Author
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Darwish, Ahmed |
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Submitted to: Journal of Aquatic Animal Health
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/13/2006 Publication Date: 3/12/2007 Citation: Darwish, A.M. 2007. The efficacy of florfenicol against stretococcus iniae infection in sunshine bass. Journal of Aquatic Animal Health. 19:1-7. Interpretive Summary: Sunshine bass is the fastest growing segment of the aquaculture industry however the industry has been plagued by streptococcosis; an infectious disease that causes economic losses of about 2 million dollars annually. In the United States there is currently no approved drug by the Food and Drug Administration (FDA) to control this disease. The objective of this research was to test the effectiveness of florfenicol (an antibiotic therapeutant) as a candidate to control streptococcosis in sunshine bass. Sunshine bass fingerlings were experimentally infected by Streptococcus iniae (the causative agent of the disease) and fed different levels of florfenicol in the diet. Fish fed florfenicol in the diet at levels of 5, 10, 15 and 30 mg/kg body weight/day for 10 days had survival rates of 69.2, 86.7, 94.2 and 94.2 %, respectively, whereas infected fish fed diet with no florfenicol had a survival rate of 4.2 %. The results of this study clearly demonstrated the usefulness of florfenicol as a potential candidate for controlling streptococcosis in sunshine bass. Technical Abstract: An Experimental feeding trial was performed to evaluate the efficacy of florfenicol (FF) in controlling Streptococcus iniae infection in sunshine bass (SB), Morone chrysops female ' Morone saxatilis male. Doses of FF evaluated were 0, 5, 10, 15 and 30 mg active ingredient per kilogram of fish body weight per day. Administration of medicated feed started within 22-24 h post challenge by waterborne exposure to virulent S. iniae. The FF medication was continued for 10 consecutive days, followed by a 25 d post treatment observation. Oral administration of FF medicated feed for 10 d at 5, 10, 15 and 30 mg FF/ BW/d significantly increased (P<0.05) the survival of S. iniae infected SB from 4.2 % in challenged non-medicated positive control to 69.2, 86.7, 94.2 and 94.2 %, respectively. The survival rate was significantly higher in the 15 and 30 mg treatments (94.2 and 94.2 %, respectively) than the 5 mg treatment (69.2) but there was no significant difference among the treatments 10 mg and higher. At the conclusion of the experiment no carriers were detected in any challenged group receiving FF medicated diet while the bacterium was recovered from the non-medicated challenged survivors of the infection. |
