Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5-6
pubmed:dateCreated
2001-5-17
pubmed:abstractText
Brown ring disease (BRD) is a shell disease caused by Vibrio tapetis. This pathogen disturbs the periostracal lamina causing the appearance of a brown conchiolin deposit on the inner face of the shell, within the extrapallial space. Although differences in resistance to BRD have been documented, their relationship to possible defense functions has never been investigated. In this study, flow cytometry was used to analyze cellular parameters in asymptomatic and experimentally infected Ruditapes philippinarum from France and the west coast of the USA. Parallel analyses were made on Ruditapes decussatus, the native European clam, which is highly resistant to BRD. In the haemolymph and extrapallial fluid of animals without BRD, total haemocyte counts, the percentage of granulocytes, and the phagocytic activity against latex beads or V. tapetis by the haemocytes were significantly higher in American R. philippinarum than in French R. philippinarum. In most cases, levels in R. decussatus were the highest of all three groups. Four weeks following challenge with V. tapetis, BRD prevalence reached 52 in American clams and 100% in French specimens, but only 37% in R. decussatus. In symptomatic animals, phagocytosis of V. tapetis increased significantly in the resistant species of clam, R. decussatus, was unchanged in US clams, and decreased significantly in FR specimens when compared to asymptomatic individuals from each population. Ingestion of V. tapetis by haemocytes in the extrapallial fluid, which is in contact with the periostracal lamina, could be the main defense mechanism used to counter the pathogen. Our results suggest that resistance to BRD may well be related to the concentration of granular haemocytes and the phagocytic activity of haemocytes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0145-305X
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
365-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Haemocyte parameters associated with resistance to brown ring disease in Ruditapes spp. clams.
pubmed:affiliation
Haskin Shellfish Research Laboratory, Rutgers University, Port Norris, NJ 08349, USA. bassem.allam@univ-ag.fr
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't