Modified culture methods for the detection of Vibrio spp. from estuarine waters

The purpose of this study was to improve and speed up the isolation and recovery of Vibrio spp. from water using modifications of the currently used culture techniques. Thiosulfate Citrate Bile Salts (TCBS) and Alkaline Peptone Salt Broth (APSB) media were modified by the addition of NaCl and Tris buffer. None of the modifications had a negative effect on the recovery of Vibrio spp. when compared to the unmodified media. The modifications giving the best results were 3% and 6% NaCl and Tris buffer 0.05 M at pH 8.4. Under these conditions, the background microflora was drastically reduced in both TCBS and APSB making the detection of the target colonies extremely easy. The presence of sulfur-producing microorganisms was reduced and in most cases completely eliminated. The use of a more selective medium also allows for an easier application of molecular techniques. Colony hybridizations are easily done, since the growth of interfering microorganisms is reduced. These studies are being expanded to include the detection of V. cholerae 01 and non-01 in waters from Latin American countries affected by the cholera epidemic.