Streptococcus parauberis infection in turbot Scophthalmus maximus in Northern Portugal

Abstract

High mortalities of turbot Scophthalmus maximus were observed at a fish farm in northern Portugal from May to August in 2004. Moribund fish exhibited typical symptoms of streptococcosis, such as uni- or bilateral exophthalmia and hemorrhages and edema in the dorsal trunk region and the base of fins. Gram-positive a-haemolytic cocci were isolated from moribund fish and identified as Streptococcus parauberis based on physiological, biochemical and serological characteristics and 16S rDNAtargeted PCR. Histopathological examinations revealed occurrence of meningitis and presence of bacteria in the connective tissue of examined organs. This is the first report of S. parauberis infection in cultured turbot in Portugal. © 2012 The Japanese Society of Fish Pathology.