BACTERIAL-FLORA OF THE SCHISTOSOME VECTOR SNAIL BIOMPHALARIA-GLABRATA

The aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail B. glabrata was examined. Internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. The numerically predominant bacterial genera in individual snails included Pseudomonas, Acinetobacter, Aeromonas, Vibrio and several members of the Enterobacteriaceae. Enterobacteriaceae seldom predominated in laboratory colonies. V. extorquens [Protaminobacter ruber] and a Pasteurella sp. tended to predominate in high-bacterial-density snails. These snails may be compromised and may harbor opportunistic snail pathogens. [These findings may have relevance to microbiological control of this vector.].