Leptospira weilii serovar Topaz, a new member of the Tarassovi serogroup isolated from a bovine source in Queensland, Australia

1 Animal Research Institute, Queensland Department of Primary Industries and Fisheries, Yeerongpilly, Australia 2 WHO/FAO/OIE Collaborating Centre for Reference & Research on Leptospirosis, Western Pacific Region, Communicable Diseases, Queensland Health Forensic and Scientific Services, Brisbane, Australia 3 University of Queensland, St Lucia, Australia Correspondence L. D. Smythe Lee_Smythe{at}health.qld.gov.au This paper reports on a Leptospira isolate of bovine origin and its identification as belonging to a previously unknown serovar, for which the name Topaz is proposed. The isolate (94-79970/3) was cultured from bovine urine from a north Queensland dairy farm in Australia. Strain 94-79970/3 grew at 30 °C in Ellinghausen McCullough Johnson Harris (EMJH) medium but failed to grow at 13 °C in EMJH medium or in the presence of 8-azaguanine. Serologically, strain 94-79970/3 produced titres against the Leptospira borgpetersenii serovar Tarassovi, the reference strain for the Tarassovi serogroup; however, no significant titres to any other serovars within the serogroup were obtained. Using 16S rRNA and DNA gyrase subunit B gene analysis, strain 94-79970/3 was identified as a member of the species Leptospira weilii . We propose that the serovar be named Topaz, after the location where the original isolate was obtained. The reference strain for this serovar is 94-79970/3 (=KIT 94-79970/3=LT722). Abbreviations: CAAT, cross-agglutinin absorption test; MAT, microscopic agglutination test These authors contributed equally to this work and wish to be recognized as joint first authors. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA and gyrB gene sequences of Leptospira weilii serovar Topaz strain 94-79970/3 are DQ483058 and DQ483059 , respectively.