Dermonecrotic toxin production by strains of Pasteurella multocida isolated from man.

Ninety-four clinical isolates of Pasteurella multocida of human origin were tested for dermonecrotic toxin (DNT) production by three methods: dermonecrotic test in guinea-pigs, Vero cell culture cytotoxicity and ELISA. The strains were isolated from patients living in a rural area with widespread intensive pig breeding. Six strains were found to be toxigenic by the three tests. A major protein band of Mr 145 Kda corresponding to DNT on immunoblots was demonstrated in extracts from these strains. All were isolated from respiratory tract (diseases 5, healthy carriage 1). The difference between isolates from the respiratory tract and isolates from wounds inflicted by pets was statistically significant with regard to DNT production (p less than 0.02). A possible role of the toxin in pulmonary diseases caused by P. multocida has yet to be established.