Spiroplasma penaei sp. nov., associated with mortalities in Penaeus vannamei, Pacific white shrimp.

A new bacterial strain, designated SHRIMP(T), isolated from the haemolymph of the Pacific white shrimp, Penaeus vannamei, was serologically distinct from other spiroplasmas. Cells of this strain were helical in form and variable in length. Examination by electron microscopy revealed wall-less cells delineated by a single cytoplasmic membrane. The organisms grew well in M1D media supplemented with 2 % NaCl. Strain SHRIMP(T) grew at temperatures of 20-37 degrees C, with optimum growth occurring at 28 degrees C. The strain catabolized glucose and hydrolysed arginine, but did not hydrolyse urea. The G+C content of the DNA was 29 +/-1 mol%. Strain SHRIMP(T) (=ATCC BAA-1082T=CAIM 1252T) is designated the type strain of a novel species, Spiroplasma penaei sp. nov., which represents a new subgroup (I-9) of the group I spiroplasmas.