Genetic characterization of the lobster pathogen Aerococcus viridans var. homari by 16S rRNA gene sequence and RAPD

• Published in: Diseases of aquatic organisms Vol. 63; no. 2-3; pp. 237 - 246
• Main Authors: GREENWOOD, Spencer J, KEITH, Ian R, DESPRES, Béatrice M, CAWTHORN, Richard J
• Format: Journal Article
• Language: English
• Published: Oldendorf Inter-Research 28.02.2005
• Subjects: Animals; Atlantic Ocean; Bacteriology; Base Sequence; Biological and medical sciences; Cluster Analysis; Crustacea; DNA Primers; Fundamental and applied biological sciences. Psychology; Genetic Variation; Geography; Invertebrates; Marine; Microbiology; Molecular Sequence Data; Nephropidae - microbiology; Pathology; Phenotype; Phylogeny; Random Amplified Polymorphic DNA Technique; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Streptococcaceae - classification; Streptococcaceae - genetics; Systematics; Atlantic Ocean; Aerococcus viridans; 16S rRNA; Genetic variability; RAPD; Zoopathogen; Phylogeny; Random amplified polymorphic DNA marker; Macrura; Crustacea; Marine environment; Streptococcaceae; Homarus americanus; Edible crustacean; Aerococcus viridans var. homari; Lobster; Gene; Arthropoda; 16S-RNA; Micrococcales; Bacteria; Decapoda; Gaffkemia; Invertebrata
• ISSN: 0177-5103; 1616-1580
• DOI: 10.3354/dao063237

A combination of 16S rRNA sequencing and random amplified polymorphic DNA (RAPD) analysis was used to evaluate the genetic diversity within Aerococcus viridans var. homari, the causative agent of gaffkemia in lobsters. A collection of 7 A. viridans var. homari strains and 2 avirulent A. viridans-like cocci isolated from homarid lobsters harvested from different regions on the Atlantic Coast of North America were analyzed. The isolates are separated geographically and temporally between the years 1947 and 2000. Sequencing of 16S rRNA genes confirmed the inclusion of all 9 isolates in the monophyletic A. viridans clade (99.8 to 100% similarity). RAPD analysis revealed that the 9 A. viridans var. homari isolates could be separated into 2 distinct subtypes. Subtype 1 included the 7 pathogenic lobster isolates and constituted a homogeneous group regardless of their geographical, temporal or virulence differences. Subtype 2 contained the 2 avirulent A. viridans-like cocci that had distinct RAPD patterns and clustered separately with the non-marine A. viridans. RAPD analysis represented a useful method for determining molecular subtyping for the intraspecific classification and epidemiological investigations of A. viridans var. homari.