[A gene related to inhibition of sperm mobility in Staphylococcus aureus from the sperm of infertile men].

OBJECTIVE: To analyze the whole genome sequences of Staphylococcus aureus strains from the sperm of infertile males and identify the gene which may induce the inhibition of sperm motility (ISM). METHODS: Twenty-two Staphylococcus aureus strains were isolated from the sperm of infertile males in the First Hospital Affiliated to Wenzhou Medical University and, according to the ability of ISM, divided into an ISM and a non-ISM group. Two strains most representative of the biological function of each group were selected, namely MJ015 from the ISM and MJ163 from the non-ISM group, and DNA extracted from them for whole genome sequencing. The data obtained were subjected to whole-genome sequence assembly and submitted to NCBI for annotation, with the accession number of CP038183 for MJ015 and CP038229 for MJ163. The whole genome sequences of MJ015 and MJ163 were compared in full detail using BRIG and Artemis software suite to identify the target gene. RESULTS: The whole genome sequence of MJ015 was 2 784 836 bp in length, containing 2 plasmids, and that of MJ163 was 2 746 673, containing 1 plasmid, each with a 32.13%, 32.08% content of guanine-cytosine (GC), and annotated with 2 921 and 2 844 genes respectively. Comparison between the whole genome sequences of MJ015 and MJ163 revealed an almost 130 kb gap, in which a gene named sak was found to express a potential serum inhibition factor, whose transcription product was proved to be a differentially expressed protein in the two strains. CONCLUSIONS: The gene sak in MJ015 may play a key role in the inhibition of sperm mobility, but the inhibition intensity of its transcription product staphylococcus kinase has to be further studied.