Flaviflexus equikiangi sp. nov. isolated from faeces of Equus kiang (Tibetan wild ass) and carrying a class 1 integron gene cassette in its genome

Abstract

Two Gram-stain-positive, catalase-negative, non-spore-forming, cocci-shaped strains (dk850T and JY899) were isolated from the feces of Equus kiang in the Qinghai-Tibet Plateau of China. 16S rRNA gene sequence-based phylogenetic analyses showed that strains dk850T and JY899 belong to the genus Flaviflexus, closest to F. salsibiostraticola KCTC 33148T, F. ciconiae KCTC 49253T and F. huanghaiensis H5T. The DNA G + C content of strain dk850T was 62.9%. The digital DNA-DNA hybridization values of strain dk850T with the closely related species were below the 70% threshold for species demarcation. The two strains grew best at 28°C on brain heart infusion (BHI) agar with 5% sheep blood. All strains had C18:1ω9c and C16:0 as the major cellular fatty acids. MK-9(H4) was the major menaquinone in strain dk850T. The major polar lipids included diphosphatidylglycerol and an unidentified phospholipid. Strains dk850T and JY899 were identified as carrying a class 1 integron containing the aminoglycoside resistance gene aadA11, both strains were resistant to spectinomycin and streptomycin. Based on several lines of evidence from phenotypic and phylogenetic analyses, strains dk850T and JY899 represent a novel species of the genus Flaviflexus, for which the name Flaviflexus equikiangi sp. nov. is proposed. The type strain is dk850T(= CGMCC 1.16593T = JCM 33598T).