Fédération de Microbiologie Clinique, Hôpital de la Timone, Marseille, France.
Clin Infect Dis. 2012 Jan 15;54(2):202-10. doi: 10.1093/cid/cir797. Epub 2011 Dec 5.
The bacterial flora involved in brain abscess is often complex. In a previous study, using a metagenomic approach based on 16S ribosomal DNA (rDNA) amplification, we demonstrated that the diversity of the microbial flora involved in these infections was underestimated.
We performed a 16S rDNA-based metagenomic analysis of cerebral abscesses from patients diagnosed from 2006 through 2010. All bacteria present in brain abscess specimens were identified, in view of the clinical and epidemiological characteristics of the patients.
Fifty-one patients were included in our study. By detecting polymicrobial infections in 19 patients, our strategy was significantly more discriminatory and enabled the identification of a greater number of bacterial taxa than did culture and conventional 16S rDNA polymerase chain reaction (PCR) and sequencing, respectively (P < 10(-2)). Data mining discriminated 2 distinct bacterial populations in brain abscess from dental and sinusal origin. In addition, of the 80 detected bacterial species, we identified 44 bacteria that had never been found in brain abscess specimens, including 22 uncultured bacteria. These uncultured agents mostly originated from the buccal or sinusal floras (P < 10(-2)) and were found in polymicrobial specimens (P < 10(-2)).
Cloning and sequencing of PCR-amplified 16S rDNA is a highly valuable method to identify bacterial agents of brain abscesses.
脑脓肿涉及的细菌菌群通常很复杂。在之前的一项研究中，我们采用基于 16S 核糖体 DNA（rDNA）扩增的宏基因组方法，证明了这些感染中涉及的微生物菌群多样性被低估了。
我们对 2006 年至 2010 年间诊断为脑脓肿的患者的脑脓肿标本进行了基于 16S rDNA 的宏基因组分析。根据患者的临床和流行病学特征，鉴定了脑脓肿标本中存在的所有细菌。
我们的研究共纳入了 51 名患者。通过在 19 名患者中检测到混合感染，我们的策略具有更高的区分度，比培养和常规 16S rDNA 聚合酶链反应（PCR）和测序分别识别出更多的细菌分类群（P < 10(-2)）。数据挖掘区分了来自牙科和鼻窦的脑脓肿中的 2 个不同细菌种群。此外，在检测到的 80 种细菌中，我们鉴定出 44 种从未在脑脓肿标本中发现的细菌，包括 22 种未培养的细菌。这些未培养的细菌主要来自口腔或鼻窦菌群（P < 10(-2)），并存在于混合感染标本中（P < 10(-2)）。
PCR 扩增 16S rDNA 的克隆和测序是鉴定脑脓肿细菌病原体的一种非常有价值的方法。
