Characteristics of 20 human Pasteurella isolates from animal bite wounds.

The bacteriological characteristics of 18 isolates of Pasteurella multocida and two isolates of Pasteurella pneumotropica from infected animal bite wounds have been studied. A high proportion (8/18) of the P. multocida isolates fermented lactose and five fermented maltose. Two failed to ferment sorbitol. Neither of the P. pneumotropica strains showed ornithine decarboxylase activity. Other biochemical characteristics were mainly in agreement with previous reports. The susceptibility of the isolates to 10 antibacterial agents has been determined by the disc diffusion method. Ampicillin, cephalothin and cotrimoxazole showed uniformly good activity whereas penicillin G and doxycycline were slightly less active. Apart from one horse bite, all bites were inflicted by cats and dogs. Two cases were serious. P. multocida seems to be a commoner occurrence in infected animal bite wounds than reports suggest. P. pneumotropica bite infections are seemingly uncommon.