Omphalitis, urachocystitis and septicemia by Streptococcus dysgalactiae in a southern right whale calf Eubalaena australis, Brazil.

Abstract

Southern right whales Eubalaena australis (SRW) use the southern coast of Brazil as a wintering and calving ground. Other than anthropogenic threats, there is limited knowledge on health and disease aspects for this species. We report the gross and microscopic findings and microbiological identification of streptococcal septicemia in a SRW calf. Main gross findings included fibrinosuppurative omphalitis and urachocystitis, suppurative cystitis, valvular endocarditis and myocarditis, embolic pneumonia, suppurative myositis and osteoarthritis, and lymphadenomegaly. Histological examination confirmed the above inflammatory processes and indicated disseminated Gram-positive coccoid septicemia. PCR analysis, based on the 16S rRNA gene from bacteria isolated on blood agar, identified Streptococcus dysgalactiae. Pathologic and microbiologic analysis indicated that β-hemolytic S. dysgalactiae septicemia, presumably initiated as ascending omphalic infection, was responsible for stranding and death in this individual. These results further confirm pathogenicity of streptococci in cetaceans and add to the limited health and disease related pathology knowledge for this species.