DAO 36:121-127 (1999)  -  doi:10.3354/dao036121

Red drum Sciaenops ocellatus mortalities associated with Streptococcus iniae infection

A. Eldar1, S. Perl2, P. F. Frelier3, H. Bercovier4,*

1Department of Poultry and Fish Diseases, The Kimron Veterinary Institute, POB 12, Bet Dagan 50250, Israel
2Department of Pathology, The Kimron Veterinary Institute, POB 12, Bet Dagan 50250, Israel
3The Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas 77843-4467, USA
4Department of Clinical Microbiology, The Hebrew University-Hadassah Medical School, POB 12272 Jerusalem, 91010 Israel
*Addressee for correspondence. E-mail:

ABSTRACT: We isolated for the first time Streptococcus iniae strains associated with diseased marine fish. Diseased red drum Sciaenops ocellatus were lethargic, and presented external signs (exophthalmia and loss of orientation) resembling those of freshwater fish infected by S. iniae. Skin lesions, extending to a necrotizing myositis, were typical of S. iniae infection of red drum. Histopathological findings indicate that S. iniae infection in red drum produces a chronic disease with systemic involvement characterized by multiple necrotic foci. Molecular epidemiology (RFLP [restriction fragment length polymorphism] ribotyping) revealed that 2 different ribotypes were involved in a single outbreak. The first is the EcoRI 'Israeli' trout and tilapine ribotype (Hind III type a strains), while the second is the EcoRI 'American' ribotype (Hind III type b strains), typical of tilapines farmed in Texas and Idaho.


KEY WORDS: Red drum · Streptococcus iniae · Pathology · DNA · Ribotyping


Full text in pdf format