Identification of Roseomonas xinghualingensis sp. nov. isolated from hospital air.

The genus Roseomonas comprises Gram-negative bacteria widely distributed in the environment and can cause human infections. However, the genomic characteristics and pathogenicity of Roseomonas remain poorly studied. Two new Gram-negative, mesothermic, aerobic and coccoid strains (SXEYE001^T and SXEYE002) were isolated from hospital air. Colonies grown on R2A plates at 28 °C for 3 days were round with neat, raised edges and a pale pink colour. Sequencing of the 16S rRNA gene revealed that the two strains are 98.4% similar to 'Roseomonas chloroacetimidivorans' BUT 13^T. The 16S rRNA gene sequence was observed to be 97.4% similar to Roseomonas pecuniae N75^T. Genome-based phylogeny demonstrated that Roseomonas harenae CPCC 101081^T and 'R. chloroacetimidivorans' BUT-13^Tspecies are close relatives to strains SXEYE001^T and SXEYE002. The average nucleotide identity between the strains and species of the genus Roseomonas was <95.0%. The G+C contents of strains SXEYE001^T and SXEYE002 were calculated to be 67.8mol% and 67.9mol%, respectively. The major polar lipids were determined to be diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine, with coenzyme Q-10 serving as the primary respiratory quinone. Based on comprehensive genotypic, phenotypic, phylogenetic and phylogenomic analyses, we concluded that strains SXEYE001^T and SXEYE002 were indicative of a novel species within the genus Roseomonas, for which the name Roseomonas xinghualingensis sp. nov. is proposed, with SXEYE001^T (=GDMCC 1.3626^T=JCM 35902^T) as the type strain.