A case of Escherichia coli and Peptoniphilus species mixed osteomyelitis successfully identified by MALDI TOF-MS with a review of the literature

Background: Peptoniphilus species are Gram-positive anaerobic cocci that are commensals of the human vagina and gut. Methods and results: We describe a case of mixed Escherichia coli and Peptoniphilus spp. osteomyelitis identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry as Peptoniphilus harei and present a short literature review. Conclusion: To our knowledge, only six cases of P. harei osteomyelitis have been reported to date.