IDDF2021-ABS-0094 Virulence factors and resistance genes carried differences of klebsiella pneumoniae isolated from patients with pneumonia and pyogenic liver abscess

Abstract

<h3>Background</h3> The bacterium Klebsiella pneumoniae of family Enterobacteriacea is a well-known opportunistic pathogen that colonizes intestinal and respiratory tract. While K. pneumoniae is a common cause of nosocomial and community-acquired infections, including diarrhea, pneumonia and pyogenic liver abscess, little is known about the population structure of this bacterium. Thus it is likely that the epidemiological characteristics of K. pneumoniae isolate from carriers and clinic patients, when combined to their genomic information, might provide some insight into pathogenic Klebsiella prevention and control. <h3>Methods</h3> Two hundred and thirty-two K. pneumoniae isolates (including 38 isolates from carriers, 124 isolates from pyogenic liver abscess patients and 70 isolates from pneumonia patients) were collected from 9 provinces of China in 2013-2020. Sequencing was performed on the Illumina Hiseq PE150 platform, and the genome sequences were assembled by SOAP denovo. Multilocus sequence typing (MLST) analysis was done by submitting sequences to the Institute Pasteur K. pneumoniae MLST database. Pan-genome analysis was performed by software Snippy, Gubbins and Roary, and the gene contents were identified by software VFanalyzer, Resfinder and PlasmidFinder. <h3>Results</h3> The 232 isolates were subtyped into 74 STs. The isolates from different sources have their own STs, and the predominant subtypes of liver abscess patients and pneumonia patients were ST23 and ST11, respectively. PCA analysis (<i>p</i> = 0.001) on accessory gene content also distinguished the three phylogroups, which are consistent with the source of isolates. The isolates collected from liver abscess patients carried significantly more (<i>p</i> = 0.000) virulence factors, and the isolates sourced from pneumonia patients harbored significantly more (<i>p</i> = 0.000) resistance genes and replicons. Besides, there was a strong link between Salmonchelin and the isolates sourced from liver abscess patients. Ninety-eight percent isolates of liver abscess strongly correlated STs and only two percent isolates of pneumoniae correlated STs carried Salmonchelin. <h3>Conclusions</h3> These data provide genomic support for the proposal that isolates collected from carrier, liver abscess and pneumoniae patients have their distinct genomic features. And the isolates from different sources are largely nonoverlapping.