Abstract 39: Human Oral, Gut, and Blood Microbiota in Patients with Kawasaki Disease
Objective: We studied microbiome of throat swab, rectal swab, and venous blood obtained from patients with Kawasaki disease (KD) to determine whether bacterial nuclei are detectable in circulating blood of KD patients and whether the microbial composition resembles to that of oral cavity or gut.
Methods: We initially studied 7 patients (4 males and 3 females, 20-59 months) and obtained swabs and blood samples before IVIG treatment (day 4-5) to prepare DNA and cDNA library. Next, we studied 14 patients (8 males and 6 females, 2-47 months) and prepared blood cDNA library before IVIG treatment (day 2-8) and before discharge (day 10-15). Samples were sequenced by Illumina HiSeq2000 and the results were analyzed using MePIC for human genome subtraction and megablast search, followed by taxonomic analysis with MEGAN viewer.
Results: The number of sequences homologous to bacterial genome per swab sample obtained from DNA or cDNA libraries varied 20,000~4,700,000 or 500,000~2,400,000, respectively. In most of the throat samples, the sequences were classified in descending order of phyla, Firmicutes > Proteobacteria > Bacteroidetes > Actinobacteria. In rectal samples, Proteobacteria and Bacteroidetes were more abundantly and Firmicutes was less abundantly represented than throat samples. The total number of sequences per blood sample was 30,000,000~70,000,000 and 99.0~99.9% of them were homologous to human genome. The number of sequences homologous to bacterial genome per DNA or cDNA library was 221-286 or 125-593, respectively. In blood samples, the frequencies of phyla were arranged in descending order, Proteobacteria = Actinobacteria > Firmicutes >> Bacteroides. The sequences homologous to Burkholderia, Streptococcus and Neisseria, the indigenous bacteria in the oral cavity, were present in most of the patients. Among them, the abundance of Streptococcus was significantly (p=0.03) reduced in the cDNA libraries during convalescence.
Conclusion: A variety of sequences homologous to bacterial genome were detected from the venous blood obtained from KD patients during the acute as well as the convalescent phase. Further study is necessary to investigate the specificity and the characteristics of these sequences in patients with KD.
Author Disclosures: J. Abe: None. R. Ebata: None. N. Saito: None. K. Okunushi: None. K. Nakabayashi: None. M. Kuroda: None.
- © 2015 by American Heart Association, Inc.