STUDIES ON THE ADAPTATION OF INFECTIOUS BRONCHITIS VIRUS OF CHICKENS TO MICE

98 Pages·3.851 MB·English

by  SHIPKOWITZ, NATHAN L

STUDIES ON THE ADAPTATION OP INFECTIOUS
BRONCHITIS VIRUS OP CHICKENS TO MICE
By
Nathan L« Shipkowitz
A THESIS
tibmitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of
DOCTOR OP PHILOSOPHY
Department of Bacteriology and public Health
Year 1952
STUDIES ON THE ADAPTATION OP INFECTIOUS
BRONCHITIS VIRUS OP CHICKENS TO MICE
By
Nathan L. Shipkowitz
AN ABSTRACT
Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of
DOCTOR OP PHILOSOPHY
Department of Bacteriology and Public Health
Year 19^2
X
Approved ♦
/
Nathan L. Shipkowit
This study was undertaken in an attempt to ascertain
if the virus of infectious bronchitis of chickens is capable
of growing in Swiss albino mice. The importance of such
a study is that experimentally produced virus variants have,
in many instances, resulted in a reduction in the virulence
without drastically altering its antigenicity, so that the
new strain could serve as a protective agent against the
original virulent form of the virus.
Chicken-propagated and egg-propagated strains of the
undiluted and diluted virus were carried through six intra­
nasal mouse-passages. The lungs in the first two passages
showed slight congestion. The lungs in the last four
passages were normal. The embryo mortality was negligible
indicating that the virus was no longer present in the lungs
and that the virulence of the virus for mice did not
increase as the serial mouse-passage was continued.
The experiments to determine the exact time the
undiluted egg-strain of the virus could be retained after
intranasal inoculation of mice indicated that the virus
would persist in the lungs for 12 hours but not for 16 hours.
It was possible to carry the egg strain of the virus
•through three mouse-passages by use of the alternate
("zig-zag”) intranasal passage. The virus was passed
through mice, then eggs, and then back through mice. The
virus persisted for a period of 17 hours in the third
mouse-passage o
In the experiments to determine whether variation in
Nathan L. Shipkowitz
the routes of inoculation would aid in the adaptation of
the undiluted egg strain of the virus it was found that folloxtfing
the intraperitoneal, intravenous, and intracerebral routes;
the virus could not be recovered*
Serial intranasal passage of both strains of the virus
through three-day old suckling mice indicated that the
virus was unable to be retained,.
The experiments to determine the length of time both
strains of the virus could be retained by intranasal
inoculation into three-day old suckling mice, indicated
that the virus could not be retained in the lungs«
This work is
respectfully dedicated
to
MY PARENTS
ACKNOWLEDGMENTS
The author wishes to express his deep appreciation
to Dr. C. H. Cunningham for his advice and encouragement
throughout this study.
The author also wishes to thank Dr. H. J. Stafseth
for his help and constructive criticism.
Technical assistance by Mrs. Martha P. Spring during
various phases of this problem is gratefully acknowledged0
TABLE OP CONTENTS
Page
INTRODUCTION ......................................... 1
REVIEW OP LITERATURE................ ................ 2
Variation........................................... 2
Natural variation. . . . . .................. •• 2
Experimental variation .......................... 2
Yellow fever...........* ..................... 2
Poliomyelitis ........ .................... 2
Influenza ............................... 3
Homologous serum jaundice • • • • ........ »o 3
Newcastle disease . . • • ................ . .
k
Powl plague ............ . . . . . . . . . . . k
Infectious Bronchitis of Chickens........... . . • • k
Historical . . . « • ................ •
Symptoms........ ................................ k5
Pathology. . . . . . . . ........... . . . . . . . 5
Geographical distribution......................... 6
Etiology ............ ...................... 6
Physical and chemical studies on infectious
bronchitis virus...................... ........ 7
Temperature........... ........................ 7
Chemical agents ............................... 7
pH......................... 8 . . . .
Distribution in the host .................... .. 8
Transmission of the virus.................... .. 8
Cultivation of infectious bronchitis virus in
embryonating eggs • ............ . . . . . . . 10
Immunity.............................. .. 12
Diagnosis.............................. .. 13
MATERIALS AND METHODS................................. 15
Strains of Virus...................... ............ 15
Mice.................... ...................... 17
EXPERIMENTAL ......................................... 18
Serial Passage of the Virus........................ 18
Survival of Chicken-propagated Strain of Infectious
Bronchitis Virus in Mice................. . . » • 26
Survival of Egg-propagated Strain of Infectious
Bronchitis Virus in Mice -I .................... 32
Survival of Egg-propagated Strain of Infectious
Bronchitis Virus in Mice - II• * ................ 39
Survival of Egg-propagated Strain of Infectious
Bronchitis Virus in Mice - III • • • • .......... i+2
TABLE OF CONTENTS CONT.
Page
Survival of Egg-propagated Strain of Infectious
Bronchitis Virus During Serial Passage in Mice . 8 46
Alternate (Zig-Zag) Passage Through Mice and
Embryonating Eggs Using Egg-propagated and
Chicken-propagated Strains of Infectious
Bronchitis Virus •• 53
Serial Passage and Variation in the Routes of
Inoculation Using Egg-propagated strain of
Infectious Bronchitis Virus. 60
Determining the Length of Time Egg-propagated
and Chicken-propagated Strains of Infectious
Bronchitis Virus are Retained by Baby Mice . . • • 66
Determining the Survival Time Egg-propagated
and Chicken-propagated Strains of Infectious
Bronchitis Virus are Retained During Serial
Passage in Baby Mice.............. 71
RESULTS AND DISCUSSION . ......................... 77
SUMMARY AND CONCLUSIONS.................................83
REFERENCES............................ 85
INTRODUCTION
This study was undertaken in an attempt to ascertain
if the virus of infectious bronchitis of chickens is
capable of growing in the Swiss albino mouse, The mouse
was used since it Is a convenient and readily available
laboratory animal.
The importance of such a study is that experimentally
produced virus variants have, In many instances, resulted
in a reduction in the virulence without drastically
altering its antigenicity, so that the new strain could
serve as a protective agent against the original virulent
form of the virus#
REVIEW OP LITERATURE
Variation
Natural variation
The extent to which virus variation occurs in nature
is not known, but, it has been repeatedly demonstrated
that the properties of viruses can be experimentally changed
by altering the environmental conditions«
A natural variation occurs between the eastern and
western strains of equine encephalomyelitis virus» The
strains differ in virulence and are not immunologically
related. Cross protection does not occur (59)*
Experimental variation
Yellow fever. Yellow fever virus, which is not usually
pathogenic for mice, is an important example of an experi­
mentally produced variant. After repeated intracerebral
passage in mice the variant produced has an enhanced affinity
for nervous tissue, but greatly reduced pathogenicity for
the original host by subcutaneous or intraperitoneal in­
jection (33, 63).
Poliomyelitis. In 1937 a sample of brain and spinal
cord from a boy who had died of bulbar poliomyelitis in
Lansing, Michigan was put through 15 monkey passages.
Several species of rodents, including a cotton rat, rat,