Outbreaks of Streptococcus gallolyticus subsp. pasteurianus in goslings characterized by central nervous symptoms

SummaryThe present report describes outbreaks of Streptococcus gallolyticus subsp. pasteurianus in young geese flocks in Austria. The flocks, which comprised 160-1450 goslings of 2 to 3 weeks of age, experienced increased mortalities The clinical signs were characterized by severe central nervous symptoms, namely leg paddling and torticollis. The post-mortem investigation revealed hepatitis, splenitis and low amount of liquid fluid in the coelomic cavity. Livers were of fragile texture, with white necrotic areas. The latter was also found in spleens. No macroscopic lesions were seen in brains. Bacteriological investigation followed by bacterial identification by MALDI-TOF MS and phylogenetic analysis based on partial 16S rRNA region revealed the presence in heart, liver, spleen and brain of Streptococcus gallolyticus subsp. pasteurianus . Histological investigation revealed multifocal necrosis in liver and spleen samples together with infiltration of mononuclear cells and heterophilic granulocytes. Furthermore, in the lesions coccoid bacteria could be identified. No histopathological changes were observed in brain samples from goslings, except in one bird in which accumulation of coccoid bacteria in blood vessels of the brain samples was present.Antibiotic sensitivity tests revealed identical profiles for all strains. The strains were susceptible to penicillins, cephalosporins, chloramphenicol, imipenem and tylosin. However, resistance was found against quinolones, aminoglycosides, tetracycline and trimethoprim-sulfamethoxazole which are commonly used to treat infections with gram-positive bacteria.