Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal; URSZ-Mycology, Department of Infectious Diseases, National Institute of Health Dr. Ricardo Jorge, Lisbon, Portugal.
Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal.
Clin Microbiol Infect. 2015 Oct;21(10):954.e1-8. doi: 10.1016/j.cmi.2015.06.001. Epub 2015 Jun 10.
Candida parapsilosis emerged as an important opportunistic pathogen, causing candidaemia worldwide. Nosocomial outbreaks triggered by this species have been frequently described, particularly in cancer patients. For a better understanding of its epidemiology, several typing methods are used and microsatellite analysis has been reported as highly discriminant. The main objective of this work was to study C. parapsilosis isolates by application of microsatellite genotyping to distinguish epidemiologically related strains, compare clinical and environmental isolates and determine possible routes of dispersion of the isolates in the hospital setting. A total of 129 C. parapsilosis isolates from different origins, including hospital environment and hands of healthcare workers, were genotyped using four microsatellite markers. The isolates were recovered from different health institutions. Analysis of C. parapsilosis isolates from hospital environment showed great genotypic diversity; however, the same or very similar genotypes were also found. The same multilocus genotype was shared by isolates recovered from the hand of a healthcare worker, from the hospital environment and from patients of the same healthcare institution, suggesting that these could be possible routes of transmission and that infections due to C. parapsilosis may be mainly related with exogenous transmission to the patient. Examination of sequential isolates from the same patients showed that colonizing and bloodstream isolates had the same multilocus genotype in the majority of cases. We demonstrate that this typing method is able to distinguish clonal clusters from genetically unrelated genotypes and can be a valuable tool to support epidemiologic investigations in the hospital setting.
近平滑假丝酵母已成为一种重要的机会致病菌，在全球范围内引起念珠菌血症。该物种引发的医院感染暴发时有发生，尤其是在癌症患者中。为了更好地了解其流行病学，使用了几种分型方法，微卫星分析已被报道具有高度的区分能力。这项工作的主要目的是应用微卫星基因分型来研究近平滑假丝酵母的分离株，以区分具有流行病学相关性的菌株，比较临床和环境分离株，并确定医院环境中分离株可能的传播途径。共对 129 株来自不同来源的近平滑假丝酵母分离株（包括医院环境和医护人员的手部）进行了基因分型，使用了 4 个微卫星标记。这些分离株是从不同的医疗机构中分离出来的。对来自医院环境的近平滑假丝酵母分离株的分析显示出很大的基因型多样性；然而，也发现了相同或非常相似的基因型。从医护人员手部、医院环境和同一医疗机构的患者中回收的分离株具有相同的多位点基因型，这表明这些可能是可能的传播途径，并且由近平滑假丝酵母引起的感染可能主要与向患者的外源性传播有关。对同一患者的连续分离株的检查表明，定植和血流感染分离株在大多数情况下具有相同的多位点基因型。我们证明这种分型方法能够区分克隆簇和遗传上无关的基因型，并且可以成为支持医院环境中流行病学研究的有价值的工具。
