Superficieibacter electus gen. nov., sp. nov., an Extended-Spectrum β-Lactamase Possessing Member of the Enterobacteriaceae Family, Isolated From Intensive Care Unit Surfaces.

Robert F Potter,Carey-Ann D Burnham,Sanket Patel,Alaric W D'Souza,Gautam Dantas,Jennie H Kwon,Saadia Andleeb,Wandy Beatty,Angela Shupe,Meghan A Wallace,Danish Gul

doi:10.3389/fmicb.2018.01629

Abstract

Two Gram-negative bacilli strains, designated BP-1(T) and BP-2, were recovered from two different Intensive Care Unit surfaces during a longitudinal survey in Pakistan. Both strains were unidentified using the bioMerieux VITEK MS IVD v2.3.3 and Bruker BioTyper MALDI-TOF mass spectrometry platforms. To more precisely determine the taxonomic identity of BP-1(T) and BP-2, we employed a biochemical and phylogenomic approach. The 16S rRNA gene sequence of strain BP-1(T) had the highest identity to Citrobacter farmeri CDC 2991-81(T) (98.63%) Citrobacter amalonaticus CECT 863(T) (98.56%), Citrobacter sedlakii NBRC 105722(T) (97.74%) and Citrobacter rodentium NBRC 105723(T) (97.74%). The biochemical utilization scheme of BP-1(T) using the Analytic Profile Index for Enterobacteriaceae (API20E) indicated its enzymatic functions are unique within the Enterobacteriaceae but most closely resemble Kluyvera spp., Enterobacter cloacae and Citrobacter koseri/farmeri. Phylogenomic analysis of the shared genes between BP-1(T), BP-2 and type strains from Kluyvera, Citrobacter, Escherichia, Salmonella, Kosakonia, Siccibacter and Shigella indicate that BP-1(T) and BP-2 isolates form a distinct branch from these genera. Average Nucleotide Identity analysis indicates that BP-1(T) and BP-2 are the same species. The biochemical and phylogenomic analysis indicate strains BP-1(T) and BP-2 represent a novel species from a new genus within the Enterobacteriaceae family, for which the name Superficieibacter electus gen. nov., sp. nov., is proposed. The type strain is BP-1(T) (= ATCC BAA-2937, = NBRC 113412).

Highlights

The hospital built environment is a key source of nosocomial pathogens, which can cause high mortality infections in vulnerable patient populations (Oberauner et al, 2013)
The purpose of our investigation was to determine the taxonomic identity of strains BP-1(T) and BP-2, two isolates recovered from selective culturing of swabs of two Pakistani intensive care unit (ICU) room surfaces which could not be identified using MALDI-ToF mass spectroscopy
The colony morphology of strains BP-1(T) and BP-2 on blood agar is indistinguishable from non-swarming Enterobacteriaceae, but the results of growth on MacConkey plates and ChromID ESBL agar show phenotypic similarities to lactose fermenting and extended spectrum β-lactamase producing species such as E. coli and K. pneumoniae (Grohs et al, 2013)

Summary

Introduction

The hospital built environment is a key source of nosocomial pathogens, which can cause high mortality infections in vulnerable patient populations (Oberauner et al, 2013). The danger from these infections is exacerbated by the higher levels of antibiotic resistance harbored by nosocomial pathogens compared to their community-associated relatives (Horcajada et al, 2013). Documenting the appearance of novel Enterobacteriaceae species in hospital settings is an important component in surveilling and preventing emerging infectious diseases (Iredell et al, 2016)

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Results

Conclusion