Molecular epidemiology of cryptococcal genotype VNIc/ST5 in Siriraj Hospital, Thailand.
Molecular epidemiology of cryptococcal genotype VNIc/ST5 in Siriraj Hospital, Thailand.
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DOI：
10.1371/journal.pone.0173744
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Ngamskulrungroj P
中科院分区：
文献类型：
--
作者：
Hatthakaroon C;Pharkjaksu S;Chongtrakool P;Suwannakarn K;Kiratisin P;Ngamskulrungroj P
尽管新型隐球菌感染与全球患者的人类免疫缺陷病毒（HIV）状态之间存在密切联系，但远东亚洲的大多数隐球菌病病例发生在非HIV个体中。使用多位点序列分型（MLST）的分子流行病学研究表明，超过95%的隐球菌菌株属于VNI的特定亚型。然而，这种关联在亚洲其他地区从未被专门研究过。因此，在本研究中，我们调查了泰国隐球菌病患者中VNIc/ST 5基因型的分布。51 C从泰国曼谷拉吉医院的临床样品中收集新形式的分离株。分离株主要来自HIV阳性患者（88.57%），均为VNIMAT α型。MLST分析确定了五种序列类型（ST）在Alumraj医院，其中ST 4（45.10%）和ST 6（35.29%）是最常见的，ST 5（15.69%），ST 32（1.96%）和ST 93（1.96）是不常见的。与来自远东亚洲的报告相反，ST 5主要在HIV患者中发现（83.33%）（P = 0.657），过去10年ST 5的患病率没有显著变化（P = 0.548）。对合并症的进一步分析显示，合并结核病感染或无HIV感染的患者隐球菌感染的发病率较高，诊断延迟。我们的研究表明，虽然泰国人口在遗传上与远东亚洲人口密切相关，但ST 5与泰国的非艾滋病毒状态无关。因此，这种关联可能与宿主的遗传背景无关。然而，其机制仍不清楚。
Despite the strong association between Cryptococcus neoformans infection and the Human immunodeficiency virus (HIV) status of patients globally, most cryptococcosis cases in Far East Asia occur in non-HIV individuals. Molecular epidemiological studies, using multilocus sequence typing (MLST), have shown that more than 95% of cryptococcal strains belong to a specific subtype of VNI. However, this association has never been specifically examined in other parts of Asia. Therefore, in this study, we investigated the VNIc/ST5 genotype distribution among cryptococcosis patients in Thailand. Fifty-one C. neoformans isolates were collected from clinical samples in Siriraj Hospital, Bangkok, Thailand. The strains were predominantly isolated from HIV-positive patients (88.57%) and all were molecular type VNI MATα. An MLST analysis identified five sequence types (ST) in Siriraj Hospital, of which ST4 (45.10%) and ST6 (35.29%) were most common, and ST5 (15.69%), ST32 (1.96%), and ST93 (1.96) were less common. Contrary to reports from Far East Asia, ST5 was predominantly (83.33%) found in HIV patients (P = 0.657), and there was no significant change in the prevalence of ST5 over the past 10 years (P = 0.548). A further analysis of comorbidities showed higher morbidity and delays in the cryptococcal diagnosis in patients with tuberculosis coinfection or without HIV. Our study suggests that although the Thai population is genetically closely related to the Far East Asian population, ST5 is not associated with non-HIV status in Thailand. Therefore, this association may not be related to the host’s genetic background. However, its mechanism remains unclear.