Wound infection caused by Staphylococcus arlettae: a case report and metal characterization

Retained metallic foreign bodies can lead to implant-associated wound infections through bacterial colonization and biofilm formation. We report a case of a wound infection associated with a retained metallic fragment caused by Staphylococcus arlettae (S. arlettae) and evaluate the organism's early biofilm formation on common implant metals.

A 33-year-old man sustained a crush injury to his right hand and forearm, resulting in extensive soft-tissue damage and vascular injury. Emergency surgical management included meticulous debridement and vascular reconstruction. Postoperatively, purulent wound infection was effectively managed following microbiological identification of S. arlettae and antibiotic susceptibility-guided therapy. The treatment regimen involved serial debridement along with stepwise adjustments in antimicrobial dosing. Follow-up revealed that the patient's hand function had recovered well.

In vitro assays were conducted to compare early bacterial attachment and biofilm formation of the clinical S. arlettae isolate on stainless steel 304 (SS304), stainless steel 316 (SS316), and titanium alloy (TC4). The results revealed material-dependent differences in initial adherence as well as early biofilm development, establishing a link between implant surface properties and bacterial colonization propensity.

This case underscores the clinical significance of retained metallic fragments as potential foci for S. arlettae infection, emphasizing the necessity for prompt debridement, targeted antimicrobial therapy, and consideration of implant material properties. In vitro evidence demonstrating differential biofilm behavior on SS304, SS316, and TC4 has important implications for surgical decision-making, selection of implants, management of wounds, and prophylactic antibiotic strategies aimed at mitigating implant-associated infections.