Pseudomonas senegalensis sp. nov. and Pseudomonas millioni sp. nov., two novel species isolated from the breast milk of Senegalese women

Two Gram-negative, aerobic, motile and non-spore-forming bacilli, designated strains Marseille-QA0332 T and Marseille-QA0892 T , were isolated from the breast milk of nursing mothers in Senegal. Because both strains failed to be identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, a comprehensive taxonogenomic approach was employed to determine their taxonomic positions. The complete genomes consist of single circular chromosomes of 4,577,173 bp (63.65 mol% G + C) for strain Marseille-QA0332 T and 4,658,126 bp (60.22 mol% G + C) for strain Marseille-QA0892 T . The 16S rRNA gene analysis revealed a sequence similarity of 97.98% between strain Marseille-QA0332 T and Pseudomonas ceruminis BML-PP028 T , while Pseudomonas muyukensis COW39 T was identified as its closest relative based on digital DNA-DNA hybridization (dDDH 26.7%) and whole genome phylogeny on Average Nucleotide Identity (ANIb 81.3%). For strain Marseille-QA0892 T , the 16S rRNA gene sequence showed 99.00% similarity to Pseudomonas matsuisoli JCM_30078 T , its closest relative, with an ANIb of 75.0% and a dDDH value of 21.1%. All pairwise genomic values remained well below the established thresholds for bacterial species delineation, and whole genome phylogeny confirmed the stable placement of both novel lineages within the genus Pseudomonas . Based on these polyphasic results, we propose the description of two novel species, Pseudomonas senegalensis sp. nov. (Marseille-QA0332 T = CSUR QA0332 = CECT 31294; GenBank accession number JBUCKV000000000) and Pseudomonas millioni sp. nov. (Marseille-QA0892 T = CSUR QA0892 = CECT 31318; GenBank accession number JBUCKW000000000).