Enterococcus caccae sp. nov., isolated from human stools

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Two enterococcus-like strains were isolated from human stool samples.
• These isolates were referred to the Centers for Disease Control and Prevention (CDC) Streptococcus Laboratory for identification.

Purpose of the Study:

• To identify and characterize two novel enterococcus-like strains.
• To determine if these strains represent a new species within the Enterococcus genus.

Main Methods:

• Conventional physiological tests
• Whole-cell-protein electrophoresis
• AccuProbe Enterococcus genetic probe and Lancefield extracts
• 16S rRNA gene sequencing
• DNA-DNA relatedness experiments

Main Results:

• The isolates were distinct from known enterococcal species based on physiological tests.
• Protein profiles were unique but similar to Enterococcus moraviensis and Enterococcus haemoperoxidus.
• 16S rRNA gene sequencing showed 99.6% identity to E. moraviensis.
• DNA-DNA relatedness was below 32% to recognized Enterococcus species, confirming a novel taxon.

Conclusions:

• The two stool isolates constitute a novel species, Enterococcus caccae sp. nov.
• The type strain is 2215-02(T).