Abstract
Granuloma disease in a flock of free range productive layers in the Netherlands in 2017 is described. The disease resembled granuloma outbreaks in layers caused by Tetratrichomonas gallinarum in 2013 and occurred in the same area in which the rearing farm considered as the source of the 2013 outbreaks was located. Between 55 and 84 weeks of age mortality was 20.3% (breeder’s norm 3.9%). All dead hens examined (n = 20) showed granulomas especially in liver and ceca. Nine hens with or without liver and/or ceca granulomas were examined for trichomonads in mentioned organs by in situ hybridization (ISH), nested PCR, and cloning and sequencing. Ceca were also examined by culture. T. gallinarum ISH was positive in all livers and ceca with granulomas and negative in case granulomas were absent. T. gallinarum strain 13/16632, which caused the 2013 outbreaks was found in 4/8 hens with granulomas. Moreover, other trichomonads were detected: a T. gallinarum strain GPO-like and a Simplicimonas sp. strain GABC1-like. Mixed infections also occurred. Infectious causes of granuloma disease other than the afore-mentioned trichomonads could be excluded. Trichomonad DNA was not detected in environmental samples and wild ducks originating from the farm of concern, except for one duck in which the same Simplicimonas sp. as in hens was detected, leaving the source of the T. gallinarum infection in hens unknown. It is concluded that the herein described granuloma disease likely was caused by T. gallinarum strain 13/16632. However, the pathogenicity of the other trichomonads found remains to be clarified.
Highlights
Granulomas may develop when the immune system is not able to eliminate amongst others, disease inducing microorganisms resulting in chronic stimulation of the immune system
in situ hybridization (ISH) showed the presence of T. gallinarum in the granulomas in one of two ceca and in two of three livers examined while H. meleagridis ISH was always negative
In the present case report, an outbreak of granuloma disease likely caused by T. gallinarum occurring in 2017 in a flock of free range productive layers in the Netherlands is described
Summary
Granulomas may develop when the immune system is not able to eliminate amongst others, disease inducing microorganisms resulting in chronic stimulation of the immune system. Lesions mainly consist of macrophages (histiocytes), epithelioid cells and multinucleated giant cells. Other cells such as lymphocytes, plasma cells and fibroblasts may be present and necrotic/caseous debris is often found at the core of the granuloma (Williams and Williams 1983). Certain Escherichia coli strains have been described as cause of a granuloma disease called coligranulomatosis that occurs sporadically in adult chickens, turkeys and partridges. The latter disease is not economically relevant as it affects only a few birds in a flock (Hj€arre and Wramby 1945)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
