Two Gram-negative, rod-shaped strains, T2.1T and W5.1.1T, isolated from the larvae of the mosquito Anopheles arabiensis were investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity studies, strains T2.1T and W5.1.1T were shown to belong to the genus Thorsellia, both with 97.8% similarity to the type strain of T. anophelis, and with 98.1% similarity to each other. Chemotaxonomic data supported the allocation of the strains to the genus Thorsellia: their major fatty acids are C18:1ω7c, C16:0, and C14:0; they harbor a ubiquinone Q-8 quinone system and a polyamine pattern with the major compound 1,3-diaminopropane. Qualitative and quantitative differences in their polar lipid profile distinguish the two strains T2.1T and W5.1.1T from each other and from T. anophelis. Average nucleotide identity (ANI), DNA-DNA hybridization, Multi Locus sequence analysis (MLSA) as well as physiological and biochemical tests allowed to distinguish both genotypically and phenotypically T2.1T and W5.1.1T from each other and from the type strain of T. anophelis. Thus, we propose that these isolates represent two novel species of the genus Thorsellia, named Thorsellia kenyensis sp. nov. and Thorsellia kandunguensis sp. nov., respectively. The type strains are T2.1T (=CCM 8545 = LMG 28483T) and W5.1.1T (= LMG 28213T =CIP 110794T), respectively. Furthermore, phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the genus Thorsellia formed a separate branch, distinct from Enterobacteriaceae, Pasteurellaceae, and Orbaceae. As a consequence, a new family Thorselliaceae fam. nov. is proposed.
2015. Vol. 65, 444-451 p.