Epizootic shell disease (ESD) is a persistent malady that affects American lobsters (Homarus americanus) in the southern extent of the commercial fishery. Emerging at the turn of the 21st century, ESD presented as bacterial ulcerations on the carapace of affected lobsters. The research presented here examined the bacterial community of the lobster carapace and represented the first such attempt to characterize the lobster surface microbiome. Culture‐independent techniques, such as amplicon length heterogeneity and pyrosequencing, yielded sequence data of hypervariable regions of the genes for ribosomal RNA that upon comparison revealed the likely identities of the taxa present on the lobster carapace. Although some researchers have identified a novel chitinolytic bacterium of the genus Aquimarina (A. homaria) as consistently appearing on lobsters with shell disease, this research found no evidence of a correlation of this species with the disease. Instead, analysis revealed that the genus Aquimarina was ubiquitous and correlated only weakly with the diseased state. The data suggest that this disease is not caused by a single pathogen but by a state of dysbiosis where normally occurring microflora emerge as potential opportunistic pathogens when there is some apparent environmental stressor that alters the interaction of the surface biofilm of the lobster.
Part of the book: Microbial Biofilms