Serological studies on mycoplasma gallisepticum infection in chickens

Abstract EN

One day old Mycoplasma free broiler was divided into 6 groups (grs) (each of 5 chickens).

The 1st gr.

used as control without any treatment, 2nd gr.

was infected 'with Mycoplasma gallisepticum (M.G.) S6 via the thoracic air sac on the 16th day of age and left till the end of the experiment (as infected control gr.), 3rd gr.

was infected on the 16th day then passively immunized by I / P injection of egg yolk antibodies (IgY), 4th gr.

was passively immunized I/P by (IgY) and infected with M.G., then passively immunized, 5th gr.

was vaccinated with the living vaccine (F-strain) of M.G.

then infected with M.G.S6 and the 6th gr.

was orally given the therapeutic dose of enrofloxacin in the drinking water for the 1st 5 days of age, then infected with M.G.S6 and the chickens were given another dose of enrofloxacin from 20th -25th day of age nd of the 1st, 2nd, 3rd and 5th weeks of age and from grs.

(2 and 3) at the aid of the 3rd and 5th weeks for serological, hematological and biochemical tests.

The lungs, trachea and air sacs were collected for the isolation of M.G.

The infected bird's gr.

(2) revealed Leukocytosis, heterophilia and monocytosis in the 3rd and 5m weeks of age.

There was a highly signififent increase in the AST, ALT, AP, Total proteins, globulin and uric acid.

The serum albumin was decreased, while the cretonne not significant changed.

The ELISA showed positive values as early as the 5th day post infection (PI) till the end of the experiment.

The result of serum plate agglutination test (SPA) illustrated 3/5 and 5/5 at the end of the 3rd and 5 weeks of the.

a^ge respectively.

The Pulmonary tissue was congested and showed focal pneumonic areas.

The passively immunized birds of gr.

(4), before infection, showed non-significant change in leukogram but there are a significant increase in the total protein and globulin at the end of the 2nd week.

There was a positive result of the EILSA due to the injected (Ig).

The SPA was 0/5 and 0 / 5 in the 1st and 2nd weeks of age respectively.

The passively immunized and infected chicken's grs.

(3&4) showed similar results to gr.

(2) at the end of the 3rd week.

All the parameters returned to nearly the normal value in the 5th week of age except for a significant increase in the serum total protein and globulin.

The ELISA showed a positive result in the 3rd and 5th weeks of age.

The SPA showed 3 / 5 and 2 / 5 in grs.

(3&4) respectively r th in the 3rd week and 1/5 in the 5m week of age in both grs.

The actively immunized birds of gr.

(5) Showed leukocytosis, heterophilia, r th nd 3rd and rth Lymphocytosis and monocytosis at the end of the 1, 2 weeks of age.

All the parameters were not significantly changed except the total proteins and globulin which showed highly significant increase.

The ELISA was gradually increased from the 2n till the 5th week of age.

The SPA showed 0 / 5, 1 / 5, 4 / 5 and 5 / 5in the 1st, 2na, 3ra and 5m weeks of age respectively.

The enrofloxacin treated birds gr.

(6) before infection especially at the end of the 1st week of age, showed leukopenia, heterophilia, lymphopenia and a significant increase in AST, ALT, AP, uric acid and cretonne.

Meanwhile, the serum total proteins, albumin and globulin were non-significantly changed.

The ELISA showed non-significant change.

The SPA is 0/5in the 1st & 2nd weeks of age.

The enrofloxacin treated bird's gr.

(6) after infection and at the end of the 3rd week of age showed similar hematological finding to gr.

(2) at the end of the 5th week of age.

All parameters nearly regained to their normal values except for a significant increase in the total proteins and globulin.

The ELISA showed a significant increase.

The SPA was 3 / 5 and 1 / 5 at the end of the 3rd & 5th weeks respectively.

The chickens which were sacrificed at the end of the 3rd week, revealed focal hemorrhage in the lung and serofibrinous exudates.

It is recommended to vaccinate the chickens with F-strain living vaccine of M.G.