Isolation and identification of autoagglutinating serogroup O:11 Aeromonas strains in the clinical laboratory.

We evaluated the extent to which serogroup O:11 Aeromonas strains could be recovered from both clinical and environmental specimens and the cultural parameters that affected the phenotypic marker (autoagglutination) associated with this group. Of over 200 Aeromonas strains screened, serogroup O:11 was identified only among the phenospecies A. hydrophila and A. sobria and was associated with clinical isolates more frequently than with environmental strains. Blood and wound isolates accounted for almost 50% of all O:11 strains identified. The autoagglutination phenotype associated with O:11 strains could be detected in most commercial liquid media, under a wide range of growth temperatures, and within 15 min of incubation at 100 degrees C. The results suggest that clinical laboratories can recognize this important group of Aeromonas strains by two simple tests.