First Report of Wohlfahrtiimonas chitiniclastica Isolation from a Patient with Cellulitis in the United States

Abstract

We report the first documented isolation of Wohlfahrtiimonas chitiniclastica from a human in the United States. Initially misidentified as Acinetobacter lwoffii by Vitek-2, the isolate was subsequently identified as W. chitiniclastica by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing. While the clinical significance of the isolate in this case is unclear, it highlights the superior performance of MALDI-TOF MS for bacterial identification.

FIG 1

Neighbor-joining phylogenetic tree of partial 16S rRNA gene sequences. Sequences from GenBank are shown with accession numbers, species names, and strain numbers (T indicates a type strain) and were trimmed to the length of the sequence (492 nucleotides) of the patient's (pt) isolate. Bootstrap values from 1,000 replicates are shown at internal nodes. Evolutionary distance is shown as the number of base substitutions per site and was computed in MEGA6 by the maximum composite likelihood method. W. chitiniclastica = Wohlfartiimonas chitiniclastica; W. larvae = Wohlfartiimonas larvae; I. indica = Ignatzschineria indica; I. ureiclastica = Ignatzschineria ureiclastica; I. larvae = Ignatzschineria larvae; A. lwoffii = Acinetobacter lwoffii; B. diminuta = Brevundimonas diminuta.

FIG 2

Sheep blood agar colony (A) and Gram stain (B) morphologies of W. chitiniclastica.