Comparison of the short-term and long-term efficacies of the Mycoplasma gallisepticum vaccines ts-11 and 6/85.

In order to compare the short-term efficacies of the live attenuated Mycoplasma gallisepticum (MG) vaccine strains ts-11 and 6/85, four groups of SPF chickens were vaccinated with each of the vaccines using eye drop and aerosol inoculations, and were subsequently challenged with a wild-type MG strain. When administered by the recommended routes (eye drop for ts-11 and fine aerosol for 6/85), both vaccines induced substantial and comparable levels of protection against airsacculitis and tracheitis caused by wild-type MG. The long-term efficacies of the two vaccines administered by the recommended route were also assessed.

Safety and efficacy of the Mycoplasma synoviae MS-H vaccine in turkeys.

The live, attenuated, temperature-sensitive Mycoplasma synoviae (MS) vaccine strain MS-H is used to control virulent MS infection in commercial chicken flocks. However, the safety of this vaccine and its potential to prevent disease in turkeys have not been investigated. In this study, MS-H was shown to colonize the upper respiratory system and to induce an antibody response in turkeys but, even at the maximum release dose, was not found to cause air sac, joint, or tracheal lesions typical of wild-type MS infection.

Duration of immunity with Mycoplasma synoviae: comparison of the live attenuated vaccine MS-H (Vaxsafe MS) with its wild-type parent strain, 86079/7NS.

The duration of protective immunity elicited by the MS-H vaccine was evaluated by experimental challenge of chickens at 15 and 40 wk after eyedrop vaccination. Immunity induced by the parent strain of the vaccine, 86079/7NS, was also investigated for comparison. A serological response to Mycoplasma synoviae was detected in 89% to 100% of MS-H vaccinates and 86079/7NS inoculates at 15, 27, 30, 35, and 40 wk after inoculation.

Determination of the effective dose of the live Mycoplasma synoviae vaccine, Vaxsafe MS (strain MS-H) by protection against experimental challenge.

The minimum effective dose of the Mycoplasma synoviae-H (MS-H) vaccine was determined through protection against experimental challenge. Chickens were vaccinated by eyedrop with the following doses of a vaccine: 1.2 x 10(5), 2.

Onset of immunity with Mycoplasma synoviae: comparison of the live attenuated vaccine MS-H (Vaxsafe MS) with its wild-type parent strain (86079/7NS).

The onset of protective immunity with MS-H was determined through experimental challenge and compared with the parent strain 86079/7NS. MS-H vaccinates and 86079/7NS inoculates were challenged at 1, 2, 3, 4, 5, and 6 wk after vaccination, then examined 2 wk after challenge for signs of respiratory disease. Serologic results indicated that 100% of MS-H vaccinates had antibodies to MS by 3 wk after vaccination and 100% of 86079/7NS inoculates were positive by 2 wk after inoculation.

Evaluation of the non-temperature-sensitive field clonal isolates of the Mycoplasma synoviae vaccine strain MS-H.

The live attenuated temperature-sensitive (ts+) Mycoplasma synovia (MS) strain, MS-H, is used as a vaccine in a number of countries to control virulent MS infection in commercial chicken flocks. Nine out of 50 isolates made from flocks vaccinated with MS-H were found to have lost the ts+ phenotype of the original vaccine strain. In order to examine the influence of the ts- phenotype on virulence of the isolates, four of the ts- isolates, the MS-H vaccine, and the vaccine parent strain 86079/7NS were administered by aerosol in conjunction with infectious bronchitis virus to 3-wk-old specific-pathogen-free chickens.

Improved detection of antibodies to Mycoplasma synoviae vaccine MS-H using an autologous recombinant MSPB enzyme-linked immunosorbent assay.

Mycoplasma synoviae is a poultry pathogen causing respiratory disease and synovitis. An indirect enzyme-linked immunosorbent assay (ELISA) has previously been devised in our laboratory using the major membrane antigen MSPB of M. synoviae strain WVU 1853 as antigen.

Detection of antibodies to Mycoplasma gallisepticum vaccine ts-11 by an autologous pMGA enzyme-linked immunosorbent assay.

Mycoplasma gallisepticum is a poultry pathogen that causes respiratory disease and loss of egg production worldwide. A live attenuated vaccine, ts-11, has been used for control of M. gallisepticum in several countries.

Mycoplasma synoviae surface protein MSPB as a recombinant antigen in an indirect ELISA.

Mycoplasma synoviae is a poultry pathogen causing respiratory disease and synovitis. A number of serological assays have been developed for diagnosis of M. synoviae infection; however, they lack sensitivity and/or are prone to false-positive reactions.

Size and genomic location of the pMGA multigene family of Mycoplasma gallisepticum.

The pMGA multigene family encodes variant copies of the cell surface haemagglutinin of Mycoplasma gallisepticum. Quantitative Southern blotting, using an oligonucleotide probe complementary to a region conserved in the leader sequence of all known pMGA genes, was used to estimate the number of members of the family in the genome of seven strains of M. gallisepticum.