Ann Lab Med.  2017 May;37(3):272-276. 10.3343/alm.2017.37.3.272.

Laboratory Identification of Leptotrichia Species Isolated From Bacteremia Patients at a Single Institution

• Cho EH
• Park KS
• Yang M
• Song DJ
• Huh HJ
• Ki CS
• Lee NY

• KMID: 2369754
• DOI: http://doi.org/10.3343/alm.2017.37.3.272

Abstract

We describe the laboratory identification of Leptotrichia species from clinical isolates collected over a six-year period. Five isolates from blood cultures were identified as Leptotrichia species. Gram stain showed large, fusiform, gram-negative or -variable bacilli. Identification based on biochemical testing was unsuccessful; however, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry proved to be a useful tool for identifying Leptotrichia species to the genus level. Species level identification was successfully achieved by using 16S ribosomal RNA gene sequencing.

Keyword

Leptotrichia; Bacteremia; Identification; MALDI-TOF MS; 16S ribosomal RNA

MeSH Terms

Bacteremia*
Humans
Leptotrichia*
Mass Spectrometry
RNA, Ribosomal, 16S
RNA, Ribosomal, 16S

Figure

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  Fig. 1 Colony morphology and microscopy of Leptotrichia spp. Colony morphology of Leptotrichia buccalis isolated from case 3 (A) and Leptotrichia trevisanii isolated from case 5 (B). Gram stain of Leptotrichia species showing gram-negative (isolate from case 3) (C) and gram-variable (isolate from case 5) (D) cells (×1,000).

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  Fig. 2 Neighbor-joining phylogenetic tree showing the relationships of the five isolates to related Leptotrichia species and other Fusobacteriaceae. Reference sequences are from species type strains; GenBank accession numbers are given in parentheses.

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