Mechanisms of vaccine protection in chickens against challenge with virulent Mycoplasma synoviae.

The Vaxsafe MS vaccine is used globally to control infections with Mycoplasma synoviae (MS) in commercial poultry. It provides long-term protective immunity against airsacculitis and tracheitis caused by M. synoviae.

Characterisation of the tracheal transcriptional response of chickens to chronic infection with Mycoplasma synoviae.

Mycoplasma synoviae causes infectious synovitis and respiratory tract infections in chickens and is responsible for significant economic losses in the poultry industry. Effective attachment and colonisation of the trachea is critical for the persistence of the organism and progression of the disease it causes. The respiratory tract infection is usually sub-clinical, but concurrent infection with infectious bronchitis virus (IBV) is known to enhance the pathogenicity of M.

Evaluation of the safety and efficacy of the novel Mycoplasma gallisepticum vaccine, Vaxsafe MG304, after spray-vaccination of 1-day-old specific pathogen-free chicks.

Mycoplasma gallisepticum causes chronic respiratory disease in poultry. A novel vaccine, Vaxsafe MG304 (the ts-304 strain), has greater protective efficacy in chickens than the Vaxsafe MG (strain ts-11) vaccine when delivered by eye drop at 3 weeks of age. Applying this vaccine in the hatchery to 1-day-old birds, using mass administration methods, would improve animal welfare and reduce labour costs associated with handling individual birds.

Transcriptomic analysis of the effects of tylosin on the protective immunity provided by the Mycoplasma gallisepticum vaccine Vaxsafe MG ts-304.

The antimicrobial tylosin is commonly used to control mycoplasma infections, sometimes in combination with vaccination. However, the efficacy of a live mycoplasma vaccine, when combined with subsequent antimicrobial treatment, against the effects of subsequent infection with a virulent strain is unknown. This study employed differential gene expression analysis to evaluate the effects of tylosin on the protection provided by the live attenuated Vaxsafe MG ts-304 vaccine, which has been shown to be safe and to provide long-term protective immunity against infection with Mycoplasma gallisepticum.

Virulence factors of : Three genes influencing colonization, immunogenicity, and transmissibility.

Infections caused by are major welfare and economic concerns in poultry industries worldwide. These infections cause chronic respiratory disease and/or synovitis in chickens and turkeys leading to reduced production and increased mortality rates. The live attenuated vaccine strain MS-H (Vaxsafe MS), commonly used for protection against infection in many countries, contains 32 single nucleotide variations compared to its wildtype parent strain, 86079/7NS.

Effects of administration of tylosin on the duration of protective immunity induced by the novel Mycoplasma gallisepticum vaccine strain, Vaxsafe MG ts-304, in chickens.

Prophylactic use of antimicrobials after administration of live vaccines is a common practice in the poultry industry, but the impact of this on the efficacy and duration of protection induced by the vaccines is unknown. The effect of treatment with tylosin on the efficacy of vaccination with the live attenuated M. gallisepticum strain, Vaxsafe MG ts-304, was examined.

Evaluation of the MilA ELISA for the diagnosis of herd infection with Mycoplasma bovis using bulk tank milk and estimation of the prevalence of M. bovis in Australia.

Infection with Mycoplasma bovis has been identified as a growing threat in dairy industries worldwide and there is an urgent need for an inexpensive and accurate herd-level screening tool to identify herds that have been exposed to M. bovis. This study aimed to evaluate the use of the MilA ELISA for testing bulk tank milk (BTM) samples for antibodies against M.

Mucosal immune responses in the trachea after chronic infection with Mycoplasma gallisepticum in unvaccinated and vaccinated mature chickens.

Tracheitis associated with the chronic respiratory disease in chickens caused by Mycoplasma gallisepticum is marked by infiltration of leukocytes into the mucosa. Although cytokines/chemokines are known to play a key role in the recruitment, differentiation, and proliferation of leukocytes, those that are produced and secreted into the trachea during the chronic stages of infection with M. gallisepticum have not been described previously.

Effects of immunosuppression on the efficacy of vaccination against Mycoplasma gallisepticum infection in chickens.

Immunosuppression can increase the susceptibility of chickens to other disease-causing pathogens and interfere with the efficacy of vaccination against those pathogens. Chicken anaemia virus (CAV) and infectious bursal disease virus (IBDV) are common causes of immunosuppression in chickens. Immunosuppression was induced by experimental infection with either CAV or IBDV to assess the effect of immunosuppression on the efficacy of vaccination with Mycoplasma gallisepticum strain ts-304 against infection with virulent M.

Transcriptomic Analysis of Long-Term Protective Immunity Induced by Vaccination With Strain ts-304.

Live attenuated vaccines are commonly used to control infections in chickens. ts-304 is a novel live attenuated vaccine strain that has been shown to be safe and effective. In this study, the transcriptional profiles of genes in the tracheal mucosa in chickens challenged with the wild-type strain Ap3AS at 57 weeks after vaccination with ts-304 were explored and compared with the profiles of unvaccinated chickens that had been challenged with strain Ap3AS, unvaccinated and unchallenged chickens, and vaccinated but unchallenged chickens.

Duration of protective immunity induced by Mycoplasma gallisepticum strain ts-304 vaccine in chickens.

Mycoplasma gallisepticum (MG) is an important pathogen of poultry worldwide, causing chronic respiratory disease in chickens and turkeys. MG ts-304 is a GapA positive clone recovered from Vaxsafe MG (strain ts-11) that has been shown to be safe in chickens when delivered by the eye drop route to 3-week-old specific-pathogen-free chickens and to confer protection against challenge at 4 weeks after vaccination, as measured by tracheal mucosal thickness and air sac lesion scores. In this study, specific pathogen-free chickens (SPF) were vaccinated with a single dose of the MG ts-304 vaccine (10 colour changing units) at 3 weeks of age and experimentally challenged by aerosol with the virulent M.

Mycoplasma gallisepticum strain ts-304 is a safe and effective live attenuated vaccine for use in chickens.

Vaxsafe MG (strain ts-11) is a live attenuated vaccine against the important poultry pathogen Mycoplasma gallisepticum that has been used globally to improve poultry health. However, the majority of the bacterial cells in Vaxsafe MG do not express the GapA cytadhesin, reducing their capacity to colonise the respiratory tract. Vaxsafe MG (strain ts-304) is a GapA positive clone recovered from Vaxsafe MG (strain ts-11) that has been shown to be safe and efficacious in turkeys, and preliminary studies have suggested that Vaxsafe MG (strain ts-304) may have greater efficacy in chickens than Vaxsafe MG (ts-11).

Mycoplasma bovis Membrane Protein MilA Is a Multifunctional Lipase with Novel Lipid and Glycosaminoglycan Binding Activity.

The survival, replication, and virulence of mycoplasmas depend on their ability to capture and import host-derived nutrients using poorly characterized membrane proteins. Previous studies on the important bovine pathogen demonstrated that the amino-terminal end of an immunogenic 226-kDa (P226) protein, encoded by (the full-length product of which has a predicted molecular weight of 303 kDa), had lipase activity. The predicted sequence of MilA contains glycosaminoglycan binding motifs, as well as multiple copies of a domain of unknown function (DUF445) that is also found in apolipoproteins.

Differential Response of the Chicken Trachea to Chronic Infection with Virulent Mycoplasma gallisepticum Strain Ap3AS and Vaxsafe MG (Strain ts-304): a Transcriptional Profile.

is the primary etiological agent of chronic respiratory disease in chickens. Live attenuated vaccines are most commonly used in the field to control the disease, but current vaccines have some limitations. Vaxsafe MG (strain ts-304) is a new vaccine candidate that is efficacious at a lower dose than the current commercial vaccine strain ts-11, from which it is derived.