Occurrence and Characterization of Enterococcus Faecalis from Infected Farmed African Catfish in Ogun State, Nigeria

Abstract

Background: The opportunistic fish pathogen are the main cause of mass mortality in several fish species and severe economic losses in different countries. This study was conducted to determine occurrence and characterization of Enterococcus faecalis from infected farmed African catfish in Ogun State, Nigeria. Methodology: The bacteria was isolated from infected farmed African catfish (Clarias gariepinus, n=128) with clinical signs of atrophied or reduced barbels, desquamation or abrasion of the skin, and ascites were purposively sampled in Ogun State. The isolates were identified based on morphological, biochemical tests, and 16S rRNA molecular characterization. The 16S rRNA gene sequence was analyzed using BLAST, submitted to the NCBI database, and an accession number was generated. Results: The percentage occurrence of Enterococcus faecalis isolates in infected Clarias gariepinus from Ogun State were; Ogun East 30.00% (18/60); Ogun Central 17.86% (5/28); Ogun West 12.50% (5/40). The highest incidence (p < 0.05) in Ogun State recorded was in Ijebu Ode local government compared to other local governments area. All Enterococcus faecalis isolates in this study were non-motile, gram-positive cocci, showed negative reaction for catalase, negative for oxidase, negative for methyl-red, and negative for indole. 16S rRNA gene of Enterococcus faecalis isolates in infected Clarias gariepinus from Ogun State, Nigeria (OP595802.1) was closely related to 16S rRNA gene of other Enterococcus faecalis isolates Conclusions: The bacteria isolated from infected farmed Clarias gariepinus in Ogun State, Nigeria was Enterococcus faecalis, and showed an evolutionary relationship with NCBI reference global strains from different countries.