Chen Shicheng, Agah Grace, Blom Jochen, Walker Edward D
College of Health and Human Sciences, Northern Illinois University, DeKalb, IL, United States.
Bioinformatics and Systems Biology, Justus-Liebig University Giessen, Giessen, Germany.
Front Microbiol. 2025 Jul 9;16:1582121. doi: 10.3389/fmicb.2025.1582121. eCollection 2025.
is a gram-negative bacterium that causes life-threatening infections in vulnerable populations. Unlike other species in the genus, also leads to meningitis-like diseases in aquatic invertebrates such as frogs, raising concerns about its zoonotic transmission potential. Management of its infection is complicated by unclear transmission pathways and multi-drug resistance.
In this study, we analyzed three clinical strains ( Mich-1, Mich-2, and Mich-3) isolated from patients in Michigan using morphology observations, biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF/MS), and genome sequencing.
Average Nucleotide Identity (ANI) analysis revealed that the Michigan strains were nearly identical and shared 96.52% identity with the type strain DSM 14571, confirming their classification as . Comprehensive comparative genomic analyses were conducted across 28 strains, including human isolates and strains from invertebrates like frogs. The strains exhibited open pan-genome characteristics. Mich-1 shared 3,199 genes (83.2%) with human isolates but fewer genes with frog-derived isolates (ranging from 3,319 to 3,375). This phylogenetic analysis highlights regional variation and the global diversity of isolates, revealing connections between clinical and environmental strains. Antibiotic susceptibility testing revealed that the three clinical strains were resistant to 13 out of 16 tested drugs, with susceptibility only to trimethoprim/sulfamethoxazole and ciprofloxacin. The strains carried five β-lactamase-encoding genes (, , , , and ), conferring resistance to penams, cephalosporins, and carbapenems. Several virulence-associated genes were conserved across clinical and frog isolates. These genes contribute to stress adaptation, adherence, and immune modulation.
This study underscores the evolutionary adaptability of genomes, highlighting their capacity to acquire genetic traits that enable survival in diverse niches. This adaptability facilitates the emergence of more resistant and virulent strains, posing significant threats to both human and animal health.
[细菌名称]是一种革兰氏阴性菌，可在易感人群中引发危及生命的感染。与该属中的其他物种不同，它还会在青蛙等水生无脊椎动物中引发类似脑膜炎的疾病，这引发了人们对其人畜共患病传播潜力的担忧。由于传播途径不明和多重耐药性，其感染的管理变得复杂。
在本研究中，我们使用形态学观察、生化测试、基质辅助激光解吸/电离飞行时间质谱（MALDI-ToF/MS）和基因组测序，分析了从密歇根州患者中分离出的三株临床菌株（Mich-1、Mich-2和Mich-3）。
平均核苷酸同一性（ANI）分析表明，密歇根菌株几乎完全相同，与模式菌株DSM 14571的同一性为96.52%，证实了它们属于[细菌名称]的分类。对包括人类分离株和青蛙等无脊椎动物来源的菌株在内的28株菌株进行了全面的比较基因组分析。这些菌株呈现出开放的泛基因组特征。Mich-1与人类分离株共有3199个基因（83.2%），但与青蛙来源的分离株共有较少的基因（范围从3319到3375个）。这种系统发育分析突出了[细菌名称]分离株的区域差异和全球多样性，揭示了临床菌株与环境菌株之间的联系。抗生素敏感性测试表明，这三株临床菌株对16种测试药物中的13种耐药，仅对甲氧苄啶/磺胺甲恶唑和环丙沙星敏感。这些菌株携带五个编码β-内酰胺酶的基因（[基因名称1]、[基因名称2]、[基因名称3]、[基因名称4]和[基因名称5]），赋予了对青霉素类、头孢菌素类和碳青霉烯类药物的耐药性。几个与毒力相关的基因在临床和青蛙分离株中是保守的。这些基因有助于应激适应、黏附和免疫调节。
本研究强调了[细菌名称]基因组的进化适应性，突出了它们获取使在不同生态位中生存的遗传特征的能力。这种适应性促进了更具耐药性和毒力的菌株的出现，对人类和动物健康构成重大威胁。
