Proportion of toxin and non-toxin virulence factors of Staphylococcus aureus isolates from diabetic foot infection: a systematic review and meta-analysis

Background Staphylococcus aureus isolates are the leading cause of diabetic foot infections (DFIs).

Identification of specific virulence factors of S. aureus involved in the pathogenesis of DFIs may help control the infection more effectively.

Since the most prevalent virulence factor genes are probably related to the DFI pathogenesis, the aim of this study is to evaluate the proportion of virulence factor genes of S. aureus isolates from DFIs.

Materials and methods We conducted a systematic search of PubMed, Embase, Web of Science, and Scopus to identify all articles reporting the proportion of different types of virulence factors of S. aureus isolates from DFI samples.

Results Seventeen studies were eligible, in which 1062 S. aureus isolates were obtained from 1948 patients and 2131 DFI samples.

Among the toxin virulence factors, hld 100.0% (95% CI: 97.0, 100.0%), hlg 88.0% (95% CI: 58.0, 100.0%), hla 80.0% (95% CI: 31.0, 100.0%), hlgv 79.0% (95% CI: 35.0, 100.0%) and luk-ED 72.0% (95% CI: 42.0, 95.0%) had the highest proportion respectively.

Among the genes associated with biofilm formation, both icaA and icaD had the highest proportion 100.0% (95% CI: 95.6, 100.0%).

Conclusion The results of the present study showed that among the toxin virulence factors, hemolysins ( hld , hlg , hla , hlgv ) and luk-ED and among the non-toxin virulence factors, icaA and icaD have the greatest proportion in S. aureus isolates from DFIs.

These prevalent genes may have the potential to evaluate as virulence factors involved in DFI pathogenesis.

Finding these probable virulence factor genes can help control diabetic foot infection more effectively via anti-virulence therapy or preparation of multi-epitope vaccines.