Infectious Disease Division, University of Texas Medical Branch, Galveston, Texas, USA.
Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.
Clin Infect Dis. 2024 Nov 22;79(5):1144-1152. doi: 10.1093/cid/ciae272.
Aeromonas virulence may not be entirely dependent on the host's immune status. Pathophysiologic determinants of disease progression and severity remain unclear.
One hundred five patients with Aeromonas infections and 112 isolates were identified, their clinical presentations and outcomes were analyzed, and their antimicrobial resistance (AMR) patterns were assessed. Two isolates (A and B) from fatal cases of Aeromonas dhakensis bacteremia were characterized using whole-genome sequencing. Virulence factor- and AMR-encoding genes from these isolates were compared with a well-characterized diarrheal isolate A. dhakensis SSU and environmental isolate Aeromonas hydrophila American Type Culture Collection_7966T.
Skin and soft tissue infections, traumatic wound infections, sepsis, burns, and intraabdominal infections were common. Diabetes, malignancy, and cirrhosis were frequent comorbidities. Male sex, age ≥ 65 years, hospitalization, burns, and intensive care admission were associated with complicated disease. High rates of AMR to carbapenems and piperacillin-tazobactam were found. Treatment failure was observed in 25.7% of cases. Septic shock and hospital-acquired infections were predictors of treatment failure. All 4 isolates harbored assorted broad-spectrum AMR genes including blaOXA, ampC, cphA, and efflux pumps. Only clinical isolates possessed both polar and lateral flagellar genes, genes for various surface adhesion proteins, type 3 and 6 secretion systems and their effectors, and toxin genes, including exotoxin A. Both isolates A and B were resistant to colistin and harbored the mobile colistin resistance-3 (mcr-3) gene.
Empirical therapy tailored to local antibiograms may facilitate favorable outcomes, while advanced diagnostic methods may aid in identifying correct Aeromonas spp. of significant clinical importance.
气单胞菌的毒力可能不完全依赖于宿主的免疫状态。疾病进展和严重程度的病理生理决定因素仍不清楚。
确定了 105 例气单胞菌感染患者和 112 株分离株，分析了他们的临床表现和结局，并评估了他们的抗菌药物耐药性（AMR）模式。对两株来自气单胞菌 dhakensis 菌血症致死病例的分离株（A 和 B）进行了全基因组测序。比较这两株分离株与一株经过充分表征的腹泻气单胞菌 dhakensis SSU 分离株和环境分离株嗜水气单胞菌美国典型培养物保藏中心_7966T 的毒力因子和 AMR 编码基因。
皮肤和软组织感染、创伤性伤口感染、败血症、烧伤和腹腔内感染较为常见。糖尿病、恶性肿瘤和肝硬化是常见的合并症。男性、年龄≥65 岁、住院、烧伤和入住重症监护病房与复杂疾病相关。发现对碳青霉烯类和哌拉西林-他唑巴坦的耐药率较高。观察到 25.7%的病例治疗失败。感染性休克和医院获得性感染是治疗失败的预测因素。所有 4 株分离株均携带各种广谱 AMR 基因，包括 blaOXA、ampC、cphA 和外排泵。只有临床分离株同时具有极性和侧向鞭毛基因、各种表面黏附蛋白基因、III 型和 VI 型分泌系统及其效应物基因和毒素基因，包括外毒素 A。分离株 A 和 B 均对粘菌素耐药，并携带移动粘菌素耐药基因 3（mcr-3）。
根据当地药敏试验结果量身定制经验性治疗可能有助于获得良好的结局，而先进的诊断方法可能有助于识别具有重要临床意义的正确气单胞菌。
