Parvimonas micra (P.micra) is a difficult to culture gram positive anaerobic microorganism, typically found in the human microbiota, specially in the oral cavity. There are limited cases in literature reporting prosthetic joint infection due to this bacteria, although its isolation has been reported in different settings in later years. We present the case of a late onset knee prosthetic joint infection caused by Parvimonas micra in an 87 year old woman treated with antibiotics and two-step surgery with prosthetic material removal, antibiotic-loaded cement spacer placement and new prosthetic material replacement after 2 weeks of intravenous antimicrobial therapy followed by 6 weeks of oral therapy.

Parvimonas micra (P.micra)是一种难以培养的革兰氏阳性厌氧微生物，通常存在于人体微生物群中，特别是在口腔中。文献中报道了由这种细菌引起的假体关节感染的病例有限，尽管后来在不同的环境中报道了这种细菌的分离。我们介绍了一名 87 岁女性由Parvimonas micra引起的迟发性膝关节假体关节感染，该病例接受了抗生素治疗，并在 2 周后进行了两步手术，包括假体材料去除、抗生素负荷水泥垫片放置和新的假体材料更换。静脉内抗菌治疗，然后是 6 周的口服治疗。