Universlty of Manitoba, ln Partîal Fulfiìlment - MSpace at the ...

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5.4 BACTERt4L CUTTURE 0F UlNpohrEp EGGS
One of the hazards of the windowing technic is the possibîlity of
acquired infection, which might play a role Ín the teratogen¡c action
of ân introduced air space. Furthermore, one of the hypotheses to
account for the pathogenes¡s of anencephaly s.uggests thât it may result
from an extensive întra-uterine encephalomyel îtis (Brouwer, t9l6).
For both these reasons the sterility of the standard wîndowing
techníc was assessed by making aerobic cultures of albumen on bloodagar
ât the times of windowing (26 hours) and of fixation (72 hours).
Bacterial cultures were taken from experimentêl eggs wíth embryos
shovring early death and necrosis, as wel I as those developing to later
stages' The control eggs were only cultured at the time of fixation.
Examínation of the plates after A days growth at 3go0 reveôled
some colonies on the track smeared by the wire loop,and some on background
areas of the medium (which were regarded "a
contaminants).
"¡a-uoan.
Tables 20 e 2_1: show that the rnortal ity and malformations rêtes in
experîmental (windowed) and control embryos at 72 hours correspond to
those in other exper¡ments. ln Table 22 a number of blood-agar plates
show Oorynebacterium colonies as background contam¡nants. There is no
evídence of significant ínfection in wíndowed eggs.