Pathogenicity of Mycoplasma synoviae in Broiler Chickens

Department of Veterinary Pathobiology, Auburn University, AL 36849, USA.
Veterinary Pathology (Impact Factor: 1.87). 06/1998; 35(3):178-90. DOI: 10.1177/030098589803500303
Source: PubMed


Six isolates of Mycoplasma synoviae, identified as WVU 1853, K1968, K1858, 92D8034, F10-2AS, and FMT, were compared for pathogenicity in broiler chickens. Specific-pathogen-free chickens were inoculated, in two groups of 20, with each isolate by footpad or eyedrop inoculation at 1 day of age and were examined at necropsy 7, 14, 28, and 42 days postinoculation. Specimens were taken for histopathology, culture, polymerase chain reaction assay, and hemagglutination-inhibition serology. Isolates were grouped according to pathogenicity on the basis of differences in lesion development and tissue distribution in the respiratory system, other viscera, and the skeletal system. K1968 (pathogenic) induced lesions in all sites examined in both the footpad and eyedrop inoculation groups. It was detected in all sites following footpad inoculation and in all sites except viscera following eyedrop inoculation. WVU 1853, K1858, and 92D8034 (moderately pathogenic) induced lesions and were detected in all sites following footpad inoculation. With eyedrop inoculation, lesions were identified only in upper and lower respiratory sites, and organisms were detected only in upper respiratory sites. F10-2AS (moderately pathogenic) was similar; however, footpad inoculation failed to induce visceral lesions or permit organism detection in any site. F10-2AS was detected in upper and lower respiratory tissues following eyedrop inoculation. FMT (mildly pathogenic) induced only upper respiratory lesions when either footpad or eyedrop inoculation was used, and detection was restricted to upper respiratory sites following eyedrop inoculation. These results are useful in comparative evaluations of the virulence of other M. synoviae isolates and form a basis for characterization of virulence factors of M. synoviae.

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Available from: Fred Hoerr, Oct 13, 2014
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    • "M. synoviae is a major poultry pathogen causing respiratory and systemic disease, autoimmune disorders, and infectious synovitis in chickens and turkeys [1]. It has been detected in many internal organs, as well as in the synovial fluid and joint tissues of chickens with infectious synovitis [2] [3] [4]. M. synoviae also invades nonphagocytic chicken cells in vitro, including chicken chondrocytes (CCH) [5]. "
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    ABSTRACT: In infectious synovitis caused by Mycoplasma synoviae chicken chondrocytes (CCH) may come into direct contact with these bacteria that are also capable of invading CCH in vitro. In this study, phenotype microarrays were used to evaluate the influence of Mycoplasma synoviae on the global metabolic activity of CCH. Therefore, CCH were cultured in the presence of 504 individual compounds, spotted in wells of 11 phenotype microarrays for eukaryotic cells, and exposed to Mycoplasma synoviae membranes or viable Mycoplasma synoviae. Metabolic activity and sensitivity of normal cells versus infected cells were evaluated. Metabolic profiles of CCH treated with viable Mycoplasma synoviae or its membranes were significantly different from those of CCH alone. CCH treated with Mycoplasma synoviae membranes were able to use 48 carbon/nitrogen sources not used by CCH alone. Treatment also influenced ion uptake in CCH and intensified the sensitivity to 13 hormones, 5 immune mediators, and 29 cytotoxic chemicals. CCH were even more sensitive to hormones/immune mediators when exposed to viable Mycoplasma synoviae. Our results indicate that exposure to Mycoplasma synoviae or its membranes induces a wide range of metabolic and sensitivity modifications in CCH that can contribute to pathological processes in the development of infectious synovitis.
    Full-text · Article · Aug 2014 · BioMed Research International
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    • "In poultry the most pathogenic species are Mycoplasma synoviae and Mycoplasma gallisepticum. Mycoplasma synoviae most frequently colonizes the upper respiratory tract, causing subclinical infections, although this condition can also lead to the development of systemic infection and/or infectious synovitis in chickens and turkeys [2,3]. In the absence of a cell wall, the majority of the mycoplasma surface antigens are lipoproteins. "
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    ABSTRACT: Avian-specific toll like receptor 15 (TLR15) is functionally equivalent to a group of TLR2 family proteins that the mammalian innate immune system utilizes to recognize a broad spectrum of microbe-associated molecular patterns, including bacterial lipoproteins. In this study we examined the role of chicken TLR2 family members in the innate immune response to the avian pathogenic bacterium, Mycoplasma synoviae. We found that Mycoplasma synoviae, and specifically the N-terminal diacylated lipopeptide (MDLP) representing the amino-terminal portion of its mature haemagglutinin protein, significantly induces the expression of TLR15, but not TLR1 and TLR2 in chicken macrophages and chondrocytes. TLR15 activation is specific and depends on diacylation of the lipopeptide. Activation of TLR15 after stimulation with Mycoplasma synoviae and MDLP triggers an increase in the expression of transcription factor nuclear factor kappa B and nitric oxide production. Moreover, transfection of avian macrophage cells with small interfering RNA reduces the expression of TLR15 after stimulation with MDLP. This leads to decreased activation of the innate immune response, as measured by nitric oxide production. Additionally, pretreatment of cells with neutralizing anti-TLR15 antibody results in a notable attenuation of MDLP-driven release of nitric oxide. This positive correlation may constitute a mechanism for stimulating the innate immune response against avian mycoplasmas in chicken cells via TLR15.
    Full-text · Article · Oct 2013 · Veterinary Research
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    • "The growth of poultry industry is often limited by infectious diseases that affect birds. Mycoplasma synoviae is a major avian extracellular pathogen associated with synovitis in chickens and turkeys [1] [2]. Disease can occur as chronical subclinical to severe upper respiratory infection and, under unknown conditions, become systemic and cause arthritis [3]. "
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    ABSTRACT: Mycoplasma synoviae is a Gram positive bacteria lacking of cell wall that affects chickens and turkeys causing infection in the upper respiratory tract and in some cases arthritis, with economical impact to broiler breeders. Treatment and prevention of avian synovitis depend on knowledge of the infectious process. Secreted or surface-exposed proteins play a critical role in disease because they often mediate interactions between host and pathogen. In the present work, we sought to identify possible M. synoviae secreted proteins by cultivating the bacteria in a modified protein-free Frey medium. Using this approach, we were able to detect in the cell-free fraction a number of proteins that have been shown in other organisms to be secreted, suggesting that they may also be secreted by M. synoviae.
    Full-text · Article · Sep 2012
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