This study was conducted from September 2006 to September 2007 to identify major pathogens, especially bacteria, of diseased frog (Rana tigerina) farmed in the peri –urban area of Ho Chi Minh City. Challenge of cultured frog with Aeromonas hydrophila. That were isolated from diseased frogs with clinical signs of ulcerative syndrome were carried out. Experimental frogs were injected on the vetral left thigh with a variety of bacterial concentrations. Average 18-25g sized frog (Rana tigerina) were stocked at 10 frogs/tank. . | 180 NGHIÊN CỨU KHOA HOC KY THUAT PHAN LẬP va ĐINH DANH VI KHUAN Aeromonas hydrophila TREN ECH THAI LAN Rana tigerina NUOI TAI KHU VựC VEN ĐO THANH pho ho CHÍ MINH CHARACTERIZATION OF BACTERIA ISOLATED FROM FARMED FROG Rana tigerina IN PERI - URBAN OF HCM CITY Tran Hong Thuy Bộ môn Sinh hoc va Quan ly Nguon lợi Thuy san Khoa Thuy san Trường Đại hoc Nông Lam Tp. HCM ABSTRACT This study was conducted from September 2006 to September 2007 to identify major pathogens especially bacteria of diseased frog Rana tigerina farmed in the peri -urban area of Ho Chi Minh City. Challenge of cultured frog with Aeromonas hydrophila. That were isolated from diseased frogs with clinical signs of ulcerative syndrome were carried out. Experimental frogs were injected on the vetral left thigh with a variety of bacterial concentrations. Average 18-25g sized frog Rana tigerina were stocked at 10 frogs tank. There were four treatments with triplicate each control injected with sterile NaCl 9x106 cfu ml 9x107 cfu ml and 9x108 cfu ml for bacterial infection challenges. The mortalities occurred at bacterial concentration of 9x106 cfu ml 9x107 cfu ml and 9x108 cfu ml were 57 90 and 100 respectively. No bacteria were isolated from frogs in the control at the end of experiment. Signs of moribund frogs included light-reddish fluid in the body cavity and haemorrhage on the skin of abdomen and thigh. Aeromonas hydrophila were isolated frog diseased frog in bacterial injection challenge treatments. Those results point out the importance of Aeromonas hydrophila as causal agents of ulcerative syndrome in frog. GIỚI THIÊU Thành PhoHo Chí Minh những nam gan đây ro len phong trao nuoi ếch với nhieu hình thữc nuoi khac nhau. Nguon ếch giong đữớc nhập ve từ Thai Lan. Ech Thai Lan Rana tigerina vong đới ngan tang trữớng nhanh va thích hớp với đieu kiện nuoi tai khu vữc ven đo Thanh pho Ho Chí Minh. Tuy nhien song song với sữ phat trien nuoi ếch cong nghiẹp đo la sự gia tang đang ke tình hình dịch bẹnh
