PATHOLOGY AND MOLECULAR IDENTIFICATION OF DEVELOPING HENNEGUYA SPP. ACTINOSPORES WITHIN THE INTESTINAL EPITHELIUM OF DERO DIGITATA DURING AN OUTBREAK OF PROLIFERATIVE GILL DISEASE IN A COMMERCIAL CATFISH POND.

Dero digitata, a freshwater oligochaete worm found worldwide, serves as the definitive host for the myxozoan Henneguya ictaluri, the cause of proliferative gill disease (PGD) in ictalurid catfish. The study objectives were to describe pathologic changes associated with developing actinospores within D. digitata from a commercial catfish pond during an active PGD outbreak.

Streptococcus dysgalactiae From Farm-Raised Channel Catfish in Mississippi, USA, With Notes on Fish-Associated Group C S. dysgalactiae.

Lancefield serological group C Streptococcus dysgalactiae (GCSD) is an emerging cause of fish disease worldwide, largely associated with mariculture in Asia. In the United States (US), GCSD had been a pathogen of minimal concern for fish, but recent cases indicate a putative emergence in wild and cultured freshwater fish populations in the Americas. The current study discusses three novel cases of GCSD-associated streptococcosis in US farm-raised channel catfish (Ictalurus punctatus) occurring in Mississippi, US, in 2022 and 2023.