Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
Departamento de Bioquímica, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
Curr Microbiol. 2021 Jun;78(6):2259-2263. doi: 10.1007/s00284-021-02493-x. Epub 2021 May 4.
Burkholderia cepacia complex (Bcc) comprises 24 related species genetically distinct, associated with high mortality in cystic fibrosis (CF) patients. Due to a high level of similarity among Bcc species, accurate identification has been problematic, and most conventional and automated phenotypic tests have shown low accuracy. We evaluated accuracy of MALDI-ToF MS decreasing the cut-off score value to distinguish Bcc species compared to recA gene sequencing. A total of 145 Bcc isolates were analyzed. B. vietnamiensis (41.37%), B. cenocepacia IIIA (23.44%), B. multivorans (20%), B. cenocepacia IIIB (11.03%), and B. contaminans (2.75%) among other species were identified by recA sequencing. MALDI-ToF MS identified 100% of Bcc isolates at the genus level and 53.1% at the species level. By decreasing cut-off values for ≥1.70, the correct identification at the species level increased to 74.5%. MALDI-ToF MS proved to be useful at the genus level identification, but it still requires improvements that allow more precise identification, requiring continuous updates and addition of new spectra to its database. A review of interpretative criteria is a field to be explored with a large collection of Bcc species.
洋葱伯克霍尔德菌复合体（Bcc）由 24 个具有遗传差异的相关物种组成，与囊性纤维化（CF）患者的高死亡率有关。由于 Bcc 物种之间存在高度相似性，因此准确识别一直存在问题，大多数传统和自动化表型测试的准确性都较低。我们评估了 MALDI-ToF MS 降低区分 Bcc 物种的截止评分值的准确性，与 recA 基因测序相比。共分析了 145 株 Bcc 分离株。通过 recA 测序鉴定出 B. vietnamiensis（41.37%）、B. cenocepacia IIIA（23.44%）、B. multivorans（20%）、B. cenocepacia IIIB（11.03%）和 B. contaminans（2.75%）等其他物种。MALDI-ToF MS 在属水平上可识别 100%的 Bcc 分离株，在种水平上可识别 53.1%。通过降低≥1.70 的截止值，种水平的正确识别率增加到 74.5%。MALDI-ToF MS 证明在属水平的鉴定上是有用的，但仍需要改进，以实现更精确的鉴定，需要不断更新和添加新的光谱到其数据库。对解释标准的审查是一个需要用大量 Bcc 物种进行探索的领域。
