Identification and Whole Genome Sequencing of the First Case of Kosakonia radicincitans Causing a Human Bloodstream Infection.

Micah D Bhatti,Awdhesh Kalia,David E Greenberg,Samuel A Shelburne,Jiwoong Kim,Pranoti Sahasrabhojane

doi:10.3389/fmicb.2017.00062

Abstract

The taxonomy of Enterobacter species is rapidly changing. Herein we report a bloodstream infection isolate originally identified as Enterobacter cloacae by Vitek2 methodology that we found to be Kosakonia radicincitans using genetic means. Comparative whole genome sequencing of our isolate and other published Kosakonia genomes revealed these organisms lack the AmpC β-lactamase present on the chromosome of Enterobacter sp. A fimbriae operon primarily found in Escherichia coli O157:H7 isolates was present in our organism and other available K. radicincitans genomes. This is the first report of a Kosakonia species, which are typically associated with plants, causing a human infection.

Highlights

Enterobacter species are major causes of human infections and are prominent nosocomial pathogens due to their broad array of antimicrobial resistance elements (Mezzatesta et al, 2012)
We report the first case of a human infection caused by a Kosakonia genus organism, K. radicincitans
Known as Enterobacter radicincitans, all prior reports of this organism have described it as a plant associated bacteria and have mainly focused on its growth promoting properties (Kampfer et al, 2005; Schreiner et al, 2009; Witzel et al, 2012; Brock et al, 2013; Suhaimi et al, 2014; Bergottini et al, 2015)

Summary

Introduction

Enterobacter species are major causes of human infections and are prominent nosocomial pathogens due to their broad array of antimicrobial resistance elements (Mezzatesta et al, 2012). Genetic methodologies for analyzing bacterial strains has revealed the complex nature of the Enterobacter genus which in turn has resulted in numerous reclassifications of Enterobacter and Enterobacter-like organisms (Brady et al, 2013). E. cloacae complex strains, which are the most common cause of Enterobacter disease in humans, remain in the Enterobacter genus (Brady et al, 2013). We report the first infection in a human caused by a Kosakonia species and use whole genome analyses of the infecting isolate to identify variant and conserved aspects of virulence and antimicrobial resistance present in Kosakonia species relative to E. cloacae and other Enterobacter-like organisms

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