Department of Rheumatology, Chubu Rosai Hospital, 2-10-15, Komei-cho, Minato-ku, Nagoya, Aichi, 455-8530, Japan.
Department of Clinical Laboratory, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, 466-8650, Japan.
BMC Infect Dis. 2020 Aug 5;20(1):578. doi: 10.1186/s12879-020-05305-y.
Gram-positive anaerobic (GPA) bacteria inhabit different parts of the human body as commensals but can also cause bacteremia. In this retrospective observational study, we analyzed GPA bacteremia pathogens before (2013-2015) and after (2016-2018) the introduction of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).
We conducted a retrospective observational study by searching the microbiology database to identify all positive GPA blood cultures of patients with GPA bacteremia diagnosed using the new technique, MALDI-TOF MS, between January 1, 2016 and December 31, 2018; and using a conventional phenotypic method between January 1, 2013 and December 31, 2015 at a single tertiary center in Japan. Parvimonas micra (P. micra) (17.5%) was the second most frequently identified GPA (MALDI-TOF MS); we then retrospectively reviewed electronic medical records for 25 P. micra bacteremia cases at our hospital. We also conducted a literature review of published cases in PubMed from January 1, 1980, until December 31, 2019; 27 cases were retrieved.
Most cases of P. micra bacteremia were identified after 2015, both, at our institute and from the literature review. They were of mostly elderly patients and had comorbid conditions (malignancies and diabetes). In our cases, laryngeal pharynx (7/25, 28%) and gastrointestinal tract (GIT; 6/25, 24%) were identified as the most likely sources of bacteremia; however, the infection source was not identified in 9 cases (36%). P. micra bacteremia were frequently associated with spondylodiscitis (29.6%), oropharyngeal infection (25.9%), intra-abdominal abscess (14.8%), infective endocarditis (11.1%), septic pulmonary emboli (11.1%), and GIT infection (11.1%) in the literature review. Almost all cases were treated successfully with antibiotics and by abscess drainage. The 30-day mortalities were 4 and 3.7% for our cases and the literature cases, respectively.
Infection sites of P. micra are predominantly associated with GIT, oropharyngeal, vertebral spine, intra-abdominal region, pulmonary, and heart valves. Patients with P. micra bacteremia could have good prognosis following appropriate treatment.
革兰阳性厌氧（GPA）细菌作为共生菌栖息在人体的不同部位，但也可引起菌血症。在这项回顾性观察研究中，我们分析了在引入基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）之前（2013-2015 年）和之后（2016-2018 年）的 GPA 菌血症病原体。
我们通过搜索微生物学数据库进行了一项回顾性观察研究，以鉴定所有在日本一家单中心医院于 2016 年 1 月 1 日至 2018 年 12 月 31 日期间使用 MALDI-TOF MS 新技术诊断为 GPA 菌血症的患者的阳性 GPA 血液培养物，并在 2013 年 1 月 1 日至 2015 年 12 月 31 日期间使用传统表型方法进行鉴定。小韦荣球菌（P. micra）（17.5%）是第二种最常被鉴定的 GPA（MALDI-TOF MS）；然后，我们回顾性地查阅了我院 25 例 P. micra 菌血症病例的电子病历。我们还对 1980 年 1 月 1 日至 2019 年 12 月 31 日在 PubMed 上发表的文献进行了文献回顾，共检索到 27 例病例。
无论是在我们的研究所还是从文献综述中，大多数 P. micra 菌血症病例都是在 2015 年后发现的。它们主要发生在老年患者和患有合并症（恶性肿瘤和糖尿病）的患者中。在我们的病例中，咽喉（7/25，28%）和胃肠道（GIT；6/25，24%）被认为是菌血症的最可能来源；然而，有 9 例（36%）未确定感染源。P. micra 菌血症常与脊椎炎（29.6%）、口咽感染（25.9%）、腹腔脓肿（14.8%）、感染性心内膜炎（11.1%）、化脓性肺栓塞（11.1%）和 GIT 感染（11.1%）相关在文献综述中。几乎所有病例均通过抗生素治疗和脓肿引流成功治愈。我们的病例和文献病例的 30 天死亡率分别为 4%和 3.7%。
小韦荣球菌的感染部位主要与胃肠道、口咽、脊椎、腹腔、肺部和心脏瓣膜有关。在适当的治疗下，P. micra 菌血症患者的预后良好。
