In all
these strains the porin omp2 genes were different from those from marine mammal strains isolated on European coasts [30]. Briefly, the omp2 selleck chemicals llc genes of these isolates from the Pacific share common features with both marine mammal (from Europe) and terrestrial mammal strains [29]. Another interesting observation is that all the Pacific isolates investigated so far (including the three reported human cases) carry fragment I identified by IRS-PCR which is part of a putative genomic island specific for B. pinnipedialis [12]. Since these cetacean isolates are quite distinct from European marine mammal isolates there might be a third marine mammal Brucella species or subspecies found in Pacific waters. Owing to the simplicity of selleck compound MLVA-16 typing, and in particular of panel 1 which can be typed on regular agarose
gels and already provides a high informativity in classifying marine mammal strains (Figure 3), more CH5424802 in vivo typing information on Pacific Ocean strains (including the strains described in [29–31]) will likely be made available in a near future. The Brucella2009 genotyping database available at http://mlva.u-psud.fr/ and based upon the data provided in Additional file1 can be used for this purpose. Figure 4 shows the global population structure of the nine species currently constituting the Brucella genus, as can be revealed by MLVA-16 typing using this dataset (the extended data set provided here may provide new opportunities to evaluate additional methods for Brucella MLVA data clustering recently proposed [34]). Conclusion MLVA-16 proved to be useful for molecular classification of a high number of marine mammal
Brucella strains and allows the typing of large populations, while providing a clustering in agreement with all previously reported methods, together with a much higher discriminatory power. From the clustering achieved, a few representative strains can be selected for whole genome sequencing. Methods Brucella strains MLVA analysis was performed on 294 isolates from 173 marine mammals and one human patient. The strains essentially originate from the Northern Atlantic, from three main sources, Scotland (216 isolates from 116 animals), Germany Etomidate (58 isolates from 42 animals) [35] and Norway (18 isolates from 13 animals) [27]. Six additional strains from various geographic origins were analysed. Two strains were obtained from France (one strain from a bottlenose dolphin (Tursiops truncatus) and one from a harbour porpoise (Phocoena phocoena)), one from Spain (from a striped dolphin (Stenella coeruleoalba)) [36] and two from The Netherlands (two strains from one harbour porpoise (Phocoena phocoena)). The sixth strain was a human isolate from New-Zealand (strain 02/611 genotype 117) [14]. Strains (one strain per genotype and animal) are listed in Figures 1 and 2 and in Additional file1.