PDF(Pubmed)
Abstract：
Acinetobacter baumannii is one of the most successful pathogens that can cause difficult-to-treat nosocomial infections. Outbreaks and infections caused by multi-drug resistant A. baumannii are prevalent worldwide, with only a few antibiotics are currently available for treatments. Plasmids represent an ideal vehicle for acquiring and transferring resistance genes in A. baumannii. Five extensively drug-resistant A. baumannii clinical isolates from three major Jordanian hospitals were fully sequenced. Whole-Genome Sequences (WGS) were used to study the antimicrobial resistance and virulence genes, sequence types, and phylogenetic relationship of the isolates. Plasmids were characterized In-silico, followed by conjugation, and plasmid curing experiments. Eight plasmids were recovered; resistance plasmids carrying either aminoglycosides or sulfonamide genes were detected. Chromosomal resistance genes included blaOXA-66, blaOXA-91, and blaOXA-23, and the detected virulence factors were involved in biofilm formation, adhesion, and many other mechanisms. Conjugation and plasmid curing experiments resulted in the transfer or loss of several resistance phenotypes. Plasmid profiling along with phylogenetic analyses revealed high similarities between two A. baumannii isolates recovered from two different intensive care units (ICU). The high similarities between the isolates of the study, especially the two ICU isolates, suggest that there is a common A. baumannii strain prevailing in different ICU wards in Jordanian hospitals. Three resistance genes were plasmid-borne, and the transfer of the resistance phenotype emphasizes the role and importance of conjugative plasmids in spreading resistance among A. baumannii clinical strains.
摘要：
鲍曼不动杆菌是最成功的病原体之一，可引起难以治疗的医院感染。由多重耐药鲍曼不动杆菌引起的暴发和感染在世界范围内普遍存在，目前只有少数抗生素可用于治疗。质粒代表在鲍曼不动杆菌中获得和转移抗性基因的理想载体。对来自三个主要约旦医院的五个广泛耐药的鲍曼不动杆菌临床分离株进行了完整测序。全基因组序列(WGS)用于研究抗菌素耐药性和毒力基因,序列类型,和分离株的系统发育关系。质粒进行了表征，然后是共轭，和质粒固化实验。回收了八个质粒；检测到携带氨基糖苷类或磺酰胺基因的抗性质粒。染色体抗性基因包括blaOXA-66、blaOXA-91和blaOXA-23，检测到的毒力因子参与生物膜的形成，附着力,和许多其他机制。缀合和质粒固化实验导致几种抗性表型的转移或丧失。质粒谱分析和系统发育分析揭示了从两个不同的重症监护病房(ICU)回收的两个鲍曼不动杆菌分离株之间的高度相似性。该研究的分离株之间的高度相似性，尤其是两个ICU分离株,这表明在约旦医院的不同ICU病房中普遍存在一种常见的鲍曼不动杆菌菌株。三个抗性基因是质粒携带的，抗性表型的转移强调了接合质粒在鲍曼不动杆菌临床菌株中传播抗性的作用和重要性。
