Clinicopathological Studies on Some Antibiotics Used in Nile Tilapia Infected With Streptococcus Iniae

S. iniae has become one of the most serious aquatic pathogens in the last decade, causing large losses in wild and farmed fish worldwide, especially tilapia, so the presented workwas performed to study the effect of S. iniae in fish and the efficacyof florfenicol and R. ofJicinalis in treatment of this bacterium.This study was carried out on two hundred and ten Niletilapia (Oreochromis niloticus) of 50 gm average body weight. ’These fish were randomly divided into 7 groups, each including 30fish. Gp. 1 was kept as a normal control. Gp.2 administeredflorfenicol by dosage of 10 mg/kg b.wt/day for 10 successive daysthrough medicated feed. Gp. 3 administered dry leaves of R.officinalis which ground to fine powder and mixed with grainedcommercial fish feed in a ratio of 3: 17 w/w. Gp. 4 was infectedintraperitoneally with 25!l1 of S. iniae at conc. of 1.2x 108 CFU/ ml.Gp. 5 infected intraperitoneally with 25!l1 of S. iniae at a conc. of1.2xl08 CFU/ ml, then treated with florfenicol (dose and durationas gp.2) Gp. 6 infected intraperitoneally with 25!l1 of S. iniae at acone. of 1.2x108 CFU/ ml, then treated with dry leaves of R.ofJicinalis. Gp. 7 was feed dry leaves of R. ofJicinalis for 5 daysthen infected intraperitoneally with S. iniae then fed dry leaves ofR. officinalis for 10 days. All treatments were 48 hours from theinfection. In all groups, blood samples were collected at two and’four weeks post treatments from the caudal vessels. The 1 st sampleof blood was taken in clean Wassennan tubes containingdipotassium salts of EDT A to be used for hematologicalexamination. The 2nd sample was taken without anticoagulant in a