neutralize the acidity with buffering tablets 
or sodium carbonate. 
c. Urine may be contaminated with acid-fast 
saprophytes present on the external genitals, 
so a catheterized specimen is preferable. If 
catheterization is impractical, a midstream 
sample, collected in a sterile container, after 
careful washing of the external genitals, 
may be acceptable. 
d. Other materials such as samples of spinal, 
pleural, or synovial fluid, and pus, may be 
collected for diagnostic examination. Asepn 
tic collection in sterile tubes and the addi- 
tion, where indicated, of an anticoagulant 
such as ammonium oxalate, are essential to 
maintain the specimen in a fluid state. 
14. Tularemia. The laboratory diagnosis of tula- 
remia may be accomplished by either a) the 
agglutination test, or b) cultural examination. 
The extreme infectivity of Pasteurella tularensis, 
however, makes routine culture inadvisable, 
and agglutination tests are the method of choice 
in the diagnostic laboratory. 
a. Specimens for isolation of the agent 
Culture of P. tularensis from any one of the 
natural hosts such as ground squirrels, wild 
rabbits, wild mice, quail, or other animals 
should not be attempted except in a ref- 
erence laboratory. If such an animal is 
shipped, the body should be wrapped in 
cloth soaked in cresol, placed in a container 
with dry ice, and forwarded to the labora- 
tory immediately. Identification of the or- 
ganism in smears made from the blood or 
tissues of the host is not possible; but in 
human cases, cultures may be made from 
any of the organs or from the sputum, blood, 
or exudates, and the organism may be 
identified by specific agglutinating antisera. 
Sp>ecific FA conjugate may also be used. 
b. Specimens for serologic tests 
Blood should be drawn aseptically, allowed 
to clot, and the serum removed for agglu- 
tination tests. Care should be taken to assure 
that the blood is not hemolyzed due to ex- 
posure to excessive heat or cold in transit 
to the laboratory. To demonstrate a rise in 
antibody titer, preferably at least two blood 
specimens should be obtained — the first 
during the acute stage of the disease, and the 
second about three weeks later. Precipitin 
tests arc also possible; but these, together 
with FA tests, probably will be available 
only in a reference laboratory. 
MYCOTIC DISEASES 
Fungus diseases are conveniently classified as cuta- 
neous, subcutaneous, and systemic infections. The 
etiologic agent is identified by study of its mor- 
phology as seen in clinical material and by its mor- 
phological and physiological characteristics as ob- 
served in pure culture. Serological methods, for 
example, agar gel precipitin tests, agglutination tests, 
and FA techniques, are also of value in the identifi- 
cation of certain pathogenic fungi. 
Specimens taken for laboratory examination vary 
with the disease and the tissues involved. Specimens 
include sputum, gastric washings, spinal fluid, blood 
smears, citrated blood, blood serum, bone marrow, 
pus, pleural fluid, urine, biopsy or surgical sp>ecimens, 
scrapings from edges of lesions, skin scrapings, hair, 
and nail clippings. If competent local laboratory as- 
sistance is available, it should be used for the proper 
collection of clinical materials. Since many clinical 
materials such as sputum, lesion exudates, and tis- 
sues are readily overgrown by contaminating bacteria 
and saprophytic fungi, it is usually wise to make 
cultures on selective and nonselective media and to 
ship these, rather than the clinical materials, to the 
reference laboratory. The use of penicillin and strep- 
tomycin or chloramphenicol as antibacterial inhib- 
itors in the specimen may be helpful if cultures can- 
not be made before shipment. 
It must be borne in mind, however, that certain of the 
pathogenic fungi, particularly Nocardia asteroides 
and Actinomyces israelii, are sensitive to antibacterial 
antibiotics. Furthermore, others, particularly Histo- 
plasma capsulatum, die out rather quickly in clinical 
material. Refrigeration of the specimen in transit will 
help to overcome this difficulty. In general, refrigera- 
tion of specimens in transit serves not only to 
maintain viability of fungus pathogens but also to 
decrease growth of contaminants. 
1 . Cutaneous fungus infections. Careful choice of 
specimens for laboratory study is important. The 
Wood’s lamp is useful in the collection of speci- 
mens in tinea capitis infections since hairs in- 
fected by most members of the genus Micro- 
sporum frequently exhibit fluorescence under a 
Wood’s lamp. However, in tinea capitis due to 
Trichophyton species, infected hairs usually do 
not fluoresce. 
a. .Specimen collection for laboratory examina- 
tion 
Fluorc.scent hairs, or nonlluoresccnt hairs 
which are broken off and appear dis- 
eased, should be plucked with a sterile 
forcep, or, if diseased hair stubs arc not 
16 
