Air Sac Lesion Scores Research Articles

Correlation of Titer, Preservation Method, and Storage of Mycoplasma gallisepticum F Strain and the Immune Response in Chickens

The F strain of Mycoplasma gallisepticum (MG) was used either fresh or after lyophilization or freezing at -60 C to vaccinate young leghorn chickens. Vaccine stored either frozen or lyophilized for 22 months was also used. Each vaccine preparation was given at dosages ranging from 10(5) to 10(9) colony-forming units/ml. All dosage levels of MG significantly (P less than 0.05) reduced air-sac lesion scores after aerosol challenge with the R strain of MG at 6 weeks postvaccination, regardless of the method of vaccine preservation or storage.

Infectious bronchitis and mixed infections of Mycoplasma synoviae and Escherichia coli in gnotobiotic chickens. I. Synergistic role in the airsacculitis syndrome.

The synergistic role of infectious bronchitis virus (IBV) and mixed infections of Mycoplasma synoviae (MS) and Escherichia coli (EC) in the airsacculitis syndrome was evaluated in gnotobiotic chickens. Relative air sac lesion score indexes, in descending order of severity, from various combinations of organisms were: 9.5-IBV, MS, EC; 6.8-IBV, EC; 4.5-IBV, MS; 2.7-IBV; and 0.5-MS, EC. Infectious bronchitis virus caused a mild fibrinous inflammation. M. synoviae combined with IBV increased heterophilic and follicular lymphoid infiltration and mortality. E. coli combined with IBV increased exudation and prolonged airsacculitis. Concentrations of fibrinogen, gamma globulin, and total plasma proteins were elevated significantly by combined infections of IBV, MS, and EC (P < 0.01).