Abstract：
Carbapenem-resistant Klebsiella pneumoniae (CRKP) are usually multidrug resistant (MDR) and cause serious therapeutic problems. Colistin is a critical last-resort therapeutic option for MDR bacterial infections. However, increasing colistin use has led to the emergence of extensively drug-resistant (XDR) strains, raising a significant challenge for healthcare. In order to gain insight into the antibiotic resistance mechanisms of CRKP and identify potential drug targets, we compared the molecular characteristics and the proteomes among drug-sensitive (DS), MDR, and XDR K. pneumoniae strains. All drug-resistant isolates belonged to ST11, harboring blaKPC and hypervirulent genes. None of the plasmid-encoded mcr genes were detected in the colistin-resistant XDR strains. Through a tandem mass tag (TMT)-labeled proteomic technique, a total of 3531 proteins were identified in the current study. Compared to the DS strains, there were 247 differentially expressed proteins (DEPs) in the MDR strains and 346 DEPs in the XDR strains, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that a majority of the DEPs were involved in various metabolic pathways, which were beneficial to the evolution of drug resistance in K. pneumoniae. In addition, a total of 67 DEPs were identified between the MDR and XDR strains. KEGG enrichment and protein-protein interaction network analysis showed their participation in cationic antimicrobial peptide resistance and two-component systems. In conclusion, our results highlight the emergence of colistin-resistant and hypervirulent CRKP, which is a noticeable superbug. The DEPs identified in our study are of great significance for the exploration of effective control strategies against infections of CRKP.
摘要：
耐碳青霉烯类肺炎克雷伯菌（CRKP）通常是多药耐药（MDR）并引起严重的治疗问题。粘菌素是MDR细菌感染的关键最后手段治疗选择。然而,粘菌素使用的增加导致广泛耐药（XDR）菌株的出现，对医疗保健提出了重大挑战。为了深入了解CRKP的抗生素耐药机制并确定潜在的药物靶标，我们比较了药物敏感（DS）的分子特征和蛋白质组，MDR,和XDR肺炎克雷伯菌菌株。所有耐药菌株均属于ST11，具有blaKPC和高毒力基因。在粘菌素抗性XDR菌株中未检测到质粒编码的mcr基因。通过串联质量标签（TMT）标记的蛋白质组学技术，本研究共鉴定出3531种蛋白质.与DS菌株相比，MDR菌株中有247种差异表达蛋白（DEP），XDR菌株中有346种DEP，分别。基因本体论（GO）和京都基因和基因组百科全书（KEGG）富集分析显示，大多数DEP参与各种代谢途径，有利于肺炎克雷伯菌耐药性的演变。此外,在MDR和XDR菌株之间共鉴定出67个DEP.KEGG富集和蛋白质-蛋白质相互作用网络分析显示它们参与了阳离子抗菌肽抗性和双组分系统。总之,我们的结果强调了粘菌素抗性和高毒力CRKP的出现，这是一个明显的超级细菌。我们研究中确定的DEP对于探索针对CRKP感染的有效控制策略具有重要意义。
