Emerging pathogen Christensenella hongkongensis in Australia: case series and literature review

Newly renamed anaerobic bacterium Christensenella hongkongensis is an emerging pathogen associated with high mortality. Antimicrobial susceptibility profile and pathogenesis of C. hongkongensis are yet to be fully elucidated. Since its first description from Hong Kong and Canada in 2007, 20 Christensenella hongkongensis bloodstream infections (BSI) have been reported. We report the additional five cases of C. hongkongensis BSI from Australia and present their descriptive genomic epidemiology. We review the antimicrobial susceptibilities, clinical features and outcomes of cases of all C. hongkongensis BSI reported to date. C. hongkongensis BSI is associated with high mortality in patients with underlying gastro-intestinal tract malignancy and often isolated in the setting of polymicrobial bacteraemia.