Systemic Mycoplasma synoviae infection in broiler chickens

Figures & data

Figure 1. 1a: Subcutaneous, diffuse accumulation of fibrinous exudate in and around the keel bursa of a broiler chicken carcass infected with M. synoviae. 1b: Extensive localized accumulation of caseous exudate in the keel bursa of a 47-day-old broiler chicken infected with M. synoviae.

Figure 2. Enlarged liver with greenish tinge and scattered pale reticular pattern from a 47-day-old broiler chicken infected with M. synoviae.

Figure 3. Enlarged mottled spleen of a 47-day-old broiler chicken infected with M. synoviae.

Table 1. Frequency and severity of gross lesions associated with M. synoviae in selected organs of broiler chickens

	Severity of lesions
Lesion	+	+%	++	++%	+++	+++%
Keel bursitis	8	15	21	39	20	37
Synovitis	–	–	5	9	–	–
Tracheitis	11	20	–	–	–	–
Airsacculitis	–	–	5	9	5	9
Pericarditis	1	2	1	2	3	6
Hepatitis	–	–	14	26	6	11
Splenitis	–	–	6	11	9	17
Nephritis	3	6	3	6	5	9
Number of birds examined=54. +, mild; ++, moderate; +++, severe.

Table 2. Relative frequency and severity of microscopic lesions associated with M. synoviae in selected organs of broiler chickens

		Severity of lesions
Lesion	Sections examined	+	+%	++	++%	+++	+++%
Keel bursitis	57	1	2	10	18	31	57
Synovitis	17	–	–	2	12	5	29
Hepatitis	47	13	28	10	21	19	40
Splenitis	22	–	–	10	45	12	55
Tracheitis	26	5	19	10	38	2	7
Airsacculitis	9	–	–	–	–	9	100
Pneumonia	15	4	27	3	20	1	20
Nephritis	21	8	38	5	24	1	5
Encephalitis	8	–	–	2	25	2	25
Conjunctivitis/choroiditis	6	–	–	3	50	3	50
+, mild; ++, moderate; +++, severe.

Figure 4. 4a: Keel bursa from a 47-day-old broiler chicken infected with M. synoviae showing severe perivascular cuffing (arrows) by mononuclear inflammatory cells. Haematoxylin and eosin, bar=200 μm. 4b:Higher magnification of one field from 4a showing in more detail prominent endothelial cells and infiltration by lymphocytes, a few plasma cells and macrophages in and around a blood vessel. Haematoxylin and eosin, bar=50 μm.

Figure 5. Liver from a 47-day-old broiler chicken infected with M. synoviae, showing prominent and vacuolated endothelial cells and infiltration by lymphocytes, a few plasma cells and macrophages in and around a blood vessel. Haematoxylin and eosin, bar=75 μm.

Figure 6. Brain from a 47-day-old broiler chicken infected with M. synoviae, in which there is infiltration of primarily lymphocytes in and around the blood vessel. Haematoxylin and eosin, bar=85 μm.

Figure 7. Choroid (*) of the eye from a 47-day-old broiler chicken infected with M. synoviae, in which there is infiltration of lymphocytes mixed with a few plasma cells. Haematoxylin and eosin, bar=100 μm.

Figure 8. RAPD analysis of M. synoviae isolates. Lanes 1 and 2, isolates from 47-day-old broiler chickens; lanes 3 and 4, isolates from 33-day-old to 39-day-old broiler chickens; lane 5, isolate from a turkey; lane 6, isolate from a broiler breeder; lane 7, MS-H reference strain; lane 8, WVU 1853 reference strain; lane 9, F10-2AS reference strain; lane 10, negative control; lane 11, 100 base pair ladder.