title: Rapid identification of pathogenic streptococci isolated from moribund red tilapia (Oreochromis spp.).
abstract: Accurate and rapid identification of bacterial pathogens of fish is essential for the effective treatment and speedy control of infections. Massive mortalities in market-sized red tilapia (Oreochromis spp.) were noticed in mariculture concrete ponds in northern Egypt. Histopathological examination revealed marked congestion in the central vein of the liver with the presence of bacterial aggregates inside the lumen and in the vicinity of the central vein. A total of 12 isolates of streptococci were obtained from the moribund fish. This study documented the ability of the MicroSeq 500 16S bacterial sequencing method to accurately identify Streptococcus agalactiae and S. dysgalactiae mixed infections from moribund red tilapia that were difficult to be recognised by the commercial biochemical systems. The continuously decreasing cost of the sequencing technique should encourage its application in routine diagnostic procedures.
authors.affiliation: Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Cairo University , Giza , Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelsalam
authors.affiliation: Department of Hydrobiology, Veterinary Research Division, National Research Centre , Dokki, Giza , Egypt.
authors.forename: Mamdouh Y
authors.initials: MY
authors.lastname: Elgendy
authors.affiliation: Department of Pathology, Faculty of Veterinary Medicine, Cairo University , Giza , Egypt.|Clinical Division of Fish Medicine, University of Veterinary Medicine , Veterinärplatz 1, A-1210 Vienna , Austria.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shaalan
authors.affiliation: Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Cairo University , Giza , Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Moustafa
authors.affiliation: National Institute of Infectious Diseases , Tokyo , Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujino
mesh_terms: D000818:Animals; D017756:Aquaculture; D004534:Egypt / Q000453:epidemiology; D005393:Fish Diseases / Q000453:epidemiology / Q000382:microbiology*; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D017210:Tilapia / Q000382:microbiology*
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: MicroSeq 500; S. dysgalactiae; Streptococcus agalactiae; histopathology; red tilapia