Prevalence of Mycoplasma gallisepticum in commerical poultry flocks in Belgium

Abstract

Mycoplasma gallisepticum is a common cause of chronic respiratory disease (CRD) in chickens, resulting in sneezing, coughing, air sac lesions, decreased weight gain and decreased egg production. It is unknown to what extent Mycoplasma gallisepticum is spread in commercial poultry in Belgium and whether they may act as reservoirs for breeder flocks, in which the disease is officially to be declared. Specific stamping out measures are applied on flocks in which infections with M. gallisepticum are demonstrated. In this study both layers and broilers were investigated. Broiler and layer flocks were selected randomly from the national Sanitrace database. A total of 3660 serum samples were collected from 61 layer flocks and analyzed using a serum agglutination test. Positive results were confirmed using a blocking enzyme-linked immunosorbent assay (Svanovir® Mg-Ab, Svanova). Because of their short lifespan and the slow immunological reaction caused by mycoplasma infection, an alternative and faster method was used in broilers. A total of 840 tracheal swabs were collected from 70 broiler flocks and analyzed with a commercial realtime PCR kit (Adiavet® Myco-AV, Biomérieux). After confirmation with ELISA, 3.3 per cent of the layer flocks tested positive for the presence of antibodies against Mycoplasma gallisepticum. In broilers, 5.7 per cent of flocks tested positive for the presence of DNA of the bacteria. Flocks were considered positive if at least 1 sample gave a positive result. A total of 1.3 % of the laying hens and 0.6 % of the broilers were positive. These findings suggest that in general, the prevalence of Mycoplasma gallisepticum in layers and broilers is low. Further epidemiological studies are ongoing to determine whether layers and broilers may act as reservoirs for MG. Acknowledgements: T. Michiels is supported by the Federal Public Service of Health, Food Chain Safety and Environment (RT 12/4 MYCOPLASMA). The study was funded by the Federal Agency for the Safety of the Food Chain