Efficacy of Experimental Inactivated Mycoplasma gallisepticum Oil-Emulsion Bacterin in Egg-Layer Chickens

Abstract

Six groups of white leghorn pullets were studied to determine the ability of beta-propiolactone-inactivated Mycoplasma gallisepticum (MG) oil-emulsion bacterins to counteract reductions in egg production caused by MG infection. The pullets were inoculated with 0.5 ml of MG bacterin subcutaneously in the neck at about 20 weeks of age and were challenged with MG near 28 weeks of age, when they were in peak egg production. Various challenge schemes with infectious bronchitis virus were used at the time of MG challenge to increase the reduction in egg production. MG bacterins afforded protection against moderate drops in egg production in at least three of the studies, where the unvaccinated challenged control hens exhibited reduced egg production.

Trial for preparation and evaluation of combined vaccine against ND, IB and M. gallisepticum diseases in chickens

“…Culturing, inactivation and vaccine preparation of M. gallisepticum. The seed culture was grown in Frey's media at 37 o C for 36-48 hours, then harvested by centrifugation at 13000 xg then resuspended in 0.01 M PBS (PH 7.2) to give a final concentration of 1x10 10 CCU/ml just prior to inactivation with Bpropiolacton using the methods described by Yoder and Hopkins, (1985). ND and IB bivalent vaccine.…”

A modified live Mycoplasma gallisepticum vaccine to protect chickens from respiratory disease

“…Killed, whole-cell M. gallisepticum bacterins do not prevent colonization of the chicken respiratory tract, but can reduce the severity of disease. These vaccines confer protection to chickens challenged with homologous strains, but are frequently ineffective against field strains [2][3][4][5][6][7][8][9]. This failure may in part be due to the organism's capacity to alter the expression of antigenic surface proteins (phenotypic variations), thereby providing a means of evading the host immune response.…”

Natural infection of ducks withmycoplasma synoviaeandmycoplasma gallisepticumandmycoplasmaegg transmission

“…It has been reported that specific maternal antibodies reduced mortality of embryonated chicken eggs, even though they did not prevent MG reisolation from yolk sac membrane (Levisohn et al, 1985). However, information concerning maternal antibodies of MG and MS in yolk are lacking and contradictory, even in chicken eggs (Devos et al, 1968;Yoder et al, 1985;Mohammed et al, 1986). During testing yolk preparations by RPA a few positive reactions to MG or by MS antigen were observed, while all parent duck sera were negative.…”