Abstract：
BACKGROUND: A. baumannii is an important and common clinical pathogen, especially in the intensive care unit (ICU). This study aimed to characterize one hypervirulent A. baumannii strain in a patient with community-acquired pneumonia and herpes simplex type 1 virus infection.
METHODS: Minimum inhibitory concentrations (MICs) were determined using the Kirby-Bauer (K-B) and broth microdilution methods. Galleria mellonella infection model experiment was conducted. Whole-genome sequencing (WGS) was performed using the Illumina and Nanopore platforms. The resistance and virulence determinants were identified using the ABRicate program with ResFinder and the VFDB database. The capsular polysaccharide locus (K locus) and lipooligosaccharide outer core locus (OC locus) were identified using Kleborate with Kaptive. Phylogenetic analyses were conducted using the BacWGSTdb server.
RESULTS: A. baumannii XH2146 strain belongs to ST10Pas and ST447Oxf. The strain was resistant to cefazolin, ciprofloxacin, and trimethoprim/sulfamethoxazole (TMP-SMX). Bautype and Kaptive analyses showed that XH2146 contains OCL2 and KL49. WGS analysis revealed that the strain harbored blaADC-76, blaOXA-68, ant(3\'\')-IIa, tet(B), and sul2. Notably, tet(B) and sul2, both were located within a 114,700-bp plasmid (designated pXH2146-1). Virulence assay revealed A. baumannii XH2146 possessed higher virulence than A. baumannii AB5075 at 12 h. Comparative genomic analysis showed that A. baumannii ST447 strains were mainly isolated from the USA and exhibited a relatively close genetic relationship. Importantly, 11 strains were observed to carry blaOXA-58; blaOXA-23 was identified in 11 isolates and three ST447 A. baumannii strains harbored blaNDM-1.
CONCLUSIONS: Early detection of community-acquired hypervirulent Acinetobacter baumannii strains is recommended to prevent their extensive spread in hospitals.
METHODS: Minimum inhibitory concentrations (MICs) were determined using the Kirby-Bauer (K-B) and broth microdilution methods. Galleria mellonella infection model experiment was conducted. Whole-genome sequencing (WGS) was performed using the Illumina and Nanopore platforms. The resistance and virulence determinants were identified using the ABRicate program with ResFinder and the VFDB database. The capsular polysaccharide locus (K locus) and lipooligosaccharide outer core locus (OC locus) were identified using Kleborate with Kaptive. Phylogenetic analyses were conducted using the BacWGSTdb server.
RESULTS: A. baumannii XH2146 strain belongs to ST10Pas and ST447Oxf. The strain was resistant to cefazolin, ciprofloxacin, and trimethoprim/sulfamethoxazole (TMP-SMX). Bautype and Kaptive analyses showed that XH2146 contains OCL2 and KL49. WGS analysis revealed that the strain harbored blaADC-76, blaOXA-68, ant(3\'\')-IIa, tet(B), and sul2. Notably, tet(B) and sul2, both were located within a 114,700-bp plasmid (designated pXH2146-1). Virulence assay revealed A. baumannii XH2146 possessed higher virulence than A. baumannii AB5075 at 12 h. Comparative genomic analysis showed that A. baumannii ST447 strains were mainly isolated from the USA and exhibited a relatively close genetic relationship. Importantly, 11 strains were observed to carry blaOXA-58; blaOXA-23 was identified in 11 isolates and three ST447 A. baumannii strains harbored blaNDM-1.
CONCLUSIONS: Early detection of community-acquired hypervirulent Acinetobacter baumannii strains is recommended to prevent their extensive spread in hospitals.
摘要：
背景：A.鲍曼不动杆菌是一种重要而常见的临床病原菌,特别是在重症监护病房（ICU）。这项研究旨在表征社区获得性肺炎和单纯疱疹病毒1型感染患者的一种高毒力鲍曼不动杆菌菌株。
方法:使用Kirby-Bauer(K-B)和肉汤微量稀释法测定最小抑制浓度(MIC)。进行了海棠感染模型实验。使用Illumina和Nanopore平台进行全基因组测序(WGS)。使用具有ResFinder和VFDB数据库的ABRicate程序鉴定抗性和毒力决定子。使用具有Kaptive的Kleborate鉴定了荚膜多糖基因座（K基因座）和脂寡糖外核心基因座（OC基因座）。使用BacWGSTdb服务器进行系统发育分析。
结果：A.鲍曼不动杆菌XH2146菌株属于ST10Pas和ST447Oxf。该菌株对头孢唑啉具有抗性，环丙沙星,和甲氧苄啶/磺胺甲恶唑（TMP-SMX）。Bautype和Kaptive分析显示XH2146含有OCL2和KL49。WGS分析显示该菌株含有blaADC-76，blaOXA-68，ant（3\'\'）-IIa，tet(B),sul2值得注意的是,tet(B)和sul2均位于114,700-bp质粒(命名为pXH2146-1)内。毒力测定显示鲍曼不动杆菌XH2146在12h具有比鲍曼不动杆菌AB5075更高的毒力。比较基因组分析表明，鲍曼不动杆菌ST447菌株主要从美国分离，并表现出相对密切的遗传关系。重要的是,观察到11个菌株携带blaOXA-58；在11个分离物中鉴定出blaOXA-23，三个ST447鲍曼不动杆菌菌株携带blaNDM-1。
结论：建议早期检测社区获得性高毒力鲍曼不动杆菌菌株，以防止其在医院的广泛传播。
方法:使用Kirby-Bauer(K-B)和肉汤微量稀释法测定最小抑制浓度(MIC)。进行了海棠感染模型实验。使用Illumina和Nanopore平台进行全基因组测序(WGS)。使用具有ResFinder和VFDB数据库的ABRicate程序鉴定抗性和毒力决定子。使用具有Kaptive的Kleborate鉴定了荚膜多糖基因座（K基因座）和脂寡糖外核心基因座（OC基因座）。使用BacWGSTdb服务器进行系统发育分析。
结果：A.鲍曼不动杆菌XH2146菌株属于ST10Pas和ST447Oxf。该菌株对头孢唑啉具有抗性，环丙沙星,和甲氧苄啶/磺胺甲恶唑（TMP-SMX）。Bautype和Kaptive分析显示XH2146含有OCL2和KL49。WGS分析显示该菌株含有blaADC-76，blaOXA-68，ant（3\'\'）-IIa，tet(B),sul2值得注意的是,tet(B)和sul2均位于114,700-bp质粒(命名为pXH2146-1)内。毒力测定显示鲍曼不动杆菌XH2146在12h具有比鲍曼不动杆菌AB5075更高的毒力。比较基因组分析表明，鲍曼不动杆菌ST447菌株主要从美国分离，并表现出相对密切的遗传关系。重要的是,观察到11个菌株携带blaOXA-58；在11个分离物中鉴定出blaOXA-23，三个ST447鲍曼不动杆菌菌株携带blaNDM-1。
结论：建议早期检测社区获得性高毒力鲍曼不动杆菌菌株，以防止其在医院的广泛传播。
