Chryseobacterium culicis sp. nov., isolated from the midgut of the mosquito Culex quinquefasciatus

Abstract

A yellow-pigmented bacterial strain, R4-1A(T), isolated from the midgut of the mosquito Culex quinquefasciatus (a vector of lymphatic filariasis), was studied using a polyphasic approach. Cells of the isolate were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequence of this organism with sequences of type strains of the most closely related species clearly showed an allocation to the genus Chryseobacterium, with the highest sequence similarities (all 97.9 %) to Chryseobacterium jejuense JS17-8(T), C. indologenes ATCC 29897(T), C. arthrosphaerae CC-VM-7(T) and C. aquifrigidense CW9(T). 16S rRNA gene sequence similarities to type strains of other Chryseobacterium species were below 97.5 %. The fatty acid profile of strain R4-1A(T) included the major fatty acids iso-15 : 0, summed feature 4 (comprising iso-15 : 0 2-OH and/or 16 : 1ω7c), iso-17 : 1ω9c and iso-17 : 0 3-OH. DNA-DNA hybridizations with C. jejuense KACC 12501(T), C. indologenes CCUG 14556(T), C. arthrosphaerae CC-VM-7(T) and C. aquifrigidense KCTC 12894(T) resulted in relatedness values of 38.3 % (reciprocal 30.5 %), 29.4 % (32.1 %), 23.2 % (37.2 %) and 29.5 % (47.1 %), respectively. These results and the differentiating biochemical and chemotaxonomic properties show that strain R4-1A(T) represents a novel species, for which the name Chryseobacterium culicis sp. nov. is proposed. The type strain is R4-1A(T) (=LMG 25442(T) =CCM 7716(T)).