From the Research
Gram-Positive Anaerobic Cocci
- Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of organisms defined by their morphological appearance and their inability to grow in the presence of oxygen 1
- Most clinical isolates are identified to species in the genus Peptostreptococcus, which includes species such as Peptostreptococcus magnus and Peptostreptococcus micros 1
- Other genera of GPAC include Anaerococcus, Finegoldia, Parvimonas, and Peptoniphilus, which are also commonly isolated from human infections 2
Identification and Classification
- The identification of GPAC has been improved by the development of molecular techniques, such as 16S rRNA gene sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) 3, 4
- These techniques have allowed for the identification of new species and the reclassification of existing species, resulting in changes to the nomenclature of GPAC 2
Characteristics and Pathogenicity
- GPAC are part of the normal flora of all mucocutaneous surfaces and are often isolated from infections such as deep organ abscesses, obstetric and gynecological sepsis, and intraoral infections 1
- Some species of GPAC, such as Peptostreptococcus magnus and Peptostreptococcus micros, have been shown to possess virulence factors and are increasingly recognized as important pathogens in certain infections 1, 2
- Staphylococcus aureus, a gram-positive coccus that can form clusters, is a major commensal bacterium and a human pathogen that causes a wide range of clinical infections, but it is not an anaerobe 5