Microbial diversity and core microbiota in leg ulcer and skin of patients with Sickle Cell Disease

INTRODUCTION: Leg ulcer is a common complication of Sickle Cell Disease (SCD), which is painful and difficult to treat, due to its extended healing process. The microbiota compositional structure of these wounds is still poorly known. OBJECTIVE: To investigate the diversity and core of the microbiota in leg ulcers and intact skin of SCD patients and intact skin of controls. METHODS: This is a cross-sectional study that included leg ulcer samples (G1), adjacent intact skin to the ulcer (G2), intact skin from patients with SCD without ulcer (G3) and intact skin from healthy controls (G4). Microbiota was characterized by sequencing the 16S rRNA gene. RESULTS: A total of 84 samples were sequenced. Leg ulcers samples had lower alpha and beta microbial diversity as compared to intact skin. The genus Staphylococcus significantly predominated in the leg ulcers (p=0.002); while Ralstonia predominated in intact skin (p= 0.042) when samples from the same patient (G1 versus G2) were compared. Intact skin from SCD patients (G2 and G3) significantly differ from healthy controls (G4) when beta diversity was analyzed by different indexes. Ralstonia was the only genera showing a significant difference (p=0.023), with a median percentage of 11.03 (G2), 13.60(G3) and 5.61(G4). CONCLUSION: Microbial diversity is lower in SCD leg ulcer samples. Intact skin from SCD patients have a different beta diversity as compared to healthy controls. Staphylococcus predominanted in leg ulcers. More studies are needed to understand if Ralstonia has a role in the development of leg ulcers in SCD patients.

引言：腿部溃疡是镰状细胞病（Sickle Cell Disease, SCD）的常见并发症，其伴随剧烈疼痛且愈合周期漫长，治疗难度极大。目前学界对这类伤口的微生物群落组成结构仍缺乏深入了解。
研究目的：本研究旨在探究镰状细胞病患者腿部溃疡、溃疡周边完整皮肤，以及健康对照者完整皮肤的微生物群落多样性与核心菌群组成。
研究方法：本研究为横断面研究，共纳入4组样本：腿部溃疡样本（G1）、溃疡邻近完整皮肤样本（G2）、无溃疡镰状细胞病患者的完整皮肤样本（G3），以及健康对照者的完整皮肤样本（G4）。通过对16S rRNA基因进行测序，对微生物群落进行表征分析。
研究结果：本研究共完成84份样本的测序。与完整皮肤样本相比，腿部溃疡样本的微生物群落α多样性与β多样性均显著更低。对同一患者的配对样本（G1与G2）进行比较后发现，葡萄球菌属（Staphylococcus）在腿部溃疡样本中显著富集（p=0.002），而罗尔斯通氏菌属（Ralstonia）则在溃疡邻近完整皮肤样本中占优（p=0.042）。采用不同多样性指数分析β多样性时，镰状细胞病患者的完整皮肤样本（G2与G3）与健康对照样本（G4）存在显著差异。仅罗尔斯通氏菌属的相对丰度存在显著组间差异（p=0.023），其相对丰度中位数分别为G2组11.03%、G3组13.60%、G4组5.61%。
结论：镰状细胞病患者腿部溃疡样本的微生物群落多样性更低。镰状细胞病患者的完整皮肤与健康对照者的完整皮肤相比，β多样性存在显著差异。葡萄球菌属在腿部溃疡样本中占主导地位。未来仍需开展更多研究，以明确罗尔斯通氏菌属是否参与镰状细胞病患者腿部溃疡的发生发展。