HYALURONIDASES OF THE GASTROINTESTINAL INVASIVE NEMATODES ANCYLOSTOMA-CANINUM AND ANISAKIS SIMPLEX - POSSIBLE FUNCTIONS IN THE PATHOGENESISOF HUMAN ZOONOSES

The gastrointestinal invasive stages of two parasitic nematodes, Ancyl ostoma caninum and Anisakis simplex, were each found to release in vit ro a hydrolytic enzyme that degrades the glycosaminoglycan hyaluronic acid. The parasite hyaluronidases were partially purified by ion-excha nge chromatography and biochemically characterized. The hyaluronidase from A. caninum adult worms had a molecular weight of 65,000 and a pH optimum of 6 with activity at neutral pH, while the hyaluronidase from A. simplex larvae had a molecular weight of 40,000 and a pH optimum o f 4 with no activity at neutral pH. Both parasite hyaluronidases also degraded the glycosaminoglycan chondroitin sulfate A. Cupric sulfate a nd high concentrations of sodium chloride were inhibitory. The nematod e hyaluronidases are postulated to have a role in tissue histolysis an d mucosal invasion; their distinct biochemical properties have relevan ce to the pathogenesis of the zoonoses anisakiasis and eosinophilic en teritis.