Aeromonas sobriain chlorinated drinking water supplies

Aeromonasspecies were recovered from over 27% of 183 chlorinated drinking water samples collected during an 18-month period. Sixteen of 20 isolates tested elicited a cytotoxic response by Y-1 mouse adrenal cells. None of the strains was either enterotoxigenic by the rabbit ligated ileal loop assay, exhibited piliation, or showed significant mannose resistant adherence to human buccal cells. TheAeromonasisolates were further identified to beA. sobriaand were resistant to ampicillin and susceptible to chloramphenicol, kanamycin, streptomycin, and tetracycline. Total coliform levels did not correlate withAeromonasdensities in distribution water. With 85% of the samplings,Aeromonasoccurred in distribution water when no coliforms were detectable by either the membrane filter or most-probable-number techniques. A significant correlation (P<.001) existed between standard plate count levels andAeromonas.