ABSTRACT
A new species of Astropecten is described, supported by morphological and molecular evidence, from the Gulf of Mexico and the East Florida Shelf with most specimens from 30-60 m in depth. The new species, A. mcedwardi n. sp., is small, with a maximum major radius 30 mm. Specimens of A. mcedwardi n. sp. have been found in five museums as an undescribed species or misidentified under several names. The spination of the oral surface most closely resembles that of Astropecten antillensis Lütken, 1859 from the Caribbean, but the body form is similar to that of Astropecten duplicatus Gray, 1840, which is found in the same geographic range. Examination of specimens from different collections indicates that the new species may overlap in distribution with A. antillensis along the East Florida Shelf. Sequencing and phylogenetic analysis of two mitochondrial genes reveal that A. mcedwardi is closely related to A. antillensis but that its phylogenetic lineage is distinct from that of A. antillensis.
Subject(s)
Echinodermata , Animals , Caribbean Region , Florida , Gulf of Mexico , Mexico , PhylogenyABSTRACT
Salmonella Enteritidis became the main serovar isolated from gastroenteritis cases in Brazil after the 90's. In this study we used whole genome sequence analysis to determine the phylogenetic relationships among a collection of strains isolated in Brazil to identify possible genomic differences between the strains isolated in the pre and post-epidemic period. Also, we compared our data from strains isolated in Brazil to strains available in the public domain from other South American countries. Illumina technology was used to sequence the genome of 256 Salmonella Enteritidis strains isolated over a 48 year-period in Brazil, comprising the pre- and post-epidemic period. Phylogenetic analyses revealed distinct lineages for strains isolated before and after 1994. Moreover, the phage region SE20 that may be related to the emergence of Salmonella Enteritidis worldwide was present only in strains of the post-epidemic cluster. In conclusion, our results showed that the genomic profile of Salmonella Enteritidis strains isolated in Brazil shifted after 1994, replaced by a global epidemic group of strains. It may be hypothesized that the presence of the prophage SE20 might have conferred to these strains a better ability to colonize chicken and consequently to infect and cause disease in humans, which might better explain the increase in the number of S. Enteritidis cases in Brazil and other South American countries. However, to verify this hypothesis further studies are needed.