Characterization of a novel Gram-stain-positive anaerobic coccus isolated from the female genital tract: Genome sequence and description of Murdochiella vaginalis sp. nov

Abstract

Strain Marseille-P2341^T , a nonmotile, nonspore-forming, Gram-stain-positive anaerobic coccus, was isolated in the vaginal specimen of a patient with bacterial vaginosis using culturomics. Its growth occurred at temperatures ranging from 25 to 42°C, with pH between 6.5 and 8.5, and at NaCl concentrations lower than 5%. The major fatty acids were C_18:1n9 (27.7%) and C_16:0 (24.4%). Its genome is 1,671,491 bp long with 49.48 mol% of G+C content. It is composed of 1,501 genes: 1,446 were protein-coding genes and 55 were RNAs. Strain Marseille-P2341^T shared 97.3% of 16S rRNA gene sequence similarity with Murdochiella asaccharolytica, the phylogenetically closest species. These results enabled the classification of strain Marseille-P2341^T as a new species of the genus Murdochiella for which we proposed the name Murdochiella vaginalis sp. nov. The type strain is strain Marseille-P2341^T (=DSM 102237, =CSUR P2341).

Keywords: Murdochiella vaginalis; bacterial vaginosis; culturomics; genome; taxono-genomics; vaginal microbiota.

Figure 1

Phylogenetic tree highlighting the position of Murdochiella vaginalis strain Marseille‐P2341^T relative to other close strains. GenBank accession numbers of each 16S rRNA are noted in parenthesis. Sequences were aligned using Muscle v3.8.31 with default parameters and phylogenetic inferences were obtained using the neighbor‐joining method with 500 bootstrap replicates, within MEGA6 software. The scale bar represents a 2% nucleotide sequence divergence

Figure 2

MALDI‐TOF information. (a) Reference mass spectrum from Murdochiella vaginalis strain Marseille‐P2341T spectra. (b) Gel view comparing M. vaginalis strain Marseille‐P2341T to other species within Peptoniphilaceae family. The gel view displays the raw spectra of loaded spectrum files arranged with a pseudo‐gel like appearance. The x‐axis records the m/z value. The left y‐axis displays the running spectrum number originating from subsequent spectra loading. The peak intensity is expressed by a gray scale scheme code. The right y‐axis indicates the relation between the color of a peak and its intensity, in arbitrary units. Displayed species are indicated on the left

Figure 3

Transmission electron microscopy of Murdochiella vaginalis strain Marseille‐P2341^T, using a Tecnai G20 transmission electron microscope (FEI Company). The scale bar represents 100 nm

Figure 4

Graphical circular map of the genome. From outside to the center: Contigs (red/gray), COG category of genes on the forward strand (three circles), genes on forward strand (blue circle), genes on the reverse strand (red circle), COG category on the reverse strand (three circles), GC content

Figure 5

Distribution of functional classes of predicted genes according to the clusters of orthologous groups of proteins of Murdochiella vaginalis strain Marseille‐P2341T among other species