Department of Pathology, University of California, San Diego, California, USA.
Department of Pediatrics, School of Medicine, University of California, San Diego, California, USA.
mSystems. 2024 Jul 23;9(7):e0051624. doi: 10.1128/msystems.00516-24. Epub 2024 Jun 27.
is a Gram-negative commensal bacterium commonly found in the human colon, which differentiates into two genomospecies termed divisions I and II. Through a comprehensive collection of 694 whole genome sequences, we identify novel features distinguishing these divisions. Our study reveals a distinct geographic distribution with division I strains predominantly found in North America and division II strains in Asia. Additionally, division II strains are more frequently associated with bloodstream infections, suggesting a distinct pathogenic potential. We report differences between the two divisions in gene abundance related to metabolism, virulence, stress response, and colonization strategies. Notably, division II strains harbor more antimicrobial resistance (AMR) genes than division I strains. These findings offer new insights into the functional roles of division I and II strains, indicating specialized niches within the intestine and potential pathogenic roles in extraintestinal sites.
Understanding the distinct functions of microbial species in the gut microbiome is crucial for deciphering their impact on human health. Classifying division II strains as can lead to erroneous associations, as researchers may mistakenly attribute characteristics observed in division II strains to the more extensively studied division I . Our findings underscore the necessity of recognizing these divisions as separate species with distinct functions. We unveil new findings of differential gene prevalence between division I and II strains in genes associated with intestinal colonization and survival strategies, potentially influencing their role as gut commensals and their pathogenicity in extraintestinal sites. Despite the significant niche overlap and colonization patterns between these groups, our study highlights the complex dynamics that govern strain distribution and behavior, emphasizing the need for a nuanced understanding of these microorganisms.
是一种常见于人类结肠的革兰氏阴性共生菌，可分为两个基因组种，称为 I 类和 II 类。通过综合收集 694 个全基因组序列，我们确定了区分这些类别的新特征。我们的研究揭示了一种独特的地理分布，I 类菌株主要分布在北美洲，II 类菌株分布在亚洲。此外，II 类菌株更频繁地与血流感染相关，表明其具有明显的致病性潜力。我们报告了两个类之间与代谢、毒力、应激反应和定植策略相关的基因丰度差异。值得注意的是，II 类菌株比 I 类菌株携带更多的抗生素耐药（AMR）基因。这些发现为 I 类和 II 类菌株的功能角色提供了新的见解，表明它们在肠道内具有特定的生态位，并可能在肠道外部位具有潜在的致病作用。
了解肠道微生物组中微生物物种的独特功能对于破译它们对人类健康的影响至关重要。将 II 类菌株分类为 可能导致错误的关联，因为研究人员可能会错误地将在 II 类菌株中观察到的特征归因于研究更为广泛的 I 类菌株。我们的发现强调了将这些菌株视为具有不同功能的独立物种的必要性。我们揭示了 I 类和 II 类菌株之间与肠道定植和生存策略相关的基因中差异基因流行率的新发现，这些基因可能影响它们作为肠道共生菌的作用及其在肠道外部位的致病性。尽管这些群体之间存在显著的生态位重叠和定植模式，但我们的研究强调了控制菌株分布和行为的复杂动态，强调了对这些微生物进行细致理解的必要性。
