the newborn may be caused by Salmonella, 
Shigella, or viruses. Many otherwise unex- 
plained epidemics of infantile diarrheal dis- 
ease in which certain serotypes of Escher- 
ichia coli were recovered have, however, 
occurred. For these particular serotypes, 
the term enteropathogenic E. coli, or EEC, 
is commonly used. In order to control the 
spread of infantile diarrhea, the causative 
organism must be accurately and rapidly 
identified. 
Earlier attempts at differentiation of the 
enteropathogenic coli strains were unsuc- 
cessful because only biochemical methods 
were employed and, as is now known, differ- 
ent E. coli serotypes produce identical bio- 
chemical reactions. These biochemically 
similar organisms fall naturally into certain 
groups, and serologic methods must be used 
to determine the serotypes within each bio- 
chemical group. 
The determination of E. coli serotypes is 
dependent on the determination of the “O,” 
“B,” and “H” antigens of the bacterium. 
The E. coli responsible for the disease can 
be distinguished from the E. coli constitut- 
ing the normal intestinal flora only by use 
of specific antisera. 
Specimens to be collected for isolation of 
the agent 
Fecal material should be collected either 
as a stool or on a rectal swab before anti- 
biotic therapy is begun. The stool specimen 
or rectal swab should be placed in a screw- 
cap vial containing 30% buffered glycerin- 
saline solution, or (if there will be more 
than a two-hour delay before it can be 
planted in the laboratory) on Amies’ mod- 
ification of Stuart’s transport medium. 
Specimens for enteropathogenic E. coli di- 
agnosis by FA technic. 
Specimens preserved with any fluids con- 
taining glycerol are not satisfactory for FA 
staining. A separate buffered swab (as sup- 
plied with Amies’ transport medium) should 
be sent to the laboratory in a separate tube 
containing no preservative or medium. 
6. Gonorrhea. Difficulties in the laboratory diag- 
nosis of gonorrhea are increased when the 
clinician fails to exercise care in securing suit- 
able exudates for examination. This is especially 
true in chronic gonorrhea of women and in “test 
of cure” where only minimal numbers of gon- 
ococci may be present in the exudates obtained 
from endocervical, Skene’s, and Bartholin’s 
glands. The exudate is taken with sterile cotton- 
tipped applicator sticks; the cotton tip should 
be small enough to enter easily the urethra and 
cervical os. Sometimes a platinum loop is found 
more suitable for taking the small amount of 
exudate from the urethra or cervix. 
For culture examination the exudate should be 
rolled out on part of the agar surface as soon 
as it is obtained. Care must be exercised in 
rolling the swab over the surface so as not to 
penetrate the relatively soft agar. If agar plates 
cannot be supplied to the clinician, the swabs 
may be introduced into sterile test tubes con- 
taining a little broth. 
The specimen should be sent at once to the 
laboratory. If the clinician inoculated the plates, 
they are further streaked in the laboratory or, if 
swabs are sent in carrying tubes, plates are im- 
mediately inoculated and streaked. The longer 
the time interval between collection and inocula- 
tion of the specimen on the culture medium, 
the greater the decrease in the number of 
positive cultures. If cultures are collected 
sporadically over a period of several hours, 
they should be placed in a closed candle ex- 
tinction jar. 
For the primary cultivation of specimens from 
the urethra, cervix, vagina, or rectum, the 
Thayer-Martin medium selective for gonococci 
is recommended. Antibiotic supplements of 
polymyxin B-ristocetin or of vancomycin-colis- 
tin-nystatin for use in the selective medium may 
be obtained from commercial sources. 
Subcultures of oxidase-positive colonies of gram- 
negative diplococci should be made on chocolate 
agar slants in screw-capped tubes and incubated 
for 18 to 24 hours in a candle extinction jar. 
After this time, if gram-negative diplococci in 
pure culture are present, the cap should be 
tightened and the tube mailed to the State health 
laboratory for identification or transmittal to 
the Venereal Disease Research Laboratory. 
7. Hemolytic Streptococcus Infections. Specimens 
usually submitted are material from the anterior 
nasal or nasopharyngeal areas, or from the 
throat, or pus, sputum, spinal fluid, discharges, 
exudates, urine, blood, and milk. The technic 
of swabbing an area to be cultured is as im- 
portant in the isolation of streptococci as is the 
cultivation of the specimen taken. In strepto- 
coccal infections of the upper respiratory tract, 
the organisms may be cultured from the nose or 
throat specimen. When the specimen is from the 
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