Co-infections are very common in nature and occur when hosts are infected by two or more different pathogens either by simultaneous or secondary infections so that two or more infectious agents are active together in the same host. Vibrio parahaemolyticus and theencysted metacercaria of Heterophes sp. were obtained from Liza ramada with prevalence
rate 50% and 80% respectively at marine fish farm in Damietta Governorate (Egypt). Vibrio parahaemolyticus were retrieved and presumptively identified using morpho-chemical characterization and API*20E system. Antibiogram has revealed that isolates were sensitive to ciprofloxacin, enrofloxacin, nalidixic acid and oxolinic acid while resistant to ampicillin,
amoxicillin, and lincomyci. The naturally infected Liza ramada could be treated successfully in the farm by Biofarm in a single dose (3ppm for 30 minutes) as a short duration bath and then fed a ration containing Ciprofloxacin (150 mg / Kg body wt.) for ten days. The recovery rate increased, the clinical signs disappeared and the fish returned to a normal state of health.
The aim of this study is assessment of applying antibiotic after sensitivity test in comparing with using biofarm in treatment of co- infection by encysted Metacercaria and Vibriosis.