Proposal of Thorsellia kenyensis sp. nov. and Thorsellia kandunguensis sp. nov., isolated from larvae of Anopheles arabiensis, as members of the family Thorselliaceae fam. nov

Two Gram-negative, rod-shaped strains, T2.1 ᵀ and W5.1.1 ᵀ, isolated from larvae of the mosquito Anopheles arabiensis , were investigated using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity studies, strains T2.1 ᵀ and W5.1.1 ᵀ were shown to belong to the genus Thorsellia , both showing 97.8 % similarity to the type strain of Thorsellia anophelis , with 98.1 % similarity to each other. Chemotaxonomic data supported the allocation of the strains to the genus Thorsellia : their major fatty acids were C ₁₈ : ₁ω7 c , C ₁₆ : ₀ and C ₁₄ : ₀ and they harboured 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 profiles distinguished strains T2.1 ᵀ and W5.1.1 ᵀ from each other and from T. anophelis . Average nucleotide identity (ANI), DNA–DNA hybridization, multilocus sequence analysis (MLSA) as well as physiological and biochemical tests allowed T2.1 ᵀ and W5.1.1 ᵀ to be distinguished both genotypically and phenotypically 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. (type strain T2.1 ᵀ = CCM 8545 ᵀ = LMG 28483 ᵀ = CIP 110829 ᵀ) and Thorsellia kandunguensis sp. nov. (type strain W5.1.1 ᵀ = LMG 28213 ᵀ = CIP 110794 ᵀ). Furthermore, phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the genus Thorsellia forms a separate branch, distinct from the families Enterobacteriaceae , Pasteurellaceae and Orbaceae . As a consequence, a new family Thorselliaceae fam. nov. is proposed. An emended description of Thorsellia anophelis is also provided.