Isolation and characterization of the Enterococcus faecalis strain isolated from red tilapia (Oreochromis hybrid) in Indonesia: A preliminary report

The number of fishes were conducted a series of bacteriological examinations to confirm the clinical symptoms that appeared and led to streptococcal infection. Results of the external examination from two moribund red tilapia found the hemorrhagic traces in some parts of the body such as the cranial area near the mouth, eyes, operculum, and some body parts and erosion on the tail, pectoral, and dorsal fin. Internally, no pathological changes were found in the brain and visceral organs. The morphological, biochemical, and molecular examination using the 16S rRNA universal gene and sequencing analysis of PCR products from two moribund red tilapia resulted in both isolates are Enterococcus faecalis bacteria with low virulence. Antibiotics susceptibility test indicated that the isolates were resistant to ampicillin and penicillin. Based on the results of the comprehensive bacterial examination, we concluded that E. faecalis were found as the cause of streptococcosis, infecting and causing mild lesions in red tilapia. To our knowledge, this finding is the first report of isolation and characterisation of the E. faecalis strain isolated from red tilapia in Indonesia.