Studies on host-parasite relationships in gaffkemia

Abstract

Gaffkya homari, the etiologic agent of the bacterial disease of the American lobster, Homarus americanus, known as gaffkemia was found to infect lobsters of ages less than 1 month to over 10 years. G. homari produced infection in the crab Libinia emarginata, though to a lesser degree than in the lobster, and to an even lesser degree in the crab Cancer borealis. Little evidence for infection was found in inoculated horseshoe crabs ( Limulus polyphemus). Recalcified clotting times and amebocyte counts of gaffkemic and nongaffkemic lobsters were similar. A culture filtrate of G. homari induced casting-off of inoculated chelae and/or hyperactivity in 11 of 19 individual lobsters. A naturally gaffkemic lobster was found to recover from the infection and to possess thereafter a partial resistance to challenge with G. homari. No correlation was found between the degree of stimulation produced by individual lobster sera on the growth of G. homari in vitro and the individual susceptibility of the lobster on direct inoculation. Attempts to transmit the infection by contact with infected lobsters or contaminated water or by feeding were negative.