Enteroccocus pallens as a potential novel human pathogen: three cases of spontaneous bacterial peritonitis

INTRODUCTION: Enterococcus pallens is one of the four yellow-pigmented members of the genus Enterococcus. To date, a single report of E. pallens isolated from a human sample has been published. CASE PRESENTATION: We report three cases of E. pallens spontaneous bacterial peritonitis in patients with liver cirrhosis that all occurred in Quebec, Canada. Ascitic fluid analysis revealed the presence of E. pallens in culture. Identification was made by classical biochemical testing and MALDI-TOF MS, as well as 16S rRNA and elongation factor (tuf) gene sequencing. Two of the three patients recovered after antimicrobial treatment. CONCLUSION: This report identifies E. pallens as a novel human pathogen that appears to possess particular but as-yet unidentified virulence factors that favour the development of peritoneal fluid infections, as previously reported for other Enterococcus species. Clinical microbiologist should be aware of this micro-organism which can be identified by phenotypic and molecular methods.