SESSION P 142 Mycoplasma gallisepticum isolates from chicken - flocks in Jordan and their relation to live vaccines

S OF PAPERS 235 larly and intranasally with virulent Ark virus on day 30. Necropsy was performed on day 35 and clinical signs, sera, and virus detection were analyzed. Vaccine replication was not detected in a significant number of broilers until day 24 post vaccination and SPF chickens until day 28 post vaccination. Following challenge, 14 of 20 SPF and 9 of 20 broiler chickens tested positive for virus by qRT-PCR. These data demonstrate poor vaccine virus replication resulting in poor protection from challenge, which is consistent with previous studies. This trial also shows that Ark vaccine will spread to other chickens in a flock, indicating that multiple peaks of vaccine replication seen in previous trials may be the result of multiple infections of vaccine virus.