OCCURRENCE AND ANTIGENIC HETEROGENEITY OF L-2,4-DIAMINOBUTYRATE DECARBOXYLASE IN ACINETOBACTER SPECIES

We have previously reported that a novel enzyme, L-2,4-diaminobutyrate decarboxylase (DABA DC), which is responsible for the formation of 1, 3-diaminopropane, occurs in two Acinetobacter species. The present stu dy extends this observation to additional Acinetobacter species and st rains (6 reference strains and 30 clinical isolates). Furthermore, the DABA DC protein was detected in every strain by Western blot analysis with the antiserum against the enzyme purified from A. baumannii ATCC 19606. However, only the DABA DCs in the A. calcoaceticus and Acineto bacter genospecies 3 in addition to A. baumannii strains strongly cros s-reacted with the antiserum, suggesting antigenic heterogeneity among the DABA DC proteins in Acinetobacter species. Therefore, immunologic al testing of the DABA DC protein may provide an additional method for differentiating and identifying Acinetobacter strains.