Streptococcus penaeicida sp. nov., isolated from a diseased farmed Pacific white shrimp (Penaeus vannamei)

Strain CAIM 1838^T, isolated from the hepatopancreas of a cultured diseased Pacific white shrimp (Penaeus vannamei), was subjected to characterization by a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence analysis, strain CAIM 1838^T was most closely related to Streptococcus bovimastitidis 99.3 % and to other species of the Pyogenes clade of Streptococcus with lower similarity values. Average nucleotide identity values and the genome-to-genome distance of strain CAIM 1838^T, as compared with the type strains, confirmed the separate species status with closely related species of the genus Streptococcus and were all below the thresholds to delimit a species, 93.1 and 49.4 %, respectively. The DNA G+C content was 38.1 mol%. Differential phylogenetic distinctiveness together with phenotypic properties obtained in this study revealed that strain CAIM 1838^T could be differentiated from the closely related species. Based on these results it is proposed that strain CAIM 1838^T represents a novel species in the genus Streptococcus, for which the name Streptococcus penaeicida sp. nov is proposed (type strain, CAIM 1838^T=CECT 8596^T,=DSM26545^T), is proposed.