Chorost Matthew S, Smith Nancy C, Hutter Jack N, Ong Ann C, Stam Jason A, McGann Patrick T, Hinkle Mary K, Schaecher Kurt E, Kamau Edwin
Walter Reed National Military Medical Center, Bethesda, MD, USA.
Walter Reed Army Institute of Research, Silver Spring, MD, USA.
JMM Case Rep. 2018 Oct 31;5(11):e005169. doi: 10.1099/jmmcr.0.005169. eCollection 2018 Nov.
spp. are yellow-pigmented Gram-positive coryneform rods found in various environmental sources, such as soil and water samples. They rarely cause human infection, mostly infecting immunocompromised patients and catheter insertion sites, making them challenging to identify in clinical settings.
We report a case of a 61-year-old female on long-term prednisone therapy for sarcoidosis with minimal exposure to environmental sources, who presented with an overtly infected Hickman catheter site and presyncope. The patient had a central venous catheter (CVC) that had been in place for the previous 6 years for treatment of refractory hypertension and congestive heart failure. Blood cultures obtained from the CVC on initial presentation were positive for a mixed infection, which was subcultured and grew , , and based on the Becton Dickinson Phoenix Automated Microbiology System. The , designated as isolate 4120, was further analysed, since infections associated with this organism are uncommon, and it was the only organism to grow from the patient's catheter tip. Matrix-assisted laser desorption ionization-time of flight MS identified isolate 4120 as . To resolve the conflicting results, additional analyses of isolate 4120 were carried out and compared to several reference strains. Isolate 4120 was found to have intermediate susceptibility to ciprofloxacin and non-susceptibility to vancomycin. Morphology, susceptibility, biochemical characteristics and whole-genome sequencing confirmed the clinical isolate as .
In this case, we identified an organism that is rarely seen in clinical settings and characterized it with a comprehensive laboratory analysis. The patient in our case responded to replacement of the CVC, and treatment with levofloxacin by mouth and intravenous vancomycin.
[菌种名称]是黄色色素沉着的革兰氏阳性棒状杆菌，存在于各种环境来源中，如土壤和水样。它们很少引起人类感染，主要感染免疫功能低下的患者和导管插入部位，这使得它们在临床环境中难以识别。
我们报告一例61岁女性，因结节病长期接受泼尼松治疗，极少接触环境源，出现明显感染的希克曼导管部位和晕厥前症状。该患者有一根中心静脉导管（CVC），此前已放置6年用于治疗难治性高血压和充血性心力衰竭。初次就诊时从CVC采集的血培养显示为混合感染阳性，经传代培养后，根据贝克曼库尔特菲尼克斯自动化微生物系统培养出[多种细菌名称]。其中的[特定细菌名称]，指定为分离株4120，由于与该菌相关的感染不常见，且它是唯一从患者导管尖端生长出来的细菌，因此对其进行了进一步分析。基质辅助激光解吸电离飞行时间质谱鉴定分离株4120为[具体菌种]。为解决相互矛盾的结果，对分离株4120进行了额外分析，并与几种参考菌株进行比较。发现分离株4120对环丙沙星具有中度敏感性，对万古霉素不敏感。形态学、敏感性、生化特征和全基因组测序证实该临床分离株为[具体菌种]。
在本病例中，我们鉴定出一种在临床环境中罕见的细菌，并通过全面的实验室分析对其进行了表征。我们病例中的患者对更换CVC以及口服左氧氟沙星和静脉注射万古霉素治疗有反应。
