Kantonsspital St.Gallen
login

First two cases of severe multifocal infections caused by Klebsiella pneumoniae in Switzerland: characterization of an atypical non-K1/K2-serotype strain causing liver abscess and endocarditis

Baharak Babouee Flury, Valentina Donà, Niccolo Buetti, Hansjakob Furrer & Andrea Endimiani

abstract

BACKGROUND
We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland.

METHODS
Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates.

RESULTS
Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases. However, only Kp1 was string test positive. Kp1 was of ST380 and caused liver abscess as well as pneumonia and orbital phlegmon in an Eritrean patient. It belonged to the hypervirulent capsular serotype K2 and harboured the classic virulence-associated rmpA and aerobactin genes, fulfilling both the clinical and microbiological definitions for an invasive K. pneumoniae syndrome. Kp2 was of ST1043 and caused both liver abscess and endocarditis in a Swiss patient. Moreover, it did not possess the classic virulence-associated genes. Whole genome sequencing identified less well-known virulence factors in Kp2 that might have contributed to its virulence. Among these there were genes important for intestinal colonization and/or invasion, such as genes involved in adhesion (e.g., fimABCD and mrkABCD), regulation of capsule polysaccharide biosynthesis (e.g., evgS-evgA), as well as iron uptake (iroN), energy conversion, and metabolism.

DISCUSSION
This report confirms the continuous dissemination of hypervirulent K. pneumoniae strains among patients of non-Asian descent in Europe. Moreover, it highlights the genetic background of an atypical hypervirulent K. pneumoniae causing a severe invasive infection despite not possessing the classical virulence characteristics of hypermucoviscous strains.
   
citation Babouee Flury B, Donà V, Buetti N, Furrer H, Endimiani A. First two cases of severe multifocal infections caused by Klebsiella pneumoniae in Switzerland: characterization of an atypical non-K1/K2-serotype strain causing liver abscess and endocarditis. J Glob Antimicrob Resist 2017; 10:165-170.
   
type journal paper/review (English)
date of publishing 17-07-2017
journal title J Glob Antimicrob Resist (10)
ISSN electronic 2213-7173
pages 165-170
PubMed 28729207
DOI 10.1016/j.jgar.2017.04.006