Bacterial diversity on fishes and in waters from southern rivers in Mali

Abstract

Microbial diversity of fishes of river water from Bagoé, Baoulé and Sankarani in the Niger River basin in southern Mali, was investigated. Gills and intestines were sampled on forty-three (43) fishes. Also, five water samples were collected for microbial diversity analysis. Total mesophilic flora and fauna, indicator contamination were investigated in water and in the gills and intestines fish species of economic interest, freshly caught. Conventional microbiological analysis methods were used. Biochemical tests were performed for bacterial identification. The main results obtained were: (i) the bacterial density in fishes was 152.106 to 66.106 CFU/g in gills and 112±53.106 to 50±8.5.106 CFU / g in intestine, (ii ) bacterial flora in fishes from rivers is composed 61% of Gram-negative and 39% Gram-positive bacilli. River waters were composed of 91% of Gram-negative bacilli and 9% of Gram-positive bacilli. In waters and fishes investigated, the different bacteria identified belong to three bacterial families: Pseudomonadaceae, Enterobacteriaceae and Bacillaceae. Bacterial flora of fishes from southern rivers was found similar to those of investigated river waters. But, the bacterial flora of the river waters had a higher proportion of Gram-negative bacilli than those in fishes.