Durán Estela Liliana, Mujica Maria Teresa, Jewtuchowicz Virginia Marta, Finquelievich Jorge Luis, Pinoni Maria Victoria, Iovannitti Cristina Adela
Centro de Micología, Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Rev Iberoam Micol. 2007 Dec 31;24(4):268-71. doi: 10.1016/s1130-1406(07)70054-2.
Biofilms are microbial communities encased in a self-produced polymeric matrix and represent a common mode of microbial growth. Candida albicans is able to colonize the surface of catheters, prostheses, and epithelia, forming biofilms that are highly resistant to antimicrobial drugs. The objective of this study was the genotypic characterization of biofilm-forming C. albicans clinical isolates using RAPD (Random Amplified Polymorphic DNA). We have studied 25 clinical isolates of C. albicans from oral cavities, blood, skin, nail, stool, oesophagus biopsy and vaginal fluids from patients suffering from candidiasis. For each strain biofilm formation was analysed by measuring the ability to adhere to and grow on polystyrene plastic surfaces using XTT [2,3-bis(2-methoxi-4nitro-5sulfophenil)-2H tetrazolium-5carboxanilide] reduction assay. The similarity coefficients generated by RAPD using four different primers varied from 49 to 91%, indicating a high degree of genetic variability between the clinical isolates. The dendrogram clustered the isolates in four related groups, all groups included strains with very different abilities to form biofilms. The isolates with similar genotypes often showed very different biofilm formation abilities. Strains were grouped into clusters independently of their clinical sources. Our results suggested that a direct correlation does not exist between the biofilm-forming ability of natural populations of C. albicans and the genotype as determined by RAPD.
生物膜是包裹在自身产生的聚合物基质中的微生物群落，代表了一种常见的微生物生长模式。白色念珠菌能够在导管、假体和上皮表面定殖，形成对抗菌药物具有高度抗性的生物膜。本研究的目的是使用随机扩增多态性DNA（RAPD）对形成生物膜的白色念珠菌临床分离株进行基因分型。我们研究了25株来自念珠菌病患者口腔、血液、皮肤、指甲、粪便、食管活检组织和阴道分泌物的白色念珠菌临床分离株。对于每一株菌株，通过使用XTT [2,3-双(2-甲氧基-4-硝基-5-磺基苯基)-2H四唑-5-羧基苯胺] 还原试验测量其在聚苯乙烯塑料表面的黏附能力和生长能力，来分析生物膜的形成情况。使用四种不同引物通过RAPD产生的相似系数在49%至91%之间变化，表明临床分离株之间存在高度的遗传变异性。聚类图将分离株聚为四个相关组，所有组都包括形成生物膜能力差异很大的菌株。具有相似基因型的分离株通常表现出非常不同的生物膜形成能力。菌株被分组，与其临床来源无关。我们的结果表明，白色念珠菌自然群体的生物膜形成能力与通过RAPD确定的基因型之间不存在直接相关性。
