Genotyping and antifungal susceptibility testing of Cryptococcus neoformans isolates from Cameroonian HIV-positive adult patients
Genotyping and antifungal susceptibility testing of Cryptococcus neoformans isolates from Cameroonian HIV-positive adult patients
复制标题
DOI：
10.1111/1469-0691.12019
复制
发表时间：
2013-08-01
影响因子：
14.2
通讯作者：
Mallie, M.
中科院分区：
文献类型：
--
作者：
Bertout, S.;Drakulovski, P.;Mallie, M.
新型隐球菌是非洲成年艾滋病毒/艾滋病患者脑膜炎的最常见原因。氟康唑的广泛使用可能导致易感性降低的分离株的出现。我们研究了从 HIV 感染隐球菌性脑膜炎患者中分离出的新型隐球菌。进行基因分型和抗真菌测试，以评估抗真菌药物的遗传多样性、混合感染的发生率和体外活性。在全身抗真菌治疗之前从脑脊液中回收分离株。每个样本研究了 6 个分离株（来自 19 名患者的总共 114 个分离株）。通过LAC 1和CAP 64基因扩增进行血清分型，并使用噬菌体M13核心、(GACA)(4)和(GTG)(5)引物以及URA5基因的限制性多态性分析进行基因分型。通过 Sensititre YeastOne (R) 方法测试对两性霉素 B、氟胞嘧啶、氟康唑、伏立康唑和泊沙康唑的敏感性。所有菌株均被鉴定为 C.neoformans var. grubii 血清型 A。我们鉴定了九种主要基因型。在同一样本中最多鉴定出两种基因型。没有任何分离株对所研究的药物产生耐药性。然而，114 株菌株中的 13 株表现出对氟康唑的敏感性降低，114 株菌株中的 13 株表现出对氟胞嘧啶的敏感性降低。未发现基因型和易感性之间存在相关性。这项研究证实了喀麦隆 A 型新型隐球菌的流行。两种基因型可能导致一次隐球菌病发作。治疗隐球菌病时必须考虑混合感染的可能性以及对氟康唑或氟胞嘧啶敏感性降低的情况。
Cryptococcus neoformans is the most common cause of meningitis amongst adult Africans with HIV/AIDS. The widespread use of fluconazole may lead to the emergence of isolates with reduced susceptibility. We studied C.neoformans isolates from HIV-infected patients with cryptococcal meningitis. Genotyping and antifungal testing were performed to assess the genetic diversity, occurrence of mixed infections and in vitro activity of antifungal agents. Isolates were recovered from cerebrospinal fluid prior to systemic antifungal treatment. Six isolates were studied for each sample (a total of 114 isolates from 19 patients). Serotyping was performed via LAC 1 and CAP 64 gene amplification and genotyping was performed using phage M13 core, (GACA)(4) and (GTG)(5) primers and restriction polymorphism analysis of the URA5 gene. Susceptibilities for amphotericin B, flucytosine, fluconazole, voriconazole and posaconazole were tested by the Sensititre YeastOne (R) method. All strains were identified as C.neoformans var. grubii serotype A. We identified nine major genotypes. Up to two genotypes were identified in the same sample. None of the isolates were resistant to the studied drugs. However, 13 of 114 strains exhibited a reduced susceptibility to fluconazole and 13 of 114 strains exhibited a reduced susceptibility to flucytosine. No correlation was found between the genotype and susceptibility. This study confirms the prevalence of C.neoformans serotype A in Cameroon. Two genotypes may be responsible for a single episode of cryptococcosis. The possibility of mixed infection and diminished susceptibility to fluconazole or flucytosine must be considered for the management of cryptococcosis.