Isolation and characterization of a 6/85-like Mycoplasma gallisepticum from commercial laying hens.
Eighty-three-week-old table egg layers with swollen sinuses were presented with a history of increased mortality. Serology revealed positive titers to Mycoplasma gallisepticum (MG). The birds were part of a flock in which some birds had been vaccinated with 6/85 live MG vaccine at 18 wk of age. Tracheal cultures were obtained from both vaccinated and unvaccinated birds within the flock. The cultures were indistinguishable from 6/85 vaccine by both random amplified polymorphic DNA analysis and DNA sequence analysis. Challenge studies were performed to compare the field isolates with 6/85 vaccine and the R strain of MG. The field isolates produced a greater antibody response by serum plate agglutination than did the 6/85 vaccine. The isolates effectively colonized the trachea without increasing the tracheal mucosal thickness; however, they did not extensively colonize the air sacs or cause airsacculitis in the experimental birds.
Throne Steinlage
S J
SJ
Department of Avian Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Ferguson
N
N
Sander
J E
JE
García
M
M
Subramanian
S
S
Leiting
V A
VA
Kleven
S H
SH
D000400:Air Sacs / Q000382:microbiology / Q000473:pathology; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000009:adverse effects* / Q000276:immunology; D002645:Chickens / Q000382:microbiology*; D005260:Female; D009174:Mycoplasma / Q000145:classification* / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D017422:Sequence Analysis, DNA; D014132:Trachea / Q000382:microbiology / Q000473:pathology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines