School of Public Health, Lanzhou University, Lanzhou, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
Front Cell Infect Microbiol. 2024 Jan 10;13:1325379. doi: 10.3389/fcimb.2023.1325379. eCollection 2023.
complex (Smc) comprises opportunistic Gram-negative bacilli responsible for various nosocomial infections. Limited data exists concerning its evolutionary lineage, global prevalence and pathogenicity.
We conducted an extensive genomic analysis on 734 Smc genomes, of which 90 were newly sequenced and isolated from different patients. The species composition and evolutionary relationships of Smc were examined using core protein sequence analysis. Pathogenicity evaluation was used by assays for swimming motility, biofilm formation and identification of virulence factors. The broth microdilution method was used to evaluate the drug resistance spectrum of clinical isolates.
Phylogenetic analyses delineated 24 species-level clades, dominated by (42.8%), (13.6%) and (9.9%). Geographically, strains were primarily distributed in Europe (34.2%), Asia (33.7%) and North America (24.0%), with intricate global distribution patterns. Meanwhile, 154 virulence-associated genes and 46 antimicrobial resistance genes within Smc were identified. These genes encoded span various functions, including motility, adherence, toxin, RND antibiotic efflux pumps, beta-lactamases and aminoglycoside-modifying enzymes. Moreover, significant variations were indicated in swimming motility and biofilm-forming capability across the different species, with exhibiting superior levels of both traits. Additionally, no statistically significant discrepancy was detected among Smc species to other antibiotics, despite the fact that all isolates were resistant to Ceftazidime and much higher than other species.
Our findings indicate the need to pay increased attention to other mainstream species of Smc besides in order to better manage Smc-related infections and tailor effective treatment strategies.
复合（Smc）包括机会性革兰氏阴性杆菌，负责各种医院获得性感染。关于其进化谱系、全球流行情况和致病性的资料有限。
我们对 734 个 Smc 基因组进行了广泛的基因组分析，其中 90 个是新测序并从不同患者中分离出来的。利用核心蛋白序列分析检测 Smc 的物种组成和进化关系。通过泳动、生物膜形成和毒力因子鉴定试验评估致病性。采用肉汤微量稀释法评估临床分离株的耐药谱。
系统发育分析划定了 24 个种水平的进化枝，以 （42.8%）、 （13.6%）和 （9.9%）为主导。从地理上看，菌株主要分布在欧洲（34.2%）、亚洲（33.7%）和北美（24.0%），具有复杂的全球分布模式。同时，在 Smc 中鉴定出 154 个与毒力相关的基因和 46 个抗微生物药物耐药基因。这些基因编码的功能包括运动性、粘附性、毒素、RND 抗生素外排泵、β-内酰胺酶和氨基糖苷修饰酶。此外，不同物种的泳动和生物膜形成能力存在显著差异， 表现出这两种特性的优势。此外，尽管所有 分离株均对头孢他啶耐药且耐药率高于其他物种，但 Smc 各物种之间对其他抗生素的耐药性没有统计学差异。
我们的研究结果表明，除了 之外，还需要更加关注 Smc 的其他主流物种，以便更好地管理 Smc 相关感染并制定有效的治疗策略。
