Corynebacterium timonense sp. nov. and Corynebacterium massiliense sp. nov., isolated from human blood and human articular hip fluid

Abstract

Gram-positive, facultatively anaerobic, rod-shaped bacteria were isolated from the blood of a patient with endocarditis (strain 5401744T) and from the hip joint fluid of a patient with an infected orthopaedic prosthesis (strain 5402485T). These strains were characterized by using a polyphasic taxonomic approach. Based on cellular morphology and biochemical criteria the two isolates were tentatively assigned to the genus Corynebacterium, although they did not correspond to any recognized species. The predominant fatty acids were a mix of C18:2omega6,9c and anteiso-C18:0 (32.1% of the total), C16:0 (26.3%) and C18:1omega9c (22.5%) for strain 5402485T and C18:1omega9c (36.4%), C17:1omega9c (27.1%) and C16:0 (10.9%) for strain 5401744T. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain 5401744T was closely related to the type strains of Corynebacterium auris, Corynebacterium capitovis, Corynebacterium lipophiloflavum and Corynebacterium mycetoides (97.0, 96.6, 96.5 and 96.3% similarity, respectively) and strain 5402485T was closely related to the type strains of Corynebacterium macginleyi, Corynebacterium accolens, Corynebacterium tuberculostearicum, Corynebacterium confusum, Corynebacterium mastitidis and Corynebacterium renale (95.6, 95.3, 95.3, 94.5, 94.0 and 93.5%, respectively). On the basis of phenotypic data and phylogenetic inference, these isolates are considered to represent two novel species of the genus Corynebacterium, for which the names Corynebacterium timonense sp. nov. (type strain, 5401744T=CSUR P20T=CIP 109424T=CCUG 53856T) and Corynebacterium massiliense sp. nov. (type strain, 5402485T=CSUR P19T=CIP 109423T=CCUG 53857T) are proposed.