Genome Center, Infectious Diseases Division, icddr,b, Dhaka, Bangladesh.
Emerging Infections, Infectious Diseases Division, icddr,b, Dhaka, Bangladesh.
Microbiol Spectr. 2024 Jul 2;12(7):e0354023. doi: 10.1128/spectrum.03540-23. Epub 2024 Jun 6.
, initially identified in 2009, has rapidly become a critical concern due to its antifungal resistance and significant mortality rates in healthcare-associated outbreaks. To date, whole-genome sequencing (WGS) has identified five unique clades of , with some strains displaying resistance to all primary antifungal drug classes. In this study, we presented the first WGS analysis of from Bangladesh, describing its origins, transmission dynamics, and antifungal susceptibility testing (AFST) profile. Ten isolates collected from hospital settings in Bangladesh were initially identified by CHROMagar Candida Plus, followed by VITEK2 system, and later sequenced using Illumina NextSeq 550 system. Reference-based phylogenetic analysis and variant calling pipelines were used to classify the isolates in different clades. All isolates aligned ~90% with the Clade I B11205 reference genome. Of the 10 isolates, 8 were clustered with Clade I isolates, highlighting a South Asian lineage prevalent in Bangladesh. Remarkably, the remaining two isolates formed a distinct cluster, exhibiting >42,447 single-nucleotide polymorphism differences compared to their closest Clade IV counterparts. This significant variation corroborates the emergence of a sixth clade (Clade VI) of in Bangladesh, with potential for international transmission. AFST results showed that 80% of the isolates were resistant to fluconazole and voriconazole, whereas Clade VI isolates were susceptible to azoles, echinocandins, and pyrimidine analogue. Genomic sequencing revealed _Y132F mutation conferring azole resistance while _S70R mutation found inconsequential in describing 5-flucytosine resistance. Our study underscores the pressing need for comprehensive genomic surveillance in Bangladesh to better understand the emergence, transmission dynamics, and resistance profiles of infections. Unveiling the discovery of a sixth clade (Clade VI) accentuates the indispensable role of advanced sequencing methodologies.IMPORTANCE is a nosocomial fungal pathogen that is commonly misidentified as other species. Since its emergence in 2009, this multidrug-resistant fungus has become one of the five urgent antimicrobial threats by 2019. Whole-genome sequencing (WGS) has proven to be the most accurate identification technique of which also played a crucial role in the initial discovery of this pathogen. WGS analysis of has revealed five distinct clades where isolates of each clade differ among themselves based on pathogenicity, colonization, infection mechanism, as well as other phenotypic characteristics. In Bangladesh, was first reported in 2019 from clinical samples of a large hospital in Dhaka city. To understand the origin, transmission dynamics, and antifungal-resistance profile of isolates circulating in Bangladesh, we conducted a WGS-based surveillance study on two of the largest hospital settings in Dhaka, Bangladesh.
, 最初于 2009 年被发现,由于其抗真菌耐药性和在医疗机构相关暴发中的高死亡率,已迅速成为一个严重的问题。迄今为止,全基因组测序(WGS)已确定了 5 个独特的 分支,其中一些菌株对所有主要抗真菌药物类别都具有耐药性。在本研究中,我们首次对来自孟加拉国的 进行了 WGS 分析,描述了其起源、传播动态和抗真菌药敏试验(AFST)特征。从孟加拉国医院环境中收集的 10 株 最初通过 CHROMagar Candida Plus 鉴定,然后通过 VITEK2 系统鉴定,最后使用 Illumina NextSeq 550 系统进行测序。基于参考的系统发育分析和变异调用管道用于将分离株分类到不同的分支中。所有分离株与分支 I 的 B11205 参考基因组的相似度约为 90%。在 10 株分离株中,有 8 株与分支 I 分离株聚类,突出了孟加拉国流行的南亚谱系。值得注意的是,其余两株分离株形成了一个独特的集群,与最接近的分支 IV 相比,它们的单核苷酸多态性差异超过 42,447 个。这种显著的差异证实了 第六个分支(分支 VI)在孟加拉国的出现,具有国际传播的潜力。AFST 结果显示,80%的 分离株对氟康唑和伏立康唑耐药,而分支 VI 分离株对唑类、棘白菌素类和嘧啶类似物敏感。基因组测序显示 _Y132F 突变赋予唑类耐药性,而 _S70R 突变在描述 5-氟胞嘧啶耐药性方面无意义。我们的研究强调了在孟加拉国进行全面基因组监测的迫切需要,以更好地了解 感染的出现、传播动态和耐药谱。揭示第六个分支(分支 VI)的发现突出了先进测序方法的不可或缺的作用。
重要的是一种医院真菌病原体,通常被错误地鉴定为其他 物种。自 2009 年出现以来,这种多药耐药真菌已成为 2019 年五种紧急抗微生物威胁之一。全基因组测序(WGS)已被证明是最准确的 鉴定技术,它在该病原体的最初发现中也发挥了至关重要的作用。对 的 WGS 分析显示了五个不同的分支,每个分支的分离株在致病性、定植、感染机制以及其他表型特征方面彼此不同。在孟加拉国,于 2019 年首次从达卡市一家大医院的临床样本中报告。为了了解在孟加拉国传播的 分离株的起源、传播动态和抗真菌耐药性特征,我们在孟加拉国达卡的两个最大的医院环境中进行了基于 WGS 的监测研究。