Leclercia adecarboxylata causing necrotising soft tissue infection in an immunocompetent adult

Abstract

A 72-year-old woman presented with concern for a necrotising soft tissue infection (NSTI) 6 days after a tree branch impaled her left lower extremity while hiking in Hawaii. The wound was irrigated and closed at a local clinic in Hawaii. She completed a 5-day course of clindamycin. She presented to our emergency department 1 day after completion of antibiotics due to worsening erythema and malodorous drainage. Local wound exploration revealed bullae and easy dissection of fascial planes. CT scan revealed complex heterogeneous fluid and inflammatory stranding in the posterior calf. Clinical and radiographic findings raised concern for NSTI prompting initiation of broad spectrum antibiotics and urgent operative debridement. Wound cultures and deep tissues cultures returned positive for pansusceptible Leclercia adecarboxylata She underwent two additional operative debridements and transitioned to negative pressure wound therapy during her hospitalisation. She was discharged home on oral amoxicillin/clavulanate on hospital day 6.

Keywords: accidents; general surgery; infections; injuries; plastic and reconstructive surgery; tropical medicine (infectious disease).

Figure 1

Image showing the initial laceration wound.

Figure 2

Image showing the wound 12 hours prior to patient presentation in our emergency department.

Figure 3

CT image demonstrating approximately 1.1×3.8×4.9 cm area of heterogeneous fluid collection, (white arrows) with irregular margins in the posterior calf abuting the underlying calf musculature.

Figure 4

(A) Image showing extent of wound debridement approximately 24 hours after initial operation. There was no evidence of ongoing tissue necrosis or progression of infection at this time. (B) Image showing progression of wound healing during outpatient follow-up with continued use of negative pressure dressing and CAM boot. (C) Image showing ongoing healing and the result of definitive wound closure with full thickness skin graft.

Figure 5

Image showing a side-by-side comparison of Escherichia coli (left) and Leclercia adecarboxylata (right) plated on MacConke agar. While both bacteria are lactose fermenters and thus produce pink colonies, the degree of fermentation is higher in E. coli leading to the formation of larger, darker pink colonies.