragmented hyphae
(Figs. 1-3).
T h e periphery of the lesion showed no definite capsule, and the inflamed wall with the
included hyphae extended to the surface of the specimen. T h e diagnosis was mycotic granulomatous abscess. Postoperatively, the temperature receded steadily. T h e leukocyte
count was 7900 on the fourth postoperative day. T h e patient became more alert and by t h e
fifth postoperative day was able to talk a little. Specimens of cerebrospinal fluid obtained
on t h e t e n t h and twelfth postoperative days were cultured for fungi, b u t after 2 months
no growth was observed.
Additional history. After t h e diagnosis of fungus infection had been made t h e p a t i e n t
was questioned about any illness t h a t might have been responsible for the mycotic infection. H e denied any history of otitis media, sinusitis, injury, operative procedures or pneumonia. During World War I I while in Germany he had been given penicillin for a skin
condition t h a t had been diagnosed " s c a b i e s . " In the Army and in civilian life he had usually
worked as a driver of automobiles or trucks. For 2 months before his first admission here
he had worked as a laborer laying railroad cross ties.
By the eighteenth postoperative day he talked freely and was in good spirits. On discharge, September 2, 1949, he was asymptomatic.
MYCOLOGY
Mycologic study at hospital. When the histologic diagnosis was completed the
status of the culture was immediately investigated. It was learned that, as no
bacteriologic growth had been obtained, a negative report had been made and the
F I G S . 1-6. Cladosporhcm
trichoides
F I G . 1 (upper). Wall of cerebral abscess showing granulomatous reaction and fungus.
Van Gieson's stain. X 130.
F I G . 2 (lower left). Wall of abscess. Hematoxylin and eosin stain. X 230.
F I G . 3 (lower r i g h t ) . Wall of abscess. Unstained paraffin section demonstrating pigmented fungus. X 830.
FIGS. 1-3
537
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BINFORD ET <AL.
culture discarded. Fortunately sterilization had not been started and the discarded tubes were recovered.
After centrifugation, sediment from both the aerobic (Trypticase Soy) broth
and the Thioglycollate broth was planted on Sabouraud slants. After 16 days'
incubation (at room temperature) 2 or 3 tiny gray colonies appeared on 1 of
the slants inoculated with the thioglycollate sediment. Microscopic examination
demonstrated septate hyphae and rounded or oval-shaped spores. After several
weeks similar colonies appeared on 2 other tubes planted from the thioglycollate sediment. Sediment from the aerobic broth yielded no growth.
A saline suspension of fungus scraped from a Sabouraud slant was screened
(blood transfusion filter) and 0.2 ml. injected into the tail veins of 12 mice.
Eleven that survived the injection died at intervals of 16 to 41 days. One was
found paralyzed on the thirty-third day and was killed. Autopsies were carried
out on mice that were not too badly decomposed. There was a diffuse inflammatory reaction involving the meninges and the brain. The infiltrate was composed of neutrophils and monocytes, and branched pigmented hyphae, with
bulbous swelling, were seen in abundance, especially where there was a focal
zone of softening. Morphologically the fungus appeared identical with that seen
in the abscess wall removed from the patient.
In the kidney of some animals there were 1-mm. sized pyogenically inflamed
nodules containing hyphae. Smaller nodules were seen in the pulmonary alveoli.
Bits of hyphae and globular fungus cells were observed in hepatic sinusoids.
Occasionally an inflammatory nodule was seen in the liver.
Four rabbits were inoculated intravenously with saline suspensions of the
fungus cultures. The animals died after periods ranging from 25 to 90 days or
were moribund and killed. All showed multiple small brain abscesses in which
the characteristic hyphae were demonstrated. Occasionally giant cells of foreignbody type were seen in the margins of abscesses. In one of the animals minute
mycotic abscesses were found in the kidney. The brains of mice and rabbits
yielded cultures of fungus identical with that originally obtained from the
patient.
In the hospital laboratory it was concluded that the fungus probably belonged
to the genus Cladosporium (Hormodendrum). Although it superficially resembled Phialophora, it could be differentiated from that species.
Mycologic study at the National Microbiological Institute, Bethcsda, Maryland
(C. W. E.): The fungus resembles saprophytic species of Cladosporium,* which
are ubiquitous on dead vegetation in man's environment.
It is generally recognized that Hormodendrum is an invalid synonym of
Cladosporium. When a fungus, which on its natural substrates has the septate
conidia formerly thought to be characteristic of Cladosporium, is brought into
the laboratory in pure culture it produces one-celled conidia predominantly or
exclusively and it cannot be differentiated from "Hormodendrum." It might
then have been dismissed as a contaminant except for its apparent isolation from
* For a discussion of the generally accepted usage of Cladosporium versus Hormodendrum see Tuosr, C : Naming molds. J. Washington Acad. Science, 30: 49-64, 1940.
BEAIN ABSCESS FROM CLADOSPORIUM
TRICIIOIDES
539
F I G . 4 (upper). Colonv of Cladosporium trichoides on modified Saboiiraud's agar incubated 2 weeks at 30 C.
.FIG. 5 (lower left). Conidiophore and chains of conidia.
FIG. 6 (lower right). Conidia showing variation in size and shape.
the brain tissue and the pigmentation and moiphology of the fungus observed in
tissue, which are entirely compatible with the characteristics of the fungus in
culture. Further, the fungus is pathogenic for mice and produced in experimental!}' infected mice brain lesions similar to those seen in the patient.
540
BINFORD ET A I.
This species is not unique among the cladosporium-like fungi in causing human
disease. Fungi, characterized by morphologic resemblance to Cladosporium,
production of a brownish to olivaceous pigment and formation colonies, in
culture of gray or brown to olive-black "colonies, are well known to be associated
etiologically with certain mycoses. Best known among these mycoses is chromoblastomycosis. 1 ' 2 The divergent but closely interrelated fungi causing it differ
significantly from the species to be described. Other pathogenic fungi showing
affinities to this group are Hormodendram madagascare?isis isolated from a subcutaneous and' ulcerating infection of the leg,4 H. jontoynoti from a superficial
skin infection6 and Phialophora jeanselmei isolated from a distinctive type of
mycetoma.3' s The medical literature contains a few other reports of the isolation
of pigmented fungi of this general type in cases where an etiologic relationship is
not too well established. There are other species of Ciadosporium that are'industrially important because they cause plant disease.
The clinical features of the case being reported are quite unlike those just
mentioned. Nevertheless, in identifying the fungus, one might assume that an
unusual species of Cladosporium, physiologically adapted to parasitism of the
human host, might have various clinical manifestations, and therefore might be
identical with one of the species already isolated from other clinical types of
disease of man. The fungus isolated from this brain abscess has been compared
with descriptions of the fungi isolated from these diverse clinical lesions, and
directly with available strains of fungi isolated from these cases. As will be
pointed out after a description of the fungus, it differs from all of them.
Attempts were then made to identify the fungus with one of the saprophytic
species of Cladosporium not previously found in human mycoses. In the first
25 volumes of Saccardo's Sylloge Fungorum, 259 species and varieties of Cladosporium are listed. Most of these names are accompanied in the original papers
as well as in Saccardo by only a brief description of the appearance of the fungus
on its natural substrate, and are based in most cases upon the mere fact of isolation from a new host plant or from a new geographic area. Descriptions are
wholly inadequate for purposes of modern identification.
One is faced with the alternative of making a highly questionable determination of the present species, by attaching it to one of these old and inadequately
identified names, or of describing it as a new species. Neither course is wholly
satisfactory, but the latter seems to be more desirable. No monographic study
of- species of Cladosporium in culture has been made. If such a study should show
that the fungus isolated from this brain lesion has been observed previously on
plants or decaying vegetation and given the name here given, it must fall into
synonymy.
Subcultures of this fungus have been deposited in the American Type Culture
Collection under No. 10958.
We propose for this fungus the name, Cladosporium trichoides signifying its
hyphal growth in human brain tissue. In order to comply with the International
Rules of Botanical Nomenclature, which govern the naming of fungi, a short
Latin definition is appended to the following description.
Cladosporium trichoides n. sp.
BRAIN ABSCESS FROM CLADOSPORIUM TRICHOIDES
541
Colonies on modified Sabouraud's agar* reach a diameter of 3 cm. and a depth
of 0.4 cm. after 2 weeks' incubation at 30 C ; colony flat to dome-shaped, typically
with a hemispherical eminence at the center (Fig. 4); surface of colony velvety,
not folded or wrinkled when young but developing shallow radial folds reaching
half way to the periphery of the colony in older colonies; color dark olive gray7
when old; reverse of colony dark gray to black. Streak cultures on cornmeal-agar
slides restricted at first but spreading sparsely to the edge of the slide when the
agar has become dry.
On potato dextrose agar the colony resembles that on Sabouraud's agar in
diameter and contour but the green component of the pigment is a little more
conspicuous. On Czapek's agar after incubation for 2 weeks at 30 C. the colony
is 3 cm. in diameter with a small peak at the center but the growth is very sparse,
thinning to an almost imperceptible margin.
Hyphae brown, 1-2 p. in diameter, walls smooth. Conidiophores 2 p. in diameter, often septate, straight to flexuous, bearing long sparsely branched chains
of conidia (Fig. 5).
Conidia elliptical, 2 to 2.5 by 4 to 7 p., exceptionally fusoid-cylindrical and 2
to 3 by 15 to 20 p., brown, wall smooth, borne in long sparsely branched chains
(Fig. G). Small conidia are immature cells produced by budding at ends of chains,
large conidia are older cells from basal portions of chains.
Isolated from abscess in human brain in which it grew in the form of brown
septate, branching hyphae 1 to 2 p in diameter with many intercalary vesicular
cells reaching a diameter of 8 /^.f
DISCUSSION
This species differs from P. pedrosoi in bearing smaller conidia and in much
greater length and less frequent branching of spore chains. The infrequent branching results in fewer shield-shaped subterminal conidia, which are conspicuous
features of the detached conidia of the latter species. However, occasional
conidia that have given rise to branches in the conidia! chain bear two or more
knobs at the tip, so that the distal portion of the spore is slightly widened. C.
trichoides differs also from P. pedrosoi in the lack of serial budding at the end of
a phialide, characteristic of that species and of P. verrucosa. It differs from other
pathogenic species studied and from most saprophytic species in the smaller
dimensions and smooth walls of its conidia.
Most conidia are abruptly narrowed at the ends, and the lateral walls at the
ends of the spore are slightly thickened, giving the optical effect "disjunctors."
The longer conidia, although roughly cylindrical through much of their length,
are narrower at the ends, and many are flexuous, thus further modifying the
* Difco Neopeptone 1 per cent, C. P . Dextrose 2 per cent.
f Caespilulis hemisphaericis,
lenibus, aegualibus, olivaceogriseis vel
olivaceo-bntnneis.
Conidiis ellipsoidis vel cylindraceis, 2-2.5 x 4-10 p, continvis vel l-septatis, fuscis, aeqvalibus, formatis in cateniis longis
ramosique.
Bab.: In ulcere cerebrale hominis.
(Latin diagnosis prepared by W. H . Everhard\ r , T r a n s l a t i n g Unit, National I n s t i t u t e s
of H e a l t h . )
542
BINFORD ET AL.
cylindrical shape. Most of the conidia, including those that are greatly elongated,
are one-celled, but rare conidia with one septum are found.
Further clinical observation. On December 14, 1949, the patient was readmitted.
At that time he was subject to convulsions. A diagnosis of Jacksonian epilepsy
was made and subsequently he responded to sedative treatment. .
On April 3, 1951, he was reexamined. The cell count of the cerebrospinal fluid
was 4, the globulin negative and the total protein 48 mg. At that time he had no
symptoms that could not be explained on the basis of postoperative epilepsy.
On August 2, 1951, the patient was readmitted for acute gonorrheal urethritis
and acute arthritis of the left ankle. Treatment with sulfadiazine resulted in
prompt recovery. Roentgenographic examination of the chest and of the skull
was negative. Spinal fluid examination revealed no changes of interest. Cultures
for fungi were made of sputum and spinal fluid but none were demonstrated.
On discharge from the hospital on August 13, 1951, he appeared to be fully recovered and was continued on phenobarbital medication on account of his
history of Jacksonian epileptic seizures.
Even though after 2 years'there has been no clinical or laboratory evidence of
recurrence the patient must still be kept under periodic observation. It is probable
that some mycotic material was left within the brain, since in the surgical specimen it was demonstrated that hyphae had penetrated the abscess wall.
SUMMARY
A brain abscess was surgically removed from the frontal lobe of a man aged
22. In sections and in culture a pigmented fungus was demonstrated. Intravenous
inoculation produced fatal cerebral lesions in mice and rabbits. A detailed report
is made of its cultural and morphologic characters, and comparison is made with
known species of pigmented fungi. The name proposed for this fungus is Cladosporium trichoides n. sp. After a period of 2 years the patient has shown no evidence of recurrence.
ADDENDUM
While this material was under s t u d y we received from Mr. Thomas Collette, bacteriologist a t t h e R o b e r t Packer Hospital, Sayre, P a . , a culture of a fungus, also isolated from
a patient with brain abscess, which closely resembled the strain isolated from our patient.
F u r t h e r s t u d y of cultures and of sections t h a t M r . Collette kindly sent showed t h e two to
be referable to t h e same species. T h e second case of a cerebral abscess caused by C. trichoides will be reported by D r . A. B. King and Mr. Collette.
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