Table_1_Comparison of Carbapenem-Resistant Klebsiella pneumoniae Strains Causing Intestinal Colonization and Extraintestinal Infections: Clinical, Virulence, and Molecular Epidemiological Characteristics.docx

Carbapenem-resistant Klebsiella pneumonia (CRKP) infections has become a concerning threat. However, knowledge regarding the characteristics of intestinal CRKP isolates is limited. This study aimed to investigate and compare the clinical, virulence and molecular epidemiological characteristics of intestinal colonization and extraintestinal infections CRKP strains. The clinical characteristics were investigated retrospectively. Polymerase chain reaction was used to investigate the capsular serotype, virulence genes and carbapenemase genes. Capsular polysaccharide quantification assay, serum resistance assay, biofilm formation assay, and infection model of Galleria mellonella larvae were performed to compare the virulence and pathogenicity. Besides, multilocus-sequence-typing (MLST) and pulsed-field-gel-electrophoresis (PFGE) were conducted to explore the homology of intestinal CRKP isolates. A total of 54 intestinal CRKP isolates were included. The main capsular serotypes were K14, K64, and K19. C-reactive protein and the proportion of ICU isolation of the infection group were significantly higher than that of the colonization group (P < 0.05). The carrier rates of various virulence genes of CRKP in the infection group were mostly higher than those in the colonization group, wherein the carrier rates of peg-344 and rmpA were significantly different (P < 0.05). There was no significant difference in capsular polysaccharides, antiserum ability, biofilm formation ability between the two group (P > 0.05), but the lethality of the infection group to Galleria mellonella was significantly higher than that of the colonization group (P < 0.05). The MLST categorized the 54 isolates into 13 different sequence types. PFGE revealed that homology among the 54 CRKP strains was

碳青霉烯耐药肺炎克雷伯菌（CRKP）感染已成为一项令人担忧的威胁。然而，关于肠道CRKP分离株特性的知识却十分有限。本研究旨在调查和比较肠道定植和肠外感染的CRKP菌株的临床、致病性和分子流行病学特征。临床特征通过回顾性研究进行探讨。利用聚合酶链反应技术研究荚膜血清型、致病基因和碳青霉烯酶基因。通过荚膜多糖定量分析、血清耐药性分析、生物膜形成分析以及Galleria mellonella幼虫感染模型来比较致病性和致病力。此外，通过多 locus 序列分型（MLST）和脉冲场凝胶电泳（PFGE）技术来探究肠道CRKP分离株的同源性。共纳入54株肠道CRKP分离株。主要荚膜血清型为K14、K64和K19。感染组的C反应蛋白水平和ICU隔离感染组的比例显著高于定植组（P < 0.05）。感染组CRKP中各种致病基因的携带率大多高于定植组，其中peg-344和rmpA的携带率差异显著（P < 0.05）。在荚膜多糖、抗血清能力和生物膜形成能力方面，两组之间无显著差异（P > 0.05），但感染组对Galleria mellonella的致死性显著高于定植组（P < 0.05）。MLST将54株分离株分为13种不同的序列型。PFGE显示54株CRKP菌株之间存在同源性