Biotyping of Aeromonas isolates as a correlate to delineating a species-associated disease spectrum.

A group of 147 Aeromonas isolates from diverse clinical and environmental sources was subjected to the biotyping scheme of Popoff and Veron. Of the 147 isolates biotyped, 137 (93%) could be identified, with Aeromonas hydrophila predominating (48%) and equal percentages (25 to 27%) of the other two species (Aeromonas sobria and Aeromonas caviae). A number of additional biochemical properties were found to be significantly associated with one or more of these three species. These included lysine decarboxylase activity, hemolysis of sheep erythrocytes, lecithinase production, staphylolytic activity, arbutin hydrolysis, and acid production from utilization of various carbohydrates. By incorporating these phenotypic properties into an extended biotyping system, 98% of the isolates were identified. Selective distribution of individual species with respect to certain body sites was noted.