Genomic characterisation of a multidrug-resistant Mycoplasma hominis isolate recovered from a synovial fluid sample...

Mycoplasma hominis is one of the smallest free-living opportunistic human pathogens responsible for a diverse range of infections. However, knowledge regarding the genetic and pathogenic mechanisms of M. hominis is still very limited. This study aimed to investigate the genomic features of a multidrug-resistant M. hominis isolate recovered from a synovial fluid sample in China.

Antimicrobial susceptibility of M. hominis MH-1 was determined by broth microdilution. Genomic DNA was extracted and was sequenced using an Illumina HiSeq X Ten platform. De novo genome assembly was performed using SPAdes, and the draft genome was annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). Core genome single nucleotide polymorphism (cgSNP) analysis between M. hominis MH-1 and all 25 M. hominis strains retrieved from the NCBI GenBank database was performed using BacWGSTdb server.

Antimicrobial susceptibility testing showed that M. hominis MH-1 was resistant to macrolides and fluoroquinolones. The genome size was calculated as 720 262 bp, with 608 protein-coding sequences and a G + C content of 26.8%. Several antimicrobial resistance genes, virulence genes, genomic islands and insertion sequences were identified in the genome. Phylogenetic analysis showed that the strains retrieved from NCBI as well as M. hominis MH-1 were not epidemiologically related. The closest relative of M. hominis MH-1 was recovered from the USA, which differed by 5898 SNPs.

This study reports the first genome sequence of a multidrug-resistant M. hominis isolate in China. These data may help to understand the genomic features and antimicrobial resistance mechanisms of this pathogen.