McPherson Edward J, Ishmael Chad R, Zukotynski Brian, Gallivan Robert E, Chowdhry Madhav
Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
Department of Orthopaedic Surgery, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
J Orthop Case Rep. 2022 Nov;12(11):76-82. doi: 10.13107/jocr.2022.v12.i11.3422.
Periprosthetic joint infection (PJI) remains a challenging complication of joint replacement surgery. With the more frequent use of immune modifying drugs and dietary changes in human populations, the resultant blunting of immune defenses allows for infections with less common organisms.
Lactococcus garvieae is an anaerobic, gram-positive coccus with reservoirs in fish and domesticated farm animals. Only two prior cases of PJI due to L. garvieae have been reported, both with reported marine transmission. We report a case of L. garvieae associated PJI in a cattle rancher with the first reported case of transmission from a bovine reservoir. The PJI was associated with intra-articular rice body formation, and the diagnosis confirmed with the aid of next generation DNA sequencing. A successful two stage exchange was performed. We propose a novel transmission mechanism with microbe entry via direct hematogenous inoculation during the patient's duties as a rancher.
When an unusual organism is detected in a PJI, the treatment team should research the host reservoir(s) of the organism and correlate with the patient's exposure risk. While contamination of cultures is possible, a thorough investigation should be performed prior to that assumption. This reinforces the basic concept that a careful history remains vital when treating an unusual infection presentation. Next generation DNA sequencing is a useful confirmatory tool in establishing the offending organism. Lastly, the identification of rice bodies should raise suspicion for infection. Although not always associated with infection, efforts should be redoubled to identify or rule out a causative micro-organism(s).
人工关节周围感染（PJI）仍然是关节置换手术中具有挑战性的并发症。随着免疫调节药物的使用日益频繁以及人群饮食结构的改变，由此导致的免疫防御功能减弱使得感染少见病原体成为可能。
格氏乳球菌是一种厌氧菌，革兰氏阳性球菌，在鱼类和家畜中存在宿主。此前仅报告过两例由格氏乳球菌引起的PJI病例，均有海洋传播的报道。我们报告一例在养牛场主中发生的与格氏乳球菌相关的PJI病例，这是首例报告的来自牛宿主的传播病例。该PJI与关节内米粒体形成有关，借助下一代DNA测序确诊。成功实施了两阶段置换手术。我们提出一种新的传播机制，即在患者作为牧场主工作期间，微生物通过直接血源性接种进入体内。
当在PJI中检测到不常见的病原体时，治疗团队应研究该病原体的宿主并与患者的暴露风险相关联。虽然培养物可能受到污染，但在做出该假设之前应进行全面调查。这强化了一个基本概念，即在治疗不寻常的感染表现时，仔细询问病史仍然至关重要。下一代DNA测序是确定致病病原体的有用确证工具。最后，米粒体的发现应引起对感染的怀疑。虽然并非总是与感染相关，但应加倍努力识别或排除致病微生物。
