SURVIVAL AND RECOVERY OF AEROMONAS-HYDROPHILA IN WATER - DEVELOPMENT OF METHODOLOGY FOR TESTING BOTTLED WATER IN CANADA

Proposed changes to the Regulations for bottled water in the Food and Drugs Act of Canada include criteria for Aeromonas hydrophila (0 colon y-forming units/100 mt water). The development of the methodology used to support these proposed Regulations and the survival of A. hydrophi la in inoculated water are described. The methodology used in the isol ation of A. hydrophila includes the use of hydrophobic grid membrane f ilters (HGMF), a resuscitation step on tryptic soy agar, and selective plating on membrane-Aeromonas-trehalose agar and Aeromonas medium. Ae romonas hydrophila proliferated and survived in inoculated water for u p to 60 days or longer depending on the other contaminating bacteria. The presence of Pseudomonas aeruginosa enhanced the survival of A. hyd rophila and enabled this bacteria to survive for more than 60 days.