A Gram-negative, rod-shaped, non-spore-forming bacterium (MH96 T ) was isolated from diseased larvae of the New Zealand grass grub, Costelytra zealandica (Coleoptera: Scarabaeidae). On the basis of 16S rRNA gene sequence similarity, strain MH96 T is a member of the genus Yersinia, which is a member of the class Gammaproteobacteria. The most similar 16S rRNA gene sequence to that of MH96 T is that of the type strain of Yersinia mollaretii (98.5 % similarity) followed by those of the type strains of Yersinia aldovae, Y. frederiksenii and Y. rohdei (all 98.4 % similarity). Multilocus sequence typing of five housekeeping genes (dnaJ, glnA, gyrB, groEL and recA) identified Yersinia ruckeri (81-92 % similarity) as the closest relative. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain MH96 T from the four most closely related Yersinia species with validly published names, including a Y. ruckeri isolate. Strain MH96 T therefore represents a novel species, for which the name Yersinia entomophaga sp. nov. is proposed, with the type strain MH96 T (5DSM 22339 T 5ATCC BAA-1678 T ).The genus Yersinia is a member of the class Gammaproteobacteria (Woese & Fox, 1977), within the family Enterobacteriaceae, based on biochemical tests and DNA-DNA hybridization studies (Bottone, 1997). Yersiniae have undergone extensive diversification during the course of their evolution, with pathogenic species such as Yersinia pestis, the causative agent of bubonic plague (Perry & Fetherston, 1997), and Yersinia ruckeri, the causative agent of enteric redmouth disease in salmonid fish (Ewing et al., 1978), while other species (e.g. Yersinia aldovae) have diverged into non-pathogenic organisms (Sulakvelidze, 2000). At the time of writing, the genus et al., 2008). During isolation of bacteria from a diseased larva of the New Zealand grass grub, Costelytra zealandica (Coleoptera: Scarabaeidae), strain MH96 T was recovered on Luria-Bertani (LB) agar (Oxoid) at 30 u C, showing a cream-coloured colony. On LB agar, MH96 T was able to grow at 25-42 u C, but not at 45 u C. No haemolysis was detected at either 25 or 37 u C on either Columbia sheep blood or Columbia horse blood agar (Fort Richard Laboratories).Cell morphology was observed under an Olympus BX50 light microscope at 61000 magnification, with cells grown for 24 h. Motility was checked by microscopic observation. Flagellar staining was undertaken using the Becton Dickinson flagella stain in accordance with the manufacturer's instructions. Gram-staining was performed as described by Gerhardt et al. (1994). Transmission electron microscopy was carried out with a Zeiss 902 transmission electron microscope (80 kV) with cells from an exponentially growing culture stained with 2 % phosphotungstic acid.
Identification of MH96T was performed as described by Neubauer et al. (2000) except that incubation was for 48 h. API 20E (bioMérieux) tests were performed as described by the manufacturer except that all incubations...
