DAO prepress abstract  -  doi: 10.3354/dao01920

ABSTRACT: In this study organ samples from 426 common seals Phoca vitulina, 298 harbour porpoises Phocoena phocoena, 34 grey seals Halichoerus grypus and 10 other marine mammals were assessed for the presence of Brucella species. 47 common seals, two harbour porpoises and one grey seal were found to be positive for these bacteria. Taken together, 91 Brucella strains were successfully isolated due to the fact that in several animals Brucella species were found in more than one organ sample. The primary organ in which the bacteria were present was the lung. In addition, two strains were isolated from lungworms Parafilaroides spp. 49 of the isolated strains were chosen to be further analysed via conventional phenotyping methods. Molecular characterisation was carried out by analysing the IS711- and omp2-locus. Concerning the distribution of the IS711-loci in the genome, the 49 field isolates differed strongly from the terrestrial Brucella species and marginally from the marine Brucella reference strain NCTC12890. Based on the results of the RFLP-PCR investigation of the omp2-locus, the majority of the Brucella field isolates could be classified as B. pinnipediae, recently proposed B. pinnipedialis, possessing one omp2a-gene and one omp2b-gene. Two field isolates revealed the presence of two omp2a-genes, as described for Brucella ovis. To our knowledge, these results confirm for the first time the presence of Brucella species in the marine mammal population of the German North Sea. These findings urge the necessity of additional research on these Brucella species for marine hosts and their environment.