Hypervirulent Klebsiella pneumoniae of Lineage ST66-K2 Caused Tonsillopharyngitis in a German Patient.

Christoph Lübbert,Guido Werner,Norman Lippmann,Kathleen Klaper,Sebastian Wendt,Yvonne Pfeifer

doi:10.3390/microorganisms9010133

Abstract

Hypervirulent Klebsiella pneumoniae (hvKp) is a novel pathotype that has been rarely described in Europe. This study characterizes a hvKp isolate that caused a community-acquired infection. The hypermucoviscous Klebsiella pneumoniae (K. pneumoniae) strain 18-0005 was obtained from a German patient with tonsillopharyngitis in 2017. Antibiotic susceptibility testing was performed and the genome was sequenced by Illumina and Nanopore technology. Whole genome data were analyzed by conducting core genome multilocus sequence typing (cgMLST) and single nucleotide polymorphism (SNP) analysis. Virulence genes were predicted by applying Kleborate. Phenotypic and whole genome analyses revealed a high similarity of the study isolate 18-0005 to the recently reported antibiotic-susceptible hvKp isolate SB5881 from France and the “ancestral” strain Kp52.145; both were assigned to the ST66-K2 lineage. Comparative genomic analysis of the three plasmids showed that the 18-0005 plasmid II differs from SB5881 plasmid II by an additional 3 kb integrated fragment of plasmid I. Our findings demonstrate the genetic flexibility of hvKp and the occurrence of a strain of the clonal group CG66-K2 in Germany. Hence, it emphasizes the need to improve clinical awareness and infection monitoring of hvKp.

Highlights

Klebsiella pneumoniae is a Gram-negative, rode shaped, facultative anaerobe, ubiquitous environmental bacterium of the family Enterobacteriaceae
A 33-year-old male patient presented a tonsillopharyngitis caused by a community-acquired hypervirulent K. pneumoniae (hvKp) strain
The direct association of hypervirulence with hypermucoviscosity is controversial, this case demonstrates that a positive string test is a strong indicator for presence of a hvKp strain

Summary

Introduction

Klebsiella pneumoniae is a Gram-negative, rode shaped, facultative anaerobe, ubiquitous environmental bacterium of the family Enterobacteriaceae. Due to the acquisition of multiple antibiotic resistance genes, like extendedspectrum beta-lactamases (ESBLs) and to a lesser extent carbapenemases, the treatment of infections with K. pneumoniae has become challenging [2]. The spread of various multidrugresistant K. pneumoniae strains is considered a global public health threat [3]. In the face of increasing antibiotic resistance, a new challenge for clinicians has emerged with the rise of hypervirulent K. pneumoniae (hvKp) [4]. Since the mid-1980s, the emergence and spread of severe hvKp infections, causing liver abscess, endophthalmitis and meningitis in otherwise healthy individuals has been reported [5]. HvKp have the ability for metastatic spread and cause infections at multiple body sites [6]. Reports of hvKp infections are increasing worldwide.

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