The enzymatic profile of Haemophilus ducreyi.

The enzymatic activities of two reference strains of Haemophilus ducreyi and thirty clinical isolates were investigated by conventional biochemical tests and the API-ZYM test kit system which included 97 synthetic substrates. No strains converted delta-aminolevulinic acid to porphyrins, but they all reduced nitrates to nitrites. All strains possessed aminopeptidase activity against beta-naphthylamide derivatives of L-alanine, L-arginine, L-glutamine, glycine, L-leucine, L-lysine and L-serine. No trypsinor chymotrypsin-like activities were detected. All strains had phosphatase activity with broad pH range, and phosphoamidase activity. No glycosidase was detected by the substrates tested.