“…Numerous researchers have also reported that E. tarda isolates in fish in various countries are highly resistant to ampicillin and amoxicillin (Lee & Wendy, ; Ogbonne, Ukazu, & Egbe, ; Shetty et al, ; Wimalasena et al, ). Previous studies have demonstrated that E. tarda is sensitive to oxytetracycline and sulpha‐trimethoprim (Castro, Toranzo, Barja, Nunez, & Magarinos, ; Shetty et al, ; Stock & Wiedemann, ), while the appearance in red tilapia, olive flounder, red sea bream and eels of E. tarda which is resistant to oxytetracycline and sulpha‐trimethoprim has been frequently reported (Lee & Wendy, ; Lo et al, ; Wimalasena et al, ). These observations suggest that there is a general trend of increasing resistance to oxytetracycline and sulpha‐trimethoprim of E. tarda isolates in aquaculture.…”