Identification of Bacteria Isolated from Lesions on Young of Year Smallmouth Bass

Elaine Langone Center, Terrace Room

Bacteria were cultured on Tryptic Soy or R2A agar after collection from lesions on six diseased Young of the Year (YOY) Smallmouth Bass from the West Branch Susquehanna River at Watsontown. These six fish sampled were of ten fish that had symptoms of clinical disease, a disease which has been studied for more than ten years without a known causative agent. The nearly complete 16s rRNA gene was amplified from isolates and the 5’ half was sequenced via conventional Sanger methods. Identifications were made by comparison of the quality-trimmed sequence to the EZTaxon type strain database. The most commonly isolated organisms were Plesiomonas shigelloides, Chryseobacterium gambrini, and a variety of Aeromonas species, including A. australiensis, A. veronii, and A. taiwanensis. Other less frequently isolated organisms were Acinetobacter gyllenbergii, Flavobacterium johnsonii, Exiguobacterium acetylicum, Pseudomonas mos selii, and a novel Chryseobacterium species. Additional testing must be conducted to determine whether any of these organisms is the causative agent for Smallmouth disease.