Culture-dependent characterization of the microbial community associated with epizootic shell disease lesions in American lobster, Homarus americanus

Author Posting. © National Shellfisheries Association, 2005. This article is posted here by permission of National Shellfisheries Association for personal use, not for redistribution. The definitive version was published in Journal of Shellfish Research 24 (2005): 741-747, doi:10.2983/0730-8000(2005)24[741:CCOTMC]2.0.CO;2.Epizootic shell disease in the American lobster is an important factor affecting lobster fisheries in and around the Long Island Sound. It is a strictly dermal disease, because no correlation was observed between occurrence of epizootic shell disease and hemolymph infection. The culturability of bacteria from lesions was variable and averaged around 1.1%. The lesions contained two to four orders of magnitude more bacteria than healthy carapace surfaces of the same animal. Chitinoclastic bacteria comprised a very small fraction of bacteria present in the lesions, suggesting that their role in epizootic shell disease may be limited. Phylogenetic analysis of bacteria isolated from the lesions showed no typical bacterial pathogens of lobsters such as Aerococcus viridans or Vibrio fluvialis. Moreover, bacteria commonly associated with shell disease of other Crustacea or other forms of shell disease of the American lobster were not found. Two common groups of bacteria were isolated from lesions of all lobsters used in this research: one belonging to a species complex affiliated with the Flavobacteriaceae family and the second belonging to a series of closely related if not identical strains of Pseudoalteromonas gracilis. Bacteria isolated from only a few lobsters were related to Shewanella frigidimarina, Alteromonas arctica, Vibrio lentus, Shewanella fidelia, Pseudoalteromonas tunicata and Vibrio spp. Based on the analyses of culturable isolates, overall microbial communities found in lesions of lobsters from eastern Long Island Sound and Buzzards Bay appear to be similar to each other.This research was supported by the NY Sea Grant #R/FBM-25 to AYC and RS. This publication was also supported by the National Sea Grant College Program of the US Department of Commerce’s National Oceanic and Atmospheric Administration under award #NA16RG1354 to the Research Foundation of State University of New York for New York Sea Grant