Zdziarski Przemysław, Paściak Mariola, Rogala Klaudia, Korzeniowska-Kowal Agnieszka, Gamian Andrzej
Department of Clinical Immunology, Lower Silesian Center for Cellular Transplantation, PO Box 1818, 50-385, Wrocław-46, Poland.
Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland.
BMC Infect Dis. 2017 Dec 12;17(1):763. doi: 10.1186/s12879-017-2886-7.
Elizabethkingia miricola is a rare Gram-negative bacterium found in water and clinical specimens. Typical culturing methods often misidentify Elizabethkingia spp. as Flavobacterium or Chryseobacterium. Although diagnosis is based on culturing samples taken from sterile sites, such as blood, a proper identification of this bacterium requires an expertise that goes beyond the capabilities of a typical clinical laboratory.
A 35-year-old woman diagnosed with common variable immunodeficiency was admitted to our center. Previous treatment with antibiotics (amoxicillin plus clavulanate, first and third generation of cephalosporins, macrolides) and systemic corticosteroids (up to 120 mg/day of prednisolone) failed to arrest the spread of inflammation. Gingival recession was observed in her oral cavity, resulting in an apparent lengthening of her teeth. In addition to typical commensal bacteria, including streptococci and neisseriae, strains of Rothia mucilaginosa and Elizabethkingia miricola were identified upon a detailed microbiological examination using a MALDI-TOF MS Biotyper system. The presence of the latter strain correlated with severe periodontitis, lack of IgA in her saliva and serum, a very low IgG concentration (< 50 mg/dl), IgM-paraproteinemia, decreases in C3a and C5a and microvascular abnormality. High-dose immunoglobulin (to maintain IgG > 500 mg/dl) and targeted levofloxacin treatment resulted in immune system reconstitution, oral healing, and eradication of the Elizabethkingia infection.
E. miricola rarely causes disease in healthy individuals. However, the overgrowth of commensal bacteria, lack of IgG/IgA, microvasculopathy and complement cascade activation in patients with humoral immunodeficiency may facilitate Elizabethkingia invasion. Overuse of antibiotics, particularly beta-lactams, may cause mucosal colonization by E. miricola, followed by its multiplication combined with periodontitis that prompts bacterial translocation. MALDI-TOF Biotyper analysis may become a method of choice for identification of Elizabethkingia infections.
米氏伊丽莎白菌是一种罕见的革兰氏阴性菌，存在于水和临床标本中。典型的培养方法常常将伊丽莎白菌属误鉴定为黄杆菌属或金黄杆菌属。尽管诊断基于从无菌部位（如血液）采集的样本进行培养，但要正确鉴定这种细菌需要超出典型临床实验室能力范围的专业知识。
一名35岁被诊断为常见可变免疫缺陷的女性入住我们中心。先前使用抗生素（阿莫西林加克拉维酸、第一代和第三代头孢菌素、大环内酯类）和全身用皮质类固醇（泼尼松龙每日高达120毫克）治疗未能阻止炎症扩散。在她的口腔中观察到牙龈退缩，导致牙齿明显变长。除了典型的共生菌，包括链球菌和奈瑟菌外，使用基质辅助激光解吸电离飞行时间质谱生物分型系统进行详细微生物学检查时，还鉴定出了黏液罗氏菌和米氏伊丽莎白菌菌株。后一种菌株的存在与严重牙周炎、唾液和血清中缺乏IgA、极低的IgG浓度（<50毫克/分升）、IgM副蛋白血症、C3a和C5a降低以及微血管异常相关。高剂量免疫球蛋白（维持IgG>500毫克/分升）和靶向左氧氟沙星治疗导致免疫系统重建、口腔愈合以及米氏伊丽莎白菌感染的根除。
米氏伊丽莎白菌在健康个体中很少引起疾病。然而，体液免疫缺陷患者中共生菌过度生长、缺乏IgG/IgA、微血管病变和补体级联激活可能促进米氏伊丽莎白菌的侵袭。抗生素的过度使用，尤其是β-内酰胺类抗生素，可能导致米氏伊丽莎白菌在黏膜定植，随后其繁殖并伴有牙周炎，促使细菌移位。基质辅助激光解吸电离飞行时间质谱生物分型分析可能成为鉴定米氏伊丽莎白菌感染的首选方法。
