الفهرس 
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Abstract
Experimental infections were carried out in this study by using
haemophilus orgainsms . which were isolated from clinical coryza. to
evaluate their pathogenicity for chickens.
Two hundard and fifty six samples were collected from birds
suffering from swell head. from 79 flocks representing 400 thousands
birds of different ages • breeds and different localities in Sharika
province. during 26 month (Period of investigation) .
Results obtained under expermintal conditions mentioned could
be summerized in the following :
1 - Fifteen isolates were identified as Haemophilus paragallinarum on
the base of colonial morphology. biochemical characteristics. heat
stability test and serological tests (H I. slide AGG. tube AGGand
cross test ) . Results obtained revealed that 10 isolates belonged to
serotype I . while the other 5 isolates belonged to serotype 2 .
Three of these isolates were from uncompleeated cases . while the
other 12 isolates were complicated with other bacterial agents as
Bcoll, Staph and Pseudomonus On the other hand from the 64
floocks yielded no ”mop hilus organisms .The isolated organisms
were (E.coli . ltapla, Pseudomonus ,Proteous .•••monella, Arizona
andPasteurella).AltMuah sera from these flocks were reacted to Haemophilus paragallinarum antigens with 34.1 , .
2 - from this study it was observed that haemophilus infection
increased in spring than other season-Haemopallus organisms could
not be isolated during summer inspite of clinical cases observed
during this seson. Birds at the age of 2 to 4 months were highly
suseptabile to infection and most of these isolates were from flocks
having large population.
3 - Experimental infection was carried out to study the pathogenicity of
15 ftaemophilus isolates iI L.S.L. chickens. Chickens at age of 6
wks were inoculated intransally with 0:1 ml broth contaning
108 CPUI ml .tbird. Haemophilus isolates proved pathogenic)~
disease began to appear 12 hr post inoculation in form of swollen
head . nasal discharge . conjuncitivitis . palpepheritis and closed
eyes. The morbidity reached 92.6’ . while mortality rate was 4’ .
Gross lesions in sacrified birds were congestion and edema of m.m
of the nasal cavity and paranasal sinuses. Edema was seen also in
sIc tissue or periorbital region. Larynx and trachea shoved slight
congestion. The lunas and air sacs were apparenUy normal. The
average body weight shoved decreased in experimentally infected
than control birds.
4 - Pathogenicity or strain (020) to L.S.Lchickens was carried out at
ages or 2 .3. 4. 6. 8 and 10 wks. Signs or disease in bird. at 2.3 and
4 wks were simita’ . They were in the form of unilateral or
bilateral nasal discharge. distension or the infraorbital sinuses and
conjuncitivitis . The morbidity were 201 .401 and 80l,lrespectively.
while mortality were 8’ .8’ and 4’ respectively. The course of
the disease never excedded 9th day . Gross lesions at
these ages were congestion in m.m of the nasal cavity and
paranasal sinuses , contained watery exudate which turned to
mucoid in nature. Larynx. trachea. lungs and air sacs showed no
abnormalities.
The clinca! disease in birds infected at 6, 8 and 10 wks showed
facial swelling , nasal discharge and mouth breathing •
Conjuncitivitis . palpepheritis and closure of eyes in most cases.
Morbidity were 88’.96’ and 100’ respectively. While mortality
was not observed. Gross lesions were mainly observed in the nasal
cavity and paranasal sinuses . They were filled with watery
exudate which turned to mucoid. Their m.m. were congested and
edematous. Edema was also seen in the sIc tissue of periorbital
region . The m.m of the larynx and trachea showed slight
congestion, While lungs and air sacs remained normal.
5 - ThehaematOlogica1Pieture of experimentally infected chickens using
Haemophilus paragallinarum strain (020) at the ages of 2 . 3 • <4 • 6 ,
8 and 10 wks showed significant decreuein RBCscount (anemia)
and PC V at the level of P - 0.0 I on other hand leuctoc:ytosis was
significantally at level of P - 0.0 I (at ages of 2, 3 and <4 wb ) and
P -0.00 I ( at ages of 6 , 8 and 10 wb ) . Lymphopenia at level of
P - 0.05 and P-O.O I • 1leterophila at level of P- 0.01 and p_ 0.001 .
Monocytes , basophiles and eslnophlis showed no significant
incre.asr .
6 - HI and AGGresponseswere detected in sera of inoculated birds .
AGGantibodies appeared consistantly earler and higher values
than HI antibodies.
7 - Histopathologicalchanges observed in birds at the age of 2.3 and
4 wks were localized in nasal cavity . There were congestionof the
mucosal and submucosal Bl.vs,with infilteration of lymphocytes.
macrophages and few heterophils . Focal desquamation of lining
epithelium. The histopathological changes at the ages of 6. 8 and
10 wks were observed in nasal cavity and paranasal sinuses .
while Iarynr . trachea. lungs and air sacs showed no abnormalities.