Abstract
BackgroundBacteria of the genus Brucella are the causative organisms of brucellosis in animals and man. Previous characterisation of Brucella strains originating from marine mammals showed them to be distinct from the terrestrial species and likely to comprise one or more new taxa. Recently two new species comprising Brucella isolates from marine mammals, B. pinnipedialis and B. ceti, were validly published. Here we report on an extensive study of the molecular and phenotypic characteristics of marine mammal Brucella isolates and on how these characteristics relate to the newly described species.ResultsIn this study, 102 isolates of Brucella originating from eleven species of marine mammals were characterised. Results obtained by analysis using the Infrequent Restriction Site (IRS)-Derivative PCR, PCR-RFLP of outer membrane protein genes (omp) and IS711 fingerprint profiles showed good consistency with isolates originating from cetaceans, corresponding to B. ceti, falling into two clusters. These correspond to isolates with either dolphins or porpoises as their preferred host. Isolates originating predominantly from seals, and corresponding to B. pinnipedialis, cluster separately on the basis of IS711 fingerprinting and other molecular approaches and can be further subdivided, with isolates from hooded seals comprising a distinct group. There was little correlation between phenotypic characteristics used in classical Brucella biotyping and these groups.ConclusionMolecular approaches are clearly valuable in the division of marine mammal Brucella into subtypes that correlate with apparent ecological divisions, whereas conventional bioyping is of less value. The data presented here confirm that there are significant subtypes within the newly described marine mammal Brucella species and add to a body of evidence that could lead to the recognition of additional species or sub-species within this group.
Highlights
Bacteria of the genus Brucella are the causative organisms of brucellosis in animals and man
The distribution of IS711 copies in the genomes of all of the marine strains included in this study showed little resemblance to any pattern previously observed in any other species or biovars, including those of B. ovis or B. suis bv 2 which themselves have many copies of the element
These findings indicate that marine mammal Brucella isolates may be common in parts of the world where little data has yet been reported
Summary
Bacteria of the genus Brucella are the causative organisms of brucellosis in animals and man. Ross et al (1994) [1] reported the isolation of Brucella from tissues collected post mortem from stranded marine mammals including common seal (Phoca vitulina), harbour porpoise (Phocoena phocoena) and common dolphin (Delphinus delphis) around the coast of Scotland whilst Ewalt et al (1994) [2] reported the recovery of the organism from an aborted foetus of a bottlenose dolphin (Tursiops truncatus) in the USA. The isolation of Brucella has since been described from a wide variety of marine mammals including Atlantic white-sided dolphin (Lagenorhynchus actus), striped dolphin (Stenella coeruleoalba), hooded seal (Crystophora cristata), grey seal (Halichoerus grypus), European otter (Lutra lutra) [3,4], Pacific harbour seal (Phoca vitulina richardsii) [5], minke whale (Balaenoptera acutorostrata) [6] and white beaked dolphin (Lagenorhynchus albirostris) [7]. Evidence from the southern hemisphere is less well documented there are reports of positive serological results from baleen whales (Mysticeti) from the western North Pacific [14], Hawaiian monk seals (Monachus schauinslandi) from the Northwestern Hawaiian Islands [15], bottlenose dolphins from the Solomon Islands [16], cetaceans living off the Peruvian coast [11] and seals from Antarctica [17] and Australia [18]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
