Lab Med Online.  2015 Oct;5(4):223-226. 10.3343/lmo.2015.5.4.223.

Two Cases of Enterobacter hormaechei Infection Misidentified as Cedecea davisae Infection

• Lim YK
• Kweon OJ
• Lee MK
• Park KU

• KMID: 2046386
• DOI: http://doi.org/10.3343/lmo.2015.5.4.223

Abstract

Enterobacteriaceae is a family of gram-negative, rod-shaped bacteria that consists of various species. Among these, members of the genus Cedecea has been reported as relatively rare causative pathogens of human infections. Commercially available automated identification systems that use biochemical reactions are known to accurately identify Enterobacteriaceae species. However, the accurate identification of some organisms with diverse biochemical profiles by these automated identification systems may be problematic. In this study, we report two cases of isolate misidentification, from patients with acute cholecystitis and deep vein thrombosis, as Cedecea davisae with VITEK II system. Both the isolates were correctly identified as Enterobacter hormaechei using gyrB gene sequence analysis. We also performed 16S rRNA sequence analyses and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses; however, indeterminate results were obtained from both the assays. Therefore, the sequence analysis of alternative genes, like gyrB, might be useful for accurate identification of species that belong to the family of Enterobacteriaceae.

Keyword

Enterobacteriaceae; Cedecea davisae; Enterobacter hormaechei; VITEK II; Sequence analysis

MeSH Terms

Bacteria
Cholecystitis, Acute
Enterobacter*
Enterobacteriaceae
Humans
Mass Spectrometry
Sequence Analysis
Venous Thrombosis

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