0000000000409039

AUTHOR

Robin A.j. Nicholas

Validation of Loop-Mediated Isothermal Amplification (LAMP) Field Tool for Rapid and Sensitive Diagnosis of Contagious Agalactia in Small Ruminants

Simple Summary Contagious agalactia (CA) is an infectious disease of small ruminants endemic in the Mediterranean countries, causing significant socioeconomic impacts predominantly on small-scale farmers who still subsist on marginal lands. Mycoplasma agalactiae is historically considered the principal etiological agent of CA, especially in sheep. Clinical signs are characterised by mastitis, arthritis, keratoconjunctivitis and occasionally, abortion. Rapid, accurate and cost-effective field tests are urgently needed for effective control of M. agalactiae mastitis. Our study illustrated the validation of a Loop-Mediated Isothermal Amplification (LAMP) test for the detection of M. agalactiae…

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Timing of activation of CD4+ memory cells as a possible marker to establish the efficacy of vaccines against contagious agalactia in sheep

Mycoplasma agalactiae is a major pathogen of sheep and goats in many areas of the world and particularly in Mediterranean countries. It causes contagious agalactia, an infectious disease primarily affecting mammary glands. Many vaccines against the pathogen are currently under development. The aim of the study was to investigate the involvement of T cell-mediated immunity during vaccination and challenge experiments against Mycoplasma agalactiae. A comparison of the antigen-specific expansion of interferon gamma positive T cell memory and naïve subsets was performed between vaccinated and non-vaccinated sheep to identify cellular subsets whose activation was different between protected and …

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Effect of Mycoplasma agalactiae mastitis on milk production and composition in Valle dell Belice dairy sheep

Contagious agalactia (CA), a disease caused by Mycoplasma agalactiae and other pathogenic mycoplasmas, is a well-known multietiological syndrome affecting dairy breeds of sheep and goats in the Mediterranean basin. The aim of this work was to study the effect on milk production and composition of mastitis caused by M. agalactiae in Valle del Belice dairy sheep. All ewes were manually milked twice daily and the milk from both daily milking was analysed for milk composition and somatic cell counts. Moreover the morning milk samples were collected aseptically from each animal for bacteriological analyses. A mixed linear model was utilised to consider milk production and composition between ani…

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A comparison of the efficacy of commercial and experimental vaccines for contagious agalactia in sheep

Abstract An effective vaccine that improves the control of contagious agalactia in Mediterranean regions would be beneficial for poorer farmers who use traditional husbandry methods for sheep and goat production. However while there is little published data on the efficacy of commercially available vaccines for contagious agalactia, evidence from the field suggests that some provide inadequate protection. This paper compares four different vaccine formulations, including a widely used commercial vaccine, using clinical signs and mycoplasma excretion as measures of protection in sheep. Results showed that protection afforded by the vaccines, following contact challenge with experimentally in…

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Expansion of intracellular IFN-γ positive lymphocytes during Mycoplasma agalactiae infection in sheep.

Abstract A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae . The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4 + T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by C…

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