Bacterial Diversity in Aquacultured African Catfish and Source Pond Water in Buea, Cameroon

Abstract

The catfish is a prominent freshwater fish species farmed in Cameroon to meet the escalating demand for fish products. Despite considerable growth potential, there are concerns about the occurrence of bacteria pathogenic to both fish and humans within aquaculture systems. Research on the microbiome of catfish and their habitats remains largely unexplored. Given the critical importance of understanding the microbial composition within aquaculture systems to ensure food safety and protect public health, this study aimed to generate vital preliminary data by investigating the bacteriome of catfish gills and intestines and pond water environment in Cameroon using 16S rRNA gene amplicon sequencing. The findings revealed a diverse bacterial community (30 phyla, 678 genera, and 1056 species), with Fusobacteria, Bacteroidetes, Proteobacteria, Firmicutes, and Verrucomicrobia collectively representing over 93% of the bacterial community observed. Notably, Fusobacteria emerged as the dominant phylum in catfish gills (49.98%) and intestines (65.3%), while Proteobacteria predominated in the pond water environment (40.24%). Bacteria of genus Cetobacterium dominated all three samples (gills, 49.93%; intestines, 65.19%; and pond water, 23.85%). Furthermore, this study identified many bacterial genera, including potential fish pathogens such as Edwardsiella , Aeromonas , Plesiomonas , and Flavobacterium , and human gut bacteria such as Clostridium and Bacteroides , alongside potential beneficial probiotic bacteria such as Lactococcus spp. The coexistence of both potentially pathogenic and probiotic species underscores ecological complex dynamics within freshwater fish aquaculture and highlights the need for thorough microbial management strategies. This study provides insights into the bacterial landscape of Cameroonian aquaculture, revealing potential risks and benefits of catfish farming.