title: Clinicopathological features and immunohistochemical detection of antigens in acute experimental Streptococcus agalactiae infection in red tilapia (Oreochromis spp.).
abstract: This study investigates the clinicopathological features of acute experimental streptococcosis in red tilapia using various routes of infection; intraperitoneal (IP), immersion (IM) and immersion cut (IC). Twenty four red tilapia in duplicates were inoculated intraperitoneally with 10(9) CFU/ml of S. agalactiae while another sets: intact, one with sharp cut at the tail end were exposed to bacterial inoculums 10(9) CFU/ml diluted in water while two groups of control fish were similarly manipulated. Clinical signs were recorded; samples from the gills, brain, eyes and kidneys were also taken for bacterial isolation and histopathology. Immunohistochemistry (IHC) and polymerase chain reaction (PCR) were employed to detect the antigen. The diseased fish showed skin, fin haemorrhages and exophthalmia with obvious signs in IP at 2 hpc followed by IC and IM at 4 hpc. The lesions were noticed earlier in the kidney and most severe in IP. IHC detected antigen as early as PCR and isolation with intense staining in blood vessel lumen and wall, macrophages in choroid, focal haemorrhage in the renal interstitium and meninges especially in IP followed by IC and IM. The immunolocalisation of the antigen described for the first time further explain the pathogenesis of streptococcosis in red tilapia.
authors: Department of Veterinary Pathology & Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors: Syuhaidah
authors: S
authors: Abdullah
authors: Noraini
authors: N
authors: Omar
authors: Sabri Mohd
authors: SM
authors: Yusoff
authors: Emikpe Benjamin
authors: EB
authors: Obukwho
authors: Tanko Polycarp
authors: TP
authors: Nwunuji
authors: Latifah
authors: L
authors: Hanan
authors: Jamil
authors: J
authors: Samad
keywords: IHC; PCR; Red tilapia; Streptococcus agalactiae; infection
references: Fish Shellfish Immunol. 2006 Oct;21(4):365-71
references: 16531069
references: Vaccine. 2004 Sep 9;22(27-28):3769-73
references: 15315858
references: J Fish Dis. 2008 Apr;31(4):277-83
references: 18353019
references: Dis Aquat Organ. 2004 Nov 23;62(1-2):177-80
references: 15648844
references: Vet Microbiol. 2007 May 16;122(1-2):1-15
references: 17418985
references: Vet Microbiol. 1995 Jan;43(1):33-40
references: 7716882
references: J Comp Pathol. 2010 Aug-Oct;143(2-3):227-9
references: 20334871