C-190. Characterization of Gilardi Rod Group 1 Like Isolates and Assignment to the Genus Ignatzschineria (formerly Schineria)

K. A. Bernard1, T. Burdz1, M. Yuen2;
1Natl. Microbiology Lab., Winnipeg, MB, CANADA, 2Ctr. for Infectious Diseases, Westmead, NSW, AUSTRALIA.

Background: Bacteria identified as being most consistent with (provisional taxon name) Gilardi Rod group 1, first described in the early 1990’s, are rare opportunistic human pathogens. In this report, we present salient features of these bacteria recovered in 2 countries (Canada and Australia) from clinical materials, in order to allow for more precise and rapid recognition by microbiologists. Methods: clinical information was reviewed. Strains were characterized using conventional and rapid API strip phenotypic testing, antimicrobial susceptibility testing (AST) and standard chemotaxonomic methods. Nearly full 16SrRNA sequences were obtained, BLASTed and aligned with related sequences obtained from Genbank using CLUSTAL X. Neighbour-joining distance relationships at genus and family level were inferred using MEGA 4.0. Results: 5 isolates, 4 Canadian (3 blood culture, 1 wound, from 2 provinces (Ont, Sask)), and 1 recent isolate from Australia were studied. All strains had a yellowish pigment, were biochemically asaccharolytic, grew on MacConkey and SS media, were catalase and oxidase positive, did not reduce nitrate nor nitrite, were non motile and all produced phenylalanine deaminase (PPA). 16SrRNA gene sequence data suggested that these strains best fit into 2 closely related clades assignable to the genus Ignatzschineria (formerly genus Schineria) but both were distinct from the type species, Ig. larvae. Strains in 1 clade were urea negative and so best fit the Gilardii rod description whereas strains in the 2nd clade were urea positive(conventional or API methods). CFAs were qualitatively similar to that published for Gilardi Rod gr 1 but quantitative differences were observed between the urea positive and negative groups. Conclusions: Gilardi Rod group 1 type isolates could unambiguously be assigned to the genus Ignatzschineria. Based on this study and current literature, this genus, which currently has 1 species, appears to be heterogeneic and so additional species can be described based on information reviewed here.