Multilocus sequence typing of sequential Candida albicans isolates from patients with persistent or recurrent fungemia
Multilocus sequence typing of sequential Candida albicans isolates from patients with persistent or recurrent fungemia
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DOI：
10.3109/13693780903501689
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发表时间：
2010-08-01
期刊：
影响因子：
2.9
通讯作者：
Colombo, Arnaldo L.
中科院分区：
文献类型：
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作者：
Da Matta, Daniel A.;Melo, Analy S.;Colombo, Arnaldo L.
多位点序列分型 (MLST) 是探索从侵袭性念珠菌病病例中回收的白色念珠菌分离株的系统发育学和流行病学的有用工具。本研究的目的是通过对同一患者连续分离的白色念珠菌进行 MLST 和 ABC 分型，确定相同或不同的菌株是否导致持续性或复发性真菌血症。我们将这两种分型方法应用于从 8 名持续性或复发性念珠菌血症患者中回收的 21 株白色念珠菌菌株。这些分离株是在巴西四家公立三级医院进行的多中心监测研究中收集的。持续性念珠菌血症定义为在 2 天或更长时间内两次或更多次血培养呈白色念珠菌阳性。复发性念珠菌血症定义为念珠菌属引起的感染发作明显完全消退后至少 1 个月发生的念珠菌血症发作。我们观察到，除了一名患者外，来自同一患者第一个和第二个样本的所有菌株均表现出相同的 MLST 二倍体序列类型 (DST)、ABC 类型和抗真菌药敏感性特征。在 10 天内从一名患者身上连续收集的 7 个样本中发现了 3 种不同的菌株，通过 MLST 可以很好地区分。前四个样品的菌株无法区分，第五个和第六个样品也无法区分，但与前四个和第七个样品不同。值得注意的是，第七种菌株是我们在涉及 61 名患者的总收集中发现的唯一的白色念珠菌分支 2 分离株，尽管分支 2 在世界范围内很常见。据我们所知，这是第一项描述同一名持续性血流感染患者体内三种不同白色念珠菌菌株在短时间内恢复的研究。
Multilocus sequence typing (MLST) is a useful tool to explore the phylogenetics and epidemiology of Candida albicans isolates recovered from cases of invasive candidiasis. The goal of this study was to determine whether the same or different strains were responsible for persistent or recurrent fungemia through the use of MLST and ABC typing on sequential C. albicans isolates from the same patient. We applied both typing methods to 21 C. albicans strains recovered from 8 patients with persistent or recurrent candidemia. The isolates were collected during a multicenter surveillance study in four public tertiary care hospitals in Brazil. Persistent candidemia was defined as two or more blood cultures positive for C. albicans on 2 or more separate days. Recurrent candidemia was defined as an episode of candidemia occurring at least 1 month after the apparent complete resolution of an infectious episode caused by Candida species. We observed that, except for one patient, all strains from the first and second samples of the same patient showed the same MLST diploid sequence type (DST), ABC type and susceptibility profile to antifungals. Three distinct strains, well discriminated by MLST, were found in the seven samples collected sequentially over 10 days from one patient. The strains from the first four samples were indistinguishable, the fifth and sixth were also indistinguishable but different from the first four and seventh samples. Significantly, the seventh strain was the only C. albicans clade 2 isolate found in our total collection involving 61 patients, although clade 2 is commonly found worldwide. To the best of our knowledge, this is the first study describing the recovery of three distinct C. albicans strains in the same patient with a persistent blood stream infection within a short period of time.