BORDET GENGOU AGAR BASE
INTENDED USE
Border Gengou Agar Base, with the addition of glycerol and sterile blood, is
used in qualitative procedures for the detection and isolation of Bordetelia
pertussis from clinical specimens. The medium is rendered selective by the
addition of methicillin.
SUMMARY AND EXPLANATION OF THE TEST
Bordet Gengou Blood Agar is used in clinical laboratories as a method of
diagnosing whooping cough. Bordetella pertussiss, the etiologic agent of this disease, may be isolated on cough plates, from nasopharyngeal swabs and other sources of pharyngeal exudate,'Border and Cengou introduced the medium in 1906 as a method of maintaining stock cultures.2 In 1934, Kendriclc and Eldering
replaced the 50% human or rabbit blood recommended in the original for-
rnulation with 15% sheep blood to make the medium more practical for
laboratories to produce for routine clinical procedures.3
PRINCIPLES OF THE PROCEDURE
Bordet Gengou Blood Agar is an enriched, casein peptone medium with potato
infusion and glycerol to supply the nutrients necessary to support the growth of 8. perwssis. Defibrinated sheep blood supplies additional nutrients and enables the
detection of heniolytic reactions, which aid in the identification of B. pertussis.
CLASSICAL FORMULA PER LITER PURIFIED WATER
Potato. Infusion from (Solids) 4.5G
Pancreatic Oigcst of Casein 5.0
Peptic Digest of Animal Tissue 5.0
Sodium Chloride 5.5
Agar 20.0
*Adjusted and or supplemented as required to meet performance criteda.Final
pH 6.7 S 0.2
Prepare plates of Bordet Gengou Blood Agar contain both additives (10.0 mIll
of glycerol and 15% defibrinated sheep blood).
USER QUALITY CONTROL
Bordet Gengou Blood Agar
Borderella pertussis (ATCC 9797) - Moderate to heavy growth. Weak to strong
beta hemolysis with hazy to clear zones.
Streptococcus pneumonia (ATCC 6305) - Moderate to heavy growth. Alpha
hemolysis.
PROCEDURE
If agar deeps of Border Gengou Apr Base are being
used, prepare plated medium in the following manner. Liquefy the
medium in boiling water. Cool to 45 to 5O C. Add 3 ml of sterile
detibrinated sheep blood to each tube, mix well and pour into sterile
Petri dishes. Allow to solidify for a minimum of 30 mm.
Inoculate the medium as soon as the specimen arrives at the lab-
oratory. To culture specimens from swabs on agar plates, inoculate
the medium by rolling the swab over a third of the apr surface and
streak the remainder of the plate to obtain isolated colonies. Material
not being cultured from swabs may be streaked onto the medium with
a sterilized inoculating loop. The streak plate technique is used primarily
to obtain isolated colonies from specimens containing mixed flora.
Incubate plates in an inverted position (agar side up) in a moist
chamber at 35 ± 2'C for 7 days. Examine the plates daily with and without a
dissecting microscope (oblique illumination) to detect the
presence of Oordeteila pertussis and spreading colonies or molds that
could mask the presence of this species. Use a sterile scalpel or needle
to remove the portions of the apr that contain spreading colonies or
molds. Colonies of 8. perrussis may not be visIble without the aid of
a microscope for 2 to 4 days. Plates may be discarded as negative
after incubation for 7 days.
EXPECTED RESULTS After sufficient incubation, the plates should
show isolated colonies in streaked areas and confluent growth in areas
of heavy inoculation. Bordetella pertussis produces small, domed, glistening colonies that resemble bisected pearls. The colonies are usually surrounded by a
zone of homolysis; however, some strains of 8. perrussis are not he-
molytic. Gram stains, biochemical tests and serological procedures
should be performed to confirm findings.
REFERENCES
1.
Parker and Payne. 1955. in Lennene. Balows. Hausler and Shadumny (ed).
Manual ot clinical microbiology, 4th ed. MM, Washington, D.C.
2.
Bordet and Gengou. 1906. Ann. Inst. Pasteur 2O~.731.
3.
Kendrick and Eldering. 1934. Am. I. Public Health 24:309.
BBL' CATALOG NO. ORDERING INFORMATION:Bordet Gengou Apr Base
Cat. No. 11050 Dehydrated-lCD g11051 Dehydrated-SOC g97876
Prepared Plates with Glycerol and 15% Sheep
Blood-Pkg. of 1097877
Prepared Plates with Glycerol, 15% Sheep
Blood and Methicillin-Pkg. of 1020832
Prepared Tubes-Pkg. of 10Apr
TOTAL P.02
|