M. Zamri-saad et Hr. Mera, The effect of Pasteurella haemolytica A2 infection on phagocytosis efficiency of caprine broncho-alveolar macrophages, J VET MED B, 48(7), 2001, pp. 513-518
Citations number
21
Categorie Soggetti
Veterinary Medicine/Animal Health
Journal title
JOURNAL OF VETERINARY MEDICINE SERIES B-INFECTIOUS DISEASES AND VETERINARYPUBLIC HEALTH
An experiment was designed to study the in vivo effect of Pasteurella haemo
lytica A2 infection on the phagocytosis activity of caprine broncho-alveola
r macrophages and the extent of pneumonic lesions. Twelve healthy local Kac
ang goats, about 7 months of age, were divided into two groups of six. Goat
s in group 1 were inoculated intratracheally with 4 ml inoculum containing
2.8 X 10(9) colony-forming units (CFU)/ml of Staphylococcus aureus. Goats i
n group 2 were inoculated intratracheally with 4 ml of inoculum containing
9.5 X 10(8) CFU/ml of Pasteurella haemolytica A2 isolated earlier from pneu
monic lungs of goat. At intervals of 3 and 7 days post-challenge five goats
from each group were killed and the lungs were washed with sterile phospha
te-buffered saline, Smears were prepared from the lung washing fluid and th
e number of macrophages with phagocytic activity was determined, At day 3 p
ost-infection, goats of both groups showed a similar pattern of pneumonic l
esion. The lung washing fluid of goats in group 2 was found to contain nume
rous neutrophils and macrophages. Goats in group 2 showed significantly (P
< 0.05) higher extent of lung lesions than group 1, Similarly, the average
extent of lung lesions was significantly (P < 0.05) more severe in group 2
at day 7 post-infection. The lung washing fluid contained mostly macrophage
s. The phagocytic activity following S. aureus infection was more efficient
and significantly (P < 0.01) higher compared with infection by P. haemolyt
ica A2. There were weak correlations between the extent of pneumonic lesion
and the phagocytic activity. Thus, goats with poor phagocytic activity wer
e likely to develop more extensive lung lesions.