) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
University of Baghdad
College Name
College of science
Department
Department of biology
Full Name as written
in Passport
Dr. Samir abdul amir abid ali alash
e-mail
Sameer_alash@yahoo.com
Career
Assistant Lecturer
Master
Thesis Title
Year
Abstract
.
=

Assistant
Lecturer
Professor
PhD
Professor
Role of Staphylococcus aureus cell wall protein A in the
pathogenesis of the bacteria
27 – 1 - 2009
aureus by "API – Staph . Ident . System". which were taken from the
central health laboratory . The diagnosis was repeated so as to confirm the
identity of those isolates by using biochemical tests whose results were the
same as those of the central health laboratory .
The haemagglutination test was used to investigate the presence of
protein ( A ) in all S . aureus isolates . The results markedly showed
differences in content concerning the ratio of this protein , thus isolates
numbered 1 , 5 , 6 , 7 and 9 gave high content of protein ( A ) , but the
isolates numbered 8 , 10 , 11 , 12 , 13 , 14 , 15 , 17 , 18 , 19 and 20 gave
medium content of protein ( A ) . Isolate numbered 16
was the only
isolate that has low content of protein ( A ) . On the other hand , isolates
numbered 2 , 3 and 4 gave no content of protein ( A) .
The isolate number ( 1 )has been chosen as an optimal isolate to
accomplish this study , Because of its high content of protein ( A ) ,
furthermore it was the best isolate in getting positive result concerning the
test of coagulase production , and in giving a complete and intensive result
concerning the test of hemolysin production .
Crude protein ( A ) was extracted by two steps :
Lind method ( Lind , 1974 . ) "Suspending in sodium azide" was followed
at the first step as an easy and a cheap method in getting a thorough cell –
bound protein ( A ) extracted from the isolate number ( 1 ) with high
preservation of the structural unit without any deformation .
The Seki et al .,( 1985 ) method was followed in the second step as a
completion method to the first one , by the precipitate of the supernatant
protein ( A ) using ammonium sulfate ( 85 % saturation ) . The function
of precipitated protein ( A ) was perfect .
In order to get a purified protein ( A ) extract from crude protein A ,
purification was accomplished by two
steps : Ion – exchange
chromatography by DEAE – cellulose column was used in the first step ,
) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
While Gel – filtration chromatography by Sepharose CL – 6B column was
used in the second step .
Double immunodiffusion in gel was used to investigate the preservation
of the crude and purified protein ( A ) with its full function . This test gave
a positive result by forming the precipitate lines as a result of the
interaction between protein ( A ) ( Crude and Purified ) and IgG of
guinea pig sera .
Bradford method was used to estimate protein ( A ) extracts
concentration ( Crude , Partial purified , Purified ) . The estimation was
63 microgram / ml for crude extract , 42 microgram / ml for partial
purified extract and 36 microgram / ml for purified extract .
white mice ( Balb C ) were used to investigate the pathogenic effects of
purified protein ( A ) . Intraperitonial injection method was used to inject
0.1 ml of 36 microgram / ml of purified protein ( A ) for 7 times with a one
- day separating period .
The injected mice with purified protein ( A ) showed general weakness
which was very clear after the sixth injection . there were no phenotypic
dermal change in the injection area , and no dead mice as well .
After killing and dissecting of all the mice , the organs of heart , spleen ,
liver , kidney , intestine , stomach and lung were eradicated . There were a
great enlargement in spleen and a little in liver in all injected mice in
comparison with the control mice . No phenotypic changes appeared in
heart , intestine and stomach , but black spots were shown on the outer
surface of kidney and liver tissue which were presented in all the injected
mice .
The most important results in this study is the great size of pathogenic
effects in lung . The shape of its tissue seemed strange and tended to be
faint black with which was obvious in seven mice . The lung of the three
others ( some parts ) showed during anatomy covered by blood .
The histological check for heart , intestine and stomach showed no
pathogenic effects resulted from protein ( A ) injection . In the spleen ,
there was a huge expanding in the white pulp region , with blood
congestion while the spreading of megacaryocytes has increased . The liver
showed mild degenerative change in liver cells with monocytes infiltration
especially in the entrance region which appeared expanded . Also there
was an increase in kupffer cells in all liver tissue .Kidney showed increase
in mesengial cells which are concedered the forming units of glomeruli .
The histological check of lung included the following :
1- Bloody congestions .
2- Oedema .
3- Inflammatory cells infiltration .
4- Alveolar spaces expanding forming '' Emphysema '' .
The lung was the most effected organ that showed tissue injury among
other all organs .
The normal cell lines – culture technique was followed to investigate
cellular toxicity of the purified protein ( A ) which gave a negative result ,
that means , there was no toxic effect of purified protein ( A ) on the
growth cells .